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+.. SPDX-License-Identifier: CC-BY-2.0-UK
+
+******************
+Variables Glossary
+******************
+
+This chapter lists common variables used in the OpenEmbedded build
+system and gives an overview of their function and contents.
+
+`A <#var-ABIEXTENSION>`__ :term:`B` `C <#var-CACHE>`__
+:term:`D` `E <#var-EFI_PROVIDER>`__ `F <#var-FEATURE_PACKAGES>`__
+`G <#var-GCCPIE>`__ `H <#var-HOMEPAGE>`__ `I <#var-ICECC_DISABLED>`__
+`K <#var-KARCH>`__ `L <#var-LABELS>`__ `M <#var-MACHINE>`__
+`N <#var-NATIVELSBSTRING>`__ `O <#var-OBJCOPY>`__ :term:`P`
+`R <#var-RANLIB>`__ :term:`S` :term:`T`
+`U <#var-UBOOT_CONFIG>`__ `V <#var-VOLATILE_LOG_DIR>`__
+`W <#var-WARN_QA>`__ `X <#var-XSERVER>`__
+
+.. glossary::
+
+   ABIEXTENSION
+      Extension to the Application Binary Interface (ABI) field of the GNU
+      canonical architecture name (e.g. "eabi").
+
+      ABI extensions are set in the machine include files. For example, the
+      ``meta/conf/machine/include/arm/arch-arm.inc`` file sets the
+      following extension:
+      ::
+
+         ABIEXTENSION = "eabi"
+
+   ALLOW_EMPTY
+      Specifies whether to produce an output package even if it is empty.
+      By default, BitBake does not produce empty packages. This default
+      behavior can cause issues when there is an
+      :term:`RDEPENDS` or some other hard runtime
+      requirement on the existence of the package.
+
+      Like all package-controlling variables, you must always use them in
+      conjunction with a package name override, as in:
+      ::
+
+         ALLOW_EMPTY_${PN} = "1"
+         ALLOW_EMPTY_${PN}-dev = "1"
+         ALLOW_EMPTY_${PN}-staticdev = "1"
+
+   ALTERNATIVE
+      Lists commands in a package that need an alternative binary naming
+      scheme. Sometimes the same command is provided in multiple packages.
+      When this occurs, the OpenEmbedded build system needs to use the
+      alternatives system to create a different binary naming scheme so the
+      commands can co-exist.
+
+      To use the variable, list out the package's commands that also exist
+      as part of another package. For example, if the ``busybox`` package
+      has four commands that also exist as part of another package, you
+      identify them as follows:
+      ::
+
+         ALTERNATIVE_busybox = "sh sed test bracket"
+
+      For more information on the alternatives system, see the
+      ":ref:`update-alternatives.bbclass <ref-classes-update-alternatives>`"
+      section.
+
+   ALTERNATIVE_LINK_NAME
+      Used by the alternatives system to map duplicated commands to actual
+      locations. For example, if the ``bracket`` command provided by the
+      ``busybox`` package is duplicated through another package, you must
+      use the ``ALTERNATIVE_LINK_NAME`` variable to specify the actual
+      location:
+      ::
+
+         ALTERNATIVE_LINK_NAME[bracket] = "/usr/bin/["
+
+      In this example, the binary for the ``bracket`` command (i.e. ``[``)
+      from the ``busybox`` package resides in ``/usr/bin/``.
+
+      .. note::
+
+         If ALTERNATIVE_LINK_NAME is not defined, it defaults to ${bindir}/ name.
+
+      For more information on the alternatives system, see the
+      ":ref:`update-alternatives.bbclass <ref-classes-update-alternatives>`"
+      section.
+
+   ALTERNATIVE_PRIORITY
+      Used by the alternatives system to create default priorities for
+      duplicated commands. You can use the variable to create a single
+      default regardless of the command name or package, a default for
+      specific duplicated commands regardless of the package, or a default
+      for specific commands tied to particular packages. Here are the
+      available syntax forms:
+      ::
+
+         ALTERNATIVE_PRIORITY = "priority"
+         ALTERNATIVE_PRIORITY[name] = "priority"
+         ALTERNATIVE_PRIORITY_pkg[name] = "priority"
+
+      For more information on the alternatives system, see the
+      ":ref:`update-alternatives.bbclass <ref-classes-update-alternatives>`"
+      section.
+
+   ALTERNATIVE_TARGET
+      Used by the alternatives system to create default link locations for
+      duplicated commands. You can use the variable to create a single
+      default location for all duplicated commands regardless of the
+      command name or package, a default for specific duplicated commands
+      regardless of the package, or a default for specific commands tied to
+      particular packages. Here are the available syntax forms:
+      ::
+
+         ALTERNATIVE_TARGET = "target"
+         ALTERNATIVE_TARGET[name] = "target"
+         ALTERNATIVE_TARGET_pkg[name] = "target"
+
+      .. note::
+
+         If ``ALTERNATIVE_TARGET`` is not defined, it inherits the value
+         from the :term:`ALTERNATIVE_LINK_NAME` variable.
+
+         If ``ALTERNATIVE_LINK_NAME`` and ``ALTERNATIVE_TARGET`` are the
+         same, the target for ``ALTERNATIVE_TARGET`` has "``.{BPN}``"
+         appended to it.
+
+         Finally, if the file referenced has not been renamed, the
+         alternatives system will rename it to avoid the need to rename
+         alternative files in the :ref:`ref-tasks-install`
+         task while retaining support for the command if necessary.
+
+      For more information on the alternatives system, see the
+      ":ref:`update-alternatives.bbclass <ref-classes-update-alternatives>`"
+      section.
+
+   APPEND
+      An override list of append strings for each target specified with
+      :term:`LABELS`.
+
+      See the :ref:`grub-efi <ref-classes-grub-efi>` class for more
+      information on how this variable is used.
+
+   AR
+      The minimal command and arguments used to run ``ar``.
+
+   ARCHIVER_MODE
+      When used with the :ref:`archiver <ref-classes-archiver>` class,
+      determines the type of information used to create a released archive.
+      You can use this variable to create archives of patched source,
+      original source, configured source, and so forth by employing the
+      following variable flags (varflags):
+      ::
+
+         ARCHIVER_MODE[src] = "original"                   # Uses original (unpacked) source files.
+         ARCHIVER_MODE[src] = "patched"                    # Uses patched source files. This is the default.
+         ARCHIVER_MODE[src] = "configured"                 # Uses configured source files.
+         ARCHIVER_MODE[diff] = "1"                         # Uses patches between do_unpack and do_patch.
+         ARCHIVER_MODE[diff-exclude] ?= "file file ..."    # Lists files and directories to exclude from diff.
+         ARCHIVER_MODE[dumpdata] = "1"                     # Uses environment data.
+         ARCHIVER_MODE[recipe] = "1"                       # Uses recipe and include files.
+         ARCHIVER_MODE[srpm] = "1"                         # Uses RPM package files.
+
+      For information on how the variable works, see the
+      ``meta/classes/archiver.bbclass`` file in the :term:`Source Directory`.
+
+   AS
+      Minimal command and arguments needed to run the assembler.
+
+   ASSUME_PROVIDED
+      Lists recipe names (:term:`PN` values) BitBake does not
+      attempt to build. Instead, BitBake assumes these recipes have already
+      been built.
+
+      In OpenEmbedded-Core, ``ASSUME_PROVIDED`` mostly specifies native
+      tools that should not be built. An example is ``git-native``, which
+      when specified, allows for the Git binary from the host to be used
+      rather than building ``git-native``.
+
+   ASSUME_SHLIBS
+      Provides additional ``shlibs`` provider mapping information, which
+      adds to or overwrites the information provided automatically by the
+      system. Separate multiple entries using spaces.
+
+      As an example, use the following form to add an ``shlib`` provider of
+      shlibname in packagename with the optional version:
+      ::
+
+         shlibname:packagename[_version]
+
+      Here is an example that adds a shared library named ``libEGL.so.1``
+      as being provided by the ``libegl-implementation`` package:
+      ::
+
+         ASSUME_SHLIBS = "libEGL.so.1:libegl-implementation"
+
+   AUTHOR
+      The email address used to contact the original author or authors in
+      order to send patches and forward bugs.
+
+   AUTO_LIBNAME_PKGS
+      When the :ref:`debian <ref-classes-debian>` class is inherited,
+      which is the default behavior, ``AUTO_LIBNAME_PKGS`` specifies which
+      packages should be checked for libraries and renamed according to
+      Debian library package naming.
+
+      The default value is "${PACKAGES}", which causes the debian class to
+      act on all packages that are explicitly generated by the recipe.
+
+   AUTO_SYSLINUXMENU
+      Enables creating an automatic menu for the syslinux bootloader. You
+      must set this variable in your recipe. The
+      :ref:`syslinux <ref-classes-syslinux>` class checks this variable.
+
+   AUTOREV
+      When ``SRCREV`` is set to the value of this variable, it specifies to
+      use the latest source revision in the repository. Here is an example:
+      ::
+
+         SRCREV = "${AUTOREV}"
+
+      If you use the previous statement to retrieve the latest version of
+      software, you need to be sure :term:`PV` contains
+      ``${``\ :term:`SRCPV`\ ``}``. For example, suppose you
+      have a kernel recipe that inherits the
+      :ref:`kernel <ref-classes-kernel>` class and you use the previous
+      statement. In this example, ``${SRCPV}`` does not automatically get
+      into ``PV``. Consequently, you need to change ``PV`` in your recipe
+      so that it does contain ``${SRCPV}``.
+
+      For more information see the
+      ":ref:`dev-manual/dev-manual-common-tasks:automatically incrementing a package version number`"
+      section in the Yocto Project Development Tasks Manual.
+
+   AVAILABLE_LICENSES
+      List of licenses found in the directories specified by
+      :term:`COMMON_LICENSE_DIR` and
+      :term:`LICENSE_PATH`.
+
+      .. note::
+
+         It is assumed that all changes to
+         COMMON_LICENSE_DIR
+         and
+         LICENSE_PATH
+         have been done before
+         AVAILABLE_LICENSES
+         is defined (in
+         license.bbclass
+         ).
+
+   AVAILTUNES
+      The list of defined CPU and Application Binary Interface (ABI)
+      tunings (i.e. "tunes") available for use by the OpenEmbedded build
+      system.
+
+      The list simply presents the tunes that are available. Not all tunes
+      may be compatible with a particular machine configuration, or with
+      each other in a
+      :ref:`Multilib <dev-manual/dev-manual-common-tasks:combining multiple versions of library files into one image>`
+      configuration.
+
+      To add a tune to the list, be sure to append it with spaces using the
+      "+=" BitBake operator. Do not simply replace the list by using the
+      "=" operator. See the
+      ":ref:`Basic Syntax <bitbake:bitbake-user-manual/bitbake-user-manual-metadata:basic syntax>`" section in the BitBake
+      User Manual for more information.
+
+   B
+      The directory within the :term:`Build Directory` in
+      which the OpenEmbedded build system places generated objects during a
+      recipe's build process. By default, this directory is the same as the
+      :term:`S` directory, which is defined as:
+      ::
+
+         S = "${WORKDIR}/${BP}"
+
+      You can separate the (``S``) directory and the directory pointed to
+      by the ``B`` variable. Most Autotools-based recipes support
+      separating these directories. The build system defaults to using
+      separate directories for ``gcc`` and some kernel recipes.
+
+   BAD_RECOMMENDATIONS
+      Lists "recommended-only" packages to not install. Recommended-only
+      packages are packages installed only through the
+      :term:`RRECOMMENDS` variable. You can prevent any
+      of these "recommended" packages from being installed by listing them
+      with the ``BAD_RECOMMENDATIONS`` variable:
+      ::
+
+         BAD_RECOMMENDATIONS = "package_name package_name package_name ..."
+
+      You can set this variable globally in your ``local.conf`` file or you
+      can attach it to a specific image recipe by using the recipe name
+      override:
+      ::
+
+         BAD_RECOMMENDATIONS_pn-target_image = "package_name"
+
+      It is important to realize that if you choose to not install packages
+      using this variable and some other packages are dependent on them
+      (i.e. listed in a recipe's :term:`RDEPENDS`
+      variable), the OpenEmbedded build system ignores your request and
+      will install the packages to avoid dependency errors.
+
+      Support for this variable exists only when using the IPK and RPM
+      packaging backend. Support does not exist for DEB.
+
+      See the :term:`NO_RECOMMENDATIONS` and the
+      :term:`PACKAGE_EXCLUDE` variables for related
+      information.
+
+   BASE_LIB
+      The library directory name for the CPU or Application Binary
+      Interface (ABI) tune. The ``BASE_LIB`` applies only in the Multilib
+      context. See the ":ref:`dev-manual/dev-manual-common-tasks:combining multiple versions of library files into one image`"
+      section in the Yocto Project Development Tasks Manual for information
+      on Multilib.
+
+      The ``BASE_LIB`` variable is defined in the machine include files in
+      the :term:`Source Directory`. If Multilib is not
+      being used, the value defaults to "lib".
+
+   BASE_WORKDIR
+      Points to the base of the work directory for all recipes. The default
+      value is "${TMPDIR}/work".
+
+   BB_ALLOWED_NETWORKS
+      Specifies a space-delimited list of hosts that the fetcher is allowed
+      to use to obtain the required source code. Following are
+      considerations surrounding this variable:
+
+      -  This host list is only used if ``BB_NO_NETWORK`` is either not set
+         or set to "0".
+
+      -  Limited support for wildcard matching against the beginning of
+         host names exists. For example, the following setting matches
+         ``git.gnu.org``, ``ftp.gnu.org``, and ``foo.git.gnu.org``.
+         ::
+
+            BB_ALLOWED_NETWORKS = "*.gnu.org"
+
+         .. note::
+
+            The use of the "``*``" character only works at the beginning of
+            a host name and it must be isolated from the remainder of the
+            host name. You cannot use the wildcard character in any other
+            location of the name or combined with the front part of the
+            name.
+
+            For example, ``*.foo.bar`` is supported, while ``*aa.foo.bar``
+            is not.
+
+      -  Mirrors not in the host list are skipped and logged in debug.
+
+      -  Attempts to access networks not in the host list cause a failure.
+
+      Using ``BB_ALLOWED_NETWORKS`` in conjunction with
+      :term:`PREMIRRORS` is very useful. Adding the host
+      you want to use to ``PREMIRRORS`` results in the source code being
+      fetched from an allowed location and avoids raising an error when a
+      host that is not allowed is in a :term:`SRC_URI`
+      statement. This is because the fetcher does not attempt to use the
+      host listed in ``SRC_URI`` after a successful fetch from the
+      ``PREMIRRORS`` occurs.
+
+   BB_DANGLINGAPPENDS_WARNONLY
+      Defines how BitBake handles situations where an append file
+      (``.bbappend``) has no corresponding recipe file (``.bb``). This
+      condition often occurs when layers get out of sync (e.g. ``oe-core``
+      bumps a recipe version and the old recipe no longer exists and the
+      other layer has not been updated to the new version of the recipe
+      yet).
+
+      The default fatal behavior is safest because it is the sane reaction
+      given something is out of sync. It is important to realize when your
+      changes are no longer being applied.
+
+      You can change the default behavior by setting this variable to "1",
+      "yes", or "true" in your ``local.conf`` file, which is located in the
+      :term:`Build Directory`: Here is an example:
+      ::
+
+         BB_DANGLINGAPPENDS_WARNONLY = "1"
+
+   BB_DISKMON_DIRS
+      Monitors disk space and available inodes during the build and allows
+      you to control the build based on these parameters.
+
+      Disk space monitoring is disabled by default. To enable monitoring,
+      add the ``BB_DISKMON_DIRS`` variable to your ``conf/local.conf`` file
+      found in the :term:`Build Directory`. Use the
+      following form:
+      ::
+
+         BB_DISKMON_DIRS = "action,dir,threshold [...]"
+
+         where:
+
+            action is:
+               ABORT:     Immediately abort the build when
+                          a threshold is broken.
+               STOPTASKS: Stop the build after the currently
+                          executing tasks have finished when
+                          a threshold is broken.
+               WARN:      Issue a warning but continue the
+                          build when a threshold is broken.
+                          Subsequent warnings are issued as
+                          defined by the BB_DISKMON_WARNINTERVAL
+                          variable, which must be defined in
+                          the conf/local.conf file.
+
+            dir is:
+               Any directory you choose. You can specify one or
+               more directories to monitor by separating the
+               groupings with a space.  If two directories are
+               on the same device, only the first directory
+               is monitored.
+
+            threshold is:
+               Either the minimum available disk space,
+               the minimum number of free inodes, or
+               both.  You must specify at least one.  To
+               omit one or the other, simply omit the value.
+               Specify the threshold using G, M, K for Gbytes,
+               Mbytes, and Kbytes, respectively. If you do
+               not specify G, M, or K, Kbytes is assumed by
+               default.  Do not use GB, MB, or KB.
+
+      Here are some examples:
+      ::
+
+         BB_DISKMON_DIRS = "ABORT,${TMPDIR},1G,100K WARN,${SSTATE_DIR},1G,100K"
+         BB_DISKMON_DIRS = "STOPTASKS,${TMPDIR},1G"
+         BB_DISKMON_DIRS = "ABORT,${TMPDIR},,100K"
+
+      The first example works only if you also provide the
+      :term:`BB_DISKMON_WARNINTERVAL`
+      variable in the ``conf/local.conf``. This example causes the build
+      system to immediately abort when either the disk space in
+      ``${TMPDIR}`` drops below 1 Gbyte or the available free inodes drops
+      below 100 Kbytes. Because two directories are provided with the
+      variable, the build system also issue a warning when the disk space
+      in the ``${SSTATE_DIR}`` directory drops below 1 Gbyte or the number
+      of free inodes drops below 100 Kbytes. Subsequent warnings are issued
+      during intervals as defined by the ``BB_DISKMON_WARNINTERVAL``
+      variable.
+
+      The second example stops the build after all currently executing
+      tasks complete when the minimum disk space in the ``${TMPDIR}``
+      directory drops below 1 Gbyte. No disk monitoring occurs for the free
+      inodes in this case.
+
+      The final example immediately aborts the build when the number of
+      free inodes in the ``${TMPDIR}`` directory drops below 100 Kbytes. No
+      disk space monitoring for the directory itself occurs in this case.
+
+   BB_DISKMON_WARNINTERVAL
+      Defines the disk space and free inode warning intervals. To set these
+      intervals, define the variable in your ``conf/local.conf`` file in
+      the :term:`Build Directory`.
+
+      If you are going to use the ``BB_DISKMON_WARNINTERVAL`` variable, you
+      must also use the :term:`BB_DISKMON_DIRS`
+      variable and define its action as "WARN". During the build,
+      subsequent warnings are issued each time disk space or number of free
+      inodes further reduces by the respective interval.
+
+      If you do not provide a ``BB_DISKMON_WARNINTERVAL`` variable and you
+      do use ``BB_DISKMON_DIRS`` with the "WARN" action, the disk
+      monitoring interval defaults to the following:
+      ::
+
+         BB_DISKMON_WARNINTERVAL = "50M,5K"
+
+      When specifying the variable in your configuration file, use the
+      following form:
+      ::
+
+         BB_DISKMON_WARNINTERVAL = "disk_space_interval,disk_inode_interval"
+
+         where:
+
+            disk_space_interval is:
+               An interval of memory expressed in either
+               G, M, or K for Gbytes, Mbytes, or Kbytes,
+               respectively. You cannot use GB, MB, or KB.
+
+            disk_inode_interval is:
+               An interval of free inodes expressed in either
+               G, M, or K for Gbytes, Mbytes, or Kbytes,
+               respectively. You cannot use GB, MB, or KB.
+
+      Here is an example:
+      ::
+
+         BB_DISKMON_DIRS = "WARN,${SSTATE_DIR},1G,100K"
+         BB_DISKMON_WARNINTERVAL = "50M,5K"
+
+      These variables cause the
+      OpenEmbedded build system to issue subsequent warnings each time the
+      available disk space further reduces by 50 Mbytes or the number of
+      free inodes further reduces by 5 Kbytes in the ``${SSTATE_DIR}``
+      directory. Subsequent warnings based on the interval occur each time
+      a respective interval is reached beyond the initial warning (i.e. 1
+      Gbytes and 100 Kbytes).
+
+   BB_GENERATE_MIRROR_TARBALLS
+      Causes tarballs of the source control repositories (e.g. Git
+      repositories), including metadata, to be placed in the
+      :term:`DL_DIR` directory.
+
+      For performance reasons, creating and placing tarballs of these
+      repositories is not the default action by the OpenEmbedded build
+      system.
+      ::
+
+         BB_GENERATE_MIRROR_TARBALLS = "1"
+
+      Set this variable in your
+      ``local.conf`` file in the :term:`Build Directory`.
+
+      Once you have the tarballs containing your source files, you can
+      clean up your ``DL_DIR`` directory by deleting any Git or other
+      source control work directories.
+
+   BB_NUMBER_THREADS
+      The maximum number of tasks BitBake should run in parallel at any one
+      time. The OpenEmbedded build system automatically configures this
+      variable to be equal to the number of cores on the build system. For
+      example, a system with a dual core processor that also uses
+      hyper-threading causes the ``BB_NUMBER_THREADS`` variable to default
+      to "4".
+
+      For single socket systems (i.e. one CPU), you should not have to
+      override this variable to gain optimal parallelism during builds.
+      However, if you have very large systems that employ multiple physical
+      CPUs, you might want to make sure the ``BB_NUMBER_THREADS`` variable
+      is not set higher than "20".
+
+      For more information on speeding up builds, see the
+      ":ref:`dev-manual/dev-manual-common-tasks:speeding up a build`"
+      section in the Yocto Project Development Tasks Manual.
+
+   BB_SERVER_TIMEOUT
+      Specifies the time (in seconds) after which to unload the BitBake
+      server due to inactivity. Set ``BB_SERVER_TIMEOUT`` to determine how
+      long the BitBake server stays resident between invocations.
+
+      For example, the following statement in your ``local.conf`` file
+      instructs the server to be unloaded after 20 seconds of inactivity:
+      ::
+
+         BB_SERVER_TIMEOUT = "20"
+
+      If you want the server to never be unloaded,
+      set ``BB_SERVER_TIMEOUT`` to "-1".
+
+   BBCLASSEXTEND
+      Allows you to extend a recipe so that it builds variants of the
+      software. Common variants for recipes exist such as "natives" like
+      ``quilt-native``, which is a copy of Quilt built to run on the build
+      system; "crosses" such as ``gcc-cross``, which is a compiler built to
+      run on the build machine but produces binaries that run on the target
+      :term:`MACHINE`; "nativesdk", which targets the SDK
+      machine instead of ``MACHINE``; and "mulitlibs" in the form
+      "``multilib:``\ multilib_name".
+
+      To build a different variant of the recipe with a minimal amount of
+      code, it usually is as simple as adding the following to your recipe:
+      ::
+
+         BBCLASSEXTEND =+ "native nativesdk"
+         BBCLASSEXTEND =+ "multilib:multilib_name"
+
+      .. note::
+
+         Internally, the ``BBCLASSEXTEND`` mechanism generates recipe
+         variants by rewriting variable values and applying overrides such
+         as ``_class-native``. For example, to generate a native version of
+         a recipe, a :term:`DEPENDS` on "foo" is rewritten
+         to a ``DEPENDS`` on "foo-native".
+
+         Even when using ``BBCLASSEXTEND``, the recipe is only parsed once.
+         Parsing once adds some limitations. For example, it is not
+         possible to include a different file depending on the variant,
+         since ``include`` statements are processed when the recipe is
+         parsed.
+
+   BBFILE_COLLECTIONS
+      Lists the names of configured layers. These names are used to find
+      the other ``BBFILE_*`` variables. Typically, each layer will append
+      its name to this variable in its ``conf/layer.conf`` file.
+
+   BBFILE_PATTERN
+      Variable that expands to match files from
+      :term:`BBFILES` in a particular layer. This variable
+      is used in the ``conf/layer.conf`` file and must be suffixed with the
+      name of the specific layer (e.g. ``BBFILE_PATTERN_emenlow``).
+
+   BBFILE_PRIORITY
+      Assigns the priority for recipe files in each layer.
+
+      This variable is useful in situations where the same recipe appears
+      in more than one layer. Setting this variable allows you to
+      prioritize a layer against other layers that contain the same recipe
+      - effectively letting you control the precedence for the multiple
+      layers. The precedence established through this variable stands
+      regardless of a recipe's version (:term:`PV` variable). For
+      example, a layer that has a recipe with a higher ``PV`` value but for
+      which the ``BBFILE_PRIORITY`` is set to have a lower precedence still
+      has a lower precedence.
+
+      A larger value for the ``BBFILE_PRIORITY`` variable results in a
+      higher precedence. For example, the value 6 has a higher precedence
+      than the value 5. If not specified, the ``BBFILE_PRIORITY`` variable
+      is set based on layer dependencies (see the ``LAYERDEPENDS`` variable
+      for more information. The default priority, if unspecified for a
+      layer with no dependencies, is the lowest defined priority + 1 (or 1
+      if no priorities are defined).
+
+      .. tip::
+
+         You can use the command
+         bitbake-layers show-layers
+         to list all configured layers along with their priorities.
+
+   BBFILES
+      A space-separated list of recipe files BitBake uses to build
+      software.
+
+      When specifying recipe files, you can pattern match using Python's
+      `glob <https://docs.python.org/3/library/glob.html>`_ syntax.
+      For details on the syntax, see the documentation by following the
+      previous link.
+
+   BBFILES_DYNAMIC
+      Activates content when identified layers are present. You identify
+      the layers by the collections that the layers define.
+
+      Use the ``BBFILES_DYNAMIC`` variable to avoid ``.bbappend`` files
+      whose corresponding ``.bb`` file is in a layer that attempts to
+      modify other layers through ``.bbappend`` but does not want to
+      introduce a hard dependency on those other layers.
+
+      Use the following form for ``BBFILES_DYNAMIC``:
+      collection_name:filename_pattern The following example identifies two
+      collection names and two filename patterns:
+      ::
+
+         BBFILES_DYNAMIC += " \
+            clang-layer:${LAYERDIR}/bbappends/meta-clang/*/*/*.bbappend \
+            core:${LAYERDIR}/bbappends/openembedded-core/meta/*/*/*.bbappend \
+            "
+
+      This next example shows an error message that occurs because invalid
+      entries are found, which cause parsing to abort:
+      ::
+
+         ERROR: BBFILES_DYNAMIC entries must be of the form <collection name>:<filename pattern>, not:
+             /work/my-layer/bbappends/meta-security-isafw/*/*/*.bbappend
+             /work/my-layer/bbappends/openembedded-core/meta/*/*/*.bbappend
+
+   BBINCLUDELOGS
+      Variable that controls how BitBake displays logs on build failure.
+
+   BBINCLUDELOGS_LINES
+      If :term:`BBINCLUDELOGS` is set, specifies the
+      maximum number of lines from the task log file to print when
+      reporting a failed task. If you do not set ``BBINCLUDELOGS_LINES``,
+      the entire log is printed.
+
+   BBLAYERS
+      Lists the layers to enable during the build. This variable is defined
+      in the ``bblayers.conf`` configuration file in the :term:`Build Directory`.
+      Here is an example:
+      ::
+
+         BBLAYERS = " \
+             /home/scottrif/poky/meta \ /home/scottrif/poky/meta-poky \
+             /home/scottrif/poky/meta-yocto-bsp \
+             /home/scottrif/poky/meta-mykernel \
+             "
+
+      This example enables four layers, one of which is a custom,
+      user-defined layer named ``meta-mykernel``.
+
+   BBMASK
+      Prevents BitBake from processing recipes and recipe append files.
+
+      You can use the ``BBMASK`` variable to "hide" these ``.bb`` and
+      ``.bbappend`` files. BitBake ignores any recipe or recipe append
+      files that match any of the expressions. It is as if BitBake does not
+      see them at all. Consequently, matching files are not parsed or
+      otherwise used by BitBake.
+
+      The values you provide are passed to Python's regular expression
+      compiler. Consequently, the syntax follows Python's Regular
+      Expression (re) syntax. The expressions are compared against the full
+      paths to the files. For complete syntax information, see Python's
+      documentation at http://docs.python.org/3/library/re.html#re.
+
+      The following example uses a complete regular expression to tell
+      BitBake to ignore all recipe and recipe append files in the
+      ``meta-ti/recipes-misc/`` directory:
+      ::
+
+         BBMASK = "meta-ti/recipes-misc/"
+
+      If you want to mask out multiple directories or recipes, you can
+      specify multiple regular expression fragments. This next example
+      masks out multiple directories and individual recipes: ::
+
+         BBMASK += "/meta-ti/recipes-misc/ meta-ti/recipes-ti/packagegroup/"
+         BBMASK += "/meta-oe/recipes-support/"
+         BBMASK += "/meta-foo/.*/openldap"
+         BBMASK += "opencv.*\.bbappend"
+         BBMASK += "lzma"
+
+      .. note::
+
+         When specifying a directory name, use the trailing slash character
+         to ensure you match just that directory name.
+
+   BBMULTICONFIG
+      Specifies each additional separate configuration when you are
+      building targets with multiple configurations. Use this variable in
+      your ``conf/local.conf`` configuration file. Specify a
+      multiconfigname for each configuration file you are using. For
+      example, the following line specifies three configuration files:
+      ::
+
+         BBMULTICONFIG = "configA configB configC"
+
+      Each configuration file you
+      use must reside in the :term:`Build Directory`
+      ``conf/multiconfig`` directory (e.g.
+      build_directory\ ``/conf/multiconfig/configA.conf``).
+
+      For information on how to use ``BBMULTICONFIG`` in an environment
+      that supports building targets with multiple configurations, see the
+      ":ref:`dev-building-images-for-multiple-targets-using-multiple-configurations`"
+      section in the Yocto Project Development Tasks Manual.
+
+   BBPATH
+      Used by BitBake to locate ``.bbclass`` and configuration files. This
+      variable is analogous to the ``PATH`` variable.
+
+      .. note::
+
+         If you run BitBake from a directory outside of the
+         Build Directory
+         , you must be sure to set
+         BBPATH
+         to point to the Build Directory. Set the variable as you would any
+         environment variable and then run BitBake:
+         ::
+
+                 $ BBPATH = "build_directory"
+                 $ export BBPATH
+                 $ bitbake target
+
+
+   BBSERVER
+      If defined in the BitBake environment, ``BBSERVER`` points to the
+      BitBake remote server.
+
+      Use the following format to export the variable to the BitBake
+      environment:
+      ::
+
+         export BBSERVER=localhost:$port
+
+      By default, ``BBSERVER`` also appears in
+      :term:`bitbake:BB_HASHBASE_WHITELIST`.
+      Consequently, ``BBSERVER`` is excluded from checksum and dependency
+      data.
+
+   BINCONFIG
+      When inheriting the
+      :ref:`binconfig-disabled <ref-classes-binconfig-disabled>` class,
+      this variable specifies binary configuration scripts to disable in
+      favor of using ``pkg-config`` to query the information. The
+      ``binconfig-disabled`` class will modify the specified scripts to
+      return an error so that calls to them can be easily found and
+      replaced.
+
+      To add multiple scripts, separate them by spaces. Here is an example
+      from the ``libpng`` recipe:
+      ::
+
+         BINCONFIG = "${bindir}/libpng-config ${bindir}/libpng16-config"
+
+   BINCONFIG_GLOB
+      When inheriting the :ref:`binconfig <ref-classes-binconfig>` class,
+      this variable specifies a wildcard for configuration scripts that
+      need editing. The scripts are edited to correct any paths that have
+      been set up during compilation so that they are correct for use when
+      installed into the sysroot and called by the build processes of other
+      recipes.
+
+      .. note::
+
+         The
+         BINCONFIG_GLOB
+         variable uses
+         shell globbing
+         , which is recognition and expansion of wildcards during pattern
+         matching. Shell globbing is very similar to
+         fnmatch
+         and
+         glob
+         .
+
+      For more information on how this variable works, see
+      ``meta/classes/binconfig.bbclass`` in the :term:`Source Directory`.
+      You can also find general
+      information on the class in the
+      ":ref:`binconfig.bbclass <ref-classes-binconfig>`" section.
+
+   BP
+      The base recipe name and version but without any special recipe name
+      suffix (i.e. ``-native``, ``lib64-``, and so forth). ``BP`` is
+      comprised of the following:
+      ::
+
+         ${BPN}-${PV}
+
+   BPN
+      This variable is a version of the :term:`PN` variable with
+      common prefixes and suffixes removed, such as ``nativesdk-``,
+      ``-cross``, ``-native``, and multilib's ``lib64-`` and ``lib32-``.
+      The exact lists of prefixes and suffixes removed are specified by the
+      :term:`MLPREFIX` and
+      :term:`SPECIAL_PKGSUFFIX` variables,
+      respectively.
+
+   BUGTRACKER
+      Specifies a URL for an upstream bug tracking website for a recipe.
+      The OpenEmbedded build system does not use this variable. Rather, the
+      variable is a useful pointer in case a bug in the software being
+      built needs to be manually reported.
+
+   BUILD_ARCH
+      Specifies the architecture of the build host (e.g. ``i686``). The
+      OpenEmbedded build system sets the value of ``BUILD_ARCH`` from the
+      machine name reported by the ``uname`` command.
+
+   BUILD_AS_ARCH
+      Specifies the architecture-specific assembler flags for the build
+      host. By default, the value of ``BUILD_AS_ARCH`` is empty.
+
+   BUILD_CC_ARCH
+      Specifies the architecture-specific C compiler flags for the build
+      host. By default, the value of ``BUILD_CC_ARCH`` is empty.
+
+   BUILD_CCLD
+      Specifies the linker command to be used for the build host when the C
+      compiler is being used as the linker. By default, ``BUILD_CCLD``
+      points to GCC and passes as arguments the value of
+      :term:`BUILD_CC_ARCH`, assuming
+      ``BUILD_CC_ARCH`` is set.
+
+   BUILD_CFLAGS
+      Specifies the flags to pass to the C compiler when building for the
+      build host. When building in the ``-native`` context,
+      :term:`CFLAGS` is set to the value of this variable by
+      default.
+
+   BUILD_CPPFLAGS
+      Specifies the flags to pass to the C preprocessor (i.e. to both the C
+      and the C++ compilers) when building for the build host. When
+      building in the ``-native`` context, :term:`CPPFLAGS`
+      is set to the value of this variable by default.
+
+   BUILD_CXXFLAGS
+      Specifies the flags to pass to the C++ compiler when building for the
+      build host. When building in the ``-native`` context,
+      :term:`CXXFLAGS` is set to the value of this variable
+      by default.
+
+   BUILD_FC
+      Specifies the Fortran compiler command for the build host. By
+      default, ``BUILD_FC`` points to Gfortran and passes as arguments the
+      value of :term:`BUILD_CC_ARCH`, assuming
+      ``BUILD_CC_ARCH`` is set.
+
+   BUILD_LD
+      Specifies the linker command for the build host. By default,
+      ``BUILD_LD`` points to the GNU linker (ld) and passes as arguments
+      the value of :term:`BUILD_LD_ARCH`, assuming
+      ``BUILD_LD_ARCH`` is set.
+
+   BUILD_LD_ARCH
+      Specifies architecture-specific linker flags for the build host. By
+      default, the value of ``BUILD_LD_ARCH`` is empty.
+
+   BUILD_LDFLAGS
+      Specifies the flags to pass to the linker when building for the build
+      host. When building in the ``-native`` context,
+      :term:`LDFLAGS` is set to the value of this variable
+      by default.
+
+   BUILD_OPTIMIZATION
+      Specifies the optimization flags passed to the C compiler when
+      building for the build host or the SDK. The flags are passed through
+      the :term:`BUILD_CFLAGS` and
+      :term:`BUILDSDK_CFLAGS` default values.
+
+      The default value of the ``BUILD_OPTIMIZATION`` variable is "-O2
+      -pipe".
+
+   BUILD_OS
+      Specifies the operating system in use on the build host (e.g.
+      "linux"). The OpenEmbedded build system sets the value of
+      ``BUILD_OS`` from the OS reported by the ``uname`` command - the
+      first word, converted to lower-case characters.
+
+   BUILD_PREFIX
+      The toolchain binary prefix used for native recipes. The OpenEmbedded
+      build system uses the ``BUILD_PREFIX`` value to set the
+      :term:`TARGET_PREFIX` when building for
+      ``native`` recipes.
+
+   BUILD_STRIP
+      Specifies the command to be used to strip debugging symbols from
+      binaries produced for the build host. By default, ``BUILD_STRIP``
+      points to
+      ``${``\ :term:`BUILD_PREFIX`\ ``}strip``.
+
+   BUILD_SYS
+      Specifies the system, including the architecture and the operating
+      system, to use when building for the build host (i.e. when building
+      ``native`` recipes).
+
+      The OpenEmbedded build system automatically sets this variable based
+      on :term:`BUILD_ARCH`,
+      :term:`BUILD_VENDOR`, and
+      :term:`BUILD_OS`. You do not need to set the
+      ``BUILD_SYS`` variable yourself.
+
+   BUILD_VENDOR
+      Specifies the vendor name to use when building for the build host.
+      The default value is an empty string ("").
+
+   BUILDDIR
+      Points to the location of the :term:`Build Directory`.
+      You can define this directory indirectly through the
+      ````` <#structure-core-script>`__ script by passing in a Build
+      Directory path when you run the script. If you run the script and do
+      not provide a Build Directory path, the ``BUILDDIR`` defaults to
+      ``build`` in the current directory.
+
+   BUILDHISTORY_COMMIT
+      When inheriting the :ref:`buildhistory <ref-classes-buildhistory>`
+      class, this variable specifies whether or not to commit the build
+      history output in a local Git repository. If set to "1", this local
+      repository will be maintained automatically by the ``buildhistory``
+      class and a commit will be created on every build for changes to each
+      top-level subdirectory of the build history output (images, packages,
+      and sdk). If you want to track changes to build history over time,
+      you should set this value to "1".
+
+      By default, the ``buildhistory`` class does not commit the build
+      history output in a local Git repository:
+      ::
+
+         BUILDHISTORY_COMMIT ?= "0"
+
+   BUILDHISTORY_COMMIT_AUTHOR
+      When inheriting the :ref:`buildhistory <ref-classes-buildhistory>`
+      class, this variable specifies the author to use for each Git commit.
+      In order for the ``BUILDHISTORY_COMMIT_AUTHOR`` variable to work, the
+      :term:`BUILDHISTORY_COMMIT` variable must
+      be set to "1".
+
+      Git requires that the value you provide for the
+      ``BUILDHISTORY_COMMIT_AUTHOR`` variable takes the form of "name
+      email@host". Providing an email address or host that is not valid
+      does not produce an error.
+
+      By default, the ``buildhistory`` class sets the variable as follows:
+      ::
+
+         BUILDHISTORY_COMMIT_AUTHOR ?= "buildhistory <buildhistory@${DISTRO}>"
+
+   BUILDHISTORY_DIR
+      When inheriting the :ref:`buildhistory <ref-classes-buildhistory>`
+      class, this variable specifies the directory in which build history
+      information is kept. For more information on how the variable works,
+      see the ``buildhistory.class``.
+
+      By default, the ``buildhistory`` class sets the directory as follows:
+      ::
+
+         BUILDHISTORY_DIR ?= "${TOPDIR}/buildhistory"
+
+   BUILDHISTORY_FEATURES
+      When inheriting the :ref:`buildhistory <ref-classes-buildhistory>`
+      class, this variable specifies the build history features to be
+      enabled. For more information on how build history works, see the
+      ":ref:`dev-manual/dev-manual-common-tasks:maintaining build output quality`"
+      section in the Yocto Project Development Tasks Manual.
+
+      You can specify these features in the form of a space-separated list:
+
+      -  *image:* Analysis of the contents of images, which includes the
+         list of installed packages among other things.
+
+      -  *package:* Analysis of the contents of individual packages.
+
+      -  *sdk:* Analysis of the contents of the software development kit
+         (SDK).
+
+      -  *task:* Save output file signatures for
+         :ref:`shared state <overview-manual/overview-manual-concepts:shared state cache>`
+         (sstate) tasks.
+         This saves one file per task and lists the SHA-256 checksums for
+         each file staged (i.e. the output of the task).
+
+      By default, the ``buildhistory`` class enables the following
+      features:
+      ::
+
+         BUILDHISTORY_FEATURES ?= "image package sdk"
+
+   BUILDHISTORY_IMAGE_FILES
+      When inheriting the :ref:`buildhistory <ref-classes-buildhistory>`
+      class, this variable specifies a list of paths to files copied from
+      the image contents into the build history directory under an
+      "image-files" directory in the directory for the image, so that you
+      can track the contents of each file. The default is to copy
+      ``/etc/passwd`` and ``/etc/group``, which allows you to monitor for
+      changes in user and group entries. You can modify the list to include
+      any file. Specifying an invalid path does not produce an error.
+      Consequently, you can include files that might not always be present.
+
+      By default, the ``buildhistory`` class provides paths to the
+      following files:
+      ::
+
+         BUILDHISTORY_IMAGE_FILES ?= "/etc/passwd /etc/group"
+
+   BUILDHISTORY_PUSH_REPO
+      When inheriting the :ref:`buildhistory <ref-classes-buildhistory>`
+      class, this variable optionally specifies a remote repository to
+      which build history pushes Git changes. In order for
+      ``BUILDHISTORY_PUSH_REPO`` to work,
+      :term:`BUILDHISTORY_COMMIT` must be set to
+      "1".
+
+      The repository should correspond to a remote address that specifies a
+      repository as understood by Git, or alternatively to a remote name
+      that you have set up manually using ``git remote`` within the local
+      repository.
+
+      By default, the ``buildhistory`` class sets the variable as follows:
+      ::
+
+         BUILDHISTORY_PUSH_REPO ?= ""
+
+   BUILDSDK_CFLAGS
+      Specifies the flags to pass to the C compiler when building for the
+      SDK. When building in the ``nativesdk-`` context,
+      :term:`CFLAGS` is set to the value of this variable by
+      default.
+
+   BUILDSDK_CPPFLAGS
+      Specifies the flags to pass to the C pre-processor (i.e. to both the
+      C and the C++ compilers) when building for the SDK. When building in
+      the ``nativesdk-`` context, :term:`CPPFLAGS` is set
+      to the value of this variable by default.
+
+   BUILDSDK_CXXFLAGS
+      Specifies the flags to pass to the C++ compiler when building for the
+      SDK. When building in the ``nativesdk-`` context,
+      :term:`CXXFLAGS` is set to the value of this variable
+      by default.
+
+   BUILDSDK_LDFLAGS
+      Specifies the flags to pass to the linker when building for the SDK.
+      When building in the ``nativesdk-`` context,
+      :term:`LDFLAGS` is set to the value of this variable
+      by default.
+
+   BUILDSTATS_BASE
+      Points to the location of the directory that holds build statistics
+      when you use and enable the
+      :ref:`buildstats <ref-classes-buildstats>` class. The
+      ``BUILDSTATS_BASE`` directory defaults to
+      ``${``\ :term:`TMPDIR`\ ``}/buildstats/``.
+
+   BUSYBOX_SPLIT_SUID
+      For the BusyBox recipe, specifies whether to split the output
+      executable file into two parts: one for features that require
+      ``setuid root``, and one for the remaining features (i.e. those that
+      do not require ``setuid root``).
+
+      The ``BUSYBOX_SPLIT_SUID`` variable defaults to "1", which results in
+      splitting the output executable file. Set the variable to "0" to get
+      a single output executable file.
+
+   CACHE
+      Specifies the directory BitBake uses to store a cache of the
+      :term:`Metadata` so it does not need to be parsed every time
+      BitBake is started.
+
+   CC
+      The minimal command and arguments used to run the C compiler.
+
+   CFLAGS
+      Specifies the flags to pass to the C compiler. This variable is
+      exported to an environment variable and thus made visible to the
+      software being built during the compilation step.
+
+      Default initialization for ``CFLAGS`` varies depending on what is
+      being built:
+
+      -  :term:`TARGET_CFLAGS` when building for the
+         target
+
+      -  :term:`BUILD_CFLAGS` when building for the
+         build host (i.e. ``-native``)
+
+      -  :term:`BUILDSDK_CFLAGS` when building for
+         an SDK (i.e. ``nativesdk-``)
+
+   CLASSOVERRIDE
+      An internal variable specifying the special class override that
+      should currently apply (e.g. "class-target", "class-native", and so
+      forth). The classes that use this variable (e.g.
+      :ref:`native <ref-classes-native>`,
+      :ref:`nativesdk <ref-classes-nativesdk>`, and so forth) set the
+      variable to appropriate values.
+
+      .. note::
+
+         CLASSOVERRIDE
+         gets its default "class-target" value from the
+         bitbake.conf
+         file.
+
+      As an example, the following override allows you to install extra
+      files, but only when building for the target:
+      ::
+
+         do_install_append_class-target() {
+             install my-extra-file ${D}${sysconfdir}
+         }
+
+      Here is an example where ``FOO`` is set to
+      "native" when building for the build host, and to "other" when not
+      building for the build host:
+      ::
+
+         FOO_class-native = "native"
+         FOO = "other"
+
+      The underlying mechanism behind ``CLASSOVERRIDE`` is simply
+      that it is included in the default value of
+      :term:`OVERRIDES`.
+
+   CLEANBROKEN
+      If set to "1" within a recipe, ``CLEANBROKEN`` specifies that the
+      ``make clean`` command does not work for the software being built.
+      Consequently, the OpenEmbedded build system will not try to run
+      ``make clean`` during the :ref:`ref-tasks-configure`
+      task, which is the default behavior.
+
+   COMBINED_FEATURES
+      Provides a list of hardware features that are enabled in both
+      :term:`MACHINE_FEATURES` and
+      :term:`DISTRO_FEATURES`. This select list of
+      features contains features that make sense to be controlled both at
+      the machine and distribution configuration level. For example, the
+      "bluetooth" feature requires hardware support but should also be
+      optional at the distribution level, in case the hardware supports
+      Bluetooth but you do not ever intend to use it.
+
+   COMMON_LICENSE_DIR
+      Points to ``meta/files/common-licenses`` in the
+      :term:`Source Directory`, which is where generic license
+      files reside.
+
+   COMPATIBLE_HOST
+      A regular expression that resolves to one or more hosts (when the
+      recipe is native) or one or more targets (when the recipe is
+      non-native) with which a recipe is compatible. The regular expression
+      is matched against :term:`HOST_SYS`. You can use the
+      variable to stop recipes from being built for classes of systems with
+      which the recipes are not compatible. Stopping these builds is
+      particularly useful with kernels. The variable also helps to increase
+      parsing speed since the build system skips parsing recipes not
+      compatible with the current system.
+
+   COMPATIBLE_MACHINE
+      A regular expression that resolves to one or more target machines
+      with which a recipe is compatible. The regular expression is matched
+      against :term:`MACHINEOVERRIDES`. You can use
+      the variable to stop recipes from being built for machines with which
+      the recipes are not compatible. Stopping these builds is particularly
+      useful with kernels. The variable also helps to increase parsing
+      speed since the build system skips parsing recipes not compatible
+      with the current machine.
+
+   COMPLEMENTARY_GLOB
+      Defines wildcards to match when installing a list of complementary
+      packages for all the packages explicitly (or implicitly) installed in
+      an image.
+
+      .. note::
+
+         The
+         COMPLEMENTARY_GLOB
+         variable uses Unix filename pattern matching (
+         fnmatch
+         ), which is similar to the Unix style pathname pattern expansion (
+         glob
+         ).
+
+      The resulting list of complementary packages is associated with an
+      item that can be added to
+      :term:`IMAGE_FEATURES`. An example usage of
+      this is the "dev-pkgs" item that when added to ``IMAGE_FEATURES``
+      will install -dev packages (containing headers and other development
+      files) for every package in the image.
+
+      To add a new feature item pointing to a wildcard, use a variable flag
+      to specify the feature item name and use the value to specify the
+      wildcard. Here is an example:
+      ::
+
+         COMPLEMENTARY_GLOB[dev-pkgs] = '*-dev'
+
+   COMPONENTS_DIR
+      Stores sysroot components for each recipe. The OpenEmbedded build
+      system uses ``COMPONENTS_DIR`` when constructing recipe-specific
+      sysroots for other recipes.
+
+      The default is
+      "``${``\ :term:`STAGING_DIR`\ ``}-components``."
+      (i.e.
+      "``${``\ :term:`TMPDIR`\ ``}/sysroots-components``").
+
+   CONF_VERSION
+      Tracks the version of the local configuration file (i.e.
+      ``local.conf``). The value for ``CONF_VERSION`` increments each time
+      ``build/conf/`` compatibility changes.
+
+   CONFFILES
+      Identifies editable or configurable files that are part of a package.
+      If the Package Management System (PMS) is being used to update
+      packages on the target system, it is possible that configuration
+      files you have changed after the original installation and that you
+      now want to remain unchanged are overwritten. In other words,
+      editable files might exist in the package that you do not want reset
+      as part of the package update process. You can use the ``CONFFILES``
+      variable to list the files in the package that you wish to prevent
+      the PMS from overwriting during this update process.
+
+      To use the ``CONFFILES`` variable, provide a package name override
+      that identifies the resulting package. Then, provide a
+      space-separated list of files. Here is an example:
+      ::
+
+         CONFFILES_${PN} += "${sysconfdir}/file1 \
+             ${sysconfdir}/file2 ${sysconfdir}/file3"
+
+      A relationship exists between the ``CONFFILES`` and ``FILES``
+      variables. The files listed within ``CONFFILES`` must be a subset of
+      the files listed within ``FILES``. Because the configuration files
+      you provide with ``CONFFILES`` are simply being identified so that
+      the PMS will not overwrite them, it makes sense that the files must
+      already be included as part of the package through the ``FILES``
+      variable.
+
+      .. note::
+
+         When specifying paths as part of the
+         CONFFILES
+         variable, it is good practice to use appropriate path variables.
+         For example,
+         ${sysconfdir}
+         rather than
+         /etc
+         or
+         ${bindir}
+         rather than
+         /usr/bin
+         . You can find a list of these variables at the top of the
+         meta/conf/bitbake.conf
+         file in the
+         Source Directory
+         .
+
+   CONFIG_INITRAMFS_SOURCE
+      Identifies the initial RAM filesystem (initramfs) source files. The
+      OpenEmbedded build system receives and uses this kernel Kconfig
+      variable as an environment variable. By default, the variable is set
+      to null ("").
+
+      The ``CONFIG_INITRAMFS_SOURCE`` can be either a single cpio archive
+      with a ``.cpio`` suffix or a space-separated list of directories and
+      files for building the initramfs image. A cpio archive should contain
+      a filesystem archive to be used as an initramfs image. Directories
+      should contain a filesystem layout to be included in the initramfs
+      image. Files should contain entries according to the format described
+      by the ``usr/gen_init_cpio`` program in the kernel tree.
+
+      If you specify multiple directories and files, the initramfs image
+      will be the aggregate of all of them.
+
+      For information on creating an initramfs, see the
+      ":ref:`building-an-initramfs-image`" section
+      in the Yocto Project Development Tasks Manual.
+
+   CONFIG_SITE
+      A list of files that contains ``autoconf`` test results relevant to
+      the current build. This variable is used by the Autotools utilities
+      when running ``configure``.
+
+   CONFIGURE_FLAGS
+      The minimal arguments for GNU configure.
+
+   CONFLICT_DISTRO_FEATURES
+      When inheriting the
+      :ref:`distro_features_check <ref-classes-distro_features_check>`
+      class, this variable identifies distribution features that would be
+      in conflict should the recipe be built. In other words, if the
+      ``CONFLICT_DISTRO_FEATURES`` variable lists a feature that also
+      appears in ``DISTRO_FEATURES`` within the current configuration, an
+      error occurs and the build stops.
+
+   COPYLEFT_LICENSE_EXCLUDE
+      A space-separated list of licenses to exclude from the source
+      archived by the :ref:`archiver <ref-classes-archiver>` class. In
+      other words, if a license in a recipe's
+      :term:`LICENSE` value is in the value of
+      ``COPYLEFT_LICENSE_EXCLUDE``, then its source is not archived by the
+      class.
+
+      .. note::
+
+         The
+         COPYLEFT_LICENSE_EXCLUDE
+         variable takes precedence over the
+         COPYLEFT_LICENSE_INCLUDE
+         variable.
+
+      The default value, which is "CLOSED Proprietary", for
+      ``COPYLEFT_LICENSE_EXCLUDE`` is set by the
+      :ref:`copyleft_filter <ref-classes-copyleft_filter>` class, which
+      is inherited by the ``archiver`` class.
+
+   COPYLEFT_LICENSE_INCLUDE
+      A space-separated list of licenses to include in the source archived
+      by the :ref:`archiver <ref-classes-archiver>` class. In other
+      words, if a license in a recipe's :term:`LICENSE`
+      value is in the value of ``COPYLEFT_LICENSE_INCLUDE``, then its
+      source is archived by the class.
+
+      The default value is set by the
+      :ref:`copyleft_filter <ref-classes-copyleft_filter>` class, which
+      is inherited by the ``archiver`` class. The default value includes
+      "GPL*", "LGPL*", and "AGPL*".
+
+   COPYLEFT_PN_EXCLUDE
+      A list of recipes to exclude in the source archived by the
+      :ref:`archiver <ref-classes-archiver>` class. The
+      ``COPYLEFT_PN_EXCLUDE`` variable overrides the license inclusion and
+      exclusion caused through the
+      :term:`COPYLEFT_LICENSE_INCLUDE` and
+      :term:`COPYLEFT_LICENSE_EXCLUDE`
+      variables, respectively.
+
+      The default value, which is "" indicating to not explicitly exclude
+      any recipes by name, for ``COPYLEFT_PN_EXCLUDE`` is set by the
+      :ref:`copyleft_filter <ref-classes-copyleft_filter>` class, which
+      is inherited by the ``archiver`` class.
+
+   COPYLEFT_PN_INCLUDE
+      A list of recipes to include in the source archived by the
+      :ref:`archiver <ref-classes-archiver>` class. The
+      ``COPYLEFT_PN_INCLUDE`` variable overrides the license inclusion and
+      exclusion caused through the
+      :term:`COPYLEFT_LICENSE_INCLUDE` and
+      :term:`COPYLEFT_LICENSE_EXCLUDE`
+      variables, respectively.
+
+      The default value, which is "" indicating to not explicitly include
+      any recipes by name, for ``COPYLEFT_PN_INCLUDE`` is set by the
+      :ref:`copyleft_filter <ref-classes-copyleft_filter>` class, which
+      is inherited by the ``archiver`` class.
+
+   COPYLEFT_RECIPE_TYPES
+      A space-separated list of recipe types to include in the source
+      archived by the :ref:`archiver <ref-classes-archiver>` class.
+      Recipe types are ``target``, ``native``, ``nativesdk``, ``cross``,
+      ``crosssdk``, and ``cross-canadian``.
+
+      The default value, which is "target*", for ``COPYLEFT_RECIPE_TYPES``
+      is set by the :ref:`copyleft_filter <ref-classes-copyleft_filter>`
+      class, which is inherited by the ``archiver`` class.
+
+   COPY_LIC_DIRS
+      If set to "1" along with the
+      :term:`COPY_LIC_MANIFEST` variable, the
+      OpenEmbedded build system copies into the image the license files,
+      which are located in ``/usr/share/common-licenses``, for each
+      package. The license files are placed in directories within the image
+      itself during build time.
+
+      .. note::
+
+         The
+         COPY_LIC_DIRS
+         does not offer a path for adding licenses for newly installed
+         packages to an image, which might be most suitable for read-only
+         filesystems that cannot be upgraded. See the
+         LICENSE_CREATE_PACKAGE
+         variable for additional information. You can also reference the "
+         Providing License Text
+         " section in the Yocto Project Development Tasks Manual for
+         information on providing license text.
+
+   COPY_LIC_MANIFEST
+      If set to "1", the OpenEmbedded build system copies the license
+      manifest for the image to
+      ``/usr/share/common-licenses/license.manifest`` within the image
+      itself during build time.
+
+      .. note::
+
+         The
+         COPY_LIC_MANIFEST
+         does not offer a path for adding licenses for newly installed
+         packages to an image, which might be most suitable for read-only
+         filesystems that cannot be upgraded. See the
+         LICENSE_CREATE_PACKAGE
+         variable for additional information. You can also reference the "
+         Providing License Text
+         " section in the Yocto Project Development Tasks Manual for
+         information on providing license text.
+
+   CORE_IMAGE_EXTRA_INSTALL
+      Specifies the list of packages to be added to the image. You should
+      only set this variable in the ``local.conf`` configuration file found
+      in the :term:`Build Directory`.
+
+      This variable replaces ``POKY_EXTRA_INSTALL``, which is no longer
+      supported.
+
+   COREBASE
+      Specifies the parent directory of the OpenEmbedded-Core Metadata
+      layer (i.e. ``meta``).
+
+      It is an important distinction that ``COREBASE`` points to the parent
+      of this layer and not the layer itself. Consider an example where you
+      have cloned the Poky Git repository and retained the ``poky`` name
+      for your local copy of the repository. In this case, ``COREBASE``
+      points to the ``poky`` folder because it is the parent directory of
+      the ``poky/meta`` layer.
+
+   COREBASE_FILES
+      Lists files from the :term:`COREBASE` directory that
+      should be copied other than the layers listed in the
+      ``bblayers.conf`` file. The ``COREBASE_FILES`` variable exists for
+      the purpose of copying metadata from the OpenEmbedded build system
+      into the extensible SDK.
+
+      Explicitly listing files in ``COREBASE`` is needed because it
+      typically contains build directories and other files that should not
+      normally be copied into the extensible SDK. Consequently, the value
+      of ``COREBASE_FILES`` is used in order to only copy the files that
+      are actually needed.
+
+   CPP
+      The minimal command and arguments used to run the C preprocessor.
+
+   CPPFLAGS
+      Specifies the flags to pass to the C pre-processor (i.e. to both the
+      C and the C++ compilers). This variable is exported to an environment
+      variable and thus made visible to the software being built during the
+      compilation step.
+
+      Default initialization for ``CPPFLAGS`` varies depending on what is
+      being built:
+
+      -  :term:`TARGET_CPPFLAGS` when building for
+         the target
+
+      -  :term:`BUILD_CPPFLAGS` when building for the
+         build host (i.e. ``-native``)
+
+      -  :term:`BUILDSDK_CPPFLAGS` when building
+         for an SDK (i.e. ``nativesdk-``)
+
+   CROSS_COMPILE
+      The toolchain binary prefix for the target tools. The
+      ``CROSS_COMPILE`` variable is the same as the
+      :term:`TARGET_PREFIX` variable.
+
+      .. note::
+
+         The OpenEmbedded build system sets the
+         CROSS_COMPILE
+         variable only in certain contexts (e.g. when building for kernel
+         and kernel module recipes).
+
+   CVSDIR
+      The directory in which files checked out under the CVS system are
+      stored.
+
+   CXX
+      The minimal command and arguments used to run the C++ compiler.
+
+   CXXFLAGS
+      Specifies the flags to pass to the C++ compiler. This variable is
+      exported to an environment variable and thus made visible to the
+      software being built during the compilation step.
+
+      Default initialization for ``CXXFLAGS`` varies depending on what is
+      being built:
+
+      -  :term:`TARGET_CXXFLAGS` when building for
+         the target
+
+      -  :term:`BUILD_CXXFLAGS` when building for the
+         build host (i.e. ``-native``)
+
+      -  :term:`BUILDSDK_CXXFLAGS` when building
+         for an SDK (i.e. ``nativesdk-``)
+
+   D
+      The destination directory. The location in the :term:`Build Directory`
+      where components are installed by the
+      :ref:`ref-tasks-install` task. This location defaults
+      to:
+      ::
+
+         ${WORKDIR}/image
+
+      .. note::
+
+         Tasks that read from or write to this directory should run under
+         fakeroot
+         .
+
+   DATE
+      The date the build was started. Dates appear using the year, month,
+      and day (YMD) format (e.g. "20150209" for February 9th, 2015).
+
+   DATETIME
+      The date and time on which the current build started. The format is
+      suitable for timestamps.
+
+   DEBIAN_NOAUTONAME
+      When the :ref:`debian <ref-classes-debian>` class is inherited,
+      which is the default behavior, ``DEBIAN_NOAUTONAME`` specifies a
+      particular package should not be renamed according to Debian library
+      package naming. You must use the package name as an override when you
+      set this variable. Here is an example from the ``fontconfig`` recipe:
+      ::
+
+         DEBIAN_NOAUTONAME_fontconfig-utils = "1"
+
+   DEBIANNAME
+      When the :ref:`debian <ref-classes-debian>` class is inherited,
+      which is the default behavior, ``DEBIANNAME`` allows you to override
+      the library name for an individual package. Overriding the library
+      name in these cases is rare. You must use the package name as an
+      override when you set this variable. Here is an example from the
+      ``dbus`` recipe:
+      ::
+
+         DEBIANNAME_${PN} = "dbus-1"
+
+   DEBUG_BUILD
+      Specifies to build packages with debugging information. This
+      influences the value of the ``SELECTED_OPTIMIZATION`` variable.
+
+   DEBUG_OPTIMIZATION
+      The options to pass in ``TARGET_CFLAGS`` and ``CFLAGS`` when
+      compiling a system for debugging. This variable defaults to "-O
+      -fno-omit-frame-pointer ${DEBUG_FLAGS} -pipe".
+
+   DEFAULT_PREFERENCE
+      Specifies a weak bias for recipe selection priority.
+
+      The most common usage of this is variable is to set it to "-1" within
+      a recipe for a development version of a piece of software. Using the
+      variable in this way causes the stable version of the recipe to build
+      by default in the absence of ``PREFERRED_VERSION`` being used to
+      build the development version.
+
+      .. note::
+
+         The bias provided by
+         DEFAULT_PREFERENCE
+         is weak and is overridden by
+         BBFILE_PRIORITY
+         if that variable is different between two layers that contain
+         different versions of the same recipe.
+
+   DEFAULTTUNE
+      The default CPU and Application Binary Interface (ABI) tunings (i.e.
+      the "tune") used by the OpenEmbedded build system. The
+      ``DEFAULTTUNE`` helps define
+      :term:`TUNE_FEATURES`.
+
+      The default tune is either implicitly or explicitly set by the
+      machine (:term:`MACHINE`). However, you can override
+      the setting using available tunes as defined with
+      :term:`AVAILTUNES`.
+
+   DEPENDS
+      Lists a recipe's build-time dependencies. These are dependencies on
+      other recipes whose contents (e.g. headers and shared libraries) are
+      needed by the recipe at build time.
+
+      As an example, consider a recipe ``foo`` that contains the following
+      assignment:
+      ::
+
+          DEPENDS = "bar"
+
+      The practical effect of the previous
+      assignment is that all files installed by bar will be available in
+      the appropriate staging sysroot, given by the
+      :term:`STAGING_DIR* <STAGING_DIR>` variables, by the time the
+      :ref:`ref-tasks-configure` task for ``foo`` runs.
+      This mechanism is implemented by having ``do_configure`` depend on
+      the :ref:`ref-tasks-populate_sysroot` task of
+      each recipe listed in ``DEPENDS``, through a
+      ``[``\ :ref:`deptask <bitbake:bitbake-user-manual/bitbake-user-manual-metadata:variable flags>`\ ``]``
+      declaration in the :ref:`base <ref-classes-base>` class.
+
+      .. note::
+
+         It seldom is necessary to reference, for example,
+         STAGING_DIR_HOST
+         explicitly. The standard classes and build-related variables are
+         configured to automatically use the appropriate staging sysroots.
+
+      As another example, ``DEPENDS`` can also be used to add utilities
+      that run on the build machine during the build. For example, a recipe
+      that makes use of a code generator built by the recipe ``codegen``
+      might have the following:
+      ::
+
+         DEPENDS = "codegen-native"
+
+      For more
+      information, see the :ref:`native <ref-classes-native>` class and
+      the :term:`EXTRANATIVEPATH` variable.
+
+      .. note::
+
+         -  ``DEPENDS`` is a list of recipe names. Or, to be more precise,
+            it is a list of :term:`PROVIDES` names, which
+            usually match recipe names. Putting a package name such as
+            "foo-dev" in ``DEPENDS`` does not make sense. Use "foo"
+            instead, as this will put files from all the packages that make
+            up ``foo``, which includes those from ``foo-dev``, into the
+            sysroot.
+
+         -  One recipe having another recipe in ``DEPENDS`` does not by
+            itself add any runtime dependencies between the packages
+            produced by the two recipes. However, as explained in the
+            ":ref:`overview-manual/overview-manual-concepts:automatically added runtime dependencies`"
+            section in the Yocto Project Overview and Concepts Manual,
+            runtime dependencies will often be added automatically, meaning
+            ``DEPENDS`` alone is sufficient for most recipes.
+
+         -  Counterintuitively, ``DEPENDS`` is often necessary even for
+            recipes that install precompiled components. For example, if
+            ``libfoo`` is a precompiled library that links against
+            ``libbar``, then linking against ``libfoo`` requires both
+            ``libfoo`` and ``libbar`` to be available in the sysroot.
+            Without a ``DEPENDS`` from the recipe that installs ``libfoo``
+            to the recipe that installs ``libbar``, other recipes might
+            fail to link against ``libfoo``.
+
+      For information on runtime dependencies, see the
+      :term:`RDEPENDS` variable. You can also see the
+      ":ref:`Tasks <bitbake:bitbake-user-manual/bitbake-user-manual-metadata:tasks>`" and
+      ":ref:`Dependencies <bitbake:bitbake-user-manual/bitbake-user-manual-execution:dependencies>`" sections in the
+      BitBake User Manual for additional information on tasks and
+      dependencies.
+
+   DEPLOY_DIR
+      Points to the general area that the OpenEmbedded build system uses to
+      place images, packages, SDKs, and other output files that are ready
+      to be used outside of the build system. By default, this directory
+      resides within the :term:`Build Directory` as
+      ``${TMPDIR}/deploy``.
+
+      For more information on the structure of the Build Directory, see
+      ":ref:`ref-manual/ref-structure:the build directory - \`\`build/\`\``" section.
+      For more detail on the contents of the ``deploy`` directory, see the
+      ":ref:`Images <images-dev-environment>`", ":ref:`Package
+      Feeds <package-feeds-dev-environment>`", and
+      ":ref:`sdk-dev-environment`" sections all in the
+      Yocto Project Overview and Concepts Manual.
+
+   DEPLOY_DIR_DEB
+      Points to the area that the OpenEmbedded build system uses to place
+      Debian packages that are ready to be used outside of the build
+      system. This variable applies only when
+      :term:`PACKAGE_CLASSES` contains
+      "package_deb".
+
+      The BitBake configuration file initially defines the
+      ``DEPLOY_DIR_DEB`` variable as a sub-folder of
+      :term:`DEPLOY_DIR`:
+      ::
+
+         DEPLOY_DIR_DEB = "${DEPLOY_DIR}/deb"
+
+      The :ref:`package_deb <ref-classes-package_deb>` class uses the
+      ``DEPLOY_DIR_DEB`` variable to make sure the
+      :ref:`ref-tasks-package_write_deb` task
+      writes Debian packages into the appropriate folder. For more
+      information on how packaging works, see the ":ref:`Package
+      Feeds <package-feeds-dev-environment>`" section
+      in the Yocto Project Overview and Concepts Manual.
+
+   DEPLOY_DIR_IMAGE
+      Points to the area that the OpenEmbedded build system uses to place
+      images and other associated output files that are ready to be
+      deployed onto the target machine. The directory is machine-specific
+      as it contains the ``${MACHINE}`` name. By default, this directory
+      resides within the :term:`Build Directory` as
+      ``${DEPLOY_DIR}/images/${MACHINE}/``.
+
+      For more information on the structure of the Build Directory, see
+      ":ref:`ref-manual/ref-structure:the build directory - \`\`build/\`\``" section.
+      For more detail on the contents of the ``deploy`` directory, see the
+      ":ref:`Images <images-dev-environment>`" and
+      ":ref:`sdk-dev-environment`" sections both in
+      the Yocto Project Overview and Concepts Manual.
+
+   DEPLOY_DIR_IPK
+      Points to the area that the OpenEmbedded build system uses to place
+      IPK packages that are ready to be used outside of the build system.
+      This variable applies only when
+      :term:`PACKAGE_CLASSES` contains
+      "package_ipk".
+
+      The BitBake configuration file initially defines this variable as a
+      sub-folder of :term:`DEPLOY_DIR`:
+      ::
+
+         DEPLOY_DIR_IPK = "${DEPLOY_DIR}/ipk"
+
+      The :ref:`package_ipk <ref-classes-package_ipk>` class uses the
+      ``DEPLOY_DIR_IPK`` variable to make sure the
+      :ref:`ref-tasks-package_write_ipk` task
+      writes IPK packages into the appropriate folder. For more information
+      on how packaging works, see the ":ref:`Package
+      Feeds <package-feeds-dev-environment>`" section
+      in the Yocto Project Overview and Concepts Manual.
+
+   DEPLOY_DIR_RPM
+      Points to the area that the OpenEmbedded build system uses to place
+      RPM packages that are ready to be used outside of the build system.
+      This variable applies only when
+      :term:`PACKAGE_CLASSES` contains
+      "package_rpm".
+
+      The BitBake configuration file initially defines this variable as a
+      sub-folder of :term:`DEPLOY_DIR`:
+      ::
+
+         DEPLOY_DIR_RPM = "${DEPLOY_DIR}/rpm"
+
+      The :ref:`package_rpm <ref-classes-package_rpm>` class uses the
+      ``DEPLOY_DIR_RPM`` variable to make sure the
+      :ref:`ref-tasks-package_write_rpm` task
+      writes RPM packages into the appropriate folder. For more information
+      on how packaging works, see the ":ref:`Package
+      Feeds <package-feeds-dev-environment>`" section
+      in the Yocto Project Overview and Concepts Manual.
+
+   DEPLOY_DIR_TAR
+      Points to the area that the OpenEmbedded build system uses to place
+      tarballs that are ready to be used outside of the build system. This
+      variable applies only when
+      :term:`PACKAGE_CLASSES` contains
+      "package_tar".
+
+      The BitBake configuration file initially defines this variable as a
+      sub-folder of :term:`DEPLOY_DIR`:
+      ::
+
+         DEPLOY_DIR_TAR = "${DEPLOY_DIR}/tar"
+
+      The :ref:`package_tar <ref-classes-package_tar>` class uses the
+      ``DEPLOY_DIR_TAR`` variable to make sure the
+      :ref:`ref-tasks-package_write_tar` task
+      writes TAR packages into the appropriate folder. For more information
+      on how packaging works, see the ":ref:`Package
+      Feeds <package-feeds-dev-environment>`" section
+      in the Yocto Project Overview and Concepts Manual.
+
+   DEPLOYDIR
+      When inheriting the :ref:`deploy <ref-classes-deploy>` class, the
+      ``DEPLOYDIR`` points to a temporary work area for deployed files that
+      is set in the ``deploy`` class as follows:
+      ::
+
+         DEPLOYDIR = "${WORKDIR}/deploy-${:term:`PN`}"
+
+      Recipes inheriting the ``deploy`` class should copy files to be
+      deployed into ``DEPLOYDIR``, and the class will take care of copying
+      them into :term:`DEPLOY_DIR_IMAGE`
+      afterwards.
+
+   DESCRIPTION
+      The package description used by package managers. If not set,
+      ``DESCRIPTION`` takes the value of the :term:`SUMMARY`
+      variable.
+
+   DISTRO
+      The short name of the distribution. For information on the long name
+      of the distribution, see the :term:`DISTRO_NAME`
+      variable.
+
+      The ``DISTRO`` variable corresponds to a distribution configuration
+      file whose root name is the same as the variable's argument and whose
+      filename extension is ``.conf``. For example, the distribution
+      configuration file for the Poky distribution is named ``poky.conf``
+      and resides in the ``meta-poky/conf/distro`` directory of the
+      :term:`Source Directory`.
+
+      Within that ``poky.conf`` file, the ``DISTRO`` variable is set as
+      follows:
+      ::
+
+         DISTRO = "poky"
+
+      Distribution configuration files are located in a ``conf/distro``
+      directory within the :term:`Metadata` that contains the
+      distribution configuration. The value for ``DISTRO`` must not contain
+      spaces, and is typically all lower-case.
+
+      .. note::
+
+         If the
+         DISTRO
+         variable is blank, a set of default configurations are used, which
+         are specified within
+         meta/conf/distro/defaultsetup.conf
+         also in the Source Directory.
+
+   DISTRO_CODENAME
+      Specifies a codename for the distribution being built.
+
+   DISTRO_EXTRA_RDEPENDS
+      Specifies a list of distro-specific packages to add to all images.
+      This variable takes affect through ``packagegroup-base`` so the
+      variable only really applies to the more full-featured images that
+      include ``packagegroup-base``. You can use this variable to keep
+      distro policy out of generic images. As with all other distro
+      variables, you set this variable in the distro ``.conf`` file.
+
+   DISTRO_EXTRA_RRECOMMENDS
+      Specifies a list of distro-specific packages to add to all images if
+      the packages exist. The packages might not exist or be empty (e.g.
+      kernel modules). The list of packages are automatically installed but
+      you can remove them.
+
+   DISTRO_FEATURES
+      The software support you want in your distribution for various
+      features. You define your distribution features in the distribution
+      configuration file.
+
+      In most cases, the presence or absence of a feature in
+      ``DISTRO_FEATURES`` is translated to the appropriate option supplied
+      to the configure script during the
+      :ref:`ref-tasks-configure` task for recipes that
+      optionally support the feature. For example, specifying "x11" in
+      ``DISTRO_FEATURES``, causes every piece of software built for the
+      target that can optionally support X11 to have its X11 support
+      enabled.
+
+      Two more examples are Bluetooth and NFS support. For a more complete
+      list of features that ships with the Yocto Project and that you can
+      provide with this variable, see the "`Distro
+      Features <#ref-features-distro>`__" section.
+
+   DISTRO_FEATURES_BACKFILL
+      Features to be added to ``DISTRO_FEATURES`` if not also present in
+      ``DISTRO_FEATURES_BACKFILL_CONSIDERED``.
+
+      This variable is set in the ``meta/conf/bitbake.conf`` file. It is
+      not intended to be user-configurable. It is best to just reference
+      the variable to see which distro features are being backfilled for
+      all distro configurations. See the "`Feature
+      Backfilling <#ref-features-backfill>`__" section for more
+      information.
+
+   DISTRO_FEATURES_BACKFILL_CONSIDERED
+      Features from ``DISTRO_FEATURES_BACKFILL`` that should not be
+      backfilled (i.e. added to ``DISTRO_FEATURES``) during the build. See
+      the "`Feature Backfilling <#ref-features-backfill>`__" section for
+      more information.
+
+   DISTRO_FEATURES_DEFAULT
+      A convenience variable that gives you the default list of distro
+      features with the exception of any features specific to the C library
+      (``libc``).
+
+      When creating a custom distribution, you might find it useful to be
+      able to reuse the default
+      :term:`DISTRO_FEATURES` options without the
+      need to write out the full set. Here is an example that uses
+      ``DISTRO_FEATURES_DEFAULT`` from a custom distro configuration file:
+      ::
+
+         DISTRO_FEATURES ?= "${DISTRO_FEATURES_DEFAULT} myfeature"
+
+   DISTRO_FEATURES_FILTER_NATIVE
+      Specifies a list of features that if present in the target
+      :term:`DISTRO_FEATURES` value should be
+      included in ``DISTRO_FEATURES`` when building native recipes. This
+      variable is used in addition to the features filtered using the
+      :term:`DISTRO_FEATURES_NATIVE`
+      variable.
+
+   DISTRO_FEATURES_FILTER_NATIVESDK
+      Specifies a list of features that if present in the target
+      :term:`DISTRO_FEATURES` value should be
+      included in ``DISTRO_FEATURES`` when building nativesdk recipes. This
+      variable is used in addition to the features filtered using the
+      :term:`DISTRO_FEATURES_NATIVESDK`
+      variable.
+
+   DISTRO_FEATURES_NATIVE
+      Specifies a list of features that should be included in
+      :term:`DISTRO_FEATURES` when building native
+      recipes. This variable is used in addition to the features filtered
+      using the
+      :term:`DISTRO_FEATURES_FILTER_NATIVE`
+      variable.
+
+   DISTRO_FEATURES_NATIVESDK
+      Specifies a list of features that should be included in
+      :term:`DISTRO_FEATURES` when building
+      nativesdk recipes. This variable is used in addition to the features
+      filtered using the
+      :term:`DISTRO_FEATURES_FILTER_NATIVESDK`
+      variable.
+
+   DISTRO_NAME
+      The long name of the distribution. For information on the short name
+      of the distribution, see the :term:`DISTRO` variable.
+
+      The ``DISTRO_NAME`` variable corresponds to a distribution
+      configuration file whose root name is the same as the variable's
+      argument and whose filename extension is ``.conf``. For example, the
+      distribution configuration file for the Poky distribution is named
+      ``poky.conf`` and resides in the ``meta-poky/conf/distro`` directory
+      of the :term:`Source Directory`.
+
+      Within that ``poky.conf`` file, the ``DISTRO_NAME`` variable is set
+      as follows:
+      ::
+
+         DISTRO_NAME = "Poky (Yocto Project Reference Distro)"
+
+      Distribution configuration files are located in a ``conf/distro``
+      directory within the :term:`Metadata` that contains the
+      distribution configuration.
+
+      .. note::
+
+         If the
+         DISTRO_NAME
+         variable is blank, a set of default configurations are used, which
+         are specified within
+         meta/conf/distro/defaultsetup.conf
+         also in the Source Directory.
+
+   DISTRO_VERSION
+      The version of the distribution.
+
+   DISTROOVERRIDES
+      A colon-separated list of overrides specific to the current
+      distribution. By default, this list includes the value of
+      :term:`DISTRO`.
+
+      You can extend ``DISTROOVERRIDES`` to add extra overrides that should
+      apply to the distribution.
+
+      The underlying mechanism behind ``DISTROOVERRIDES`` is simply that it
+      is included in the default value of
+      :term:`OVERRIDES`.
+
+   DL_DIR
+      The central download directory used by the build process to store
+      downloads. By default, ``DL_DIR`` gets files suitable for mirroring
+      for everything except Git repositories. If you want tarballs of Git
+      repositories, use the
+      :term:`BB_GENERATE_MIRROR_TARBALLS`
+      variable.
+
+      You can set this directory by defining the ``DL_DIR`` variable in the
+      ``conf/local.conf`` file. This directory is self-maintaining and you
+      should not have to touch it. By default, the directory is
+      ``downloads`` in the :term:`Build Directory`.
+      ::
+
+         #DL_DIR ?= "${TOPDIR}/downloads"
+
+      To specify a different download directory,
+      simply remove the comment from the line and provide your directory.
+
+      During a first build, the system downloads many different source code
+      tarballs from various upstream projects. Downloading can take a
+      while, particularly if your network connection is slow. Tarballs are
+      all stored in the directory defined by ``DL_DIR`` and the build
+      system looks there first to find source tarballs.
+
+      .. note::
+
+         When wiping and rebuilding, you can preserve this directory to
+         speed up this part of subsequent builds.
+
+      You can safely share this directory between multiple builds on the
+      same development machine. For additional information on how the build
+      process gets source files when working behind a firewall or proxy
+      server, see this specific question in the
+      "`FAQ <#how-does-the-yocto-project-obtain-source-code-and-will-it-work-behind-my-firewall-or-proxy-server>`__"
+      chapter. You can also refer to the
+      ":yocto_wiki:`Working Behind a Network Proxy </wiki/Working_Behind_a_Network_Proxy>`"
+      Wiki page.
+
+   DOC_COMPRESS
+      When inheriting the :ref:`compress_doc <ref-classes-compress_doc>`
+      class, this variable sets the compression policy used when the
+      OpenEmbedded build system compresses man pages and info pages. By
+      default, the compression method used is gz (gzip). Other policies
+      available are xz and bz2.
+
+      For information on policies and on how to use this variable, see the
+      comments in the ``meta/classes/compress_doc.bbclass`` file.
+
+   EFI_PROVIDER
+      When building bootable images (i.e. where ``hddimg``, ``iso``, or
+      ``wic.vmdk`` is in :term:`IMAGE_FSTYPES`), the
+      ``EFI_PROVIDER`` variable specifies the EFI bootloader to use. The
+      default is "grub-efi", but "systemd-boot" can be used instead.
+
+      See the :ref:`systemd-boot <ref-classes-systemd-boot>` and
+      :ref:`image-live <ref-classes-image-live>` classes for more
+      information.
+
+   ENABLE_BINARY_LOCALE_GENERATION
+      Variable that controls which locales for ``glibc`` are generated
+      during the build (useful if the target device has 64Mbytes of RAM or
+      less).
+
+   ERR_REPORT_DIR
+      When used with the :ref:`report-error <ref-classes-report-error>`
+      class, specifies the path used for storing the debug files created by
+      the :ref:`error reporting
+      tool <dev-manual/dev-manual-common-tasks:using the error reporting tool>`, which
+      allows you to submit build errors you encounter to a central
+      database. By default, the value of this variable is
+      ``${``\ :term:`LOG_DIR`\ ``}/error-report``.
+
+      You can set ``ERR_REPORT_DIR`` to the path you want the error
+      reporting tool to store the debug files as follows in your
+      ``local.conf`` file:
+      ::
+
+         ERR_REPORT_DIR = "path"
+
+   ERROR_QA
+      Specifies the quality assurance checks whose failures are reported as
+      errors by the OpenEmbedded build system. You set this variable in
+      your distribution configuration file. For a list of the checks you
+      can control with this variable, see the
+      ":ref:`insane.bbclass <ref-classes-insane>`" section.
+
+   EXCLUDE_FROM_SHLIBS
+      Triggers the OpenEmbedded build system's shared libraries resolver to
+      exclude an entire package when scanning for shared libraries.
+
+      .. note::
+
+         The shared libraries resolver's functionality results in part from
+         the internal function
+         package_do_shlibs
+         , which is part of the
+         do_package
+         task. You should be aware that the shared libraries resolver might
+         implicitly define some dependencies between packages.
+
+      The ``EXCLUDE_FROM_SHLIBS`` variable is similar to the
+      :term:`PRIVATE_LIBS` variable, which excludes a
+      package's particular libraries only and not the whole package.
+
+      Use the ``EXCLUDE_FROM_SHLIBS`` variable by setting it to "1" for a
+      particular package:
+      ::
+
+         EXCLUDE_FROM_SHLIBS = "1"
+
+   EXCLUDE_FROM_WORLD
+      Directs BitBake to exclude a recipe from world builds (i.e.
+      ``bitbake world``). During world builds, BitBake locates, parses and
+      builds all recipes found in every layer exposed in the
+      ``bblayers.conf`` configuration file.
+
+      To exclude a recipe from a world build using this variable, set the
+      variable to "1" in the recipe.
+
+      .. note::
+
+         Recipes added to
+         EXCLUDE_FROM_WORLD
+         may still be built during a world build in order to satisfy
+         dependencies of other recipes. Adding a recipe to
+         EXCLUDE_FROM_WORLD
+         only ensures that the recipe is not explicitly added to the list
+         of build targets in a world build.
+
+   EXTENDPE
+      Used with file and pathnames to create a prefix for a recipe's
+      version based on the recipe's :term:`PE` value. If ``PE``
+      is set and greater than zero for a recipe, ``EXTENDPE`` becomes that
+      value (e.g if ``PE`` is equal to "1" then ``EXTENDPE`` becomes "1").
+      If a recipe's ``PE`` is not set (the default) or is equal to zero,
+      ``EXTENDPE`` becomes "".
+
+      See the :term:`STAMP` variable for an example.
+
+   EXTENDPKGV
+      The full package version specification as it appears on the final
+      packages produced by a recipe. The variable's value is normally used
+      to fix a runtime dependency to the exact same version of another
+      package in the same recipe:
+      ::
+
+         RDEPENDS_${PN}-additional-module = "${PN} (= ${EXTENDPKGV})"
+
+      The dependency relationships are intended to force the package
+      manager to upgrade these types of packages in lock-step.
+
+   EXTERNAL_KERNEL_TOOLS
+      When set, the ``EXTERNAL_KERNEL_TOOLS`` variable indicates that these
+      tools are not in the source tree.
+
+      When kernel tools are available in the tree, they are preferred over
+      any externally installed tools. Setting the ``EXTERNAL_KERNEL_TOOLS``
+      variable tells the OpenEmbedded build system to prefer the installed
+      external tools. See the
+      :ref:`kernel-yocto <ref-classes-kernel-yocto>` class in
+      ``meta/classes`` to see how the variable is used.
+
+   EXTERNALSRC
+      When inheriting the :ref:`externalsrc <ref-classes-externalsrc>`
+      class, this variable points to the source tree, which is outside of
+      the OpenEmbedded build system. When set, this variable sets the
+      :term:`S` variable, which is what the OpenEmbedded build
+      system uses to locate unpacked recipe source code.
+
+      For more information on ``externalsrc.bbclass``, see the
+      ":ref:`externalsrc.bbclass <ref-classes-externalsrc>`" section. You
+      can also find information on how to use this variable in the
+      ":ref:`dev-manual/dev-manual-common-tasks:building software from an external source`"
+      section in the Yocto Project Development Tasks Manual.
+
+   EXTERNALSRC_BUILD
+      When inheriting the :ref:`externalsrc <ref-classes-externalsrc>`
+      class, this variable points to the directory in which the recipe's
+      source code is built, which is outside of the OpenEmbedded build
+      system. When set, this variable sets the :term:`B` variable,
+      which is what the OpenEmbedded build system uses to locate the Build
+      Directory.
+
+      For more information on ``externalsrc.bbclass``, see the
+      ":ref:`externalsrc.bbclass <ref-classes-externalsrc>`" section. You
+      can also find information on how to use this variable in the
+      ":ref:`dev-manual/dev-manual-common-tasks:building software from an external source`"
+      section in the Yocto Project Development Tasks Manual.
+
+   EXTRA_AUTORECONF
+      For recipes inheriting the :ref:`autotools <ref-classes-autotools>`
+      class, you can use ``EXTRA_AUTORECONF`` to specify extra options to
+      pass to the ``autoreconf`` command that is executed during the
+      :ref:`ref-tasks-configure` task.
+
+      The default value is "--exclude=autopoint".
+
+   EXTRA_IMAGE_FEATURES
+      A list of additional features to include in an image. When listing
+      more than one feature, separate them with a space.
+
+      Typically, you configure this variable in your ``local.conf`` file,
+      which is found in the :term:`Build Directory`.
+      Although you can use this variable from within a recipe, best
+      practices dictate that you do not.
+
+      .. note::
+
+         To enable primary features from within the image recipe, use the
+         IMAGE_FEATURES
+         variable.
+
+      Here are some examples of features you can add:
+
+        - "dbg-pkgs" - Adds -dbg packages for all installed packages including
+          symbol information for debugging and profiling.
+
+        - "debug-tweaks" - Makes an image suitable for debugging. For example, allows root logins without passwords and
+          enables post-installation logging. See the 'allow-empty-password' and
+          'post-install-logging' features in the "`Image
+          Features <#ref-features-image>`__" section for more information.
+        - "dev-pkgs" - Adds -dev packages for all installed packages. This is
+          useful if you want to develop against the libraries in the image.
+        - "read-only-rootfs" - Creates an image whose root filesystem is
+          read-only. See the
+          ":ref:`dev-manual/dev-manual-common-tasks:creating a read-only root filesystem`"
+          section in the Yocto Project Development Tasks Manual for more
+          information
+        - "tools-debug" - Adds debugging tools such as gdb and strace.
+        - "tools-sdk" - Adds development tools such as gcc, make,
+          pkgconfig and so forth.
+        - "tools-testapps" - Adds useful testing tools
+          such as ts_print, aplay, arecord and so forth.
+
+      For a complete list of image features that ships with the Yocto
+      Project, see the "`Image Features <#ref-features-image>`__" section.
+
+      For an example that shows how to customize your image by using this
+      variable, see the ":ref:`usingpoky-extend-customimage-imagefeatures`"
+      section in the Yocto Project Development Tasks Manual.
+
+   EXTRA_IMAGECMD
+      Specifies additional options for the image creation command that has
+      been specified in :term:`IMAGE_CMD`. When setting
+      this variable, use an override for the associated image type. Here is
+      an example:
+      ::
+
+         EXTRA_IMAGECMD_ext3 ?= "-i 4096"
+
+   EXTRA_IMAGEDEPENDS
+      A list of recipes to build that do not provide packages for
+      installing into the root filesystem.
+
+      Sometimes a recipe is required to build the final image but is not
+      needed in the root filesystem. You can use the ``EXTRA_IMAGEDEPENDS``
+      variable to list these recipes and thus specify the dependencies. A
+      typical example is a required bootloader in a machine configuration.
+
+      .. note::
+
+         To add packages to the root filesystem, see the various
+         \*RDEPENDS and \*RRECOMMENDS
+         variables.
+
+   EXTRANATIVEPATH
+      A list of subdirectories of
+      ``${``\ :term:`STAGING_BINDIR_NATIVE`\ ``}``
+      added to the beginning of the environment variable ``PATH``. As an
+      example, the following prepends
+      "${STAGING_BINDIR_NATIVE}/foo:${STAGING_BINDIR_NATIVE}/bar:" to
+      ``PATH``:
+      ::
+
+         EXTRANATIVEPATH = "foo bar"
+
+   EXTRA_OECMAKE
+      Additional `CMake <https://cmake.org/overview/>`__ options. See the
+      :ref:`cmake <ref-classes-cmake>` class for additional information.
+
+   EXTRA_OECONF
+      Additional ``configure`` script options. See
+      :term:`PACKAGECONFIG_CONFARGS` for
+      additional information on passing configure script options.
+
+   EXTRA_OEMAKE
+      Additional GNU ``make`` options.
+
+      Because the ``EXTRA_OEMAKE`` defaults to "", you need to set the
+      variable to specify any required GNU options.
+
+      :term:`PARALLEL_MAKE` and
+      :term:`PARALLEL_MAKEINST` also make use of
+      ``EXTRA_OEMAKE`` to pass the required flags.
+
+   EXTRA_OESCONS
+      When inheriting the :ref:`scons <ref-classes-scons>` class, this
+      variable specifies additional configuration options you want to pass
+      to the ``scons`` command line.
+
+   EXTRA_USERS_PARAMS
+      When inheriting the :ref:`extrausers <ref-classes-extrausers>`
+      class, this variable provides image level user and group operations.
+      This is a more global method of providing user and group
+      configuration as compared to using the
+      :ref:`useradd <ref-classes-useradd>` class, which ties user and
+      group configurations to a specific recipe.
+
+      The set list of commands you can configure using the
+      ``EXTRA_USERS_PARAMS`` is shown in the ``extrausers`` class. These
+      commands map to the normal Unix commands of the same names:
+      ::
+
+         # EXTRA_USERS_PARAMS = "\
+         # useradd -p '' tester; \
+         # groupadd developers; \
+         # userdel nobody; \
+         # groupdel -g video; \
+         # groupmod -g 1020 developers; \
+         # usermod -s /bin/sh tester; \
+         # "
+
+   FEATURE_PACKAGES
+      Defines one or more packages to include in an image when a specific
+      item is included in :term:`IMAGE_FEATURES`.
+      When setting the value, ``FEATURE_PACKAGES`` should have the name of
+      the feature item as an override. Here is an example:
+      ::
+
+         FEATURE_PACKAGES_widget = "package1 package2"
+
+      In this example, if "widget" were added to ``IMAGE_FEATURES``,
+      package1 and package2 would be included in the image.
+
+      .. note::
+
+         Packages installed by features defined through
+         FEATURE_PACKAGES
+         are often package groups. While similarly named, you should not
+         confuse the
+         FEATURE_PACKAGES
+         variable with package groups, which are discussed elsewhere in the
+         documentation.
+
+   FEED_DEPLOYDIR_BASE_URI
+      Points to the base URL of the server and location within the
+      document-root that provides the metadata and packages required by
+      OPKG to support runtime package management of IPK packages. You set
+      this variable in your ``local.conf`` file.
+
+      Consider the following example:
+      ::
+
+         FEED_DEPLOYDIR_BASE_URI = "http://192.168.7.1/BOARD-dir"
+
+      This example assumes you are serving
+      your packages over HTTP and your databases are located in a directory
+      named ``BOARD-dir``, which is underneath your HTTP server's
+      document-root. In this case, the OpenEmbedded build system generates
+      a set of configuration files for you in your target that work with
+      the feed.
+
+   FILES
+      The list of files and directories that are placed in a package. The
+      :term:`PACKAGES` variable lists the packages
+      generated by a recipe.
+
+      To use the ``FILES`` variable, provide a package name override that
+      identifies the resulting package. Then, provide a space-separated
+      list of files or paths that identify the files you want included as
+      part of the resulting package. Here is an example:
+      ::
+
+         FILES_${PN} += "${bindir}/mydir1 ${bindir}/mydir2/myfile"
+
+      .. note::
+
+         -  When specifying files or paths, you can pattern match using
+            Python's
+            `glob <https://docs.python.org/3/library/glob.html>`_
+            syntax. For details on the syntax, see the documentation by
+            following the previous link.
+
+         -  When specifying paths as part of the ``FILES`` variable, it is
+            good practice to use appropriate path variables. For example,
+            use ``${sysconfdir}`` rather than ``/etc``, or ``${bindir}``
+            rather than ``/usr/bin``. You can find a list of these
+            variables at the top of the ``meta/conf/bitbake.conf`` file in
+            the :term:`Source Directory`. You will also
+            find the default values of the various ``FILES_*`` variables in
+            this file.
+
+      If some of the files you provide with the ``FILES`` variable are
+      editable and you know they should not be overwritten during the
+      package update process by the Package Management System (PMS), you
+      can identify these files so that the PMS will not overwrite them. See
+      the :term:`CONFFILES` variable for information on
+      how to identify these files to the PMS.
+
+   FILES_SOLIBSDEV
+      Defines the file specification to match
+      :term:`SOLIBSDEV`. In other words,
+      ``FILES_SOLIBSDEV`` defines the full path name of the development
+      symbolic link (symlink) for shared libraries on the target platform.
+
+      The following statement from the ``bitbake.conf`` shows how it is
+      set:
+      ::
+
+         FILES_SOLIBSDEV ?= "${base_libdir}/lib*${SOLIBSDEV} ${libdir}/lib*${SOLIBSDEV}"
+
+   FILESEXTRAPATHS
+      Extends the search path the OpenEmbedded build system uses when
+      looking for files and patches as it processes recipes and append
+      files. The default directories BitBake uses when it processes recipes
+      are initially defined by the :term:`FILESPATH`
+      variable. You can extend ``FILESPATH`` variable by using
+      ``FILESEXTRAPATHS``.
+
+      Best practices dictate that you accomplish this by using
+      ``FILESEXTRAPATHS`` from within a ``.bbappend`` file and that you
+      prepend paths as follows:
+      ::
+
+         FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}:"
+
+      In the above example, the build system first
+      looks for files in a directory that has the same name as the
+      corresponding append file.
+
+      .. note::
+
+         When extending ``FILESEXTRAPATHS``, be sure to use the immediate
+         expansion (``:=``) operator. Immediate expansion makes sure that
+         BitBake evaluates :term:`THISDIR` at the time the
+         directive is encountered rather than at some later time when
+         expansion might result in a directory that does not contain the
+         files you need.
+
+         Also, include the trailing separating colon character if you are
+         prepending. The trailing colon character is necessary because you
+         are directing BitBake to extend the path by prepending directories
+         to the search path.
+
+      Here is another common use:
+      ::
+
+         FILESEXTRAPATHS_prepend := "${THISDIR}/files:"
+
+      In this example, the build system extends the
+      ``FILESPATH`` variable to include a directory named ``files`` that is
+      in the same directory as the corresponding append file.
+
+      This next example specifically adds three paths:
+      ::
+
+         FILESEXTRAPATHS_prepend := "path_1:path_2:path_3:"
+
+      A final example shows how you can extend the search path and include
+      a :term:`MACHINE`-specific override, which is useful
+      in a BSP layer:
+      ::
+
+          FILESEXTRAPATHS_prepend_intel-x86-common := "${THISDIR}/${PN}:"
+
+      The previous statement appears in the
+      ``linux-yocto-dev.bbappend`` file, which is found in the
+      :ref:`overview-manual/overview-manual-development-environment:yocto project source repositories` in
+      ``meta-intel/common/recipes-kernel/linux``. Here, the machine
+      override is a special :term:`PACKAGE_ARCH`
+      definition for multiple ``meta-intel`` machines.
+
+      .. note::
+
+         For a layer that supports a single BSP, the override could just be
+         the value of
+         MACHINE
+         .
+
+      By prepending paths in ``.bbappend`` files, you allow multiple append
+      files that reside in different layers but are used for the same
+      recipe to correctly extend the path.
+
+   FILESOVERRIDES
+      A subset of :term:`OVERRIDES` used by the
+      OpenEmbedded build system for creating
+      :term:`FILESPATH`. The ``FILESOVERRIDES`` variable
+      uses overrides to automatically extend the
+      :term:`FILESPATH` variable. For an example of how
+      that works, see the :term:`FILESPATH` variable
+      description. Additionally, you find more information on how overrides
+      are handled in the
+      ":ref:`bitbake:bitbake-user-manual/bitbake-user-manual-metadata:conditional syntax (overrides)`"
+      section of the BitBake User Manual.
+
+      By default, the ``FILESOVERRIDES`` variable is defined as:
+      ::
+
+         FILESOVERRIDES = "${TRANSLATED_TARGET_ARCH}:${MACHINEOVERRIDES}:${DISTROOVERRIDES}"
+
+      .. note::
+
+         Do not hand-edit the
+         FILESOVERRIDES
+         variable. The values match up with expected overrides and are used
+         in an expected manner by the build system.
+
+   FILESPATH
+      The default set of directories the OpenEmbedded build system uses
+      when searching for patches and files.
+
+      During the build process, BitBake searches each directory in
+      ``FILESPATH`` in the specified order when looking for files and
+      patches specified by each ``file://`` URI in a recipe's
+      :term:`SRC_URI` statements.
+
+      The default value for the ``FILESPATH`` variable is defined in the
+      ``base.bbclass`` class found in ``meta/classes`` in the
+      :term:`Source Directory`:
+      ::
+
+         FILESPATH = "${@base_set_filespath(["${FILE_DIRNAME}/${BP}", \
+             "${FILE_DIRNAME}/${BPN}", "${FILE_DIRNAME}/files"], d)}"
+
+      The
+      ``FILESPATH`` variable is automatically extended using the overrides
+      from the :term:`FILESOVERRIDES` variable.
+
+      .. note::
+
+         -  Do not hand-edit the ``FILESPATH`` variable. If you want the
+            build system to look in directories other than the defaults,
+            extend the ``FILESPATH`` variable by using the
+            :term:`FILESEXTRAPATHS` variable.
+
+         -  Be aware that the default ``FILESPATH`` directories do not map
+            to directories in custom layers where append files
+            (``.bbappend``) are used. If you want the build system to find
+            patches or files that reside with your append files, you need
+            to extend the ``FILESPATH`` variable by using the
+            ``FILESEXTRAPATHS`` variable.
+
+      You can take advantage of this searching behavior in useful ways. For
+      example, consider a case where the following directory structure
+      exists for general and machine-specific configurations:
+      ::
+
+         files/defconfig
+         files/MACHINEA/defconfig
+         files/MACHINEB/defconfig
+
+      Also in the example, the ``SRC_URI`` statement contains
+      "file://defconfig". Given this scenario, you can set
+      :term:`MACHINE` to "MACHINEA" and cause the build
+      system to use files from ``files/MACHINEA``. Set ``MACHINE`` to
+      "MACHINEB" and the build system uses files from ``files/MACHINEB``.
+      Finally, for any machine other than "MACHINEA" and "MACHINEB", the
+      build system uses files from ``files/defconfig``.
+
+      You can find out more about the patching process in the
+      ":ref:`patching-dev-environment`" section
+      in the Yocto Project Overview and Concepts Manual and the
+      ":ref:`new-recipe-patching-code`" section in
+      the Yocto Project Development Tasks Manual. See the
+      :ref:`ref-tasks-patch` task as well.
+
+   FILESYSTEM_PERMS_TABLES
+      Allows you to define your own file permissions settings table as part
+      of your configuration for the packaging process. For example, suppose
+      you need a consistent set of custom permissions for a set of groups
+      and users across an entire work project. It is best to do this in the
+      packages themselves but this is not always possible.
+
+      By default, the OpenEmbedded build system uses the ``fs-perms.txt``,
+      which is located in the ``meta/files`` folder in the :term:`Source Directory`.
+      If you create your own file
+      permissions setting table, you should place it in your layer or the
+      distro's layer.
+
+      You define the ``FILESYSTEM_PERMS_TABLES`` variable in the
+      ``conf/local.conf`` file, which is found in the :term:`Build Directory`,
+      to point to your custom
+      ``fs-perms.txt``. You can specify more than a single file permissions
+      setting table. The paths you specify to these files must be defined
+      within the :term:`BBPATH` variable.
+
+      For guidance on how to create your own file permissions settings
+      table file, examine the existing ``fs-perms.txt``.
+
+   FIT_HASH_ALG
+      Specifies the hash algorithm used in creating the FIT Image. For e.g. sha256.
+
+   FIT_SIGN_ALG
+      Specifies the signature algorithm used in creating the FIT Image.
+      For e.g. rsa2048.
+
+   FONT_EXTRA_RDEPENDS
+      When inheriting the :ref:`fontcache <ref-classes-fontcache>` class,
+      this variable specifies the runtime dependencies for font packages.
+      By default, the ``FONT_EXTRA_RDEPENDS`` is set to "fontconfig-utils".
+
+   FONT_PACKAGES
+      When inheriting the :ref:`fontcache <ref-classes-fontcache>` class,
+      this variable identifies packages containing font files that need to
+      be cached by Fontconfig. By default, the ``fontcache`` class assumes
+      that fonts are in the recipe's main package (i.e.
+      ``${``\ :term:`PN`\ ``}``). Use this variable if fonts you
+      need are in a package other than that main package.
+
+   FORCE_RO_REMOVE
+      Forces the removal of the packages listed in ``ROOTFS_RO_UNNEEDED``
+      during the generation of the root filesystem.
+
+      Set the variable to "1" to force the removal of these packages.
+
+   FULL_OPTIMIZATION
+      The options to pass in ``TARGET_CFLAGS`` and ``CFLAGS`` when
+      compiling an optimized system. This variable defaults to "-O2 -pipe
+      ${DEBUG_FLAGS}".
+
+   GCCPIE
+      Enables Position Independent Executables (PIE) within the GNU C
+      Compiler (GCC). Enabling PIE in the GCC makes Return Oriented
+      Programming (ROP) attacks much more difficult to execute.
+
+      By default the ``security_flags.inc`` file enables PIE by setting the
+      variable as follows:
+      ::
+
+         GCCPIE ?= "--enable-default-pie"
+
+   GCCVERSION
+      Specifies the default version of the GNU C Compiler (GCC) used for
+      compilation. By default, ``GCCVERSION`` is set to "8.x" in the
+      ``meta/conf/distro/include/tcmode-default.inc`` include file:
+      ::
+
+         GCCVERSION ?= "8.%"
+
+      You can override this value by setting it in a
+      configuration file such as the ``local.conf``.
+
+   GDB
+      The minimal command and arguments to run the GNU Debugger.
+
+   GITDIR
+      The directory in which a local copy of a Git repository is stored
+      when it is cloned.
+
+   GLIBC_GENERATE_LOCALES
+      Specifies the list of GLIBC locales to generate should you not wish
+      to generate all LIBC locals, which can be time consuming.
+
+      .. note::
+
+         If you specifically remove the locale
+         en_US.UTF-8
+         , you must set
+         IMAGE_LINGUAS
+         appropriately.
+
+      You can set ``GLIBC_GENERATE_LOCALES`` in your ``local.conf`` file.
+      By default, all locales are generated.
+      ::
+
+         GLIBC_GENERATE_LOCALES = "en_GB.UTF-8 en_US.UTF-8"
+
+   GROUPADD_PARAM
+      When inheriting the :ref:`useradd <ref-classes-useradd>` class,
+      this variable specifies for a package what parameters should be
+      passed to the ``groupadd`` command if you wish to add a group to the
+      system when the package is installed.
+
+      Here is an example from the ``dbus`` recipe:
+      ::
+
+         GROUPADD_PARAM_${PN} = "-r netdev"
+
+      For information on the standard Linux shell command
+      ``groupadd``, see http://linux.die.net/man/8/groupadd.
+
+   GROUPMEMS_PARAM
+      When inheriting the :ref:`useradd <ref-classes-useradd>` class,
+      this variable specifies for a package what parameters should be
+      passed to the ``groupmems`` command if you wish to modify the members
+      of a group when the package is installed.
+
+      For information on the standard Linux shell command ``groupmems``,
+      see http://linux.die.net/man/8/groupmems.
+
+   GRUB_GFXSERIAL
+      Configures the GNU GRand Unified Bootloader (GRUB) to have graphics
+      and serial in the boot menu. Set this variable to "1" in your
+      ``local.conf`` or distribution configuration file to enable graphics
+      and serial in the menu.
+
+      See the :ref:`grub-efi <ref-classes-grub-efi>` class for more
+      information on how this variable is used.
+
+   GRUB_OPTS
+      Additional options to add to the GNU GRand Unified Bootloader (GRUB)
+      configuration. Use a semi-colon character (``;``) to separate
+      multiple options.
+
+      The ``GRUB_OPTS`` variable is optional. See the
+      :ref:`grub-efi <ref-classes-grub-efi>` class for more information
+      on how this variable is used.
+
+   GRUB_TIMEOUT
+      Specifies the timeout before executing the default ``LABEL`` in the
+      GNU GRand Unified Bootloader (GRUB).
+
+      The ``GRUB_TIMEOUT`` variable is optional. See the
+      :ref:`grub-efi <ref-classes-grub-efi>` class for more information
+      on how this variable is used.
+
+   GTKIMMODULES_PACKAGES
+      When inheriting the
+      :ref:`gtk-immodules-cache <ref-classes-gtk-immodules-cache>` class,
+      this variable specifies the packages that contain the GTK+ input
+      method modules being installed when the modules are in packages other
+      than the main package.
+
+   HOMEPAGE
+      Website where more information about the software the recipe is
+      building can be found.
+
+   HOST_ARCH
+      The name of the target architecture, which is normally the same as
+      :term:`TARGET_ARCH`. The OpenEmbedded build system
+      supports many architectures. Here is an example list of architectures
+      supported. This list is by no means complete as the architecture is
+      configurable:
+
+      - arm
+      - i586
+      - x86_64
+      - powerpc
+      - powerpc64
+      - mips
+      - mipsel
+
+   HOST_CC_ARCH
+      Specifies architecture-specific compiler flags that are passed to the
+      C compiler.
+
+      Default initialization for ``HOST_CC_ARCH`` varies depending on what
+      is being built:
+
+      -  :term:`TARGET_CC_ARCH` when building for the
+         target
+
+      -  ``BUILD_CC_ARCH`` when building for the build host (i.e.
+         ``-native``)
+
+      -  ``BUILDSDK_CC_ARCH`` when building for an SDK (i.e.
+         ``nativesdk-``)
+
+   HOST_OS
+      Specifies the name of the target operating system, which is normally
+      the same as the :term:`TARGET_OS`. The variable can
+      be set to "linux" for ``glibc``-based systems and to "linux-musl" for
+      ``musl``. For ARM/EABI targets, there are also "linux-gnueabi" and
+      "linux-musleabi" values possible.
+
+   HOST_PREFIX
+      Specifies the prefix for the cross-compile toolchain. ``HOST_PREFIX``
+      is normally the same as :term:`TARGET_PREFIX`.
+
+   HOST_SYS
+      Specifies the system, including the architecture and the operating
+      system, for which the build is occurring in the context of the
+      current recipe.
+
+      The OpenEmbedded build system automatically sets this variable based
+      on :term:`HOST_ARCH`,
+      :term:`HOST_VENDOR`, and
+      :term:`HOST_OS` variables.
+
+      .. note::
+
+         You do not need to set the variable yourself.
+
+      Consider these two examples:
+
+      -  Given a native recipe on a 32-bit x86 machine running Linux, the
+         value is "i686-linux".
+
+      -  Given a recipe being built for a little-endian MIPS target running
+         Linux, the value might be "mipsel-linux".
+
+   HOSTTOOLS
+      A space-separated list (filter) of tools on the build host that
+      should be allowed to be called from within build tasks. Using this
+      filter helps reduce the possibility of host contamination. If a tool
+      specified in the value of ``HOSTTOOLS`` is not found on the build
+      host, the OpenEmbedded build system produces an error and the build
+      is not started.
+
+      For additional information, see
+      :term:`HOSTTOOLS_NONFATAL`.
+
+   HOSTTOOLS_NONFATAL
+      A space-separated list (filter) of tools on the build host that
+      should be allowed to be called from within build tasks. Using this
+      filter helps reduce the possibility of host contamination. Unlike
+      :term:`HOSTTOOLS`, the OpenEmbedded build system
+      does not produce an error if a tool specified in the value of
+      ``HOSTTOOLS_NONFATAL`` is not found on the build host. Thus, you can
+      use ``HOSTTOOLS_NONFATAL`` to filter optional host tools.
+
+   HOST_VENDOR
+      Specifies the name of the vendor. ``HOST_VENDOR`` is normally the
+      same as :term:`TARGET_VENDOR`.
+
+   ICECC_DISABLED
+      Disables or enables the ``icecc`` (Icecream) function. For more
+      information on this function and best practices for using this
+      variable, see the ":ref:`icecc.bbclass <ref-classes-icecc>`"
+      section.
+
+      Setting this variable to "1" in your ``local.conf`` disables the
+      function:
+      ::
+
+         ICECC_DISABLED ??= "1"
+
+      To enable the function, set the variable as follows:
+      ::
+
+         ICECC_DISABLED = ""
+
+   ICECC_ENV_EXEC
+      Points to the ``icecc-create-env`` script that you provide. This
+      variable is used by the :ref:`icecc <ref-classes-icecc>` class. You
+      set this variable in your ``local.conf`` file.
+
+      If you do not point to a script that you provide, the OpenEmbedded
+      build system uses the default script provided by the
+      ``icecc-create-env.bb`` recipe, which is a modified version and not
+      the one that comes with ``icecc``.
+
+   ICECC_PARALLEL_MAKE
+      Extra options passed to the ``make`` command during the
+      :ref:`ref-tasks-compile` task that specify parallel
+      compilation. This variable usually takes the form of "-j x", where x
+      represents the maximum number of parallel threads ``make`` can run.
+
+      .. note::
+
+         The options passed affect builds on all enabled machines on the
+         network, which are machines running the
+         iceccd
+         daemon.
+
+      If your enabled machines support multiple cores, coming up with the
+      maximum number of parallel threads that gives you the best
+      performance could take some experimentation since machine speed,
+      network lag, available memory, and existing machine loads can all
+      affect build time. Consequently, unlike the
+      :term:`PARALLEL_MAKE` variable, there is no
+      rule-of-thumb for setting ``ICECC_PARALLEL_MAKE`` to achieve optimal
+      performance.
+
+      If you do not set ``ICECC_PARALLEL_MAKE``, the build system does not
+      use it (i.e. the system does not detect and assign the number of
+      cores as is done with ``PARALLEL_MAKE``).
+
+   ICECC_PATH
+      The location of the ``icecc`` binary. You can set this variable in
+      your ``local.conf`` file. If your ``local.conf`` file does not define
+      this variable, the :ref:`icecc <ref-classes-icecc>` class attempts
+      to define it by locating ``icecc`` using ``which``.
+
+   ICECC_USER_CLASS_BL
+      Identifies user classes that you do not want the Icecream distributed
+      compile support to consider. This variable is used by the
+      :ref:`icecc <ref-classes-icecc>` class. You set this variable in
+      your ``local.conf`` file.
+
+      When you list classes using this variable, you are "blacklisting"
+      them from distributed compilation across remote hosts. Any classes
+      you list will be distributed and compiled locally.
+
+   ICECC_USER_PACKAGE_BL
+      Identifies user recipes that you do not want the Icecream distributed
+      compile support to consider. This variable is used by the
+      :ref:`icecc <ref-classes-icecc>` class. You set this variable in
+      your ``local.conf`` file.
+
+      When you list packages using this variable, you are "blacklisting"
+      them from distributed compilation across remote hosts. Any packages
+      you list will be distributed and compiled locally.
+
+   ICECC_USER_PACKAGE_WL
+      Identifies user recipes that use an empty
+      :term:`PARALLEL_MAKE` variable that you want to
+      force remote distributed compilation on using the Icecream
+      distributed compile support. This variable is used by the
+      :ref:`icecc <ref-classes-icecc>` class. You set this variable in
+      your ``local.conf`` file.
+
+   IMAGE_BASENAME
+      The base name of image output files. This variable defaults to the
+      recipe name (``${``\ :term:`PN`\ ``}``).
+
+   IMAGE_BOOT_FILES
+      A space-separated list of files installed into the boot partition
+      when preparing an image using the Wic tool with the
+      ``bootimg-partition`` or ``bootimg-efi`` source plugin. By default,
+      the files are
+      installed under the same name as the source files. To change the
+      installed name, separate it from the original name with a semi-colon
+      (;). Source files need to be located in
+      :term:`DEPLOY_DIR_IMAGE`. Here are two
+      examples:
+      ::
+
+         IMAGE_BOOT_FILES = "u-boot.img uImage;kernel"
+         IMAGE_BOOT_FILES = "u-boot.${UBOOT_SUFFIX} ${KERNEL_IMAGETYPE}"
+
+      Alternatively, source files can be picked up using a glob pattern. In
+      this case, the destination file must have the same name as the base
+      name of the source file path. To install files into a directory
+      within the target location, pass its name after a semi-colon (;).
+      Here are two examples:
+      ::
+
+         IMAGE_BOOT_FILES = "bcm2835-bootfiles/*"
+         IMAGE_BOOT_FILES = "bcm2835-bootfiles/*;boot/"
+
+      The first example
+      installs all files from ``${DEPLOY_DIR_IMAGE}/bcm2835-bootfiles``
+      into the root of the target partition. The second example installs
+      the same files into a ``boot`` directory within the target partition.
+
+      You can find information on how to use the Wic tool in the
+      ":ref:`dev-manual/dev-manual-common-tasks:creating partitioned images using wic`"
+      section of the Yocto Project Development Tasks Manual. Reference
+      material for Wic is located in the
+      ":doc:`../ref-manual/ref-kickstart`" chapter.
+
+   IMAGE_CLASSES
+      A list of classes that all images should inherit. You typically use
+      this variable to specify the list of classes that register the
+      different types of images the OpenEmbedded build system creates.
+
+      The default value for ``IMAGE_CLASSES`` is ``image_types``. You can
+      set this variable in your ``local.conf`` or in a distribution
+      configuration file.
+
+      For more information, see ``meta/classes/image_types.bbclass`` in the
+      :term:`Source Directory`.
+
+   IMAGE_CMD
+      Specifies the command to create the image file for a specific image
+      type, which corresponds to the value set set in
+      :term:`IMAGE_FSTYPES`, (e.g. ``ext3``,
+      ``btrfs``, and so forth). When setting this variable, you should use
+      an override for the associated type. Here is an example:
+      ::
+
+         IMAGE_CMD_jffs2 = "mkfs.jffs2 --root=${IMAGE_ROOTFS} \
+             --faketime --output=${DEPLOY_DIR_IMAGE}/${IMAGE_NAME}.rootfs.jffs2 \
+             ${EXTRA_IMAGECMD}"
+
+      You typically do not need to set this variable unless you are adding
+      support for a new image type. For more examples on how to set this
+      variable, see the :ref:`image_types <ref-classes-image_types>`
+      class file, which is ``meta/classes/image_types.bbclass``.
+
+   IMAGE_DEVICE_TABLES
+      Specifies one or more files that contain custom device tables that
+      are passed to the ``makedevs`` command as part of creating an image.
+      These files list basic device nodes that should be created under
+      ``/dev`` within the image. If ``IMAGE_DEVICE_TABLES`` is not set,
+      ``files/device_table-minimal.txt`` is used, which is located by
+      :term:`BBPATH`. For details on how you should write
+      device table files, see ``meta/files/device_table-minimal.txt`` as an
+      example.
+
+   IMAGE_FEATURES
+      The primary list of features to include in an image. Typically, you
+      configure this variable in an image recipe. Although you can use this
+      variable from your ``local.conf`` file, which is found in the
+      :term:`Build Directory`, best practices dictate that you do
+      not.
+
+      .. note::
+
+         To enable extra features from outside the image recipe, use the
+         EXTRA_IMAGE_FEATURES
+         variable.
+
+      For a list of image features that ships with the Yocto Project, see
+      the "`Image Features <#ref-features-image>`__" section.
+
+      For an example that shows how to customize your image by using this
+      variable, see the ":ref:`usingpoky-extend-customimage-imagefeatures`"
+      section in the Yocto Project Development Tasks Manual.
+
+   IMAGE_FSTYPES
+      Specifies the formats the OpenEmbedded build system uses during the
+      build when creating the root filesystem. For example, setting
+      ``IMAGE_FSTYPES`` as follows causes the build system to create root
+      filesystems using two formats: ``.ext3`` and ``.tar.bz2``:
+      ::
+
+         IMAGE_FSTYPES = "ext3 tar.bz2"
+
+      For the complete list of supported image formats from which you can
+      choose, see :term:`IMAGE_TYPES`.
+
+      .. note::
+
+         -  If an image recipe uses the "inherit image" line and you are
+            setting ``IMAGE_FSTYPES`` inside the recipe, you must set
+            ``IMAGE_FSTYPES`` prior to using the "inherit image" line.
+
+         -  Due to the way the OpenEmbedded build system processes this
+            variable, you cannot update its contents by using ``_append``
+            or ``_prepend``. You must use the ``+=`` operator to add one or
+            more options to the ``IMAGE_FSTYPES`` variable.
+
+   IMAGE_INSTALL
+      Used by recipes to specify the packages to install into an image
+      through the :ref:`image <ref-classes-image>` class. Use the
+      ``IMAGE_INSTALL`` variable with care to avoid ordering issues.
+
+      Image recipes set ``IMAGE_INSTALL`` to specify the packages to
+      install into an image through ``image.bbclass``. Additionally,
+      "helper" classes such as the
+      :ref:`core-image <ref-classes-core-image>` class exist that can
+      take lists used with ``IMAGE_FEATURES`` and turn them into
+      auto-generated entries in ``IMAGE_INSTALL`` in addition to its
+      default contents.
+
+      When you use this variable, it is best to use it as follows:
+      ::
+
+         IMAGE_INSTALL_append = " package-name"
+
+      Be sure to include the space
+      between the quotation character and the start of the package name or
+      names.
+
+      .. note::
+
+         -  When working with a
+            ```core-image-minimal-initramfs`` <#images-core-image-minimal-initramfs>`__
+            image, do not use the ``IMAGE_INSTALL`` variable to specify
+            packages for installation. Instead, use the
+            :term:`PACKAGE_INSTALL` variable, which
+            allows the initial RAM filesystem (initramfs) recipe to use a
+            fixed set of packages and not be affected by ``IMAGE_INSTALL``.
+            For information on creating an initramfs, see the
+            ":ref:`building-an-initramfs-image`"
+            section in the Yocto Project Development Tasks Manual.
+
+         -  Using ``IMAGE_INSTALL`` with the
+            :ref:`+= <bitbake:appending-and-prepending>`
+            BitBake operator within the ``/conf/local.conf`` file or from
+            within an image recipe is not recommended. Use of this operator
+            in these ways can cause ordering issues. Since
+            ``core-image.bbclass`` sets ``IMAGE_INSTALL`` to a default
+            value using the
+            :ref:`?= <bitbake:bitbake-user-manual/bitbake-user-manual-metadata:setting a default value (?=)>`
+            operator, using a ``+=`` operation against ``IMAGE_INSTALL``
+            results in unexpected behavior when used within
+            ``conf/local.conf``. Furthermore, the same operation from
+            within an image recipe may or may not succeed depending on the
+            specific situation. In both these cases, the behavior is
+            contrary to how most users expect the ``+=`` operator to work.
+
+   IMAGE_LINGUAS
+      Specifies the list of locales to install into the image during the
+      root filesystem construction process. The OpenEmbedded build system
+      automatically splits locale files, which are used for localization,
+      into separate packages. Setting the ``IMAGE_LINGUAS`` variable
+      ensures that any locale packages that correspond to packages already
+      selected for installation into the image are also installed. Here is
+      an example:
+      ::
+
+         IMAGE_LINGUAS = "pt-br de-de"
+
+      In this example, the build system ensures any Brazilian Portuguese
+      and German locale files that correspond to packages in the image are
+      installed (i.e. ``*-locale-pt-br`` and ``*-locale-de-de`` as well as
+      ``*-locale-pt`` and ``*-locale-de``, since some software packages
+      only provide locale files by language and not by country-specific
+      language).
+
+      See the :term:`GLIBC_GENERATE_LOCALES`
+      variable for information on generating GLIBC locales.
+
+   IMAGE_MANIFEST
+      The manifest file for the image. This file lists all the installed
+      packages that make up the image. The file contains package
+      information on a line-per-package basis as follows:
+      ::
+
+          packagename packagearch version
+
+      The :ref:`image <ref-classes-image>` class defines the manifest
+      file as follows:
+      ::
+
+         IMAGE_MANIFEST ="${DEPLOY_DIR_IMAGE}/${IMAGE_NAME}.rootfs.manifest"
+
+      The location is
+      derived using the :term:`DEPLOY_DIR_IMAGE`
+      and :term:`IMAGE_NAME` variables. You can find
+      information on how the image is created in the ":ref:`image-generation-dev-environment`"
+      section in the Yocto Project Overview and Concepts Manual.
+
+   IMAGE_NAME
+      The name of the output image files minus the extension. This variable
+      is derived using the :term:`IMAGE_BASENAME`,
+      :term:`MACHINE`, and :term:`DATETIME`
+      variables:
+      ::
+
+         IMAGE_NAME = "${IMAGE_BASENAME}-${MACHINE}-${DATETIME}"
+
+   IMAGE_OVERHEAD_FACTOR
+      Defines a multiplier that the build system applies to the initial
+      image size for cases when the multiplier times the returned disk
+      usage value for the image is greater than the sum of
+      ``IMAGE_ROOTFS_SIZE`` and ``IMAGE_ROOTFS_EXTRA_SPACE``. The result of
+      the multiplier applied to the initial image size creates free disk
+      space in the image as overhead. By default, the build process uses a
+      multiplier of 1.3 for this variable. This default value results in
+      30% free disk space added to the image when this method is used to
+      determine the final generated image size. You should be aware that
+      post install scripts and the package management system uses disk
+      space inside this overhead area. Consequently, the multiplier does
+      not produce an image with all the theoretical free disk space. See
+      ``IMAGE_ROOTFS_SIZE`` for information on how the build system
+      determines the overall image size.
+
+      The default 30% free disk space typically gives the image enough room
+      to boot and allows for basic post installs while still leaving a
+      small amount of free disk space. If 30% free space is inadequate, you
+      can increase the default value. For example, the following setting
+      gives you 50% free space added to the image:
+      ::
+
+         IMAGE_OVERHEAD_FACTOR = "1.5"
+
+      Alternatively, you can ensure a specific amount of free disk space is
+      added to the image by using the ``IMAGE_ROOTFS_EXTRA_SPACE``
+      variable.
+
+   IMAGE_PKGTYPE
+      Defines the package type (i.e. DEB, RPM, IPK, or TAR) used by the
+      OpenEmbedded build system. The variable is defined appropriately by
+      the :ref:`package_deb <ref-classes-package_deb>`,
+      :ref:`package_rpm <ref-classes-package_rpm>`,
+      :ref:`package_ipk <ref-classes-package_ipk>`, or
+      :ref:`package_tar <ref-classes-package_tar>` class.
+
+      .. note::
+
+         The
+         package_tar
+         class is broken and is not supported. It is recommended that you
+         do not use it.
+
+      The :ref:`populate_sdk_* <ref-classes-populate-sdk-*>` and
+      :ref:`image <ref-classes-image>` classes use the ``IMAGE_PKGTYPE``
+      for packaging up images and SDKs.
+
+      You should not set the ``IMAGE_PKGTYPE`` manually. Rather, the
+      variable is set indirectly through the appropriate
+      :ref:`package_* <ref-classes-package>` class using the
+      :term:`PACKAGE_CLASSES` variable. The
+      OpenEmbedded build system uses the first package type (e.g. DEB, RPM,
+      or IPK) that appears with the variable
+
+      .. note::
+
+         Files using the
+         .tar
+         format are never used as a substitute packaging format for DEB,
+         RPM, and IPK formatted files for your image or SDK.
+
+   IMAGE_POSTPROCESS_COMMAND
+      Specifies a list of functions to call once the OpenEmbedded build
+      system creates the final image output files. You can specify
+      functions separated by semicolons:
+      ::
+
+         IMAGE_POSTPROCESS_COMMAND += "function; ... "
+
+      If you need to pass the root filesystem path to a command within the
+      function, you can use ``${IMAGE_ROOTFS}``, which points to the
+      directory that becomes the root filesystem image. See the
+      :term:`IMAGE_ROOTFS` variable for more
+      information.
+
+   IMAGE_PREPROCESS_COMMAND
+      Specifies a list of functions to call before the OpenEmbedded build
+      system creates the final image output files. You can specify
+      functions separated by semicolons:
+      ::
+
+         IMAGE_PREPROCESS_COMMAND += "function; ... "
+
+      If you need to pass the root filesystem path to a command within the
+      function, you can use ``${IMAGE_ROOTFS}``, which points to the
+      directory that becomes the root filesystem image. See the
+      :term:`IMAGE_ROOTFS` variable for more
+      information.
+
+   IMAGE_ROOTFS
+      The location of the root filesystem while it is under construction
+      (i.e. during the :ref:`ref-tasks-rootfs` task). This
+      variable is not configurable. Do not change it.
+
+   IMAGE_ROOTFS_ALIGNMENT
+      Specifies the alignment for the output image file in Kbytes. If the
+      size of the image is not a multiple of this value, then the size is
+      rounded up to the nearest multiple of the value. The default value is
+      "1". See :term:`IMAGE_ROOTFS_SIZE` for
+      additional information.
+
+   IMAGE_ROOTFS_EXTRA_SPACE
+      Defines additional free disk space created in the image in Kbytes. By
+      default, this variable is set to "0". This free disk space is added
+      to the image after the build system determines the image size as
+      described in ``IMAGE_ROOTFS_SIZE``.
+
+      This variable is particularly useful when you want to ensure that a
+      specific amount of free disk space is available on a device after an
+      image is installed and running. For example, to be sure 5 Gbytes of
+      free disk space is available, set the variable as follows:
+      ::
+
+         IMAGE_ROOTFS_EXTRA_SPACE = "5242880"
+
+      For example, the Yocto Project Build Appliance specifically requests
+      40 Gbytes of extra space with the line:
+      ::
+
+         IMAGE_ROOTFS_EXTRA_SPACE = "41943040"
+
+   IMAGE_ROOTFS_SIZE
+      Defines the size in Kbytes for the generated image. The OpenEmbedded
+      build system determines the final size for the generated image using
+      an algorithm that takes into account the initial disk space used for
+      the generated image, a requested size for the image, and requested
+      additional free disk space to be added to the image. Programatically,
+      the build system determines the final size of the generated image as
+      follows:
+      ::
+
+         if (image-du * overhead) < rootfs-size:
+             internal-rootfs-size = rootfs-size + xspace
+         else:
+             internal-rootfs-size = (image-du * overhead) + xspace
+         where:
+             image-du = Returned value of the du command on the image.
+             overhead = IMAGE_OVERHEAD_FACTOR
+             rootfs-size = IMAGE_ROOTFS_SIZE
+             internal-rootfs-size = Initial root filesystem size before any modifications.
+             xspace = IMAGE_ROOTFS_EXTRA_SPACE
+
+      See the :term:`IMAGE_OVERHEAD_FACTOR`
+      and :term:`IMAGE_ROOTFS_EXTRA_SPACE`
+      variables for related information.
+
+   IMAGE_TYPEDEP
+      Specifies a dependency from one image type on another. Here is an
+      example from the :ref:`image-live <ref-classes-image-live>` class:
+      ::
+
+         IMAGE_TYPEDEP_live = "ext3"
+
+      In the previous example, the variable ensures that when "live" is
+      listed with the :term:`IMAGE_FSTYPES` variable,
+      the OpenEmbedded build system produces an ``ext3`` image first since
+      one of the components of the live image is an ``ext3`` formatted
+      partition containing the root filesystem.
+
+   IMAGE_TYPES
+      Specifies the complete list of supported image types by default:
+
+      - btrfs
+      - container
+      - cpio
+      - cpio.gz
+      - cpio.lz4
+      - cpio.lzma
+      - cpio.xz
+      - cramfs
+      - ext2
+      - ext2.bz2
+      - ext2.gz
+      - ext2.lzma
+      - ext3
+      - ext3.gz
+      - ext4
+      - ext4.gz
+      - f2fs
+      - hddimg
+      - iso
+      - jffs2
+      - jffs2.sum
+      - multiubi
+      - squashfs
+      - squashfs-lz4
+      - squashfs-lzo
+      - squashfs-xz
+      - tar
+      - tar.bz2
+      - tar.gz
+      - tar.lz4
+      - tar.xz
+      - tar.zst
+      - ubi
+      - ubifs
+      - wic
+      - wic.bz2
+      - wic.gz
+      - wic.lzma
+
+      For more information about these types of images, see
+      ``meta/classes/image_types*.bbclass`` in the :term:`Source Directory`.
+
+   INC_PR
+      Helps define the recipe revision for recipes that share a common
+      ``include`` file. You can think of this variable as part of the
+      recipe revision as set from within an include file.
+
+      Suppose, for example, you have a set of recipes that are used across
+      several projects. And, within each of those recipes the revision (its
+      :term:`PR` value) is set accordingly. In this case, when
+      the revision of those recipes changes, the burden is on you to find
+      all those recipes and be sure that they get changed to reflect the
+      updated version of the recipe. In this scenario, it can get
+      complicated when recipes that are used in many places and provide
+      common functionality are upgraded to a new revision.
+
+      A more efficient way of dealing with this situation is to set the
+      ``INC_PR`` variable inside the ``include`` files that the recipes
+      share and then expand the ``INC_PR`` variable within the recipes to
+      help define the recipe revision.
+
+      The following provides an example that shows how to use the
+      ``INC_PR`` variable given a common ``include`` file that defines the
+      variable. Once the variable is defined in the ``include`` file, you
+      can use the variable to set the ``PR`` values in each recipe. You
+      will notice that when you set a recipe's ``PR`` you can provide more
+      granular revisioning by appending values to the ``INC_PR`` variable:
+      ::
+
+         recipes-graphics/xorg-font/xorg-font-common.inc:INC_PR = "r2"
+         recipes-graphics/xorg-font/encodings_1.0.4.bb:PR = "${INC_PR}.1"
+         recipes-graphics/xorg-font/font-util_1.3.0.bb:PR = "${INC_PR}.0"
+         recipes-graphics/xorg-font/font-alias_1.0.3.bb:PR = "${INC_PR}.3"
+
+      The
+      first line of the example establishes the baseline revision to be
+      used for all recipes that use the ``include`` file. The remaining
+      lines in the example are from individual recipes and show how the
+      ``PR`` value is set.
+
+   INCOMPATIBLE_LICENSE
+      Specifies a space-separated list of license names (as they would
+      appear in :term:`LICENSE`) that should be excluded
+      from the build. Recipes that provide no alternatives to listed
+      incompatible licenses are not built. Packages that are individually
+      licensed with the specified incompatible licenses will be deleted.
+
+      .. note::
+
+         This functionality is only regularly tested using the following
+         setting:
+         ::
+
+                 INCOMPATIBLE_LICENSE = "GPL-3.0 LGPL-3.0 AGPL-3.0"
+
+
+         Although you can use other settings, you might be required to
+         remove dependencies on or provide alternatives to components that
+         are required to produce a functional system image.
+
+      .. note::
+
+         It is possible to define a list of licenses that are allowed to be
+         used instead of the licenses that are excluded. To do this, define
+         a variable
+         COMPATIBLE_LICENSES
+         with the names of the licences that are allowed. Then define
+         INCOMPATIBLE_LICENSE
+         as:
+         ::
+
+                 INCOMPATIBLE_LICENSE = "${@' '.join(sorted(set(d.getVar('AVAILABLE_LICENSES').split()) - set(d.getVar('COMPATIBLE_LICENSES').split())))}"
+
+
+         This will result in
+         INCOMPATIBLE_LICENSE
+         containing the names of all licences from
+         AVAILABLE_LICENSES
+         except the ones specified in
+         COMPATIBLE_LICENSES
+         , thus only allowing the latter licences to be used.
+
+   INHERIT
+      Causes the named class or classes to be inherited globally. Anonymous
+      functions in the class or classes are not executed for the base
+      configuration and in each individual recipe. The OpenEmbedded build
+      system ignores changes to ``INHERIT`` in individual recipes.
+
+      For more information on ``INHERIT``, see the
+      :ref:`bitbake:bitbake-user-manual/bitbake-user-manual-metadata:\`\`inherit\`\` configuration directive`"
+      section in the Bitbake User Manual.
+
+   INHERIT_DISTRO
+      Lists classes that will be inherited at the distribution level. It is
+      unlikely that you want to edit this variable.
+
+      The default value of the variable is set as follows in the
+      ``meta/conf/distro/defaultsetup.conf`` file:
+      ::
+
+         INHERIT_DISTRO ?= "debian devshell sstate license"
+
+   INHIBIT_DEFAULT_DEPS
+      Prevents the default dependencies, namely the C compiler and standard
+      C library (libc), from being added to :term:`DEPENDS`.
+      This variable is usually used within recipes that do not require any
+      compilation using the C compiler.
+
+      Set the variable to "1" to prevent the default dependencies from
+      being added.
+
+   INHIBIT_PACKAGE_DEBUG_SPLIT
+      Prevents the OpenEmbedded build system from splitting out debug
+      information during packaging. By default, the build system splits out
+      debugging information during the
+      :ref:`ref-tasks-package` task. For more information on
+      how debug information is split out, see the
+      :term:`PACKAGE_DEBUG_SPLIT_STYLE`
+      variable.
+
+      To prevent the build system from splitting out debug information
+      during packaging, set the ``INHIBIT_PACKAGE_DEBUG_SPLIT`` variable as
+      follows:
+      ::
+
+         INHIBIT_PACKAGE_DEBUG_SPLIT = "1"
+
+   INHIBIT_PACKAGE_STRIP
+      If set to "1", causes the build to not strip binaries in resulting
+      packages and prevents the ``-dbg`` package from containing the source
+      files.
+
+      By default, the OpenEmbedded build system strips binaries and puts
+      the debugging symbols into ``${``\ :term:`PN`\ ``}-dbg``.
+      Consequently, you should not set ``INHIBIT_PACKAGE_STRIP`` when you
+      plan to debug in general.
+
+   INHIBIT_SYSROOT_STRIP
+      If set to "1", causes the build to not strip binaries in the
+      resulting sysroot.
+
+      By default, the OpenEmbedded build system strips binaries in the
+      resulting sysroot. When you specifically set the
+      ``INHIBIT_SYSROOT_STRIP`` variable to "1" in your recipe, you inhibit
+      this stripping.
+
+      If you want to use this variable, include the
+      :ref:`staging <ref-classes-staging>` class. This class uses a
+      ``sys_strip()`` function to test for the variable and acts
+      accordingly.
+
+      .. note::
+
+         Use of the
+         INHIBIT_SYSROOT_STRIP
+         variable occurs in rare and special circumstances. For example,
+         suppose you are building bare-metal firmware by using an external
+         GCC toolchain. Furthermore, even if the toolchain's binaries are
+         strippable, other files exist that are needed for the build that
+         are not strippable.
+
+   INITRAMFS_FSTYPES
+      Defines the format for the output image of an initial RAM filesystem
+      (initramfs), which is used during boot. Supported formats are the
+      same as those supported by the
+      :term:`IMAGE_FSTYPES` variable.
+
+      The default value of this variable, which is set in the
+      ``meta/conf/bitbake.conf`` configuration file in the
+      :term:`Source Directory`, is "cpio.gz". The Linux kernel's
+      initramfs mechanism, as opposed to the initial RAM filesystem
+      `initrd <https://en.wikipedia.org/wiki/Initrd>`__ mechanism, expects
+      an optionally compressed cpio archive.
+
+   INITRAMFS_IMAGE
+      Specifies the :term:`PROVIDES` name of an image
+      recipe that is used to build an initial RAM filesystem (initramfs)
+      image. In other words, the ``INITRAMFS_IMAGE`` variable causes an
+      additional recipe to be built as a dependency to whatever root
+      filesystem recipe you might be using (e.g. ``core-image-sato``). The
+      initramfs image recipe you provide should set
+      :term:`IMAGE_FSTYPES` to
+      :term:`INITRAMFS_FSTYPES`.
+
+      An initramfs image provides a temporary root filesystem used for
+      early system initialization (e.g. loading of modules needed to locate
+      and mount the "real" root filesystem).
+
+      .. note::
+
+         See the
+         meta/recipes-core/images/core-image-minimal-initramfs.bb
+         recipe in the
+         Source Directory
+         for an example initramfs recipe. To select this sample recipe as
+         the one built to provide the initramfs image, set
+         INITRAMFS_IMAGE
+         to "core-image-minimal-initramfs".
+
+      You can also find more information by referencing the
+      ``meta-poky/conf/local.conf.sample.extended`` configuration file in
+      the Source Directory, the :ref:`image <ref-classes-image>` class,
+      and the :ref:`kernel <ref-classes-kernel>` class to see how to use
+      the ``INITRAMFS_IMAGE`` variable.
+
+      If ``INITRAMFS_IMAGE`` is empty, which is the default, then no
+      initramfs image is built.
+
+      For more information, you can also see the
+      :term:`INITRAMFS_IMAGE_BUNDLE`
+      variable, which allows the generated image to be bundled inside the
+      kernel image. Additionally, for information on creating an initramfs
+      image, see the ":ref:`building-an-initramfs-image`" section
+      in the Yocto Project Development Tasks Manual.
+
+   INITRAMFS_IMAGE_BUNDLE
+      Controls whether or not the image recipe specified by
+      :term:`INITRAMFS_IMAGE` is run through an
+      extra pass
+      (:ref:`ref-tasks-bundle_initramfs`) during
+      kernel compilation in order to build a single binary that contains
+      both the kernel image and the initial RAM filesystem (initramfs)
+      image. This makes use of the
+      :term:`CONFIG_INITRAMFS_SOURCE` kernel
+      feature.
+
+      .. note::
+
+         Using an extra compilation pass to bundle the initramfs avoids a
+         circular dependency between the kernel recipe and the initramfs
+         recipe should the initramfs include kernel modules. Should that be
+         the case, the initramfs recipe depends on the kernel for the
+         kernel modules, and the kernel depends on the initramfs recipe
+         since the initramfs is bundled inside the kernel image.
+
+      The combined binary is deposited into the ``tmp/deploy`` directory,
+      which is part of the :term:`Build Directory`.
+
+      Setting the variable to "1" in a configuration file causes the
+      OpenEmbedded build system to generate a kernel image with the
+      initramfs specified in ``INITRAMFS_IMAGE`` bundled within:
+      ::
+
+         INITRAMFS_IMAGE_BUNDLE = "1"
+
+      By default, the
+      :ref:`kernel <ref-classes-kernel>` class sets this variable to a
+      null string as follows:
+      ::
+
+         INITRAMFS_IMAGE_BUNDLE ?= ""
+
+      .. note::
+
+         You must set the
+         INITRAMFS_IMAGE_BUNDLE
+         variable in a configuration file. You cannot set the variable in a
+         recipe file.
+
+      See the
+      :yocto_git:`local.conf.sample.extended </cgit/cgit.cgi/poky/tree/meta-poky/conf/local.conf.sample.extended>`
+      file for additional information. Also, for information on creating an
+      initramfs, see the ":ref:`building-an-initramfs-image`" section
+      in the Yocto Project Development Tasks Manual.
+
+   INITRAMFS_LINK_NAME
+      The link name of the initial RAM filesystem image. This variable is
+      set in the ``meta/classes/kernel-artifact-names.bbclass`` file as
+      follows:
+      ::
+
+         INITRAMFS_LINK_NAME ?= "initramfs-${KERNEL_ARTIFACT_LINK_NAME}"
+
+      The value of the
+      ``KERNEL_ARTIFACT_LINK_NAME`` variable, which is set in the same
+      file, has the following value:
+      ::
+
+         KERNEL_ARTIFACT_LINK_NAME ?= "${MACHINE}"
+
+      See the :term:`MACHINE` variable for additional
+      information.
+
+   INITRAMFS_NAME
+      The base name of the initial RAM filesystem image. This variable is
+      set in the ``meta/classes/kernel-artifact-names.bbclass`` file as
+      follows:
+      ::
+
+         INITRAMFS_NAME ?= "initramfs-${KERNEL_ARTIFACT_NAME}"
+
+      The value of the :term:`KERNEL_ARTIFACT_NAME`
+      variable, which is set in the same file, has the following value:
+      ::
+
+         KERNEL_ARTIFACT_NAME ?= "${PKGE}-${PKGV}-${PKGR}-${MACHINE}${IMAGE_VERSION_SUFFIX}"
+
+   INITRD
+      Indicates list of filesystem images to concatenate and use as an
+      initial RAM disk (``initrd``).
+
+      The ``INITRD`` variable is an optional variable used with the
+      :ref:`image-live <ref-classes-image-live>` class.
+
+   INITRD_IMAGE
+      When building a "live" bootable image (i.e. when
+      :term:`IMAGE_FSTYPES` contains "live"),
+      ``INITRD_IMAGE`` specifies the image recipe that should be built to
+      provide the initial RAM disk image. The default value is
+      "core-image-minimal-initramfs".
+
+      See the :ref:`image-live <ref-classes-image-live>` class for more
+      information.
+
+   INITSCRIPT_NAME
+      The filename of the initialization script as installed to
+      ``${sysconfdir}/init.d``.
+
+      This variable is used in recipes when using ``update-rc.d.bbclass``.
+      The variable is mandatory.
+
+   INITSCRIPT_PACKAGES
+      A list of the packages that contain initscripts. If multiple packages
+      are specified, you need to append the package name to the other
+      ``INITSCRIPT_*`` as an override.
+
+      This variable is used in recipes when using ``update-rc.d.bbclass``.
+      The variable is optional and defaults to the :term:`PN`
+      variable.
+
+   INITSCRIPT_PARAMS
+      Specifies the options to pass to ``update-rc.d``. Here is an example:
+      ::
+
+         INITSCRIPT_PARAMS = "start 99 5 2 . stop 20 0 1 6 ."
+
+      In this example, the script has a runlevel of 99, starts the script
+      in initlevels 2 and 5, and stops the script in levels 0, 1 and 6.
+
+      The variable's default value is "defaults", which is set in the
+      :ref:`update-rc.d <ref-classes-update-rc.d>` class.
+
+      The value in ``INITSCRIPT_PARAMS`` is passed through to the
+      ``update-rc.d`` command. For more information on valid parameters,
+      please see the ``update-rc.d`` manual page at
+      http://www.tin.org/bin/man.cgi?section=8&topic=update-rc.d.
+
+   INSANE_SKIP
+      Specifies the QA checks to skip for a specific package within a
+      recipe. For example, to skip the check for symbolic link ``.so``
+      files in the main package of a recipe, add the following to the
+      recipe. The package name override must be used, which in this example
+      is ``${PN}``:
+      ::
+
+         INSANE_SKIP_${PN} += "dev-so"
+
+      See the ":ref:`insane.bbclass <ref-classes-insane>`" section for a
+      list of the valid QA checks you can specify using this variable.
+
+   INSTALL_TIMEZONE_FILE
+      By default, the ``tzdata`` recipe packages an ``/etc/timezone`` file.
+      Set the ``INSTALL_TIMEZONE_FILE`` variable to "0" at the
+      configuration level to disable this behavior.
+
+   IPK_FEED_URIS
+      When the IPK backend is in use and package management is enabled on
+      the target, you can use this variable to set up ``opkg`` in the
+      target image to point to package feeds on a nominated server. Once
+      the feed is established, you can perform installations or upgrades
+      using the package manager at runtime.
+
+   KARCH
+      Defines the kernel architecture used when assembling the
+      configuration. Architectures supported for this release are:
+
+      - powerpc
+      - i386
+      - x86_64
+      - arm
+      - qemu
+      - mips
+
+      You define the ``KARCH`` variable in the :ref:`kernel-dev/kernel-dev-advanced:bsp descriptions`.
+
+   KBRANCH
+      A regular expression used by the build process to explicitly identify
+      the kernel branch that is validated, patched, and configured during a
+      build. You must set this variable to ensure the exact kernel branch
+      you want is being used by the build process.
+
+      Values for this variable are set in the kernel's recipe file and the
+      kernel's append file. For example, if you are using the
+      ``linux-yocto_4.12`` kernel, the kernel recipe file is the
+      ``meta/recipes-kernel/linux/linux-yocto_4.12.bb`` file. ``KBRANCH``
+      is set as follows in that kernel recipe file:
+      ::
+
+         KBRANCH ?= "standard/base"
+
+      This variable is also used from the kernel's append file to identify
+      the kernel branch specific to a particular machine or target
+      hardware. Continuing with the previous kernel example, the kernel's
+      append file (i.e. ``linux-yocto_4.12.bbappend``) is located in the
+      BSP layer for a given machine. For example, the append file for the
+      Beaglebone, EdgeRouter, and generic versions of both 32 and 64-bit IA
+      machines (``meta-yocto-bsp``) is named
+      ``meta-yocto-bsp/recipes-kernel/linux/linux-yocto_4.12.bbappend``.
+      Here are the related statements from that append file:
+      ::
+
+         KBRANCH_genericx86 = "standard/base"
+         KBRANCH_genericx86-64 = "standard/base"
+         KBRANCH_edgerouter = "standard/edgerouter"
+         KBRANCH_beaglebone = "standard/beaglebone"
+
+      The ``KBRANCH`` statements
+      identify the kernel branch to use when building for each supported
+      BSP.
+
+   KBUILD_DEFCONFIG
+      When used with the :ref:`kernel-yocto <ref-classes-kernel-yocto>`
+      class, specifies an "in-tree" kernel configuration file for use
+      during a kernel build.
+
+      Typically, when using a ``defconfig`` to configure a kernel during a
+      build, you place the file in your layer in the same manner as you
+      would place patch files and configuration fragment files (i.e.
+      "out-of-tree"). However, if you want to use a ``defconfig`` file that
+      is part of the kernel tree (i.e. "in-tree"), you can use the
+      ``KBUILD_DEFCONFIG`` variable and append the
+      :term:`KMACHINE` variable to point to the
+      ``defconfig`` file.
+
+      To use the variable, set it in the append file for your kernel recipe
+      using the following form:
+      ::
+
+         KBUILD_DEFCONFIG_KMACHINE ?= defconfig_file
+
+      Here is an example from a "raspberrypi2" ``KMACHINE`` build that uses
+      a ``defconfig`` file named "bcm2709_defconfig":
+      ::
+
+         KBUILD_DEFCONFIG_raspberrypi2 = "bcm2709_defconfig"
+
+      As an alternative, you can use the following within your append file:
+      ::
+
+         KBUILD_DEFCONFIG_pn-linux-yocto ?= defconfig_file
+
+      For more
+      information on how to use the ``KBUILD_DEFCONFIG`` variable, see the
+      ":ref:`kernel-dev/kernel-dev-common:using an "in-tree" \`\`defconfig\`\` file`"
+      section in the Yocto Project Linux Kernel Development Manual.
+
+   KERNEL_ALT_IMAGETYPE
+      Specifies an alternate kernel image type for creation in addition to
+      the kernel image type specified using the
+      :term:`KERNEL_IMAGETYPE` variable.
+
+   KERNEL_ARTIFACT_NAME
+      Specifies the name of all of the build artifacts. You can change the
+      name of the artifacts by changing the ``KERNEL_ARTIFACT_NAME``
+      variable.
+
+      The value of ``KERNEL_ARTIFACT_NAME``, which is set in the
+      ``meta/classes/kernel-artifact-names.bbclass`` file, has the
+      following default value:
+      ::
+
+         KERNEL_ARTIFACT_NAME ?= "${PKGE}-${PKGV}-${PKGR}-${MACHINE}${IMAGE_VERSION_SUFFIX}"
+
+      See the :term:`PKGE`, :term:`PKGV`, :term:`PKGR`, and :term:`MACHINE`
+      variables for additional information.
+
+      .. note::
+
+         The IMAGE_VERSION_SUFFIX variable is set to DATETIME.
+
+   KERNEL_CLASSES
+      A list of classes defining kernel image types that the
+      :ref:`kernel <ref-classes-kernel>` class should inherit. You
+      typically append this variable to enable extended image types. An
+      example is the "kernel-fitimage", which enables fitImage support and
+      resides in ``meta/classes/kernel-fitimage.bbclass``. You can register
+      custom kernel image types with the ``kernel`` class using this
+      variable.
+
+   KERNEL_DEVICETREE
+      Specifies the name of the generated Linux kernel device tree (i.e.
+      the ``.dtb``) file.
+
+      .. note::
+
+         Legacy support exists for specifying the full path to the device
+         tree. However, providing just the .dtb file is preferred.
+
+      In order to use this variable, the
+      :ref:`kernel-devicetree <ref-classes-kernel-devicetree>` class must
+      be inherited.
+
+   KERNEL_DTB_LINK_NAME
+      The link name of the kernel device tree binary (DTB). This variable
+      is set in the ``meta/classes/kernel-artifact-names.bbclass`` file as
+      follows:
+      ::
+
+         KERNEL_DTB_LINK_NAME ?= "${KERNEL_ARTIFACT_LINK_NAME}"
+
+      The
+      value of the ``KERNEL_ARTIFACT_LINK_NAME`` variable, which is set in
+      the same file, has the following value:
+      ::
+
+         KERNEL_ARTIFACT_LINK_NAME ?= "${MACHINE}"
+
+      See the :term:`MACHINE` variable for additional
+      information.
+
+   KERNEL_DTB_NAME
+      The base name of the kernel device tree binary (DTB). This variable
+      is set in the ``meta/classes/kernel-artifact-names.bbclass`` file as
+      follows:
+      ::
+
+         KERNEL_DTB_NAME ?= "${KERNEL_ARTIFACT_NAME}"
+
+      The value of the :term:`KERNEL_ARTIFACT_NAME`
+      variable, which is set in the same file, has the following value:
+      ::
+
+         KERNEL_ARTIFACT_NAME ?= "${PKGE}-${PKGV}-${PKGR}-${MACHINE}${IMAGE_VERSION_SUFFIX}"
+
+   KERNEL_EXTRA_ARGS
+      Specifies additional ``make`` command-line arguments the OpenEmbedded
+      build system passes on when compiling the kernel.
+
+   KERNEL_FEATURES
+      Includes additional kernel metadata. In the OpenEmbedded build
+      system, the default Board Support Packages (BSPs)
+      :term:`Metadata` is provided through the
+      :term:`KMACHINE` and :term:`KBRANCH`
+      variables. You can use the ``KERNEL_FEATURES`` variable from within
+      the kernel recipe or kernel append file to further add metadata for
+      all BSPs or specific BSPs.
+
+      The metadata you add through this variable includes config fragments
+      and features descriptions, which usually includes patches as well as
+      config fragments. You typically override the ``KERNEL_FEATURES``
+      variable for a specific machine. In this way, you can provide
+      validated, but optional, sets of kernel configurations and features.
+
+      For example, the following example from the ``linux-yocto-rt_4.12``
+      kernel recipe adds "netfilter" and "taskstats" features to all BSPs
+      as well as "virtio" configurations to all QEMU machines. The last two
+      statements add specific configurations to targeted machine types:
+      ::
+
+         KERNEL_EXTRA_FEATURES ?= "features/netfilter/netfilter.scc features/taskstats/taskstats.scc"
+         KERNEL_FEATURES_append = "${KERNEL_EXTRA_FEATURES}"
+         KERNEL_FEATURES_append_qemuall = "cfg/virtio.scc"
+         KERNEL_FEATURES_append_qemux86 = " cfg/sound.scc cfg/paravirt_kvm.scc"
+         KERNEL_FEATURES_append_qemux86-64 = "cfg/sound.scc"
+
+   KERNEL_FIT_LINK_NAME
+      The link name of the kernel flattened image tree (FIT) image. This
+      variable is set in the ``meta/classes/kernel-artifact-names.bbclass``
+      file as follows:
+      ::
+
+         KERNEL_FIT_LINK_NAME ?= "${KERNEL_ARTIFACT_LINK_NAME}"
+
+      The value of the
+      ``KERNEL_ARTIFACT_LINK_NAME`` variable, which is set in the same
+      file, has the following value:
+      ::
+
+         KERNEL_ARTIFACT_LINK_NAME ?= "${MACHINE}"
+
+      See the :term:`MACHINE` variable for additional
+      information.
+
+   KERNEL_FIT_NAME
+      The base name of the kernel flattened image tree (FIT) image. This
+      variable is set in the ``meta/classes/kernel-artifact-names.bbclass``
+      file as follows:
+      ::
+
+         KERNEL_FIT_NAME ?= "${KERNEL_ARTIFACT_NAME}"
+
+      The value of the :term:`KERNEL_ARTIFACT_NAME`
+      variable, which is set in the same file, has the following value:
+      ::
+
+         KERNEL_ARTIFACT_NAME ?= "${PKGE}-${PKGV}-${PKGR}-${MACHINE}${IMAGE_VERSION_SUFFIX}"
+
+   KERNEL_IMAGE_LINK_NAME
+      The link name for the kernel image. This variable is set in the
+      ``meta/classes/kernel-artifact-names.bbclass`` file as follows:
+      ::
+
+         KERNEL_IMAGE_LINK_NAME ?= "${KERNEL_ARTIFACT_LINK_NAME}"
+
+      The value of
+      the ``KERNEL_ARTIFACT_LINK_NAME`` variable, which is set in the same
+      file, has the following value:
+      ::
+
+         KERNEL_ARTIFACT_LINK_NAME ?= "${MACHINE}"
+
+      See the :term:`MACHINE` variable for additional
+      information.
+
+   KERNEL_IMAGE_MAXSIZE
+      Specifies the maximum size of the kernel image file in kilobytes. If
+      ``KERNEL_IMAGE_MAXSIZE`` is set, the size of the kernel image file is
+      checked against the set value during the
+      :ref:`ref-tasks-sizecheck` task. The task fails if
+      the kernel image file is larger than the setting.
+
+      ``KERNEL_IMAGE_MAXSIZE`` is useful for target devices that have a
+      limited amount of space in which the kernel image must be stored.
+
+      By default, this variable is not set, which means the size of the
+      kernel image is not checked.
+
+   KERNEL_IMAGE_NAME
+      The base name of the kernel image. This variable is set in the
+      ``meta/classes/kernel-artifact-names.bbclass`` file as follows:
+      ::
+
+         KERNEL_IMAGE_NAME ?= "${KERNEL_ARTIFACT_NAME}"
+
+      The value of the
+      :term:`KERNEL_ARTIFACT_NAME` variable,
+      which is set in the same file, has the following value:
+      ::
+
+         KERNEL_ARTIFACT_NAME ?= "${PKGE}-${PKGV}-${PKGR}-${MACHINE}${IMAGE_VERSION_SUFFIX}"
+
+   KERNEL_IMAGETYPE
+      The type of kernel to build for a device, usually set by the machine
+      configuration files and defaults to "zImage". This variable is used
+      when building the kernel and is passed to ``make`` as the target to
+      build.
+
+      If you want to build an alternate kernel image type, use the
+      :term:`KERNEL_ALT_IMAGETYPE` variable.
+
+   KERNEL_MODULE_AUTOLOAD
+      Lists kernel modules that need to be auto-loaded during boot.
+
+      .. note::
+
+         This variable replaces the deprecated
+         module_autoload
+         variable.
+
+      You can use the ``KERNEL_MODULE_AUTOLOAD`` variable anywhere that it
+      can be recognized by the kernel recipe or by an out-of-tree kernel
+      module recipe (e.g. a machine configuration file, a distribution
+      configuration file, an append file for the recipe, or the recipe
+      itself).
+
+      Specify it as follows:
+      ::
+
+         KERNEL_MODULE_AUTOLOAD += "module_name1 module_name2 module_name3"
+
+      Including ``KERNEL_MODULE_AUTOLOAD`` causes the OpenEmbedded build
+      system to populate the ``/etc/modules-load.d/modname.conf`` file with
+      the list of modules to be auto-loaded on boot. The modules appear
+      one-per-line in the file. Here is an example of the most common use
+      case:
+      ::
+
+         KERNEL_MODULE_AUTOLOAD += "module_name"
+
+      For information on how to populate the ``modname.conf`` file with
+      ``modprobe.d`` syntax lines, see the :term:`KERNEL_MODULE_PROBECONF` variable.
+
+   KERNEL_MODULE_PROBECONF
+      Provides a list of modules for which the OpenEmbedded build system
+      expects to find ``module_conf_``\ modname values that specify
+      configuration for each of the modules. For information on how to
+      provide those module configurations, see the
+      :term:`module_conf_* <module_conf>` variable.
+
+   KERNEL_PATH
+      The location of the kernel sources. This variable is set to the value
+      of the :term:`STAGING_KERNEL_DIR` within
+      the :ref:`module <ref-classes-module>` class. For information on
+      how this variable is used, see the
+      ":ref:`kernel-dev/kernel-dev-common:incorporating out-of-tree modules`"
+      section in the Yocto Project Linux Kernel Development Manual.
+
+      To help maximize compatibility with out-of-tree drivers used to build
+      modules, the OpenEmbedded build system also recognizes and uses the
+      :term:`KERNEL_SRC` variable, which is identical to
+      the ``KERNEL_PATH`` variable. Both variables are common variables
+      used by external Makefiles to point to the kernel source directory.
+
+   KERNEL_SRC
+      The location of the kernel sources. This variable is set to the value
+      of the :term:`STAGING_KERNEL_DIR` within
+      the :ref:`module <ref-classes-module>` class. For information on
+      how this variable is used, see the
+      ":ref:`kernel-dev/kernel-dev-common:incorporating out-of-tree modules`"
+      section in the Yocto Project Linux Kernel Development Manual.
+
+      To help maximize compatibility with out-of-tree drivers used to build
+      modules, the OpenEmbedded build system also recognizes and uses the
+      :term:`KERNEL_PATH` variable, which is identical
+      to the ``KERNEL_SRC`` variable. Both variables are common variables
+      used by external Makefiles to point to the kernel source directory.
+
+   KERNEL_VERSION
+      Specifies the version of the kernel as extracted from ``version.h``
+      or ``utsrelease.h`` within the kernel sources. Effects of setting
+      this variable do not take affect until the kernel has been
+      configured. Consequently, attempting to refer to this variable in
+      contexts prior to configuration will not work.
+
+   KERNELDEPMODDEPEND
+      Specifies whether the data referenced through
+      :term:`PKGDATA_DIR` is needed or not. The
+      ``KERNELDEPMODDEPEND`` does not control whether or not that data
+      exists, but simply whether or not it is used. If you do not need to
+      use the data, set the ``KERNELDEPMODDEPEND`` variable in your
+      ``initramfs`` recipe. Setting the variable there when the data is not
+      needed avoids a potential dependency loop.
+
+   KFEATURE_DESCRIPTION
+      Provides a short description of a configuration fragment. You use
+      this variable in the ``.scc`` file that describes a configuration
+      fragment file. Here is the variable used in a file named ``smp.scc``
+      to describe SMP being enabled:
+      ::
+
+          define KFEATURE_DESCRIPTION "Enable SMP"
+
+   KMACHINE
+      The machine as known by the kernel. Sometimes the machine name used
+      by the kernel does not match the machine name used by the
+      OpenEmbedded build system. For example, the machine name that the
+      OpenEmbedded build system understands as ``core2-32-intel-common``
+      goes by a different name in the Linux Yocto kernel. The kernel
+      understands that machine as ``intel-core2-32``. For cases like these,
+      the ``KMACHINE`` variable maps the kernel machine name to the
+      OpenEmbedded build system machine name.
+
+      These mappings between different names occur in the Yocto Linux
+      Kernel's ``meta`` branch. As an example take a look in the
+      ``common/recipes-kernel/linux/linux-yocto_3.19.bbappend`` file:
+      ::
+
+         LINUX_VERSION_core2-32-intel-common = "3.19.0"
+         COMPATIBLE_MACHINE_core2-32-intel-common = "${MACHINE}"
+         SRCREV_meta_core2-32-intel-common = "8897ef68b30e7426bc1d39895e71fb155d694974"
+         SRCREV_machine_core2-32-intel-common = "43b9eced9ba8a57add36af07736344dcc383f711"
+         KMACHINE_core2-32-intel-common = "intel-core2-32"
+         KBRANCH_core2-32-intel-common = "standard/base"
+         KERNEL_FEATURES_append_core2-32-intel-common = "${KERNEL_FEATURES_INTEL_COMMON}"
+
+      The ``KMACHINE`` statement says
+      that the kernel understands the machine name as "intel-core2-32".
+      However, the OpenEmbedded build system understands the machine as
+      "core2-32-intel-common".
+
+   KTYPE
+      Defines the kernel type to be used in assembling the configuration.
+      The linux-yocto recipes define "standard", "tiny", and "preempt-rt"
+      kernel types. See the ":ref:`kernel-dev/kernel-dev-advanced:kernel types`"
+      section in the
+      Yocto Project Linux Kernel Development Manual for more information on
+      kernel types.
+
+      You define the ``KTYPE`` variable in the
+      :ref:`kernel-dev/kernel-dev-advanced:bsp descriptions`. The
+      value you use must match the value used for the
+      :term:`LINUX_KERNEL_TYPE` value used by the
+      kernel recipe.
+
+   LABELS
+      Provides a list of targets for automatic configuration.
+
+      See the :ref:`grub-efi <ref-classes-grub-efi>` class for more
+      information on how this variable is used.
+
+   LAYERDEPENDS
+      Lists the layers, separated by spaces, on which this recipe depends.
+      Optionally, you can specify a specific layer version for a dependency
+      by adding it to the end of the layer name. Here is an example:
+      ::
+
+         LAYERDEPENDS_mylayer = "anotherlayer (=3)"
+
+      In this previous example,
+      version 3 of "anotherlayer" is compared against
+      :term:`LAYERVERSION`\ ``_anotherlayer``.
+
+      An error is produced if any dependency is missing or the version
+      numbers (if specified) do not match exactly. This variable is used in
+      the ``conf/layer.conf`` file and must be suffixed with the name of
+      the specific layer (e.g. ``LAYERDEPENDS_mylayer``).
+
+   LAYERDIR
+      When used inside the ``layer.conf`` configuration file, this variable
+      provides the path of the current layer. This variable is not
+      available outside of ``layer.conf`` and references are expanded
+      immediately when parsing of the file completes.
+
+   LAYERRECOMMENDS
+      Lists the layers, separated by spaces, recommended for use with this
+      layer.
+
+      Optionally, you can specify a specific layer version for a
+      recommendation by adding the version to the end of the layer name.
+      Here is an example:
+      ::
+
+         LAYERRECOMMENDS_mylayer = "anotherlayer (=3)"
+
+      In this previous example, version 3 of "anotherlayer" is compared
+      against ``LAYERVERSION_anotherlayer``.
+
+      This variable is used in the ``conf/layer.conf`` file and must be
+      suffixed with the name of the specific layer (e.g.
+      ``LAYERRECOMMENDS_mylayer``).
+
+   LAYERSERIES_COMPAT
+      Lists the versions of the :term:`OpenEmbedded-Core (OE-Core)` for which
+      a layer is compatible. Using the ``LAYERSERIES_COMPAT`` variable
+      allows the layer maintainer to indicate which combinations of the
+      layer and OE-Core can be expected to work. The variable gives the
+      system a way to detect when a layer has not been tested with new
+      releases of OE-Core (e.g. the layer is not maintained).
+
+      To specify the OE-Core versions for which a layer is compatible, use
+      this variable in your layer's ``conf/layer.conf`` configuration file.
+      For the list, use the Yocto Project
+      :yocto_wiki:`Release Name </wiki/Releases>` (e.g.
+      DISTRO_NAME_NO_CAP). To specify multiple OE-Core versions for the
+      layer, use a space-separated list:
+      ::
+
+         LAYERSERIES_COMPAT_layer_root_name = "DISTRO_NAME_NO_CAP DISTRO_NAME_NO_CAP_MINUS_ONE"
+
+      .. note::
+
+         Setting
+         LAYERSERIES_COMPAT
+         is required by the Yocto Project Compatible version 2 standard.
+         The OpenEmbedded build system produces a warning if the variable
+         is not set for any given layer.
+
+      See the ":ref:`dev-manual/dev-manual-common-tasks:creating your own layer`"
+      section in the Yocto Project Development Tasks Manual.
+
+   LAYERVERSION
+      Optionally specifies the version of a layer as a single number. You
+      can use this within :term:`LAYERDEPENDS` for
+      another layer in order to depend on a specific version of the layer.
+      This variable is used in the ``conf/layer.conf`` file and must be
+      suffixed with the name of the specific layer (e.g.
+      ``LAYERVERSION_mylayer``).
+
+   LD
+      The minimal command and arguments used to run the linker.
+
+   LDFLAGS
+      Specifies the flags to pass to the linker. This variable is exported
+      to an environment variable and thus made visible to the software
+      being built during the compilation step.
+
+      Default initialization for ``LDFLAGS`` varies depending on what is
+      being built:
+
+      -  :term:`TARGET_LDFLAGS` when building for the
+         target
+
+      -  :term:`BUILD_LDFLAGS` when building for the
+         build host (i.e. ``-native``)
+
+      -  :term:`BUILDSDK_LDFLAGS` when building for
+         an SDK (i.e. ``nativesdk-``)
+
+   LEAD_SONAME
+      Specifies the lead (or primary) compiled library file (i.e. ``.so``)
+      that the :ref:`debian <ref-classes-debian>` class applies its
+      naming policy to given a recipe that packages multiple libraries.
+
+      This variable works in conjunction with the ``debian`` class.
+
+   LIC_FILES_CHKSUM
+      Checksums of the license text in the recipe source code.
+
+      This variable tracks changes in license text of the source code
+      files. If the license text is changed, it will trigger a build
+      failure, which gives the developer an opportunity to review any
+      license change.
+
+      This variable must be defined for all recipes (unless
+      :term:`LICENSE` is set to "CLOSED").
+
+      For more information, see the ":ref:`usingpoky-configuring-lic_files_chksum`"
+      section in the Yocto Project Development Tasks Manual.
+
+   LICENSE
+      The list of source licenses for the recipe. Follow these rules:
+
+      -  Do not use spaces within individual license names.
+
+      -  Separate license names using \| (pipe) when there is a choice
+         between licenses.
+
+      -  Separate license names using & (ampersand) when multiple licenses
+         exist that cover different parts of the source.
+
+      -  You can use spaces between license names.
+
+      -  For standard licenses, use the names of the files in
+         ``meta/files/common-licenses/`` or the
+         :term:`SPDXLICENSEMAP` flag names defined in
+         ``meta/conf/licenses.conf``.
+
+      Here are some examples:
+      ::
+
+         LICENSE = "LGPLv2.1 | GPLv3"
+         LICENSE = "MPL-1 & LGPLv2.1"
+         LICENSE = "GPLv2+"
+
+      The first example is from the
+      recipes for Qt, which the user may choose to distribute under either
+      the LGPL version 2.1 or GPL version 3. The second example is from
+      Cairo where two licenses cover different parts of the source code.
+      The final example is from ``sysstat``, which presents a single
+      license.
+
+      You can also specify licenses on a per-package basis to handle
+      situations where components of the output have different licenses.
+      For example, a piece of software whose code is licensed under GPLv2
+      but has accompanying documentation licensed under the GNU Free
+      Documentation License 1.2 could be specified as follows:
+      ::
+
+         LICENSE = "GFDL-1.2 & GPLv2"
+         LICENSE_${PN} = "GPLv2"
+         LICENSE_${PN}-doc = "GFDL-1.2"
+
+   LICENSE_CREATE_PACKAGE
+      Setting ``LICENSE_CREATE_PACKAGE`` to "1" causes the OpenEmbedded
+      build system to create an extra package (i.e.
+      ``${``\ :term:`PN`\ ``}-lic``) for each recipe and to add
+      those packages to the
+      :term:`RRECOMMENDS`\ ``_${PN}``.
+
+      The ``${PN}-lic`` package installs a directory in
+      ``/usr/share/licenses`` named ``${PN}``, which is the recipe's base
+      name, and installs files in that directory that contain license and
+      copyright information (i.e. copies of the appropriate license files
+      from ``meta/common-licenses`` that match the licenses specified in
+      the :term:`LICENSE` variable of the recipe metadata
+      and copies of files marked in
+      :term:`LIC_FILES_CHKSUM` as containing
+      license text).
+
+      For related information on providing license text, see the
+      :term:`COPY_LIC_DIRS` variable, the
+      :term:`COPY_LIC_MANIFEST` variable, and the
+      ":ref:`dev-manual/dev-manual-common-tasks:providing license text`"
+      section in the Yocto Project Development Tasks Manual.
+
+   LICENSE_FLAGS
+      Specifies additional flags for a recipe you must whitelist through
+      :term:`LICENSE_FLAGS_WHITELIST` in
+      order to allow the recipe to be built. When providing multiple flags,
+      separate them with spaces.
+
+      This value is independent of :term:`LICENSE` and is
+      typically used to mark recipes that might require additional licenses
+      in order to be used in a commercial product. For more information,
+      see the
+      ":ref:`dev-manual/dev-manual-common-tasks:enabling commercially licensed recipes`"
+      section in the Yocto Project Development Tasks Manual.
+
+   LICENSE_FLAGS_WHITELIST
+      Lists license flags that when specified in
+      :term:`LICENSE_FLAGS` within a recipe should not
+      prevent that recipe from being built. This practice is otherwise
+      known as "whitelisting" license flags. For more information, see the
+      ":ref:`dev-manual/dev-manual-common-tasks:enabling commercially licensed recipes`"
+      section in the Yocto Project Development Tasks Manual.
+
+   LICENSE_PATH
+      Path to additional licenses used during the build. By default, the
+      OpenEmbedded build system uses ``COMMON_LICENSE_DIR`` to define the
+      directory that holds common license text used during the build. The
+      ``LICENSE_PATH`` variable allows you to extend that location to other
+      areas that have additional licenses:
+      ::
+
+         LICENSE_PATH += "path-to-additional-common-licenses"
+
+   LINUX_KERNEL_TYPE
+      Defines the kernel type to be used in assembling the configuration.
+      The linux-yocto recipes define "standard", "tiny", and "preempt-rt"
+      kernel types. See the ":ref:`kernel-dev/kernel-dev-advanced:kernel types`"
+      section in the
+      Yocto Project Linux Kernel Development Manual for more information on
+      kernel types.
+
+      If you do not specify a ``LINUX_KERNEL_TYPE``, it defaults to
+      "standard". Together with :term:`KMACHINE`, the
+      ``LINUX_KERNEL_TYPE`` variable defines the search arguments used by
+      the kernel tools to find the appropriate description within the
+      kernel :term:`Metadata` with which to build out the sources
+      and configuration.
+
+   LINUX_VERSION
+      The Linux version from ``kernel.org`` on which the Linux kernel image
+      being built using the OpenEmbedded build system is based. You define
+      this variable in the kernel recipe. For example, the
+      ``linux-yocto-3.4.bb`` kernel recipe found in
+      ``meta/recipes-kernel/linux`` defines the variables as follows:
+      ::
+
+         LINUX_VERSION ?= "3.4.24"
+
+      The ``LINUX_VERSION`` variable is used to define :term:`PV`
+      for the recipe:
+      ::
+
+         PV = "${LINUX_VERSION}+git${SRCPV}"
+
+   LINUX_VERSION_EXTENSION
+      A string extension compiled into the version string of the Linux
+      kernel built with the OpenEmbedded build system. You define this
+      variable in the kernel recipe. For example, the linux-yocto kernel
+      recipes all define the variable as follows:
+      ::
+
+         LINUX_VERSION_EXTENSION ?= "-yocto-${LINUX_KERNEL_TYPE}"
+
+      Defining this variable essentially sets the Linux kernel
+      configuration item ``CONFIG_LOCALVERSION``, which is visible through
+      the ``uname`` command. Here is an example that shows the extension
+      assuming it was set as previously shown:
+      ::
+
+         $ uname -r
+         3.7.0-rc8-custom
+
+   LOG_DIR
+      Specifies the directory to which the OpenEmbedded build system writes
+      overall log files. The default directory is ``${TMPDIR}/log``.
+
+      For the directory containing logs specific to each task, see the
+      :term:`T` variable.
+
+   MACHINE
+      Specifies the target device for which the image is built. You define
+      ``MACHINE`` in the ``local.conf`` file found in the
+      :term:`Build Directory`. By default, ``MACHINE`` is set to
+      "qemux86", which is an x86-based architecture machine to be emulated
+      using QEMU:
+      ::
+
+         MACHINE ?= "qemux86"
+
+      The variable corresponds to a machine configuration file of the same
+      name, through which machine-specific configurations are set. Thus,
+      when ``MACHINE`` is set to "qemux86" there exists the corresponding
+      ``qemux86.conf`` machine configuration file, which can be found in
+      the :term:`Source Directory` in
+      ``meta/conf/machine``.
+
+      The list of machines supported by the Yocto Project as shipped
+      include the following:
+      ::
+
+         MACHINE ?= "qemuarm"
+         MACHINE ?= "qemuarm64"
+         MACHINE ?= "qemumips"
+         MACHINE ?= "qemumips64"
+         MACHINE ?= "qemuppc"
+         MACHINE ?= "qemux86"
+         MACHINE ?= "qemux86-64"
+         MACHINE ?= "genericx86"
+         MACHINE ?= "genericx86-64"
+         MACHINE ?= "beaglebone"
+         MACHINE ?= "edgerouter"
+
+      The last five are Yocto Project reference hardware
+      boards, which are provided in the ``meta-yocto-bsp`` layer.
+
+      .. note::
+
+         Adding additional Board Support Package (BSP) layers to your
+         configuration adds new possible settings for
+         MACHINE
+         .
+
+   MACHINE_ARCH
+      Specifies the name of the machine-specific architecture. This
+      variable is set automatically from :term:`MACHINE` or
+      :term:`TUNE_PKGARCH`. You should not hand-edit
+      the ``MACHINE_ARCH`` variable.
+
+   MACHINE_ESSENTIAL_EXTRA_RDEPENDS
+      A list of required machine-specific packages to install as part of
+      the image being built. The build process depends on these packages
+      being present. Furthermore, because this is a "machine-essential"
+      variable, the list of packages are essential for the machine to boot.
+      The impact of this variable affects images based on
+      ``packagegroup-core-boot``, including the ``core-image-minimal``
+      image.
+
+      This variable is similar to the
+      ``MACHINE_ESSENTIAL_EXTRA_RRECOMMENDS`` variable with the exception
+      that the image being built has a build dependency on the variable's
+      list of packages. In other words, the image will not build if a file
+      in this list is not found.
+
+      As an example, suppose the machine for which you are building
+      requires ``example-init`` to be run during boot to initialize the
+      hardware. In this case, you would use the following in the machine's
+      ``.conf`` configuration file:
+      ::
+
+         MACHINE_ESSENTIAL_EXTRA_RDEPENDS += "example-init"
+
+   MACHINE_ESSENTIAL_EXTRA_RRECOMMENDS
+      A list of recommended machine-specific packages to install as part of
+      the image being built. The build process does not depend on these
+      packages being present. However, because this is a
+      "machine-essential" variable, the list of packages are essential for
+      the machine to boot. The impact of this variable affects images based
+      on ``packagegroup-core-boot``, including the ``core-image-minimal``
+      image.
+
+      This variable is similar to the ``MACHINE_ESSENTIAL_EXTRA_RDEPENDS``
+      variable with the exception that the image being built does not have
+      a build dependency on the variable's list of packages. In other
+      words, the image will still build if a package in this list is not
+      found. Typically, this variable is used to handle essential kernel
+      modules, whose functionality may be selected to be built into the
+      kernel rather than as a module, in which case a package will not be
+      produced.
+
+      Consider an example where you have a custom kernel where a specific
+      touchscreen driver is required for the machine to be usable. However,
+      the driver can be built as a module or into the kernel depending on
+      the kernel configuration. If the driver is built as a module, you
+      want it to be installed. But, when the driver is built into the
+      kernel, you still want the build to succeed. This variable sets up a
+      "recommends" relationship so that in the latter case, the build will
+      not fail due to the missing package. To accomplish this, assuming the
+      package for the module was called ``kernel-module-ab123``, you would
+      use the following in the machine's ``.conf`` configuration file:
+      ::
+
+         MACHINE_ESSENTIAL_EXTRA_RRECOMMENDS += "kernel-module-ab123"
+
+      .. note::
+
+         In this example, the
+         kernel-module-ab123
+         recipe needs to explicitly set its
+         PACKAGES
+         variable to ensure that BitBake does not use the kernel recipe's
+         PACKAGES_DYNAMIC
+         variable to satisfy the dependency.
+
+      Some examples of these machine essentials are flash, screen,
+      keyboard, mouse, or touchscreen drivers (depending on the machine).
+
+   MACHINE_EXTRA_RDEPENDS
+      A list of machine-specific packages to install as part of the image
+      being built that are not essential for the machine to boot. However,
+      the build process for more fully-featured images depends on the
+      packages being present.
+
+      This variable affects all images based on ``packagegroup-base``,
+      which does not include the ``core-image-minimal`` or
+      ``core-image-full-cmdline`` images.
+
+      The variable is similar to the ``MACHINE_EXTRA_RRECOMMENDS`` variable
+      with the exception that the image being built has a build dependency
+      on the variable's list of packages. In other words, the image will
+      not build if a file in this list is not found.
+
+      An example is a machine that has WiFi capability but is not essential
+      for the machine to boot the image. However, if you are building a
+      more fully-featured image, you want to enable the WiFi. The package
+      containing the firmware for the WiFi hardware is always expected to
+      exist, so it is acceptable for the build process to depend upon
+      finding the package. In this case, assuming the package for the
+      firmware was called ``wifidriver-firmware``, you would use the
+      following in the ``.conf`` file for the machine:
+      ::
+
+         MACHINE_EXTRA_RDEPENDS += "wifidriver-firmware"
+
+   MACHINE_EXTRA_RRECOMMENDS
+      A list of machine-specific packages to install as part of the image
+      being built that are not essential for booting the machine. The image
+      being built has no build dependency on this list of packages.
+
+      This variable affects only images based on ``packagegroup-base``,
+      which does not include the ``core-image-minimal`` or
+      ``core-image-full-cmdline`` images.
+
+      This variable is similar to the ``MACHINE_EXTRA_RDEPENDS`` variable
+      with the exception that the image being built does not have a build
+      dependency on the variable's list of packages. In other words, the
+      image will build if a file in this list is not found.
+
+      An example is a machine that has WiFi capability but is not essential
+      For the machine to boot the image. However, if you are building a
+      more fully-featured image, you want to enable WiFi. In this case, the
+      package containing the WiFi kernel module will not be produced if the
+      WiFi driver is built into the kernel, in which case you still want
+      the build to succeed instead of failing as a result of the package
+      not being found. To accomplish this, assuming the package for the
+      module was called ``kernel-module-examplewifi``, you would use the
+      following in the ``.conf`` file for the machine:
+      ::
+
+         MACHINE_EXTRA_RRECOMMENDS += "kernel-module-examplewifi"
+
+   MACHINE_FEATURES
+      Specifies the list of hardware features the
+      :term:`MACHINE` is capable of supporting. For related
+      information on enabling features, see the
+      :term:`DISTRO_FEATURES`,
+      :term:`COMBINED_FEATURES`, and
+      :term:`IMAGE_FEATURES` variables.
+
+      For a list of hardware features supported by the Yocto Project as
+      shipped, see the "`Machine Features <#ref-features-machine>`__"
+      section.
+
+   MACHINE_FEATURES_BACKFILL
+      Features to be added to ``MACHINE_FEATURES`` if not also present in
+      ``MACHINE_FEATURES_BACKFILL_CONSIDERED``.
+
+      This variable is set in the ``meta/conf/bitbake.conf`` file. It is
+      not intended to be user-configurable. It is best to just reference
+      the variable to see which machine features are being backfilled for
+      all machine configurations. See the "`Feature
+      Backfilling <#ref-features-backfill>`__" section for more
+      information.
+
+   MACHINE_FEATURES_BACKFILL_CONSIDERED
+      Features from ``MACHINE_FEATURES_BACKFILL`` that should not be
+      backfilled (i.e. added to ``MACHINE_FEATURES``) during the build. See
+      the "`Feature Backfilling <#ref-features-backfill>`__" section for
+      more information.
+
+   MACHINEOVERRIDES
+      A colon-separated list of overrides that apply to the current
+      machine. By default, this list includes the value of
+      :term:`MACHINE`.
+
+      You can extend ``MACHINEOVERRIDES`` to add extra overrides that
+      should apply to a machine. For example, all machines emulated in QEMU
+      (e.g. ``qemuarm``, ``qemux86``, and so forth) include a file named
+      ``meta/conf/machine/include/qemu.inc`` that prepends the following
+      override to ``MACHINEOVERRIDES``:
+      ::
+
+         MACHINEOVERRIDES =. "qemuall:"
+
+      This
+      override allows variables to be overriden for all machines emulated
+      in QEMU, like in the following example from the ``connman-conf``
+      recipe:
+      ::
+
+         SRC_URI_append_qemuall = "file://wired.config \
+             file://wired-setup \
+             "
+
+      The underlying mechanism behind
+      ``MACHINEOVERRIDES`` is simply that it is included in the default
+      value of :term:`OVERRIDES`.
+
+   MAINTAINER
+      The email address of the distribution maintainer.
+
+   MIRRORS
+      Specifies additional paths from which the OpenEmbedded build system
+      gets source code. When the build system searches for source code, it
+      first tries the local download directory. If that location fails, the
+      build system tries locations defined by
+      :term:`PREMIRRORS`, the upstream source, and then
+      locations specified by ``MIRRORS`` in that order.
+
+      Assuming your distribution (:term:`DISTRO`) is "poky",
+      the default value for ``MIRRORS`` is defined in the
+      ``conf/distro/poky.conf`` file in the ``meta-poky`` Git repository.
+
+   MLPREFIX
+      Specifies a prefix has been added to :term:`PN` to create a
+      special version of a recipe or package (i.e. a Multilib version). The
+      variable is used in places where the prefix needs to be added to or
+      removed from a the name (e.g. the :term:`BPN` variable).
+      ``MLPREFIX`` gets set when a prefix has been added to ``PN``.
+
+      .. note::
+
+         The "ML" in
+         MLPREFIX
+         stands for "MultiLib". This representation is historical and comes
+         from a time when
+         nativesdk
+         was a suffix rather than a prefix on the recipe name. When
+         nativesdk
+         was turned into a prefix, it made sense to set
+         MLPREFIX
+         for it as well.
+
+      To help understand when ``MLPREFIX`` might be needed, consider when
+      :term:`BBCLASSEXTEND` is used to provide a
+      ``nativesdk`` version of a recipe in addition to the target version.
+      If that recipe declares build-time dependencies on tasks in other
+      recipes by using :term:`DEPENDS`, then a dependency on
+      "foo" will automatically get rewritten to a dependency on
+      "nativesdk-foo". However, dependencies like the following will not
+      get rewritten automatically:
+      ::
+
+         do_foo[depends] += "recipe:do_foo"
+
+      If you want such a dependency to also get transformed, you can do the
+      following:
+      ::
+
+         do_foo[depends] += "${MLPREFIX}recipe:do_foo"
+
+   module_autoload
+      This variable has been replaced by the ``KERNEL_MODULE_AUTOLOAD``
+      variable. You should replace all occurrences of ``module_autoload``
+      with additions to ``KERNEL_MODULE_AUTOLOAD``, for example:
+      ::
+
+         module_autoload_rfcomm = "rfcomm"
+
+      should now be replaced with:
+      ::
+
+         KERNEL_MODULE_AUTOLOAD += "rfcomm"
+
+      See the :term:`KERNEL_MODULE_AUTOLOAD` variable for more information.
+
+   module_conf
+      Specifies `modprobe.d <http://linux.die.net/man/5/modprobe.d>`_
+      syntax lines for inclusion in the ``/etc/modprobe.d/modname.conf``
+      file.
+
+      You can use this variable anywhere that it can be recognized by the
+      kernel recipe or out-of-tree kernel module recipe (e.g. a machine
+      configuration file, a distribution configuration file, an append file
+      for the recipe, or the recipe itself). If you use this variable, you
+      must also be sure to list the module name in the
+      :term:`KERNEL_MODULE_AUTOLOAD`
+      variable.
+
+      Here is the general syntax:
+      ::
+
+         module_conf_module_name = "modprobe.d-syntax"
+
+      You must use the kernel module name override.
+
+      Run ``man modprobe.d`` in the shell to find out more information on
+      the exact syntax you want to provide with ``module_conf``.
+
+      Including ``module_conf`` causes the OpenEmbedded build system to
+      populate the ``/etc/modprobe.d/modname.conf`` file with
+      ``modprobe.d`` syntax lines. Here is an example that adds the options
+      ``arg1`` and ``arg2`` to a module named ``mymodule``:
+      ::
+
+         module_conf_mymodule = "options mymodule arg1=val1 arg2=val2"
+
+      For information on how to specify kernel modules to auto-load on
+      boot, see the :term:`KERNEL_MODULE_AUTOLOAD` variable.
+
+   MODULE_TARBALL_DEPLOY
+      Controls creation of the ``modules-*.tgz`` file. Set this variable to
+      "0" to disable creation of this file, which contains all of the
+      kernel modules resulting from a kernel build.
+
+   MODULE_TARBALL_LINK_NAME
+      The link name of the kernel module tarball. This variable is set in
+      the ``meta/classes/kernel-artifact-names.bbclass`` file as follows:
+      ::
+
+         MODULE_TARBALL_LINK_NAME ?= "${KERNEL_ARTIFACT_LINK_NAME}"
+
+      The value
+      of the ``KERNEL_ARTIFACT_LINK_NAME`` variable, which is set in the
+      same file, has the following value:
+      ::
+
+         KERNEL_ARTIFACT_LINK_NAME ?= "${MACHINE}"
+
+      See the :term:`MACHINE` variable for additional information.
+
+   MODULE_TARBALL_NAME
+      The base name of the kernel module tarball. This variable is set in
+      the ``meta/classes/kernel-artifact-names.bbclass`` file as follows:
+      ::
+
+         MODULE_TARBALL_NAME ?= "${KERNEL_ARTIFACT_NAME}"
+
+      The value of the :term:`KERNEL_ARTIFACT_NAME` variable,
+      which is set in the same file, has the following value:
+      ::
+
+         KERNEL_ARTIFACT_NAME ?= "${PKGE}-${PKGV}-${PKGR}-${MACHINE}${IMAGE_VERSION_SUFFIX}"
+
+   MULTIMACH_TARGET_SYS
+      Uniquely identifies the type of the target system for which packages
+      are being built. This variable allows output for different types of
+      target systems to be put into different subdirectories of the same
+      output directory.
+
+      The default value of this variable is:
+      ::
+
+         ${PACKAGE_ARCH}${TARGET_VENDOR}-${TARGET_OS}
+
+      Some classes (e.g.
+      :ref:`cross-canadian <ref-classes-cross-canadian>`) modify the
+      ``MULTIMACH_TARGET_SYS`` value.
+
+      See the :term:`STAMP` variable for an example. See the
+      :term:`STAGING_DIR_TARGET` variable for more information.
+
+   NATIVELSBSTRING
+      A string identifying the host distribution. Strings consist of the
+      host distributor ID followed by the release, as reported by the
+      ``lsb_release`` tool or as read from ``/etc/lsb-release``. For
+      example, when running a build on Ubuntu 12.10, the value is
+      "Ubuntu-12.10". If this information is unable to be determined, the
+      value resolves to "Unknown".
+
+      This variable is used by default to isolate native shared state
+      packages for different distributions (e.g. to avoid problems with
+      ``glibc`` version incompatibilities). Additionally, the variable is
+      checked against
+      :term:`SANITY_TESTED_DISTROS` if that
+      variable is set.
+
+   NM
+      The minimal command and arguments to run ``nm``.
+
+   NO_GENERIC_LICENSE
+      Avoids QA errors when you use a non-common, non-CLOSED license in a
+      recipe. Packages exist, such as the linux-firmware package, with many
+      licenses that are not in any way common. Also, new licenses are added
+      occasionally to avoid introducing a lot of common license files,
+      which are only applicable to a specific package.
+      ``NO_GENERIC_LICENSE`` is used to allow copying a license that does
+      not exist in common licenses.
+
+      The following example shows how to add ``NO_GENERIC_LICENSE`` to a
+      recipe:
+      ::
+
+         NO_GENERIC_LICENSE[license_name] = "license_file_in_fetched_source"
+
+      The following is an example that
+      uses the ``LICENSE.Abilis.txt`` file as the license from the fetched
+      source:
+      ::
+
+         NO_GENERIC_LICENSE[Firmware-Abilis] = "LICENSE.Abilis.txt"
+
+   NO_RECOMMENDATIONS
+      Prevents installation of all "recommended-only" packages.
+      Recommended-only packages are packages installed only through the
+      :term:`RRECOMMENDS` variable). Setting the
+      ``NO_RECOMMENDATIONS`` variable to "1" turns this feature on: ::
+
+         NO_RECOMMENDATIONS = "1"
+
+      You can set this variable globally in your ``local.conf`` file or you
+      can attach it to a specific image recipe by using the recipe name
+      override: ::
+
+         NO_RECOMMENDATIONS_pn-target_image = "1"
+
+      It is important to realize that if you choose to not install packages
+      using this variable and some other packages are dependent on them
+      (i.e. listed in a recipe's :term:`RDEPENDS`
+      variable), the OpenEmbedded build system ignores your request and
+      will install the packages to avoid dependency errors.
+
+      .. note::
+
+         Some recommended packages might be required for certain system
+         functionality, such as kernel modules. It is up to you to add
+         packages with the IMAGE_INSTALL variable.
+
+      Support for this variable exists only when using the IPK and RPM
+      packaging backend. Support does not exist for DEB.
+
+      See the :term:`BAD_RECOMMENDATIONS` and
+      the :term:`PACKAGE_EXCLUDE` variables for
+      related information.
+
+   NOAUTOPACKAGEDEBUG
+      Disables auto package from splitting ``.debug`` files. If a recipe
+      requires ``FILES_${PN}-dbg`` to be set manually, the
+      ``NOAUTOPACKAGEDEBUG`` can be defined allowing you to define the
+      content of the debug package. For example:
+      ::
+
+         NOAUTOPACKAGEDEBUG = "1"
+         FILES_${PN}-dev = "${includedir}/${QT_DIR_NAME}/Qt/*"
+         FILES_${PN}-dbg = "/usr/src/debug/"
+         FILES_${QT_BASE_NAME}-demos-doc = "${docdir}/${QT_DIR_NAME}/qch/qt.qch"
+
+   OBJCOPY
+      The minimal command and arguments to run ``objcopy``.
+
+   OBJDUMP
+      The minimal command and arguments to run ``objdump``.
+
+   OE_BINCONFIG_EXTRA_MANGLE
+      When inheriting the :ref:`binconfig <ref-classes-binconfig>` class,
+      this variable specifies additional arguments passed to the "sed"
+      command. The sed command alters any paths in configuration scripts
+      that have been set up during compilation. Inheriting this class
+      results in all paths in these scripts being changed to point into the
+      ``sysroots/`` directory so that all builds that use the script will
+      use the correct directories for the cross compiling layout.
+
+      See the ``meta/classes/binconfig.bbclass`` in the
+      :term:`Source Directory` for details on how this class
+      applies these additional sed command arguments. For general
+      information on the ``binconfig`` class, see the
+      ":ref:`binconfig.bbclass <ref-classes-binconfig>`" section.
+
+   OE_IMPORTS
+      An internal variable used to tell the OpenEmbedded build system what
+      Python modules to import for every Python function run by the system.
+
+      .. note::
+
+         Do not set this variable. It is for internal use only.
+
+   OE_INIT_ENV_SCRIPT
+      The name of the build environment setup script for the purposes of
+      setting up the environment within the extensible SDK. The default
+      value is "oe-init-build-env".
+
+      If you use a custom script to set up your build environment, set the
+      ``OE_INIT_ENV_SCRIPT`` variable to its name.
+
+   OE_TERMINAL
+      Controls how the OpenEmbedded build system spawns interactive
+      terminals on the host development system (e.g. using the BitBake
+      command with the ``-c devshell`` command-line option). For more
+      information, see the ":ref:`platdev-appdev-devshell`" section in
+      the Yocto Project Development Tasks Manual.
+
+      You can use the following values for the ``OE_TERMINAL`` variable:
+
+      - auto
+      - gnome
+      - xfce
+      - rxvt
+      - screen
+      - konsole
+      - none
+
+   OEROOT
+      The directory from which the top-level build environment setup script
+      is sourced. The Yocto Project provides a top-level build environment
+      setup script: ````` <#structure-core-script>`__. When you run this
+      script, the ``OEROOT`` variable resolves to the directory that
+      contains the script.
+
+      For additional information on how this variable is used, see the
+      initialization script.
+
+   OLDEST_KERNEL
+      Declares the oldest version of the Linux kernel that the produced
+      binaries must support. This variable is passed into the build of the
+      Embedded GNU C Library (``glibc``).
+
+      The default for this variable comes from the
+      ``meta/conf/bitbake.conf`` configuration file. You can override this
+      default by setting the variable in a custom distribution
+      configuration file.
+
+   OVERRIDES
+      A colon-separated list of overrides that currently apply. Overrides
+      are a BitBake mechanism that allows variables to be selectively
+      overridden at the end of parsing. The set of overrides in
+      ``OVERRIDES`` represents the "state" during building, which includes
+      the current recipe being built, the machine for which it is being
+      built, and so forth.
+
+      As an example, if the string "an-override" appears as an element in
+      the colon-separated list in ``OVERRIDES``, then the following
+      assignment will override ``FOO`` with the value "overridden" at the
+      end of parsing:
+      ::
+
+         FOO_an-override = "overridden"
+
+      See the
+      ":ref:`bitbake:bitbake-user-manual/bitbake-user-manual-metadata:conditional syntax (overrides)`"
+      section in the BitBake User Manual for more information on the
+      overrides mechanism.
+
+      The default value of ``OVERRIDES`` includes the values of the
+      :term:`CLASSOVERRIDE`,
+      :term:`MACHINEOVERRIDES`, and
+      :term:`DISTROOVERRIDES` variables. Another
+      important override included by default is ``pn-${PN}``. This override
+      allows variables to be set for a single recipe within configuration
+      (``.conf``) files. Here is an example:
+      ::
+
+         FOO_pn-myrecipe = "myrecipe-specific value"
+
+      .. note::
+
+         An easy way to see what overrides apply is to search for
+         OVERRIDES
+         in the output of the
+         bitbake -e
+         command. See the "
+         Viewing Variable Values
+         " section in the Yocto Project Development Tasks Manual for more
+         information.
+
+   P
+      The recipe name and version. ``P`` is comprised of the following:
+      ::
+
+         ${PN}-${PV}
+
+   PACKAGE_ADD_METADATA
+      This variable defines additional metdata to add to packages.
+
+      You may find you need to inject additional metadata into packages.
+      This variable allows you to do that by setting the injected data as
+      the value. Multiple fields can be added by splitting the content with
+      the literal separator "\n".
+
+      The suffixes '_IPK', '_DEB', or '_RPM' can be applied to the variable
+      to do package type specific settings. It can also be made package
+      specific by using the package name as a suffix.
+
+      You can find out more about applying this variable in the
+      ":ref:`dev-manual/dev-manual-common-tasks:adding custom metadata to packages`"
+      section in the Yocto Project Development Tasks Manual.
+
+   PACKAGE_ARCH
+      The architecture of the resulting package or packages.
+
+      By default, the value of this variable is set to
+      :term:`TUNE_PKGARCH` when building for the
+      target, :term:`BUILD_ARCH` when building for the
+      build host, and "${SDK_ARCH}-${SDKPKGSUFFIX}" when building for the
+      SDK.
+
+      .. note::
+
+         See
+         SDK_ARCH
+         for more information.
+
+      However, if your recipe's output packages are built specific to the
+      target machine rather than generally for the architecture of the
+      machine, you should set ``PACKAGE_ARCH`` to the value of
+      :term:`MACHINE_ARCH` in the recipe as follows:
+      ::
+
+         PACKAGE_ARCH = "${MACHINE_ARCH}"
+
+   PACKAGE_ARCHS
+      Specifies a list of architectures compatible with the target machine.
+      This variable is set automatically and should not normally be
+      hand-edited. Entries are separated using spaces and listed in order
+      of priority. The default value for ``PACKAGE_ARCHS`` is "all any
+      noarch ${PACKAGE_EXTRA_ARCHS} ${MACHINE_ARCH}".
+
+   PACKAGE_BEFORE_PN
+      Enables easily adding packages to ``PACKAGES`` before ``${PN}`` so
+      that those added packages can pick up files that would normally be
+      included in the default package.
+
+   PACKAGE_CLASSES
+      This variable, which is set in the ``local.conf`` configuration file
+      found in the ``conf`` folder of the
+      :term:`Build Directory`, specifies the package manager the
+      OpenEmbedded build system uses when packaging data.
+
+      You can provide one or more of the following arguments for the
+      variable: PACKAGE_CLASSES ?= "package_rpm package_deb package_ipk
+      package_tar"
+
+      .. note::
+
+         While it is a legal option, the
+         package_tar
+         class has limited functionality due to no support for package
+         dependencies by that backend. Therefore, it is recommended that
+         you do not use it.
+
+      The build system uses only the first argument in the list as the
+      package manager when creating your image or SDK. However, packages
+      will be created using any additional packaging classes you specify.
+      For example, if you use the following in your ``local.conf`` file:
+      ::
+
+         PACKAGE_CLASSES ?= "package_ipk"
+
+      The OpenEmbedded build system uses
+      the IPK package manager to create your image or SDK.
+
+      For information on packaging and build performance effects as a
+      result of the package manager in use, see the
+      ":ref:`package.bbclass <ref-classes-package>`" section.
+
+   PACKAGE_DEBUG_SPLIT_STYLE
+      Determines how to split up the binary and debug information when
+      creating ``*-dbg`` packages to be used with the GNU Project Debugger
+      (GDB).
+
+      With the ``PACKAGE_DEBUG_SPLIT_STYLE`` variable, you can control
+      where debug information, which can include or exclude source files,
+      is stored:
+
+      -  ".debug": Debug symbol files are placed next to the binary in a
+         ``.debug`` directory on the target. For example, if a binary is
+         installed into ``/bin``, the corresponding debug symbol files are
+         installed in ``/bin/.debug``. Source files are placed in
+         ``/usr/src/debug``.
+
+      -  "debug-file-directory": Debug symbol files are placed under
+         ``/usr/lib/debug`` on the target, and separated by the path from
+         where the binary is installed. For example, if a binary is
+         installed in ``/bin``, the corresponding debug symbols are
+         installed in ``/usr/lib/debug/bin``. Source files are placed in
+         ``/usr/src/debug``.
+
+      -  "debug-without-src": The same behavior as ".debug" previously
+         described with the exception that no source files are installed.
+
+      -  "debug-with-srcpkg": The same behavior as ".debug" previously
+         described with the exception that all source files are placed in a
+         separate ``*-src`` pkg. This is the default behavior.
+
+      You can find out more about debugging using GDB by reading the
+      ":ref:`platdev-gdb-remotedebug`" section
+      in the Yocto Project Development Tasks Manual.
+
+   PACKAGE_EXCLUDE_COMPLEMENTARY
+      Prevents specific packages from being installed when you are
+      installing complementary packages.
+
+      You might find that you want to prevent installing certain packages
+      when you are installing complementary packages. For example, if you
+      are using :term:`IMAGE_FEATURES` to install
+      ``dev-pkgs``, you might not want to install all packages from a
+      particular multilib. If you find yourself in this situation, you can
+      use the ``PACKAGE_EXCLUDE_COMPLEMENTARY`` variable to specify regular
+      expressions to match the packages you want to exclude.
+
+   PACKAGE_EXCLUDE
+      Lists packages that should not be installed into an image. For
+      example:
+      ::
+
+         PACKAGE_EXCLUDE = "package_name package_name package_name ..."
+
+      You can set this variable globally in your ``local.conf`` file or you
+      can attach it to a specific image recipe by using the recipe name
+      override:
+      ::
+
+         PACKAGE_EXCLUDE_pn-target_image = "package_name"
+
+      If you choose to not install a package using this variable and some
+      other package is dependent on it (i.e. listed in a recipe's
+      :term:`RDEPENDS` variable), the OpenEmbedded build
+      system generates a fatal installation error. Because the build system
+      halts the process with a fatal error, you can use the variable with
+      an iterative development process to remove specific components from a
+      system.
+
+      Support for this variable exists only when using the IPK and RPM
+      packaging backend. Support does not exist for DEB.
+
+      See the :term:`NO_RECOMMENDATIONS` and the
+      :term:`BAD_RECOMMENDATIONS` variables for
+      related information.
+
+   PACKAGE_EXTRA_ARCHS
+      Specifies the list of architectures compatible with the device CPU.
+      This variable is useful when you build for several different devices
+      that use miscellaneous processors such as XScale and ARM926-EJS.
+
+   PACKAGE_FEED_ARCHS
+      Optionally specifies the package architectures used as part of the
+      package feed URIs during the build. When used, the
+      ``PACKAGE_FEED_ARCHS`` variable is appended to the final package feed
+      URI, which is constructed using the
+      :term:`PACKAGE_FEED_URIS` and
+      :term:`PACKAGE_FEED_BASE_PATHS`
+      variables.
+
+      .. note::
+
+         You can use the
+         PACKAGE_FEEDS_ARCHS
+         variable to whitelist specific package architectures. If you do
+         not need to whitelist specific architectures, which is a common
+         case, you can omit this variable. Omitting the variable results in
+         all available architectures for the current machine being included
+         into remote package feeds.
+
+      Consider the following example where the ``PACKAGE_FEED_URIS``,
+      ``PACKAGE_FEED_BASE_PATHS``, and ``PACKAGE_FEED_ARCHS`` variables are
+      defined in your ``local.conf`` file:
+      ::
+
+         PACKAGE_FEED_URIS = "https://example.com/packagerepos/release \
+                              https://example.com/packagerepos/updates"
+         PACKAGE_FEED_BASE_PATHS = "rpm rpm-dev"
+         PACKAGE_FEED_ARCHS = "all core2-64"
+
+      Given these settings, the resulting package feeds are as follows:
+      ::
+
+         https://example.com/packagerepos/release/rpm/all
+         https://example.com/packagerepos/release/rpm/core2-64
+         https://example.com/packagerepos/release/rpm-dev/all
+         https://example.com/packagerepos/release/rpm-dev/core2-64
+         https://example.com/packagerepos/updates/rpm/all
+         https://example.com/packagerepos/updates/rpm/core2-64
+         https://example.com/packagerepos/updates/rpm-dev/all
+         https://example.com/packagerepos/updates/rpm-dev/core2-64
+
+   PACKAGE_FEED_BASE_PATHS
+      Specifies the base path used when constructing package feed URIs. The
+      ``PACKAGE_FEED_BASE_PATHS`` variable makes up the middle portion of a
+      package feed URI used by the OpenEmbedded build system. The base path
+      lies between the :term:`PACKAGE_FEED_URIS`
+      and :term:`PACKAGE_FEED_ARCHS` variables.
+
+      Consider the following example where the ``PACKAGE_FEED_URIS``,
+      ``PACKAGE_FEED_BASE_PATHS``, and ``PACKAGE_FEED_ARCHS`` variables are
+      defined in your ``local.conf`` file:
+      ::
+
+         PACKAGE_FEED_URIS = "https://example.com/packagerepos/release \
+                              https://example.com/packagerepos/updates"
+         PACKAGE_FEED_BASE_PATHS = "rpm rpm-dev"
+         PACKAGE_FEED_ARCHS = "all core2-64"
+
+      Given these settings, the resulting package feeds are as follows:
+      ::
+
+         https://example.com/packagerepos/release/rpm/all
+         https://example.com/packagerepos/release/rpm/core2-64
+         https://example.com/packagerepos/release/rpm-dev/all
+         https://example.com/packagerepos/release/rpm-dev/core2-64
+         https://example.com/packagerepos/updates/rpm/all
+         https://example.com/packagerepos/updates/rpm/core2-64
+         https://example.com/packagerepos/updates/rpm-dev/all
+         https://example.com/packagerepos/updates/rpm-dev/core2-64
+
+   PACKAGE_FEED_URIS
+      Specifies the front portion of the package feed URI used by the
+      OpenEmbedded build system. Each final package feed URI is comprised
+      of ``PACKAGE_FEED_URIS``,
+      :term:`PACKAGE_FEED_BASE_PATHS`, and
+      :term:`PACKAGE_FEED_ARCHS` variables.
+
+      Consider the following example where the ``PACKAGE_FEED_URIS``,
+      ``PACKAGE_FEED_BASE_PATHS``, and ``PACKAGE_FEED_ARCHS`` variables are
+      defined in your ``local.conf`` file:
+      ::
+
+         PACKAGE_FEED_URIS = "https://example.com/packagerepos/release \
+                              https://example.com/packagerepos/updates"
+         PACKAGE_FEED_BASE_PATHS = "rpm rpm-dev"
+         PACKAGE_FEED_ARCHS = "all core2-64"
+
+      Given these settings, the resulting package feeds are as follows:
+      ::
+
+         https://example.com/packagerepos/release/rpm/all
+         https://example.com/packagerepos/release/rpm/core2-64
+         https://example.com/packagerepos/release/rpm-dev/all
+         https://example.com/packagerepos/release/rpm-dev/core2-64
+         https://example.com/packagerepos/updates/rpm/all
+         https://example.com/packagerepos/updates/rpm/core2-64
+         https://example.com/packagerepos/updates/rpm-dev/all
+         https://example.com/packagerepos/updates/rpm-dev/core2-64
+
+   PACKAGE_INSTALL
+      The final list of packages passed to the package manager for
+      installation into the image.
+
+      Because the package manager controls actual installation of all
+      packages, the list of packages passed using ``PACKAGE_INSTALL`` is
+      not the final list of packages that are actually installed. This
+      variable is internal to the image construction code. Consequently, in
+      general, you should use the
+      :term:`IMAGE_INSTALL` variable to specify
+      packages for installation. The exception to this is when working with
+      the
+      ```core-image-minimal-initramfs`` <#images-core-image-minimal-initramfs>`__
+      image. When working with an initial RAM filesystem (initramfs) image,
+      use the ``PACKAGE_INSTALL`` variable. For information on creating an
+      initramfs, see the ":ref:`building-an-initramfs-image`" section
+      in the Yocto Project Development Tasks Manual.
+
+   PACKAGE_INSTALL_ATTEMPTONLY
+      Specifies a list of packages the OpenEmbedded build system attempts
+      to install when creating an image. If a listed package fails to
+      install, the build system does not generate an error. This variable
+      is generally not user-defined.
+
+   PACKAGE_PREPROCESS_FUNCS
+      Specifies a list of functions run to pre-process the
+      :term:`PKGD` directory prior to splitting the files out
+      to individual packages.
+
+   PACKAGE_WRITE_DEPS
+      Specifies a list of dependencies for post-installation and
+      pre-installation scripts on native/cross tools. If your
+      post-installation or pre-installation script can execute at rootfs
+      creation time rather than on the target but depends on a native tool
+      in order to execute, you need to list the tools in
+      ``PACKAGE_WRITE_DEPS``.
+
+      For information on running post-installation scripts, see the
+      ":ref:`dev-manual/dev-manual-common-tasks:post-installation scripts`"
+      section in the Yocto Project Development Tasks Manual.
+
+   PACKAGECONFIG
+      This variable provides a means of enabling or disabling features of a
+      recipe on a per-recipe basis. ``PACKAGECONFIG`` blocks are defined in
+      recipes when you specify features and then arguments that define
+      feature behaviors. Here is the basic block structure (broken over
+      multiple lines for readability):
+      ::
+
+         PACKAGECONFIG ??= "f1 f2 f3 ..."
+         PACKAGECONFIG[f1] = "\
+             --with-f1, \
+             --without-f1, \
+             build-deps-for-f1, \
+             runtime-deps-for-f1, \
+             runtime-recommends-for-f1, \
+             packageconfig-conflicts-for-f1"
+         PACKAGECONFIG[f2] = "\
+              ... and so on and so on ...
+
+      The ``PACKAGECONFIG`` variable itself specifies a space-separated
+      list of the features to enable. Following the features, you can
+      determine the behavior of each feature by providing up to six
+      order-dependent arguments, which are separated by commas. You can
+      omit any argument you like but must retain the separating commas. The
+      order is important and specifies the following:
+
+      1. Extra arguments that should be added to the configure script
+         argument list (:term:`EXTRA_OECONF` or
+         :term:`PACKAGECONFIG_CONFARGS`) if
+         the feature is enabled.
+
+      2. Extra arguments that should be added to ``EXTRA_OECONF`` or
+         ``PACKAGECONFIG_CONFARGS`` if the feature is disabled.
+
+      3. Additional build dependencies (:term:`DEPENDS`)
+         that should be added if the feature is enabled.
+
+      4. Additional runtime dependencies (:term:`RDEPENDS`)
+         that should be added if the feature is enabled.
+
+      5. Additional runtime recommendations
+         (:term:`RRECOMMENDS`) that should be added if
+         the feature is enabled.
+
+      6. Any conflicting (that is, mutually exclusive) ``PACKAGECONFIG``
+         settings for this feature.
+
+      Consider the following ``PACKAGECONFIG`` block taken from the
+      ``librsvg`` recipe. In this example the feature is ``gtk``, which has
+      three arguments that determine the feature's behavior.
+      ::
+
+         PACKAGECONFIG[gtk] = "--with-gtk3,--without-gtk3,gtk+3"
+
+      The
+      ``--with-gtk3`` and ``gtk+3`` arguments apply only if the feature is
+      enabled. In this case, ``--with-gtk3`` is added to the configure
+      script argument list and ``gtk+3`` is added to ``DEPENDS``. On the
+      other hand, if the feature is disabled say through a ``.bbappend``
+      file in another layer, then the second argument ``--without-gtk3`` is
+      added to the configure script instead.
+
+      The basic ``PACKAGECONFIG`` structure previously described holds true
+      regardless of whether you are creating a block or changing a block.
+      When creating a block, use the structure inside your recipe.
+
+      If you want to change an existing ``PACKAGECONFIG`` block, you can do
+      so one of two ways:
+
+      -  *Append file:* Create an append file named
+         recipename\ ``.bbappend`` in your layer and override the value of
+         ``PACKAGECONFIG``. You can either completely override the
+         variable:
+         ::
+
+            PACKAGECONFIG = "f4 f5"
+
+         Or, you can just append the variable:
+         ::
+
+            PACKAGECONFIG_append = " f4"
+
+      -  *Configuration file:* This method is identical to changing the
+         block through an append file except you edit your ``local.conf``
+         or ``mydistro.conf`` file. As with append files previously
+         described, you can either completely override the variable:
+         PACKAGECONFIG_pn-recipename = "f4 f5" Or, you can just amend the
+         variable:
+         ::
+
+            PACKAGECONFIG_append_pn-recipename = " f4"
+
+   PACKAGECONFIG_CONFARGS
+      A space-separated list of configuration options generated from the
+      :term:`PACKAGECONFIG` setting.
+
+      Classes such as :ref:`autotools <ref-classes-autotools>` and
+      :ref:`cmake <ref-classes-cmake>` use ``PACKAGECONFIG_CONFARGS`` to
+      pass ``PACKAGECONFIG`` options to ``configure`` and ``cmake``,
+      respectively. If you are using ``PACKAGECONFIG`` but not a class that
+      handles the ``do_configure`` task, then you need to use
+      ``PACKAGECONFIG_CONFARGS`` appropriately.
+
+   PACKAGEGROUP_DISABLE_COMPLEMENTARY
+      For recipes inheriting the
+      :ref:`packagegroup <ref-classes-packagegroup>` class, setting
+      ``PACKAGEGROUP_DISABLE_COMPLEMENTARY`` to "1" specifies that the
+      normal complementary packages (i.e. ``-dev``, ``-dbg``, and so forth)
+      should not be automatically created by the ``packagegroup`` recipe,
+      which is the default behavior.
+
+   PACKAGES
+      The list of packages the recipe creates. The default value is the
+      following:
+      ::
+
+         ${PN}-dbg ${PN}-staticdev ${PN}-dev ${PN}-doc ${PN}-locale ${PACKAGE_BEFORE_PN} ${PN}
+
+      During packaging, the :ref:`ref-tasks-package` task
+      goes through ``PACKAGES`` and uses the :term:`FILES`
+      variable corresponding to each package to assign files to the
+      package. If a file matches the ``FILES`` variable for more than one
+      package in ``PACKAGES``, it will be assigned to the earliest
+      (leftmost) package.
+
+      Packages in the variable's list that are empty (i.e. where none of
+      the patterns in ``FILES_``\ pkg match any files installed by the
+      :ref:`ref-tasks-install` task) are not generated,
+      unless generation is forced through the
+      :term:`ALLOW_EMPTY` variable.
+
+   PACKAGES_DYNAMIC
+      A promise that your recipe satisfies runtime dependencies for
+      optional modules that are found in other recipes.
+      ``PACKAGES_DYNAMIC`` does not actually satisfy the dependencies, it
+      only states that they should be satisfied. For example, if a hard,
+      runtime dependency (:term:`RDEPENDS`) of another
+      package is satisfied at build time through the ``PACKAGES_DYNAMIC``
+      variable, but a package with the module name is never actually
+      produced, then the other package will be broken. Thus, if you attempt
+      to include that package in an image, you will get a dependency
+      failure from the packaging system during the
+      :ref:`ref-tasks-rootfs` task.
+
+      Typically, if there is a chance that such a situation can occur and
+      the package that is not created is valid without the dependency being
+      satisfied, then you should use :term:`RRECOMMENDS`
+      (a soft runtime dependency) instead of ``RDEPENDS``.
+
+      For an example of how to use the ``PACKAGES_DYNAMIC`` variable when
+      you are splitting packages, see the
+      ":ref:`dev-manual/dev-manual-common-tasks:handling optional module packaging`"
+      section in the Yocto Project Development Tasks Manual.
+
+   PACKAGESPLITFUNCS
+      Specifies a list of functions run to perform additional splitting of
+      files into individual packages. Recipes can either prepend to this
+      variable or prepend to the ``populate_packages`` function in order to
+      perform additional package splitting. In either case, the function
+      should set :term:`PACKAGES`,
+      :term:`FILES`, :term:`RDEPENDS` and
+      other packaging variables appropriately in order to perform the
+      desired splitting.
+
+   PARALLEL_MAKE
+      Extra options passed to the ``make`` command during the
+      :ref:`ref-tasks-compile` task in order to specify
+      parallel compilation on the local build host. This variable is
+      usually in the form "-j x", where x represents the maximum number of
+      parallel threads ``make`` can run.
+
+      .. note::
+
+         In order for
+         PARALLEL_MAKE
+         to be effective,
+         make
+         must be called with
+         ${
+         EXTRA_OEMAKE
+         }
+         . An easy way to ensure this is to use the
+         oe_runmake
+         function.
+
+      By default, the OpenEmbedded build system automatically sets this
+      variable to be equal to the number of cores the build system uses.
+
+      .. note::
+
+         If the software being built experiences dependency issues during
+         the
+         do_compile
+         task that result in race conditions, you can clear the
+         PARALLEL_MAKE
+         variable within the recipe as a workaround. For information on
+         addressing race conditions, see the "
+         Debugging Parallel Make Races
+         " section in the Yocto Project Development Tasks Manual.
+
+      For single socket systems (i.e. one CPU), you should not have to
+      override this variable to gain optimal parallelism during builds.
+      However, if you have very large systems that employ multiple physical
+      CPUs, you might want to make sure the ``PARALLEL_MAKE`` variable is
+      not set higher than "-j 20".
+
+      For more information on speeding up builds, see the
+      ":ref:`dev-manual/dev-manual-common-tasks:speeding up a build`"
+      section in the Yocto Project Development Tasks Manual.
+
+   PARALLEL_MAKEINST
+      Extra options passed to the ``make install`` command during the
+      :ref:`ref-tasks-install` task in order to specify
+      parallel installation. This variable defaults to the value of
+      :term:`PARALLEL_MAKE`.
+
+      .. note::
+
+         In order for ``PARALLEL_MAKEINST`` to be effective, ``make`` must
+         be called with
+         ``${``\ :term:`EXTRA_OEMAKE`\ ``}``. An easy
+         way to ensure this is to use the ``oe_runmake`` function.
+
+         If the software being built experiences dependency issues during
+         the ``do_install`` task that result in race conditions, you can
+         clear the ``PARALLEL_MAKEINST`` variable within the recipe as a
+         workaround. For information on addressing race conditions, see the
+         ":ref:`dev-manual/dev-manual-common-tasks:debugging parallel make races`"
+         section in the Yocto Project Development Tasks Manual.
+
+   PATCHRESOLVE
+      Determines the action to take when a patch fails. You can set this
+      variable to one of two values: "noop" and "user".
+
+      The default value of "noop" causes the build to simply fail when the
+      OpenEmbedded build system cannot successfully apply a patch. Setting
+      the value to "user" causes the build system to launch a shell and
+      places you in the right location so that you can manually resolve the
+      conflicts.
+
+      Set this variable in your ``local.conf`` file.
+
+   PATCHTOOL
+      Specifies the utility used to apply patches for a recipe during the
+      :ref:`ref-tasks-patch` task. You can specify one of
+      three utilities: "patch", "quilt", or "git". The default utility used
+      is "quilt" except for the quilt-native recipe itself. Because the
+      quilt tool is not available at the time quilt-native is being
+      patched, it uses "patch".
+
+      If you wish to use an alternative patching tool, set the variable in
+      the recipe using one of the following:
+      ::
+
+         PATCHTOOL = "patch"
+         PATCHTOOL = "quilt"
+         PATCHTOOL = "git"
+
+   PE
+      The epoch of the recipe. By default, this variable is unset. The
+      variable is used to make upgrades possible when the versioning scheme
+      changes in some backwards incompatible way.
+
+      ``PE`` is the default value of the :term:`PKGE` variable.
+
+   PF
+      Specifies the recipe or package name and includes all version and
+      revision numbers (i.e. ``glibc-2.13-r20+svnr15508/`` and
+      ``bash-4.2-r1/``). This variable is comprised of the following:
+      ${:term:`PN`}-${:term:`EXTENDPE`}${:term:`PV`}-${:term:`PR`}
+
+   PIXBUF_PACKAGES
+      When inheriting the :ref:`pixbufcache <ref-classes-pixbufcache>`
+      class, this variable identifies packages that contain the pixbuf
+      loaders used with ``gdk-pixbuf``. By default, the ``pixbufcache``
+      class assumes that the loaders are in the recipe's main package (i.e.
+      ``${``\ :term:`PN`\ ``}``). Use this variable if the
+      loaders you need are in a package other than that main package.
+
+   PKG
+      The name of the resulting package created by the OpenEmbedded build
+      system.
+
+      .. note::
+
+         When using the
+         PKG
+         variable, you must use a package name override.
+
+      For example, when the :ref:`debian <ref-classes-debian>` class
+      renames the output package, it does so by setting
+      ``PKG_packagename``.
+
+   PKG_CONFIG_PATH
+      The path to ``pkg-config`` files for the current build context.
+      ``pkg-config`` reads this variable from the environment.
+
+   PKGD
+      Points to the destination directory for files to be packaged before
+      they are split into individual packages. This directory defaults to
+      the following:
+      ::
+
+         ${WORKDIR}/package
+
+      Do not change this default.
+
+   PKGDATA_DIR
+      Points to a shared, global-state directory that holds data generated
+      during the packaging process. During the packaging process, the
+      :ref:`ref-tasks-packagedata` task packages data
+      for each recipe and installs it into this temporary, shared area.
+      This directory defaults to the following, which you should not
+      change:
+      ::
+
+         ${STAGING_DIR_HOST}/pkgdata
+
+      For examples of how this data is used, see the
+      ":ref:`overview-manual/overview-manual-concepts:automatically added runtime dependencies`"
+      section in the Yocto Project Overview and Concepts Manual and the
+      ":ref:`dev-manual/dev-manual-common-tasks:viewing package information with \`\`oe-pkgdata-util\`\``"
+      section in the Yocto Project Development Tasks Manual. For more
+      information on the shared, global-state directory, see
+      :term:`STAGING_DIR_HOST`.
+
+   PKGDEST
+      Points to the parent directory for files to be packaged after they
+      have been split into individual packages. This directory defaults to
+      the following:
+      ::
+
+         ${WORKDIR}/packages-split
+
+      Under this directory, the build system creates directories for each
+      package specified in :term:`PACKAGES`. Do not change
+      this default.
+
+   PKGDESTWORK
+      Points to a temporary work area where the
+      :ref:`ref-tasks-package` task saves package metadata.
+      The ``PKGDESTWORK`` location defaults to the following:
+      ::
+
+         ${WORKDIR}/pkgdata
+
+      Do not change this default.
+
+      The :ref:`ref-tasks-packagedata` task copies the
+      package metadata from ``PKGDESTWORK`` to
+      :term:`PKGDATA_DIR` to make it available globally.
+
+   PKGE
+      The epoch of the package(s) built by the recipe. By default, ``PKGE``
+      is set to :term:`PE`.
+
+   PKGR
+      The revision of the package(s) built by the recipe. By default,
+      ``PKGR`` is set to :term:`PR`.
+
+   PKGV
+      The version of the package(s) built by the recipe. By default,
+      ``PKGV`` is set to :term:`PV`.
+
+   PN
+      This variable can have two separate functions depending on the
+      context: a recipe name or a resulting package name.
+
+      ``PN`` refers to a recipe name in the context of a file used by the
+      OpenEmbedded build system as input to create a package. The name is
+      normally extracted from the recipe file name. For example, if the
+      recipe is named ``expat_2.0.1.bb``, then the default value of ``PN``
+      will be "expat".
+
+      The variable refers to a package name in the context of a file
+      created or produced by the OpenEmbedded build system.
+
+      If applicable, the ``PN`` variable also contains any special suffix
+      or prefix. For example, using ``bash`` to build packages for the
+      native machine, ``PN`` is ``bash-native``. Using ``bash`` to build
+      packages for the target and for Multilib, ``PN`` would be ``bash``
+      and ``lib64-bash``, respectively.
+
+   PNBLACKLIST
+      Lists recipes you do not want the OpenEmbedded build system to build.
+      This variable works in conjunction with the
+      :ref:`blacklist <ref-classes-blacklist>` class, which is inherited
+      globally.
+
+      To prevent a recipe from being built, use the ``PNBLACKLIST``
+      variable in your ``local.conf`` file. Here is an example that
+      prevents ``myrecipe`` from being built:
+      ::
+
+         PNBLACKLIST[myrecipe] = "Not supported by our organization."
+
+   POPULATE_SDK_POST_HOST_COMMAND
+      Specifies a list of functions to call once the OpenEmbedded build
+      system has created the host part of the SDK. You can specify
+      functions separated by semicolons:
+      ::
+
+          POPULATE_SDK_POST_HOST_COMMAND += "function; ... "
+
+      If you need to pass the SDK path to a command within a function, you
+      can use ``${SDK_DIR}``, which points to the parent directory used by
+      the OpenEmbedded build system when creating SDK output. See the
+      :term:`SDK_DIR` variable for more information.
+
+   POPULATE_SDK_POST_TARGET_COMMAND
+      Specifies a list of functions to call once the OpenEmbedded build
+      system has created the target part of the SDK. You can specify
+      functions separated by semicolons:
+      ::
+
+         POPULATE_SDK_POST_TARGET_COMMAND += "function; ... "
+
+      If you need to pass the SDK path to a command within a function, you
+      can use ``${SDK_DIR}``, which points to the parent directory used by
+      the OpenEmbedded build system when creating SDK output. See the
+      :term:`SDK_DIR` variable for more information.
+
+   PR
+      The revision of the recipe. The default value for this variable is
+      "r0". Subsequent revisions of the recipe conventionally have the
+      values "r1", "r2", and so forth. When :term:`PV` increases,
+      ``PR`` is conventionally reset to "r0".
+
+      .. note::
+
+         The OpenEmbedded build system does not need the aid of
+         PR
+         to know when to rebuild a recipe. The build system uses the task
+         input checksums
+         along with the
+         stamp
+         and
+         shared state cache
+         mechanisms.
+
+      The ``PR`` variable primarily becomes significant when a package
+      manager dynamically installs packages on an already built image. In
+      this case, ``PR``, which is the default value of
+      :term:`PKGR`, helps the package manager distinguish which
+      package is the most recent one in cases where many packages have the
+      same ``PV`` (i.e. ``PKGV``). A component having many packages with
+      the same ``PV`` usually means that the packages all install the same
+      upstream version, but with later (``PR``) version packages including
+      packaging fixes.
+
+      .. note::
+
+         PR
+         does not need to be increased for changes that do not change the
+         package contents or metadata.
+
+      Because manually managing ``PR`` can be cumbersome and error-prone,
+      an automated solution exists. See the
+      ":ref:`dev-manual/dev-manual-common-tasks:working with a pr service`" section
+      in the Yocto Project Development Tasks Manual for more information.
+
+   PREFERRED_PROVIDER
+      If multiple recipes provide the same item, this variable determines
+      which recipe is preferred and thus provides the item (i.e. the
+      preferred provider). You should always suffix this variable with the
+      name of the provided item. And, you should define the variable using
+      the preferred recipe's name (:term:`PN`). Here is a common
+      example:
+      ::
+
+         PREFERRED_PROVIDER_virtual/kernel ?= "linux-yocto"
+
+      In the previous example, multiple recipes are providing "virtual/kernel".
+      The ``PREFERRED_PROVIDER`` variable is set with the name (``PN``) of
+      the recipe you prefer to provide "virtual/kernel".
+
+      Following are more examples:
+      ::
+
+         PREFERRED_PROVIDER_virtual/xserver = "xserver-xf86"
+         PREFERRED_PROVIDER_virtual/libgl ?= "mesa"
+
+      For more
+      information, see the ":ref:`metadata-virtual-providers`"
+      section in the Yocto Project Development Tasks Manual.
+
+      .. note::
+
+         If you use a
+         virtual/\*
+         item with
+         PREFERRED_PROVIDER
+         , then any recipe that
+         PROVIDES
+         that item but is not selected (defined) by
+         PREFERRED_PROVIDER
+         is prevented from building, which is usually desirable since this
+         mechanism is designed to select between mutually exclusive
+         alternative providers.
+
+   PREFERRED_VERSION
+      If multiple versions of recipes exist, this variable determines which
+      version is given preference. You must always suffix the variable with
+      the :term:`PN` you want to select, and you should set the
+      :term:`PV` accordingly for precedence.
+
+      The ``PREFERRED_VERSION`` variable supports limited wildcard use
+      through the "``%``" character. You can use the character to match any
+      number of characters, which can be useful when specifying versions
+      that contain long revision numbers that potentially change. Here are
+      two examples:
+      ::
+
+         PREFERRED_VERSION_python = "3.4.0"
+         PREFERRED_VERSION_linux-yocto = "5.0%"
+
+      .. note::
+
+         The use of the "%" character is limited in that it only works at the end of the
+         string. You cannot use the wildcard character in any other
+         location of the string.
+
+      The specified version is matched against :term:`PV`, which
+      does not necessarily match the version part of the recipe's filename.
+      For example, consider two recipes ``foo_1.2.bb`` and ``foo_git.bb``
+      where ``foo_git.bb`` contains the following assignment:
+      ::
+
+         PV = "1.1+git${SRCPV}"
+
+      In this case, the correct way to select
+      ``foo_git.bb`` is by using an assignment such as the following:
+      ::
+
+         PREFERRED_VERSION_foo = "1.1+git%"
+
+      Compare that previous example
+      against the following incorrect example, which does not work:
+      ::
+
+         PREFERRED_VERSION_foo = "git"
+
+      Sometimes the ``PREFERRED_VERSION`` variable can be set by
+      configuration files in a way that is hard to change. You can use
+      :term:`OVERRIDES` to set a machine-specific
+      override. Here is an example:
+      ::
+
+         PREFERRED_VERSION_linux-yocto_qemux86 = "5.0%"
+
+      Although not recommended, worst case, you can also use the
+      "forcevariable" override, which is the strongest override possible.
+      Here is an example:
+      ::
+
+         PREFERRED_VERSION_linux-yocto_forcevariable = "5.0%"
+
+      .. note::
+
+         The \_forcevariable override is not handled specially. This override
+         only works because the default value of OVERRIDES includes "forcevariable".
+
+   PREMIRRORS
+      Specifies additional paths from which the OpenEmbedded build system
+      gets source code. When the build system searches for source code, it
+      first tries the local download directory. If that location fails, the
+      build system tries locations defined by ``PREMIRRORS``, the upstream
+      source, and then locations specified by
+      :term:`MIRRORS` in that order.
+
+      Assuming your distribution (:term:`DISTRO`) is "poky",
+      the default value for ``PREMIRRORS`` is defined in the
+      ``conf/distro/poky.conf`` file in the ``meta-poky`` Git repository.
+
+      Typically, you could add a specific server for the build system to
+      attempt before any others by adding something like the following to
+      the ``local.conf`` configuration file in the
+      :term:`Build Directory`:
+      ::
+
+         PREMIRRORS_prepend = "\
+             git://.*/.* http://www.yoctoproject.org/sources/ \n \
+             ftp://.*/.* http://www.yoctoproject.org/sources/ \n \
+             http://.*/.* http://www.yoctoproject.org/sources/ \n \
+             https://.*/.* http://www.yoctoproject.org/sources/ \n"
+
+      These changes cause the
+      build system to intercept Git, FTP, HTTP, and HTTPS requests and
+      direct them to the ``http://`` sources mirror. You can use
+      ``file://`` URLs to point to local directories or network shares as
+      well.
+
+   PRIORITY
+      Indicates the importance of a package.
+
+      ``PRIORITY`` is considered to be part of the distribution policy
+      because the importance of any given recipe depends on the purpose for
+      which the distribution is being produced. Thus, ``PRIORITY`` is not
+      normally set within recipes.
+
+      You can set ``PRIORITY`` to "required", "standard", "extra", and
+      "optional", which is the default.
+
+   PRIVATE_LIBS
+      Specifies libraries installed within a recipe that should be ignored
+      by the OpenEmbedded build system's shared library resolver. This
+      variable is typically used when software being built by a recipe has
+      its own private versions of a library normally provided by another
+      recipe. In this case, you would not want the package containing the
+      private libraries to be set as a dependency on other unrelated
+      packages that should instead depend on the package providing the
+      standard version of the library.
+
+      Libraries specified in this variable should be specified by their
+      file name. For example, from the Firefox recipe in meta-browser:
+      ::
+
+         PRIVATE_LIBS = "libmozjs.so \
+                         libxpcom.so \
+                         libnspr4.so \
+                         libxul.so \
+                         libmozalloc.so \
+                         libplc4.so \
+                         libplds4.so"
+
+      For more information, see the
+      ":ref:`overview-manual/overview-manual-concepts:automatically added runtime dependencies`"
+      section in the Yocto Project Overview and Concepts Manual.
+
+   PROVIDES
+      A list of aliases by which a particular recipe can be known. By
+      default, a recipe's own ``PN`` is implicitly already in its
+      ``PROVIDES`` list and therefore does not need to mention that it
+      provides itself. If a recipe uses ``PROVIDES``, the additional
+      aliases are synonyms for the recipe and can be useful for satisfying
+      dependencies of other recipes during the build as specified by
+      ``DEPENDS``.
+
+      Consider the following example ``PROVIDES`` statement from the recipe
+      file ``eudev_3.2.9.bb``:
+      ::
+
+         PROVIDES = "udev"
+
+      The ``PROVIDES`` statement
+      results in the "eudev" recipe also being available as simply "udev".
+
+      .. note::
+
+         Given that a recipe's own recipe name is already implicitly in its
+         own
+         PROVIDES
+         list, it is unnecessary to add aliases with the "+=" operator;
+         using a simple assignment will be sufficient. In other words,
+         while you could write:
+         ::
+
+                 PROVIDES += "udev"
+
+
+         in the above, the "+=" is overkill and unnecessary.
+
+      In addition to providing recipes under alternate names, the
+      ``PROVIDES`` mechanism is also used to implement virtual targets. A
+      virtual target is a name that corresponds to some particular
+      functionality (e.g. a Linux kernel). Recipes that provide the
+      functionality in question list the virtual target in ``PROVIDES``.
+      Recipes that depend on the functionality in question can include the
+      virtual target in ``DEPENDS`` to leave the choice of provider open.
+
+      Conventionally, virtual targets have names on the form
+      "virtual/function" (e.g. "virtual/kernel"). The slash is simply part
+      of the name and has no syntactical significance.
+
+      The :term:`PREFERRED_PROVIDER` variable is
+      used to select which particular recipe provides a virtual target.
+
+      .. note::
+
+         A corresponding mechanism for virtual runtime dependencies
+         (packages) exists. However, the mechanism does not depend on any
+         special functionality beyond ordinary variable assignments. For
+         example, ``VIRTUAL-RUNTIME_dev_manager`` refers to the package of
+         the component that manages the ``/dev`` directory.
+
+         Setting the "preferred provider" for runtime dependencies is as
+         simple as using the following assignment in a configuration file:
+         ::
+
+                 VIRTUAL-RUNTIME_dev_manager = "udev"
+
+
+   PRSERV_HOST
+      The network based :term:`PR` service host and port.
+
+      The ``conf/local.conf.sample.extended`` configuration file in the
+      :term:`Source Directory` shows how the
+      ``PRSERV_HOST`` variable is set:
+      ::
+
+         PRSERV_HOST = "localhost:0"
+
+      You must
+      set the variable if you want to automatically start a local :ref:`PR
+      service <dev-manual/dev-manual-common-tasks:working with a pr service>`. You can
+      set ``PRSERV_HOST`` to other values to use a remote PR service.
+
+   PTEST_ENABLED
+      Specifies whether or not :ref:`Package
+      Test <dev-manual/dev-manual-common-tasks:testing packages with ptest>` (ptest)
+      functionality is enabled when building a recipe. You should not set
+      this variable directly. Enabling and disabling building Package Tests
+      at build time should be done by adding "ptest" to (or removing it
+      from) :term:`DISTRO_FEATURES`.
+
+   PV
+      The version of the recipe. The version is normally extracted from the
+      recipe filename. For example, if the recipe is named
+      ``expat_2.0.1.bb``, then the default value of ``PV`` will be "2.0.1".
+      ``PV`` is generally not overridden within a recipe unless it is
+      building an unstable (i.e. development) version from a source code
+      repository (e.g. Git or Subversion).
+
+      ``PV`` is the default value of the :term:`PKGV` variable.
+
+   PYTHON_ABI
+      When used by recipes that inherit the
+      :ref:`distutils3 <ref-classes-distutils3>`,
+      :ref:`setuptools3 <ref-classes-setuptools3>`,
+      :ref:`distutils <ref-classes-distutils>`, or
+      :ref:`setuptools <ref-classes-setuptools>` classes, denotes the
+      Application Binary Interface (ABI) currently in use for Python. By
+      default, the ABI is "m". You do not have to set this variable as the
+      OpenEmbedded build system sets it for you.
+
+      The OpenEmbedded build system uses the ABI to construct directory
+      names used when installing the Python headers and libraries in
+      sysroot (e.g. ``.../python3.3m/...``).
+
+      Recipes that inherit the ``distutils`` class during cross-builds also
+      use this variable to locate the headers and libraries of the
+      appropriate Python that the extension is targeting.
+
+   PYTHON_PN
+      When used by recipes that inherit the
+      `distutils3 <ref-classes-distutils3>`,
+      :ref:`setuptools3 <ref-classes-setuptools3>`,
+      :ref:`distutils <ref-classes-distutils>`, or
+      :ref:`setuptools <ref-classes-setuptools>` classes, specifies the
+      major Python version being built. For Python 3.x, ``PYTHON_PN`` would
+      be "python3". You do not have to set this variable as the
+      OpenEmbedded build system automatically sets it for you.
+
+      The variable allows recipes to use common infrastructure such as the
+      following:
+      ::
+
+         DEPENDS += "${PYTHON_PN}-native"
+
+      In the previous example,
+      the version of the dependency is ``PYTHON_PN``.
+
+   RANLIB
+      The minimal command and arguments to run ``ranlib``.
+
+   RCONFLICTS
+      The list of packages that conflict with packages. Note that packages
+      will not be installed if conflicting packages are not first removed.
+
+      Like all package-controlling variables, you must always use them in
+      conjunction with a package name override. Here is an example:
+      ::
+
+         RCONFLICTS_${PN} = "another_conflicting_package_name"
+
+      BitBake, which the OpenEmbedded build system uses, supports
+      specifying versioned dependencies. Although the syntax varies
+      depending on the packaging format, BitBake hides these differences
+      from you. Here is the general syntax to specify versions with the
+      ``RCONFLICTS`` variable:
+      ::
+
+         RCONFLICTS_${PN} = "package (operator version)"
+
+      For ``operator``, you can specify the following: = < > <=
+      >= For example, the following sets up a dependency on version 1.2 or
+      greater of the package ``foo``:
+      ::
+
+         RCONFLICTS_${PN} = "foo (>= 1.2)"
+
+   RDEPENDS
+      Lists runtime dependencies of a package. These dependencies are other
+      packages that must be installed in order for the package to function
+      correctly. As an example, the following assignment declares that the
+      package ``foo`` needs the packages ``bar`` and ``baz`` to be
+      installed:
+      ::
+
+         RDEPENDS_foo = "bar baz"
+
+      The most common types of package
+      runtime dependencies are automatically detected and added. Therefore,
+      most recipes do not need to set ``RDEPENDS``. For more information,
+      see the
+      ":ref:`overview-manual/overview-manual-concepts:automatically added runtime dependencies`"
+      section in the Yocto Project Overview and Concepts Manual.
+
+      The practical effect of the above ``RDEPENDS`` assignment is that
+      ``bar`` and ``baz`` will be declared as dependencies inside the
+      package ``foo`` when it is written out by one of the
+      ```do_package_write_*`` <#ref-tasks-package_write_deb>`__ tasks.
+      Exactly how this is done depends on which package format is used,
+      which is determined by
+      :term:`PACKAGE_CLASSES`. When the
+      corresponding package manager installs the package, it will know to
+      also install the packages on which it depends.
+
+      To ensure that the packages ``bar`` and ``baz`` get built, the
+      previous ``RDEPENDS`` assignment also causes a task dependency to be
+      added. This dependency is from the recipe's
+      :ref:`ref-tasks-build` (not to be confused with
+      :ref:`ref-tasks-compile`) task to the
+      ``do_package_write_*`` task of the recipes that build ``bar`` and
+      ``baz``.
+
+      The names of the packages you list within ``RDEPENDS`` must be the
+      names of other packages - they cannot be recipe names. Although
+      package names and recipe names usually match, the important point
+      here is that you are providing package names within the ``RDEPENDS``
+      variable. For an example of the default list of packages created from
+      a recipe, see the :term:`PACKAGES` variable.
+
+      Because the ``RDEPENDS`` variable applies to packages being built,
+      you should always use the variable in a form with an attached package
+      name (remember that a single recipe can build multiple packages). For
+      example, suppose you are building a development package that depends
+      on the ``perl`` package. In this case, you would use the following
+      ``RDEPENDS`` statement:
+      ::
+
+         RDEPENDS_${PN}-dev += "perl"
+
+      In the example,
+      the development package depends on the ``perl`` package. Thus, the
+      ``RDEPENDS`` variable has the ``${PN}-dev`` package name as part of
+      the variable.
+
+      .. note::
+
+         RDEPENDS_${PN}-dev
+         includes
+         ${
+         PN
+         }
+         by default. This default is set in the BitBake configuration file
+         (
+         meta/conf/bitbake.conf
+         ). Be careful not to accidentally remove
+         ${PN}
+         when modifying
+         RDEPENDS_${PN}-dev
+         . Use the "+=" operator rather than the "=" operator.
+
+      The package names you use with ``RDEPENDS`` must appear as they would
+      in the ``PACKAGES`` variable. The :term:`PKG` variable
+      allows a different name to be used for the final package (e.g. the
+      :ref:`debian <ref-classes-debian>` class uses this to rename
+      packages), but this final package name cannot be used with
+      ``RDEPENDS``, which makes sense as ``RDEPENDS`` is meant to be
+      independent of the package format used.
+
+      BitBake, which the OpenEmbedded build system uses, supports
+      specifying versioned dependencies. Although the syntax varies
+      depending on the packaging format, BitBake hides these differences
+      from you. Here is the general syntax to specify versions with the
+      ``RDEPENDS`` variable:
+      ::
+
+         RDEPENDS_${PN} = "package (operator version)"
+
+      For operator, you can specify the following: = < > <= >= For version,
+      provide the version number.
+
+      .. note::
+
+         You can use
+         EXTENDPKGV
+         to provide a full package version specification.
+
+      For example, the following sets up a dependency on version 1.2 or
+      greater of the package ``foo``:
+      ::
+
+         RDEPENDS_${PN} = "foo (>= 1.2)"
+
+      For information on build-time dependencies, see the
+      :term:`DEPENDS` variable. You can also see the
+      ":ref:`Tasks <bitbake:bitbake-user-manual/bitbake-user-manual-metadata:tasks>`" and
+      ":ref:`Dependencies <bitbake:bitbake-user-manual/bitbake-user-manual-execution:dependencies>`" sections in the
+      BitBake User Manual for additional information on tasks and
+      dependencies.
+
+   REQUIRED_DISTRO_FEATURES
+      When inheriting the
+      :ref:`distro_features_check <ref-classes-distro_features_check>`
+      class, this variable identifies distribution features that must exist
+      in the current configuration in order for the OpenEmbedded build
+      system to build the recipe. In other words, if the
+      ``REQUIRED_DISTRO_FEATURES`` variable lists a feature that does not
+      appear in ``DISTRO_FEATURES`` within the current configuration, an
+      error occurs and the build stops.
+
+   RM_WORK_EXCLUDE
+      With ``rm_work`` enabled, this variable specifies a list of recipes
+      whose work directories should not be removed. See the
+      ":ref:`rm_work.bbclass <ref-classes-rm-work>`" section for more
+      details.
+
+   ROOT_HOME
+      Defines the root home directory. By default, this directory is set as
+      follows in the BitBake configuration file:
+      ::
+
+         ROOT_HOME ??= "/home/root"
+
+      .. note::
+
+         This default value is likely used because some embedded solutions
+         prefer to have a read-only root filesystem and prefer to keep
+         writeable data in one place.
+
+      You can override the default by setting the variable in any layer or
+      in the ``local.conf`` file. Because the default is set using a "weak"
+      assignment (i.e. "??="), you can use either of the following forms to
+      define your override:
+      ::
+
+         ROOT_HOME = "/root"
+         ROOT_HOME ?= "/root"
+
+      These
+      override examples use ``/root``, which is probably the most commonly
+      used override.
+
+   ROOTFS
+      Indicates a filesystem image to include as the root filesystem.
+
+      The ``ROOTFS`` variable is an optional variable used with the
+      :ref:`image-live <ref-classes-image-live>` class.
+
+   ROOTFS_POSTINSTALL_COMMAND
+      Specifies a list of functions to call after the OpenEmbedded build
+      system has installed packages. You can specify functions separated by
+      semicolons:
+      ::
+
+         ROOTFS_POSTINSTALL_COMMAND += "function; ... "
+
+      If you need to pass the root filesystem path to a command within a
+      function, you can use ``${IMAGE_ROOTFS}``, which points to the
+      directory that becomes the root filesystem image. See the
+      :term:`IMAGE_ROOTFS` variable for more
+      information.
+
+   ROOTFS_POSTPROCESS_COMMAND
+      Specifies a list of functions to call once the OpenEmbedded build
+      system has created the root filesystem. You can specify functions
+      separated by semicolons:
+      ::
+
+         ROOTFS_POSTPROCESS_COMMAND += "function; ... "
+
+      If you need to pass the root filesystem path to a command within a
+      function, you can use ``${IMAGE_ROOTFS}``, which points to the
+      directory that becomes the root filesystem image. See the
+      :term:`IMAGE_ROOTFS` variable for more
+      information.
+
+   ROOTFS_POSTUNINSTALL_COMMAND
+      Specifies a list of functions to call after the OpenEmbedded build
+      system has removed unnecessary packages. When runtime package
+      management is disabled in the image, several packages are removed
+      including ``base-passwd``, ``shadow``, and ``update-alternatives``.
+      You can specify functions separated by semicolons:
+      ::
+
+         ROOTFS_POSTUNINSTALL_COMMAND += "function; ... "
+
+      If you need to pass the root filesystem path to a command within a
+      function, you can use ``${IMAGE_ROOTFS}``, which points to the
+      directory that becomes the root filesystem image. See the
+      :term:`IMAGE_ROOTFS` variable for more
+      information.
+
+   ROOTFS_PREPROCESS_COMMAND
+      Specifies a list of functions to call before the OpenEmbedded build
+      system has created the root filesystem. You can specify functions
+      separated by semicolons:
+      ::
+
+         ROOTFS_PREPROCESS_COMMAND += "function; ... "
+
+      If you need to pass the root filesystem path to a command within a
+      function, you can use ``${IMAGE_ROOTFS}``, which points to the
+      directory that becomes the root filesystem image. See the
+      :term:`IMAGE_ROOTFS` variable for more
+      information.
+
+   RPROVIDES
+      A list of package name aliases that a package also provides. These
+      aliases are useful for satisfying runtime dependencies of other
+      packages both during the build and on the target (as specified by
+      ``RDEPENDS``).
+
+      .. note::
+
+         A package's own name is implicitly already in its
+         RPROVIDES
+         list.
+
+      As with all package-controlling variables, you must always use the
+      variable in conjunction with a package name override. Here is an
+      example:
+      ::
+
+         RPROVIDES_${PN} = "widget-abi-2"
+
+   RRECOMMENDS
+      A list of packages that extends the usability of a package being
+      built. The package being built does not depend on this list of
+      packages in order to successfully build, but rather uses them for
+      extended usability. To specify runtime dependencies for packages, see
+      the ``RDEPENDS`` variable.
+
+      The package manager will automatically install the ``RRECOMMENDS``
+      list of packages when installing the built package. However, you can
+      prevent listed packages from being installed by using the
+      :term:`BAD_RECOMMENDATIONS`,
+      :term:`NO_RECOMMENDATIONS`, and
+      :term:`PACKAGE_EXCLUDE` variables.
+
+      Packages specified in ``RRECOMMENDS`` need not actually be produced.
+      However, a recipe must exist that provides each package, either
+      through the :term:`PACKAGES` or
+      :term:`PACKAGES_DYNAMIC` variables or the
+      :term:`RPROVIDES` variable, or an error will occur
+      during the build. If such a recipe does exist and the package is not
+      produced, the build continues without error.
+
+      Because the ``RRECOMMENDS`` variable applies to packages being built,
+      you should always attach an override to the variable to specify the
+      particular package whose usability is being extended. For example,
+      suppose you are building a development package that is extended to
+      support wireless functionality. In this case, you would use the
+      following:
+      ::
+
+         RRECOMMENDS_${PN}-dev += "wireless_package_name"
+
+      In the
+      example, the package name (``${PN}-dev``) must appear as it would in
+      the ``PACKAGES`` namespace before any renaming of the output package
+      by classes such as ``debian.bbclass``.
+
+      BitBake, which the OpenEmbedded build system uses, supports
+      specifying versioned recommends. Although the syntax varies depending
+      on the packaging format, BitBake hides these differences from you.
+      Here is the general syntax to specify versions with the
+      ``RRECOMMENDS`` variable:
+      ::
+
+         RRECOMMENDS_${PN} = "package (operator version)"
+
+      For ``operator``, you can specify the following:
+
+      - =
+      - <
+      - >
+      - <=
+      - >=
+
+      For example, the following sets up a recommend on version 1.2 or
+      greater of the package ``foo``:
+      ::
+
+         RRECOMMENDS_${PN} = "foo (>= 1.2)"
+
+   RREPLACES
+      A list of packages replaced by a package. The package manager uses
+      this variable to determine which package should be installed to
+      replace other package(s) during an upgrade. In order to also have the
+      other package(s) removed at the same time, you must add the name of
+      the other package to the ``RCONFLICTS`` variable.
+
+      As with all package-controlling variables, you must use this variable
+      in conjunction with a package name override. Here is an example:
+      ::
+
+         RREPLACES_${PN} = "other_package_being_replaced"
+
+      BitBake, which the OpenEmbedded build system uses, supports
+      specifying versioned replacements. Although the syntax varies
+      depending on the packaging format, BitBake hides these differences
+      from you. Here is the general syntax to specify versions with the
+      ``RREPLACES`` variable:
+      ::
+
+         RREPLACES_${PN} = "package (operator version)"
+
+      For ``operator``, you can specify the following:
+
+      - =
+      - <
+      - >
+      - <=
+      - >=
+
+      For example, the following sets up a replacement using version 1.2
+      or greater of the package ``foo``:
+      ::
+
+          RREPLACES_${PN} = "foo (>= 1.2)"
+
+   RSUGGESTS
+      A list of additional packages that you can suggest for installation
+      by the package manager at the time a package is installed. Not all
+      package managers support this functionality.
+
+      As with all package-controlling variables, you must always use this
+      variable in conjunction with a package name override. Here is an
+      example:
+      ::
+
+         RSUGGESTS_${PN} = "useful_package another_package"
+
+   S
+      The location in the :term:`Build Directory` where
+      unpacked recipe source code resides. By default, this directory is
+      ``${``\ :term:`WORKDIR`\ ``}/${``\ :term:`BPN`\ ``}-${``\ :term:`PV`\ ``}``,
+      where ``${BPN}`` is the base recipe name and ``${PV}`` is the recipe
+      version. If the source tarball extracts the code to a directory named
+      anything other than ``${BPN}-${PV}``, or if the source code is
+      fetched from an SCM such as Git or Subversion, then you must set
+      ``S`` in the recipe so that the OpenEmbedded build system knows where
+      to find the unpacked source.
+
+      As an example, assume a :term:`Source Directory`
+      top-level folder named ``poky`` and a default Build Directory at
+      ``poky/build``. In this case, the work directory the build system
+      uses to keep the unpacked recipe for ``db`` is the following:
+      ::
+
+         poky/build/tmp/work/qemux86-poky-linux/db/5.1.19-r3/db-5.1.19
+
+      The unpacked source code resides in the ``db-5.1.19`` folder.
+
+      This next example assumes a Git repository. By default, Git
+      repositories are cloned to ``${WORKDIR}/git`` during
+      :ref:`ref-tasks-fetch`. Since this path is different
+      from the default value of ``S``, you must set it specifically so the
+      source can be located:
+      ::
+
+         SRC_URI = "git://path/to/repo.git"
+         S = "${WORKDIR}/git"
+
+   SANITY_REQUIRED_UTILITIES
+      Specifies a list of command-line utilities that should be checked for
+      during the initial sanity checking process when running BitBake. If
+      any of the utilities are not installed on the build host, then
+      BitBake immediately exits with an error.
+
+   SANITY_TESTED_DISTROS
+      A list of the host distribution identifiers that the build system has
+      been tested against. Identifiers consist of the host distributor ID
+      followed by the release, as reported by the ``lsb_release`` tool or
+      as read from ``/etc/lsb-release``. Separate the list items with
+      explicit newline characters (``\n``). If ``SANITY_TESTED_DISTROS`` is
+      not empty and the current value of
+      :term:`NATIVELSBSTRING` does not appear in the
+      list, then the build system reports a warning that indicates the
+      current host distribution has not been tested as a build host.
+
+   SDK_ARCH
+      The target architecture for the SDK. Typically, you do not directly
+      set this variable. Instead, use :term:`SDKMACHINE`.
+
+   SDK_DEPLOY
+      The directory set up and used by the
+      :ref:`populate_sdk_base <ref-classes-populate-sdk>` class to which
+      the SDK is deployed. The ``populate_sdk_base`` class defines
+      ``SDK_DEPLOY`` as follows:
+      ::
+
+         SDK_DEPLOY = "${TMPDIR}/deploy/sdk"
+
+   SDK_DIR
+      The parent directory used by the OpenEmbedded build system when
+      creating SDK output. The
+      :ref:`populate_sdk_base <ref-classes-populate-sdk-*>` class defines
+      the variable as follows:
+      ::
+
+         SDK_DIR = "${WORKDIR}/sdk"
+
+      .. note::
+
+         The
+         SDK_DIR
+         directory is a temporary directory as it is part of
+         WORKDIR
+         . The final output directory is
+         SDK_DEPLOY
+         .
+
+   SDK_EXT_TYPE
+      Controls whether or not shared state artifacts are copied into the
+      extensible SDK. The default value of "full" copies all of the
+      required shared state artifacts into the extensible SDK. The value
+      "minimal" leaves these artifacts out of the SDK.
+
+      .. note::
+
+         If you set the variable to "minimal", you need to ensure
+         SSTATE_MIRRORS
+         is set in the SDK's configuration to enable the artifacts to be
+         fetched as needed.
+
+   SDK_HOST_MANIFEST
+      The manifest file for the host part of the SDK. This file lists all
+      the installed packages that make up the host part of the SDK. The
+      file contains package information on a line-per-package basis as
+      follows:
+      ::
+
+         packagename packagearch version
+
+      The :ref:`populate_sdk_base <ref-classes-populate-sdk-*>` class
+      defines the manifest file as follows:
+      ::
+
+         SDK_HOST_MANIFEST = "${SDK_DEPLOY}/${TOOLCHAIN_OUTPUTNAME}.host.manifest"
+
+      The location is derived using the :term:`SDK_DEPLOY` and
+      :term:`TOOLCHAIN_OUTPUTNAME` variables.
+
+   SDK_INCLUDE_PKGDATA
+      When set to "1", specifies to include the packagedata for all recipes
+      in the "world" target in the extensible SDK. Including this data
+      allows the ``devtool search`` command to find these recipes in search
+      results, as well as allows the ``devtool add`` command to map
+      dependencies more effectively.
+
+      .. note::
+
+         Enabling the
+         SDK_INCLUDE_PKGDATA
+         variable significantly increases build time because all of world
+         needs to be built. Enabling the variable also slightly increases
+         the size of the extensible SDK.
+
+   SDK_INCLUDE_TOOLCHAIN
+      When set to "1", specifies to include the toolchain in the extensible
+      SDK. Including the toolchain is useful particularly when
+      :term:`SDK_EXT_TYPE` is set to "minimal" to keep
+      the SDK reasonably small but you still want to provide a usable
+      toolchain. For example, suppose you want to use the toolchain from an
+      IDE or from other tools and you do not want to perform additional
+      steps to install the toolchain.
+
+      The ``SDK_INCLUDE_TOOLCHAIN`` variable defaults to "0" if
+      ``SDK_EXT_TYPE`` is set to "minimal", and defaults to "1" if
+      ``SDK_EXT_TYPE`` is set to "full".
+
+   SDK_INHERIT_BLACKLIST
+      A list of classes to remove from the :term:`INHERIT`
+      value globally within the extensible SDK configuration. The
+      :ref:`populate-sdk-ext <ref-classes-populate-sdk-*>` class sets the
+      default value:
+      ::
+
+         SDK_INHERIT_BLACKLIST ?= "buildhistory icecc"
+
+      Some classes are not generally applicable within the extensible SDK
+      context. You can use this variable to disable those classes.
+
+      For additional information on how to customize the extensible SDK's
+      configuration, see the
+      ":ref:`sdk-manual/sdk-appendix-customizing:configuring the extensible sdk`"
+      section in the Yocto Project Application Development and the
+      Extensible Software Development Kit (eSDK) manual.
+
+   SDK_LOCAL_CONF_BLACKLIST
+      A list of variables not allowed through from the OpenEmbedded build
+      system configuration into the extensible SDK configuration. Usually,
+      these are variables that are specific to the machine on which the
+      build system is running and thus would be potentially problematic
+      within the extensible SDK.
+
+      By default, ``SDK_LOCAL_CONF_BLACKLIST`` is set in the
+      :ref:`populate-sdk-ext <ref-classes-populate-sdk-*>` class and
+      excludes the following variables:
+
+      - :term:`CONF_VERSION`
+      - :term:`BB_NUMBER_THREADS`
+      - :term:`bitbake:BB_NUMBER_PARSE_THREADS`
+      - :term:`PARALLEL_MAKE`
+      - :term:`PRSERV_HOST`
+      - :term:`SSTATE_MIRRORS` :term:`DL_DIR`
+      - :term:`SSTATE_DIR` :term:`TMPDIR`
+      - :term:`BB_SERVER_TIMEOUT`
+
+      For additional information on how to customize the extensible SDK's
+      configuration, see the
+      ":ref:`sdk-manual/sdk-appendix-customizing:configuring the extensible sdk`"
+      section in the Yocto Project Application Development and the
+      Extensible Software Development Kit (eSDK) manual.
+
+   SDK_LOCAL_CONF_WHITELIST
+      A list of variables allowed through from the OpenEmbedded build
+      system configuration into the extensible SDK configuration. By
+      default, the list of variables is empty and is set in the
+      :ref:`populate-sdk-ext <ref-classes-populate-sdk-*>` class.
+
+      This list overrides the variables specified using the
+      :term:`SDK_LOCAL_CONF_BLACKLIST`
+      variable as well as any variables identified by automatic
+      blacklisting due to the "/" character being found at the start of the
+      value, which is usually indicative of being a path and thus might not
+      be valid on the system where the SDK is installed.
+
+      For additional information on how to customize the extensible SDK's
+      configuration, see the
+      ":ref:`sdk-manual/sdk-appendix-customizing:configuring the extensible sdk`"
+      section in the Yocto Project Application Development and the
+      Extensible Software Development Kit (eSDK) manual.
+
+   SDK_NAME
+      The base name for SDK output files. The name is derived from the
+      :term:`DISTRO`, :term:`TCLIBC`,
+      :term:`SDK_ARCH`,
+      :term:`IMAGE_BASENAME`, and
+      :term:`TUNE_PKGARCH` variables:
+      ::
+
+         SDK_NAME = "${DISTRO}-${TCLIBC}-${SDK_ARCH}-${IMAGE_BASENAME}-${TUNE_PKGARCH}"
+
+   SDK_OS
+      Specifies the operating system for which the SDK will be built. The
+      default value is the value of :term:`BUILD_OS`.
+
+   SDK_OUTPUT
+      The location used by the OpenEmbedded build system when creating SDK
+      output. The :ref:`populate_sdk_base <ref-classes-populate-sdk-*>`
+      class defines the variable as follows:
+      ::
+
+         SDK_DIR = "${WORKDIR}/sdk"
+         SDK_OUTPUT = "${SDK_DIR}/image"
+         SDK_DEPLOY = "${DEPLOY_DIR}/sdk"
+
+      .. note::
+
+         The SDK_OUTPUT directory is a temporary directory as it is part of
+         WORKDIR by way of SDK_DIR. The final output directory is
+         SDK_DEPLOY.
+
+   SDK_PACKAGE_ARCHS
+      Specifies a list of architectures compatible with the SDK machine.
+      This variable is set automatically and should not normally be
+      hand-edited. Entries are separated using spaces and listed in order
+      of priority. The default value for ``SDK_PACKAGE_ARCHS`` is "all any
+      noarch ${SDK_ARCH}-${SDKPKGSUFFIX}".
+
+   SDK_POSTPROCESS_COMMAND
+      Specifies a list of functions to call once the OpenEmbedded build
+      system creates the SDK. You can specify functions separated by
+      semicolons: SDK_POSTPROCESS_COMMAND += "function; ... "
+
+      If you need to pass an SDK path to a command within a function, you
+      can use ``${SDK_DIR}``, which points to the parent directory used by
+      the OpenEmbedded build system when creating SDK output. See the
+      :term:`SDK_DIR` variable for more information.
+
+   SDK_PREFIX
+      The toolchain binary prefix used for ``nativesdk`` recipes. The
+      OpenEmbedded build system uses the ``SDK_PREFIX`` value to set the
+      :term:`TARGET_PREFIX` when building
+      ``nativesdk`` recipes. The default value is "${SDK_SYS}-".
+
+   SDK_RECRDEP_TASKS
+      A list of shared state tasks added to the extensible SDK. By default,
+      the following tasks are added:
+
+      - do_populate_lic
+      - do_package_qa
+      - do_populate_sysroot
+      - do_deploy
+
+      Despite the default value of "" for the
+      ``SDK_RECRDEP_TASKS`` variable, the above four tasks are always added
+      to the SDK. To specify tasks beyond these four, you need to use the
+      ``SDK_RECRDEP_TASKS`` variable (e.g. you are defining additional
+      tasks that are needed in order to build
+      :term:`SDK_TARGETS`).
+
+   SDK_SYS
+      Specifies the system, including the architecture and the operating
+      system, for which the SDK will be built.
+
+      The OpenEmbedded build system automatically sets this variable based
+      on :term:`SDK_ARCH`,
+      :term:`SDK_VENDOR`, and
+      :term:`SDK_OS`. You do not need to set the ``SDK_SYS``
+      variable yourself.
+
+   SDK_TARGET_MANIFEST
+      The manifest file for the target part of the SDK. This file lists all
+      the installed packages that make up the target part of the SDK. The
+      file contains package information on a line-per-package basis as
+      follows:
+      ::
+
+         packagename packagearch version
+
+      The :ref:`populate_sdk_base <ref-classes-populate-sdk-*>` class
+      defines the manifest file as follows:
+      ::
+
+         SDK_TARGET_MANIFEST = "${SDK_DEPLOY}/${TOOLCHAIN_OUTPUTNAME}.target.manifest"
+
+      The location is derived using the :term:`SDK_DEPLOY` and
+      :term:`TOOLCHAIN_OUTPUTNAME` variables.
+
+   SDK_TARGETS
+      A list of targets to install from shared state as part of the
+      standard or extensible SDK installation. The default value is "${PN}"
+      (i.e. the image from which the SDK is built).
+
+      The ``SDK_TARGETS`` variable is an internal variable and typically
+      would not be changed.
+
+   SDK_TITLE
+      The title to be printed when running the SDK installer. By default,
+      this title is based on the :term:`DISTRO_NAME` or
+      :term:`DISTRO` variable and is set in the
+      :ref:`populate_sdk_base <ref-classes-populate-sdk-*>` class as
+      follows:
+      ::
+
+         SDK_TITLE ??= "${@d.getVar('DISTRO_NAME') or d.getVar('DISTRO')} SDK"
+
+      For the default distribution "poky",
+      ``SDK_TITLE`` is set to "Poky (Yocto Project Reference Distro)".
+
+      For information on how to change this default title, see the
+      ":ref:`sdk-manual/sdk-appendix-customizing:changing the extensible sdk installer title`"
+      section in the Yocto Project Application Development and the
+      Extensible Software Development Kit (eSDK) manual.
+
+   SDK_UPDATE_URL
+      An optional URL for an update server for the extensible SDK. If set,
+      the value is used as the default update server when running
+      ``devtool sdk-update`` within the extensible SDK.
+
+   SDK_VENDOR
+      Specifies the name of the SDK vendor.
+
+   SDK_VERSION
+      Specifies the version of the SDK. The distribution configuration file
+      (e.g. ``/meta-poky/conf/distro/poky.conf``) defines the
+      ``SDK_VERSION`` as follows:
+      ::
+
+         SDK_VERSION = "${@d.getVar('DISTRO_VERSION').replace('snapshot-${DATE}','snapshot')}"
+
+      For additional information, see the
+      :term:`DISTRO_VERSION` and
+      :term:`DATE` variables.
+
+   SDKEXTPATH
+      The default installation directory for the Extensible SDK. By
+      default, this directory is based on the :term:`DISTRO`
+      variable and is set in the
+      :ref:`populate_sdk_base <ref-classes-populate-sdk-*>` class as
+      follows:
+      ::
+
+         SDKEXTPATH ??= "~/${@d.getVar('DISTRO')}_sdk"
+
+      For the
+      default distribution "poky", the ``SDKEXTPATH`` is set to "poky_sdk".
+
+      For information on how to change this default directory, see the
+      ":ref:`sdk-manual/sdk-appendix-customizing:changing the default sdk installation directory`"
+      section in the Yocto Project Application Development and the
+      Extensible Software Development Kit (eSDK) manual.
+
+   SDKIMAGE_FEATURES
+      Equivalent to ``IMAGE_FEATURES``. However, this variable applies to
+      the SDK generated from an image using the following command:
+      ::
+
+         $ bitbake -c populate_sdk imagename
+
+   SDKMACHINE
+      The machine for which the SDK is built. In other words, the SDK is
+      built such that it runs on the target you specify with the
+      ``SDKMACHINE`` value. The value points to a corresponding ``.conf``
+      file under ``conf/machine-sdk/``.
+
+      You can use "i686" and "x86_64" as possible values for this variable.
+      The variable defaults to "i686" and is set in the local.conf file in
+      the Build Directory.
+      ::
+
+         SDKMACHINE ?= "i686"
+
+      .. note::
+
+         You cannot set the
+         SDKMACHINE
+         variable in your distribution configuration file. If you do, the
+         configuration will not take affect.
+
+   SDKPATH
+      Defines the path offered to the user for installation of the SDK that
+      is generated by the OpenEmbedded build system. The path appears as
+      the default location for installing the SDK when you run the SDK's
+      installation script. You can override the offered path when you run
+      the script.
+
+   SDKTARGETSYSROOT
+      The full path to the sysroot used for cross-compilation within an SDK
+      as it will be when installed into the default
+      :term:`SDKPATH`.
+
+   SECTION
+      The section in which packages should be categorized. Package
+      management utilities can make use of this variable.
+
+   SELECTED_OPTIMIZATION
+      Specifies the optimization flags passed to the C compiler when
+      building for the target. The flags are passed through the default
+      value of the :term:`TARGET_CFLAGS` variable.
+
+      The ``SELECTED_OPTIMIZATION`` variable takes the value of
+      ``FULL_OPTIMIZATION`` unless ``DEBUG_BUILD`` = "1". If that is the
+      case, the value of ``DEBUG_OPTIMIZATION`` is used.
+
+   SERIAL_CONSOLE
+      Defines a serial console (TTY) to enable using
+      `getty <https://en.wikipedia.org/wiki/Getty_(Unix)>`__. Provide a
+      value that specifies the baud rate followed by the TTY device name
+      separated by a space. You cannot specify more than one TTY device:
+      ::
+
+         SERIAL_CONSOLE = "115200 ttyS0"
+
+      .. note::
+
+         The
+         SERIAL_CONSOLE
+         variable is deprecated. Please use the
+         SERIAL_CONSOLES
+         variable.
+
+   SERIAL_CONSOLES
+      Defines a serial console (TTY) to enable using
+      `getty <https://en.wikipedia.org/wiki/Getty_(Unix)>`__. Provide a
+      value that specifies the baud rate followed by the TTY device name
+      separated by a semicolon. Use spaces to separate multiple devices:
+      ::
+
+         SERIAL_CONSOLES = "115200;ttyS0 115200;ttyS1"
+
+   SERIAL_CONSOLES_CHECK
+      Specifies serial consoles, which must be listed in
+      :term:`SERIAL_CONSOLES`, to check against
+      ``/proc/console`` before enabling them using getty. This variable
+      allows aliasing in the format: <device>:<alias>. If a device was
+      listed as "sclp_line0" in ``/dev/`` and "ttyS0" was listed in
+      ``/proc/console``, you would do the following: ::
+
+         SERIAL_CONSOLES_CHECK = "slcp_line0:ttyS0"
+
+      This variable is currently only supported with SysVinit (i.e. not
+      with systemd).
+
+   SIGGEN_EXCLUDE_SAFE_RECIPE_DEPS
+      A list of recipe dependencies that should not be used to determine
+      signatures of tasks from one recipe when they depend on tasks from
+      another recipe. For example: ::
+
+         SIGGEN_EXCLUDE_SAFE_RECIPE_DEPS += "intone->mplayer2"
+
+      In the previous example, ``intone`` depends on ``mplayer2``.
+
+      You can use the special token ``"*"`` on the left-hand side of the
+      dependency to match all recipes except the one on the right-hand
+      side. Here is an example: ::
+
+         SIGGEN_EXCLUDE_SAFE_RECIPE_DEPS += "*->quilt-native"
+
+      In the previous example, all recipes except ``quilt-native`` ignore
+      task signatures from the ``quilt-native`` recipe when determining
+      their task signatures.
+
+      Use of this variable is one mechanism to remove dependencies that
+      affect task signatures and thus force rebuilds when a recipe changes.
+
+      .. note::
+
+         If you add an inappropriate dependency for a recipe relationship,
+         the software might break during runtime if the interface of the
+         second recipe was changed after the first recipe had been built.
+
+   SIGGEN_EXCLUDERECIPES_ABISAFE
+      A list of recipes that are completely stable and will never change.
+      The ABI for the recipes in the list are presented by output from the
+      tasks run to build the recipe. Use of this variable is one way to
+      remove dependencies from one recipe on another that affect task
+      signatures and thus force rebuilds when the recipe changes.
+
+      .. note::
+
+         If you add an inappropriate variable to this list, the software
+         might break at runtime if the interface of the recipe was changed
+         after the other had been built.
+
+   SITEINFO_BITS
+      Specifies the number of bits for the target system CPU. The value
+      should be either "32" or "64".
+
+   SITEINFO_ENDIANNESS
+      Specifies the endian byte order of the target system. The value
+      should be either "le" for little-endian or "be" for big-endian.
+
+   SKIP_FILEDEPS
+      Enables removal of all files from the "Provides" section of an RPM
+      package. Removal of these files is required for packages containing
+      prebuilt binaries and libraries such as ``libstdc++`` and ``glibc``.
+
+      To enable file removal, set the variable to "1" in your
+      ``conf/local.conf`` configuration file in your:
+      :term:`Build Directory`.
+      ::
+
+         SKIP_FILEDEPS = "1"
+
+   SOC_FAMILY
+      Groups together machines based upon the same family of SOC (System On
+      Chip). You typically set this variable in a common ``.inc`` file that
+      you include in the configuration files of all the machines.
+
+      .. note::
+
+         You must include
+         conf/machine/include/soc-family.inc
+         for this variable to appear in
+         MACHINEOVERRIDES
+         .
+
+   SOLIBS
+      Defines the suffix for shared libraries used on the target platform.
+      By default, this suffix is ".so.*" for all Linux-based systems and is
+      defined in the ``meta/conf/bitbake.conf`` configuration file.
+
+      You will see this variable referenced in the default values of
+      ``FILES_${PN}``.
+
+   SOLIBSDEV
+      Defines the suffix for the development symbolic link (symlink) for
+      shared libraries on the target platform. By default, this suffix is
+      ".so" for Linux-based systems and is defined in the
+      ``meta/conf/bitbake.conf`` configuration file.
+
+      You will see this variable referenced in the default values of
+      ``FILES_${PN}-dev``.
+
+   SOURCE_MIRROR_FETCH
+      When you are fetching files to create a mirror of sources (i.e.
+      creating a source mirror), setting ``SOURCE_MIRROR_FETCH`` to "1" in
+      your ``local.conf`` configuration file ensures the source for all
+      recipes are fetched regardless of whether or not a recipe is
+      compatible with the configuration. A recipe is considered
+      incompatible with the currently configured machine when either or
+      both the :term:`COMPATIBLE_MACHINE`
+      variable and :term:`COMPATIBLE_HOST` variables
+      specify compatibility with a machine other than that of the current
+      machine or host.
+
+      .. note::
+
+         Do not set the
+         SOURCE_MIRROR_FETCH
+         variable unless you are creating a source mirror. In other words,
+         do not set the variable during a normal build.
+
+   SOURCE_MIRROR_URL
+      Defines your own :term:`PREMIRRORS` from which to
+      first fetch source before attempting to fetch from the upstream
+      specified in :term:`SRC_URI`.
+
+      To use this variable, you must globally inherit the
+      :ref:`own-mirrors <ref-classes-own-mirrors>` class and then provide
+      the URL to your mirrors. Here is the general syntax:
+      ::
+
+         INHERIT += "own-mirrors"
+         SOURCE_MIRROR_URL = "http://example.com/my_source_mirror"
+
+      .. note::
+
+         You can specify only a single URL in
+         SOURCE_MIRROR_URL
+         .
+
+   SPDXLICENSEMAP
+      Maps commonly used license names to their SPDX counterparts found in
+      ``meta/files/common-licenses/``. For the default ``SPDXLICENSEMAP``
+      mappings, see the ``meta/conf/licenses.conf`` file.
+
+      For additional information, see the :term:`LICENSE`
+      variable.
+
+   SPECIAL_PKGSUFFIX
+      A list of prefixes for :term:`PN` used by the OpenEmbedded
+      build system to create variants of recipes or packages. The list
+      specifies the prefixes to strip off during certain circumstances such
+      as the generation of the :term:`BPN` variable.
+
+   SPL_BINARY
+      The file type for the Secondary Program Loader (SPL). Some devices
+      use an SPL from which to boot (e.g. the BeagleBone development
+      board). For such cases, you can declare the file type of the SPL
+      binary in the ``u-boot.inc`` include file, which is used in the
+      U-Boot recipe.
+
+      The SPL file type is set to "null" by default in the ``u-boot.inc``
+      file as follows:
+      ::
+
+         # Some versions of u-boot build an SPL (Second Program Loader) image that
+         # should be packaged along with the u-boot binary as well as placed in the
+         # deploy directory. For those versions they can set the following variables
+         # to allow packaging the SPL.
+         SPL_BINARY ?= ""
+         SPL_BINARYNAME ?= "${@os.path.basename(d.getVar("SPL_BINARY"))}"
+         SPL_IMAGE ?= "${SPL_BINARYNAME}-${MACHINE}-${PV}-${PR}"
+         SPL_SYMLINK ?= "${SPL_BINARYNAME}-${MACHINE}"
+
+      The ``SPL_BINARY`` variable helps form
+      various ``SPL_*`` variables used by the OpenEmbedded build system.
+
+      See the BeagleBone machine configuration example in the
+      ":ref:`dev-manual/dev-manual-common-tasks:adding a layer using the \`\`bitbake-layers\`\` script`"
+      section in the Yocto Project Board Support Package Developer's Guide
+      for additional information.
+
+   SRC_URI
+      The list of source files - local or remote. This variable tells the
+      OpenEmbedded build system which bits to pull in for the build and how
+      to pull them in. For example, if the recipe or append file only needs
+      to fetch a tarball from the Internet, the recipe or append file uses
+      a single ``SRC_URI`` entry. On the other hand, if the recipe or
+      append file needs to fetch a tarball, apply two patches, and include
+      a custom file, the recipe or append file would include four instances
+      of the variable.
+
+      The following list explains the available URI protocols. URI
+      protocols are highly dependent on particular BitBake Fetcher
+      submodules. Depending on the fetcher BitBake uses, various URL
+      parameters are employed. For specifics on the supported Fetchers, see
+      the ":ref:`Fetchers <bitbake:bb-fetchers>`" section in the
+      BitBake User Manual.
+
+      -  ``file://`` - Fetches files, which are usually files shipped
+         with the :term:`Metadata`, from the local machine (e.g.
+         :ref:`patch <patching-dev-environment>` files).
+         The path is relative to the :term:`FILESPATH`
+         variable. Thus, the build system searches, in order, from the
+         following directories, which are assumed to be a subdirectories of
+         the directory in which the recipe file (``.bb``) or append file
+         (``.bbappend``) resides:
+
+         -  ``${BPN}`` - The base recipe name without any special suffix
+            or version numbers.
+
+         -  ``${BP}`` - ``${BPN}-${PV}``. The base recipe name and
+            version but without any special package name suffix.
+
+         -  *files -* Files within a directory, which is named ``files``
+            and is also alongside the recipe or append file.
+
+         .. note::
+
+            If you want the build system to pick up files specified through
+            a
+            SRC_URI
+            statement from your append file, you need to be sure to extend
+            the
+            FILESPATH
+            variable by also using the
+            FILESEXTRAPATHS
+            variable from within your append file.
+
+      -  ``bzr://`` - Fetches files from a Bazaar revision control
+         repository.
+
+      -  ``git://`` - Fetches files from a Git revision control
+         repository.
+
+      -  ``osc://`` - Fetches files from an OSC (OpenSUSE Build service)
+         revision control repository.
+
+      -  ``repo://`` - Fetches files from a repo (Git) repository.
+
+      -  ``ccrc://`` - Fetches files from a ClearCase repository.
+
+      -  ``http://`` - Fetches files from the Internet using ``http``.
+
+      -  ``https://`` - Fetches files from the Internet using ``https``.
+
+      -  ``ftp://`` - Fetches files from the Internet using ``ftp``.
+
+      -  ``cvs://`` - Fetches files from a CVS revision control
+         repository.
+
+      -  ``hg://`` - Fetches files from a Mercurial (``hg``) revision
+         control repository.
+
+      -  ``p4://`` - Fetches files from a Perforce (``p4``) revision
+         control repository.
+
+      -  ``ssh://`` - Fetches files from a secure shell.
+
+      -  ``svn://`` - Fetches files from a Subversion (``svn``) revision
+         control repository.
+
+      -  ``npm://`` - Fetches JavaScript modules from a registry.
+
+      Standard and recipe-specific options for ``SRC_URI`` exist. Here are
+      standard options:
+
+      -  ``apply`` - Whether to apply the patch or not. The default
+         action is to apply the patch.
+
+      -  ``striplevel`` - Which striplevel to use when applying the
+         patch. The default level is 1.
+
+      -  ``patchdir`` - Specifies the directory in which the patch should
+         be applied. The default is ``${``\ :term:`S`\ ``}``.
+
+      Here are options specific to recipes building code from a revision
+      control system:
+
+      -  ``mindate`` - Apply the patch only if
+         :term:`SRCDATE` is equal to or greater than
+         ``mindate``.
+
+      -  ``maxdate`` - Apply the patch only if ``SRCDATE`` is not later
+         than ``maxdate``.
+
+      -  ``minrev`` - Apply the patch only if ``SRCREV`` is equal to or
+         greater than ``minrev``.
+
+      -  ``maxrev`` - Apply the patch only if ``SRCREV`` is not later
+         than ``maxrev``.
+
+      -  ``rev`` - Apply the patch only if ``SRCREV`` is equal to
+         ``rev``.
+
+      -  ``notrev`` - Apply the patch only if ``SRCREV`` is not equal to
+         ``rev``.
+
+      Here are some additional options worth mentioning:
+
+      -  ``unpack`` - Controls whether or not to unpack the file if it is
+         an archive. The default action is to unpack the file.
+
+      -  ``destsuffix`` - Places the file (or extracts its contents) into
+         the specified subdirectory of :term:`WORKDIR` when
+         the Git fetcher is used.
+
+      -  ``subdir`` - Places the file (or extracts its contents) into the
+         specified subdirectory of ``WORKDIR`` when the local (``file://``)
+         fetcher is used.
+
+      -  ``localdir`` - Places the file (or extracts its contents) into
+         the specified subdirectory of ``WORKDIR`` when the CVS fetcher is
+         used.
+
+      -  ``subpath`` - Limits the checkout to a specific subpath of the
+         tree when using the Git fetcher is used.
+
+      -  ``name`` - Specifies a name to be used for association with
+         ``SRC_URI`` checksums when you have more than one file specified
+         in ``SRC_URI``.
+
+      -  ``downloadfilename`` - Specifies the filename used when storing
+         the downloaded file.
+
+   SRC_URI_OVERRIDES_PACKAGE_ARCH
+      By default, the OpenEmbedded build system automatically detects
+      whether ``SRC_URI`` contains files that are machine-specific. If so,
+      the build system automatically changes ``PACKAGE_ARCH``. Setting this
+      variable to "0" disables this behavior.
+
+   SRCDATE
+      The date of the source code used to build the package. This variable
+      applies only if the source was fetched from a Source Code Manager
+      (SCM).
+
+   SRCPV
+      Returns the version string of the current package. This string is
+      used to help define the value of :term:`PV`.
+
+      The ``SRCPV`` variable is defined in the ``meta/conf/bitbake.conf``
+      configuration file in the :term:`Source Directory` as
+      follows:
+      ::
+
+         SRCPV = "${@bb.fetch2.get_srcrev(d)}"
+
+      Recipes that need to define ``PV`` do so with the help of the
+      ``SRCPV``. For example, the ``ofono`` recipe (``ofono_git.bb``)
+      located in ``meta/recipes-connectivity`` in the Source Directory
+      defines ``PV`` as follows:
+      ::
+
+         PV = "0.12-git${SRCPV}"
+
+   SRCREV
+      The revision of the source code used to build the package. This
+      variable applies to Subversion, Git, Mercurial, and Bazaar only. Note
+      that if you want to build a fixed revision and you want to avoid
+      performing a query on the remote repository every time BitBake parses
+      your recipe, you should specify a ``SRCREV`` that is a full revision
+      identifier and not just a tag.
+
+      .. note::
+
+         For information on limitations when inheriting the latest revision
+         of software using
+         SRCREV
+         , see the
+         AUTOREV
+         variable description and the "
+         Automatically Incrementing a Binary Package Revision Number
+         " section, which is in the Yocto Project Development Tasks Manual.
+
+   SSTATE_DIR
+      The directory for the shared state cache.
+
+   SSTATE_MIRROR_ALLOW_NETWORK
+      If set to "1", allows fetches from mirrors that are specified in
+      :term:`SSTATE_MIRRORS` to work even when
+      fetching from the network is disabled by setting ``BB_NO_NETWORK`` to
+      "1". Using the ``SSTATE_MIRROR_ALLOW_NETWORK`` variable is useful if
+      you have set ``SSTATE_MIRRORS`` to point to an internal server for
+      your shared state cache, but you want to disable any other fetching
+      from the network.
+
+   SSTATE_MIRRORS
+      Configures the OpenEmbedded build system to search other mirror
+      locations for prebuilt cache data objects before building out the
+      data. This variable works like fetcher :term:`MIRRORS`
+      and :term:`PREMIRRORS` and points to the cache
+      locations to check for the shared state (sstate) objects.
+
+      You can specify a filesystem directory or a remote URL such as HTTP
+      or FTP. The locations you specify need to contain the shared state
+      cache (sstate-cache) results from previous builds. The sstate-cache
+      you point to can also be from builds on other machines.
+
+      When pointing to sstate build artifacts on another machine that uses
+      a different GCC version for native builds, you must configure
+      ``SSTATE_MIRRORS`` with a regular expression that maps local search
+      paths to server paths. The paths need to take into account
+      :term:`NATIVELSBSTRING` set by the
+      :ref:`uninative <ref-classes-uninative>` class. For example, the
+      following maps the local search path ``universal-4.9`` to the
+      server-provided path server_url_sstate_path:
+      ::
+
+         SSTATE_MIRRORS ?= "file://universal-4.9/(.*) http://server_url_sstate_path/universal-4.8/\1 \n"
+
+      If a mirror uses the same structure as
+      :term:`SSTATE_DIR`, you need to add "PATH" at the
+      end as shown in the examples below. The build system substitutes the
+      correct path within the directory structure.
+      ::
+
+         SSTATE_MIRRORS ?= "\
+             file://.* http://someserver.tld/share/sstate/PATH;downloadfilename=PATH \n \
+             file://.* file:///some-local-dir/sstate/PATH"
+
+   SSTATE_SCAN_FILES
+      Controls the list of files the OpenEmbedded build system scans for
+      hardcoded installation paths. The variable uses a space-separated
+      list of filenames (not paths) with standard wildcard characters
+      allowed.
+
+      During a build, the OpenEmbedded build system creates a shared state
+      (sstate) object during the first stage of preparing the sysroots.
+      That object is scanned for hardcoded paths for original installation
+      locations. The list of files that are scanned for paths is controlled
+      by the ``SSTATE_SCAN_FILES`` variable. Typically, recipes add files
+      they want to be scanned to the value of ``SSTATE_SCAN_FILES`` rather
+      than the variable being comprehensively set. The
+      :ref:`sstate <ref-classes-sstate>` class specifies the default list
+      of files.
+
+      For details on the process, see the
+      :ref:`staging <ref-classes-staging>` class.
+
+   STAGING_BASE_LIBDIR_NATIVE
+      Specifies the path to the ``/lib`` subdirectory of the sysroot
+      directory for the build host.
+
+   STAGING_BASELIBDIR
+      Specifies the path to the ``/lib`` subdirectory of the sysroot
+      directory for the target for which the current recipe is being built
+      (:term:`STAGING_DIR_HOST`).
+
+   STAGING_BINDIR
+      Specifies the path to the ``/usr/bin`` subdirectory of the sysroot
+      directory for the target for which the current recipe is being built
+      (:term:`STAGING_DIR_HOST`).
+
+   STAGING_BINDIR_CROSS
+      Specifies the path to the directory containing binary configuration
+      scripts. These scripts provide configuration information for other
+      software that wants to make use of libraries or include files
+      provided by the software associated with the script.
+
+      .. note::
+
+         This style of build configuration has been largely replaced by
+         pkg-config
+         . Consequently, if
+         pkg-config
+         is supported by the library to which you are linking, it is
+         recommended you use
+         pkg-config
+         instead of a provided configuration script.
+
+   STAGING_BINDIR_NATIVE
+      Specifies the path to the ``/usr/bin`` subdirectory of the sysroot
+      directory for the build host.
+
+   STAGING_DATADIR
+      Specifies the path to the ``/usr/share`` subdirectory of the sysroot
+      directory for the target for which the current recipe is being built
+      (:term:`STAGING_DIR_HOST`).
+
+   STAGING_DATADIR_NATIVE
+      Specifies the path to the ``/usr/share`` subdirectory of the sysroot
+      directory for the build host.
+
+   STAGING_DIR
+      Helps construct the ``recipe-sysroots`` directory, which is used
+      during packaging.
+
+      For information on how staging for recipe-specific sysroots occurs,
+      see the :ref:`ref-tasks-populate_sysroot`
+      task, the ":ref:`sdk-manual/sdk-extensible:sharing files between recipes`"
+      section in the Yocto Project Development Tasks Manual, the
+      ":ref:`configuration-compilation-and-staging-dev-environment`"
+      section in the Yocto Project Overview and Concepts Manual, and the
+      :term:`SYSROOT_DIRS` variable.
+
+      .. note::
+
+         Recipes should never write files directly under the
+         STAGING_DIR
+         directory because the OpenEmbedded build system manages the
+         directory automatically. Instead, files should be installed to
+         ${
+         D
+         }
+         within your recipe's
+         do_install
+         task and then the OpenEmbedded build system will stage a subset of
+         those files into the sysroot.
+
+   STAGING_DIR_HOST
+      Specifies the path to the sysroot directory for the system on which
+      the component is built to run (the system that hosts the component).
+      For most recipes, this sysroot is the one in which that recipe's
+      :ref:`ref-tasks-populate_sysroot` task copies
+      files. Exceptions include ``-native`` recipes, where the
+      ``do_populate_sysroot`` task instead uses
+      :term:`STAGING_DIR_NATIVE`. Depending on
+      the type of recipe and the build target, ``STAGING_DIR_HOST`` can
+      have the following values:
+
+      -  For recipes building for the target machine, the value is
+         "${:term:`STAGING_DIR`}/${:term:`MACHINE`}".
+
+      -  For native recipes building for the build host, the value is empty
+         given the assumption that when building for the build host, the
+         build host's own directories should be used.
+
+         .. note::
+
+            ``-native`` recipes are not installed into host paths like such
+            as ``/usr``. Rather, these recipes are installed into
+            ``STAGING_DIR_NATIVE``. When compiling ``-native`` recipes,
+            standard build environment variables such as
+            :term:`CPPFLAGS` and
+            :term:`CFLAGS` are set up so that both host paths
+            and ``STAGING_DIR_NATIVE`` are searched for libraries and
+            headers using, for example, GCC's ``-isystem`` option.
+
+            Thus, the emphasis is that the ``STAGING_DIR*`` variables
+            should be viewed as input variables by tasks such as
+            :ref:`ref-tasks-configure`,
+            :ref:`ref-tasks-compile`, and
+            :ref:`ref-tasks-install`. Having the real system
+            root correspond to ``STAGING_DIR_HOST`` makes conceptual sense
+            for ``-native`` recipes, as they make use of host headers and
+            libraries.
+
+   STAGING_DIR_NATIVE
+      Specifies the path to the sysroot directory used when building
+      components that run on the build host itself.
+
+   STAGING_DIR_TARGET
+      Specifies the path to the sysroot used for the system for which the
+      component generates code. For components that do not generate code,
+      which is the majority, ``STAGING_DIR_TARGET`` is set to match
+      :term:`STAGING_DIR_HOST`.
+
+      Some recipes build binaries that can run on the target system but
+      those binaries in turn generate code for another different system
+      (e.g. cross-canadian recipes). Using terminology from GNU, the
+      primary system is referred to as the "HOST" and the secondary, or
+      different, system is referred to as the "TARGET". Thus, the binaries
+      run on the "HOST" system and generate binaries for the "TARGET"
+      system. The ``STAGING_DIR_HOST`` variable points to the sysroot used
+      for the "HOST" system, while ``STAGING_DIR_TARGET`` points to the
+      sysroot used for the "TARGET" system.
+
+   STAGING_ETCDIR_NATIVE
+      Specifies the path to the ``/etc`` subdirectory of the sysroot
+      directory for the build host.
+
+   STAGING_EXECPREFIXDIR
+      Specifies the path to the ``/usr`` subdirectory of the sysroot
+      directory for the target for which the current recipe is being built
+      (:term:`STAGING_DIR_HOST`).
+
+   STAGING_INCDIR
+      Specifies the path to the ``/usr/include`` subdirectory of the
+      sysroot directory for the target for which the current recipe being
+      built (:term:`STAGING_DIR_HOST`).
+
+   STAGING_INCDIR_NATIVE
+      Specifies the path to the ``/usr/include`` subdirectory of the
+      sysroot directory for the build host.
+
+   STAGING_KERNEL_BUILDDIR
+      Points to the directory containing the kernel build artifacts.
+      Recipes building software that needs to access kernel build artifacts
+      (e.g. ``systemtap-uprobes``) can look in the directory specified with
+      the ``STAGING_KERNEL_BUILDDIR`` variable to find these artifacts
+      after the kernel has been built.
+
+   STAGING_KERNEL_DIR
+      The directory with kernel headers that are required to build
+      out-of-tree modules.
+
+   STAGING_LIBDIR
+      Specifies the path to the ``/usr/lib`` subdirectory of the sysroot
+      directory for the target for which the current recipe is being built
+      (:term:`STAGING_DIR_HOST`).
+
+   STAGING_LIBDIR_NATIVE
+      Specifies the path to the ``/usr/lib`` subdirectory of the sysroot
+      directory for the build host.
+
+   STAMP
+      Specifies the base path used to create recipe stamp files. The path
+      to an actual stamp file is constructed by evaluating this string and
+      then appending additional information. Currently, the default
+      assignment for ``STAMP`` as set in the ``meta/conf/bitbake.conf``
+      file is:
+      ::
+
+         STAMP = "${STAMPS_DIR}/${MULTIMACH_TARGET_SYS}/${PN}/${EXTENDPE}${PV}-${PR}"
+
+      For information on how BitBake uses stamp files to determine if a
+      task should be rerun, see the
+      ":ref:`overview-manual/overview-manual-concepts:stamp files and the rerunning of tasks`"
+      section in the Yocto Project Overview and Concepts Manual.
+
+      See :term:`STAMPS_DIR`,
+      :term:`MULTIMACH_TARGET_SYS`,
+      :term:`PN`, :term:`EXTENDPE`,
+      :term:`PV`, and :term:`PR` for related variable
+      information.
+
+   STAMPS_DIR
+      Specifies the base directory in which the OpenEmbedded build system
+      places stamps. The default directory is ``${TMPDIR}/stamps``.
+
+   STRIP
+      The minimal command and arguments to run ``strip``, which is used to
+      strip symbols.
+
+   SUMMARY
+      The short (72 characters or less) summary of the binary package for
+      packaging systems such as ``opkg``, ``rpm``, or ``dpkg``. By default,
+      ``SUMMARY`` is used to define the
+      :term:`DESCRIPTION` variable if ``DESCRIPTION`` is
+      not set in the recipe.
+
+   SVNDIR
+      The directory in which files checked out of a Subversion system are
+      stored.
+
+   SYSLINUX_DEFAULT_CONSOLE
+      Specifies the kernel boot default console. If you want to use a
+      console other than the default, set this variable in your recipe as
+      follows where "X" is the console number you want to use:
+      ::
+
+         SYSLINUX_DEFAULT_CONSOLE = "console=ttyX"
+
+      The :ref:`syslinux <ref-classes-syslinux>` class initially sets
+      this variable to null but then checks for a value later.
+
+   SYSLINUX_OPTS
+      Lists additional options to add to the syslinux file. You need to set
+      this variable in your recipe. If you want to list multiple options,
+      separate the options with a semicolon character (``;``).
+
+      The :ref:`syslinux <ref-classes-syslinux>` class uses this variable
+      to create a set of options.
+
+   SYSLINUX_SERIAL
+      Specifies the alternate serial port or turns it off. To turn off
+      serial, set this variable to an empty string in your recipe. The
+      variable's default value is set in the
+      :ref:`syslinux <ref-classes-syslinux>` class as follows:
+      ::
+
+         SYSLINUX_SERIAL ?= "0 115200"
+
+      The class checks for and uses the variable as needed.
+
+   SYSLINUX_SPLASH
+      An ``.LSS`` file used as the background for the VGA boot menu when
+      you use the boot menu. You need to set this variable in your recipe.
+
+      The :ref:`syslinux <ref-classes-syslinux>` class checks for this
+      variable and if found, the OpenEmbedded build system installs the
+      splash screen.
+
+   SYSLINUX_SERIAL_TTY
+      Specifies the alternate console=tty... kernel boot argument. The
+      variable's default value is set in the
+      :ref:`syslinux <ref-classes-syslinux>` class as follows:
+      ::
+
+         SYSLINUX_SERIAL_TTY ?= "console=ttyS0,115200"
+
+      The class checks for and uses the variable as needed.
+
+   SYSROOT_DESTDIR
+      Points to the temporary directory under the work directory (default
+      "``${``\ :term:`WORKDIR`\ ``}/sysroot-destdir``")
+      where the files populated into the sysroot are assembled during the
+      :ref:`ref-tasks-populate_sysroot` task.
+
+   SYSROOT_DIRS
+      Directories that are staged into the sysroot by the
+      :ref:`ref-tasks-populate_sysroot` task. By
+      default, the following directories are staged:
+      ::
+
+         SYSROOT_DIRS = " \
+             ${includedir} \
+             ${libdir} \
+             ${base_libdir} \
+             ${nonarch_base_libdir} \
+             ${datadir} \
+             "
+
+   SYSROOT_DIRS_BLACKLIST
+      Directories that are not staged into the sysroot by the
+      :ref:`ref-tasks-populate_sysroot` task. You
+      can use this variable to exclude certain subdirectories of
+      directories listed in :term:`SYSROOT_DIRS` from
+      staging. By default, the following directories are not staged:
+      ::
+
+         SYSROOT_DIRS_BLACKLIST = " \
+             ${mandir} \
+             ${docdir} \
+             ${infodir} \
+             ${datadir}/locale \
+             ${datadir}/applications \
+             ${datadir}/fonts \
+             ${datadir}/pixmaps \
+             "
+
+   SYSROOT_DIRS_NATIVE
+      Extra directories staged into the sysroot by the
+      :ref:`ref-tasks-populate_sysroot` task for
+      ``-native`` recipes, in addition to those specified in
+      :term:`SYSROOT_DIRS`. By default, the following
+      extra directories are staged:
+      ::
+
+         SYSROOT_DIRS_NATIVE = " \
+             ${bindir} \
+             ${sbindir} \
+             ${base_bindir} \
+             ${base_sbindir} \
+             ${libexecdir} \
+             ${sysconfdir} \
+             ${localstatedir} \
+             "
+
+      .. note::
+
+         Programs built by
+         -native
+         recipes run directly from the sysroot (
+         STAGING_DIR_NATIVE
+         ), which is why additional directories containing program
+         executables and supporting files need to be staged.
+
+   SYSROOT_PREPROCESS_FUNCS
+      A list of functions to execute after files are staged into the
+      sysroot. These functions are usually used to apply additional
+      processing on the staged files, or to stage additional files.
+
+   SYSTEMD_AUTO_ENABLE
+      When inheriting the :ref:`systemd <ref-classes-systemd>` class,
+      this variable specifies whether the specified service in
+      :term:`SYSTEMD_SERVICE` should start
+      automatically or not. By default, the service is enabled to
+      automatically start at boot time. The default setting is in the
+      :ref:`systemd <ref-classes-systemd>` class as follows:
+      ::
+
+         SYSTEMD_AUTO_ENABLE ??= "enable"
+
+      You can disable the service by setting the variable to "disable".
+
+   SYSTEMD_BOOT_CFG
+      When :term:`EFI_PROVIDER` is set to
+      "systemd-boot", the ``SYSTEMD_BOOT_CFG`` variable specifies the
+      configuration file that should be used. By default, the
+      :ref:`systemd-boot <ref-classes-systemd-boot>` class sets the
+      ``SYSTEMD_BOOT_CFG`` as follows:
+      ::
+
+         SYSTEMD_BOOT_CFG ?= "${:term:`S`}/loader.conf"
+
+      For information on Systemd-boot, see the `Systemd-boot
+      documentation <http://www.freedesktop.org/wiki/Software/systemd/systemd-boot/>`__.
+
+   SYSTEMD_BOOT_ENTRIES
+      When :term:`EFI_PROVIDER` is set to
+      "systemd-boot", the ``SYSTEMD_BOOT_ENTRIES`` variable specifies a
+      list of entry files (``*.conf``) to install that contain one boot
+      entry per file. By default, the
+      :ref:`systemd-boot <ref-classes-systemd-boot>` class sets the
+      ``SYSTEMD_BOOT_ENTRIES`` as follows:
+      ::
+
+          SYSTEMD_BOOT_ENTRIES ?= ""
+
+      For information on Systemd-boot, see the `Systemd-boot
+      documentation <http://www.freedesktop.org/wiki/Software/systemd/systemd-boot/>`__.
+
+   SYSTEMD_BOOT_TIMEOUT
+      When :term:`EFI_PROVIDER` is set to
+      "systemd-boot", the ``SYSTEMD_BOOT_TIMEOUT`` variable specifies the
+      boot menu timeout in seconds. By default, the
+      :ref:`systemd-boot <ref-classes-systemd-boot>` class sets the
+      ``SYSTEMD_BOOT_TIMEOUT`` as follows:
+      ::
+
+         SYSTEMD_BOOT_TIMEOUT ?= "10"
+
+      For information on Systemd-boot, see the `Systemd-boot
+      documentation <http://www.freedesktop.org/wiki/Software/systemd/systemd-boot/>`__.
+
+   SYSTEMD_PACKAGES
+      When inheriting the :ref:`systemd <ref-classes-systemd>` class,
+      this variable locates the systemd unit files when they are not found
+      in the main recipe's package. By default, the ``SYSTEMD_PACKAGES``
+      variable is set such that the systemd unit files are assumed to
+      reside in the recipes main package:
+      ::
+
+         SYSTEMD_PACKAGES ?= "${PN}"
+
+      If these unit files are not in this recipe's main package, you need
+      to use ``SYSTEMD_PACKAGES`` to list the package or packages in which
+      the build system can find the systemd unit files.
+
+   SYSTEMD_SERVICE
+      When inheriting the :ref:`systemd <ref-classes-systemd>` class,
+      this variable specifies the systemd service name for a package.
+
+      When you specify this file in your recipe, use a package name
+      override to indicate the package to which the value applies. Here is
+      an example from the connman recipe:
+      ::
+
+         SYSTEMD_SERVICE_${PN} = "connman.service"
+
+   SYSVINIT_ENABLED_GETTYS
+      When using
+      :ref:`SysVinit <dev-manual/dev-manual-common-tasks:enabling system services>`,
+      specifies a space-separated list of the virtual terminals that should
+      run a `getty <http://en.wikipedia.org/wiki/Getty_%28Unix%29>`__
+      (allowing login), assuming :term:`USE_VT` is not set to
+      "0".
+
+      The default value for ``SYSVINIT_ENABLED_GETTYS`` is "1" (i.e. only
+      run a getty on the first virtual terminal).
+
+   T
+      This variable points to a directory were BitBake places temporary
+      files, which consist mostly of task logs and scripts, when building a
+      particular recipe. The variable is typically set as follows:
+      ::
+
+         T = "${WORKDIR}/temp"
+
+      The :term:`WORKDIR` is the directory into which
+      BitBake unpacks and builds the recipe. The default ``bitbake.conf``
+      file sets this variable.
+
+      The ``T`` variable is not to be confused with the
+      :term:`TMPDIR` variable, which points to the root of
+      the directory tree where BitBake places the output of an entire
+      build.
+
+   TARGET_ARCH
+      The target machine's architecture. The OpenEmbedded build system
+      supports many architectures. Here is an example list of architectures
+      supported. This list is by no means complete as the architecture is
+      configurable:
+
+      - arm
+      - i586
+      - x86_64
+      - powerpc
+      - powerpc64
+      - mips
+      - mipsel
+
+      For additional information on machine architectures, see the
+      :term:`TUNE_ARCH` variable.
+
+   TARGET_AS_ARCH
+      Specifies architecture-specific assembler flags for the target
+      system. ``TARGET_AS_ARCH`` is initialized from
+      :term:`TUNE_ASARGS` by default in the BitBake
+      configuration file (``meta/conf/bitbake.conf``):
+      ::
+
+         TARGET_AS_ARCH = "${TUNE_ASARGS}"
+
+   TARGET_CC_ARCH
+      Specifies architecture-specific C compiler flags for the target
+      system. ``TARGET_CC_ARCH`` is initialized from
+      :term:`TUNE_CCARGS` by default.
+
+      .. note::
+
+         It is a common workaround to append
+         LDFLAGS
+         to
+         TARGET_CC_ARCH
+         in recipes that build software for the target that would not
+         otherwise respect the exported
+         LDFLAGS
+         variable.
+
+   TARGET_CC_KERNEL_ARCH
+      This is a specific kernel compiler flag for a CPU or Application
+      Binary Interface (ABI) tune. The flag is used rarely and only for
+      cases where a userspace :term:`TUNE_CCARGS` is not
+      compatible with the kernel compilation. The ``TARGET_CC_KERNEL_ARCH``
+      variable allows the kernel (and associated modules) to use a
+      different configuration. See the
+      ``meta/conf/machine/include/arm/feature-arm-thumb.inc`` file in the
+      :term:`Source Directory` for an example.
+
+   TARGET_CFLAGS
+      Specifies the flags to pass to the C compiler when building for the
+      target. When building in the target context,
+      :term:`CFLAGS` is set to the value of this variable by
+      default.
+
+      Additionally, the SDK's environment setup script sets the ``CFLAGS``
+      variable in the environment to the ``TARGET_CFLAGS`` value so that
+      executables built using the SDK also have the flags applied.
+
+   TARGET_CPPFLAGS
+      Specifies the flags to pass to the C pre-processor (i.e. to both the
+      C and the C++ compilers) when building for the target. When building
+      in the target context, :term:`CPPFLAGS` is set to the
+      value of this variable by default.
+
+      Additionally, the SDK's environment setup script sets the
+      ``CPPFLAGS`` variable in the environment to the ``TARGET_CPPFLAGS``
+      value so that executables built using the SDK also have the flags
+      applied.
+
+   TARGET_CXXFLAGS
+      Specifies the flags to pass to the C++ compiler when building for the
+      target. When building in the target context,
+      :term:`CXXFLAGS` is set to the value of this variable
+      by default.
+
+      Additionally, the SDK's environment setup script sets the
+      ``CXXFLAGS`` variable in the environment to the ``TARGET_CXXFLAGS``
+      value so that executables built using the SDK also have the flags
+      applied.
+
+   TARGET_FPU
+      Specifies the method for handling FPU code. For FPU-less targets,
+      which include most ARM CPUs, the variable must be set to "soft". If
+      not, the kernel emulation gets used, which results in a performance
+      penalty.
+
+   TARGET_LD_ARCH
+      Specifies architecture-specific linker flags for the target system.
+      ``TARGET_LD_ARCH`` is initialized from
+      :term:`TUNE_LDARGS` by default in the BitBake
+      configuration file (``meta/conf/bitbake.conf``):
+      ::
+
+         TARGET_LD_ARCH = "${TUNE_LDARGS}"
+
+   TARGET_LDFLAGS
+      Specifies the flags to pass to the linker when building for the
+      target. When building in the target context,
+      :term:`LDFLAGS` is set to the value of this variable
+      by default.
+
+      Additionally, the SDK's environment setup script sets the
+      :term:`LDFLAGS` variable in the environment to the
+      ``TARGET_LDFLAGS`` value so that executables built using the SDK also
+      have the flags applied.
+
+   TARGET_OS
+      Specifies the target's operating system. The variable can be set to
+      "linux" for glibc-based systems (GNU C Library) and to "linux-musl"
+      for musl libc. For ARM/EABI targets, "linux-gnueabi" and
+      "linux-musleabi" possible values exist.
+
+   TARGET_PREFIX
+      Specifies the prefix used for the toolchain binary target tools.
+
+      Depending on the type of recipe and the build target,
+      ``TARGET_PREFIX`` is set as follows:
+
+      -  For recipes building for the target machine, the value is
+         "${:term:`TARGET_SYS`}-".
+
+      -  For native recipes, the build system sets the variable to the
+         value of ``BUILD_PREFIX``.
+
+      -  For native SDK recipes (``nativesdk``), the build system sets the
+         variable to the value of ``SDK_PREFIX``.
+
+   TARGET_SYS
+      Specifies the system, including the architecture and the operating
+      system, for which the build is occurring in the context of the
+      current recipe.
+
+      The OpenEmbedded build system automatically sets this variable based
+      on :term:`TARGET_ARCH`,
+      :term:`TARGET_VENDOR`, and
+      :term:`TARGET_OS` variables.
+
+      .. note::
+
+         You do not need to set the TARGET_SYS variable yourself.
+
+      Consider these two examples:
+
+      -  Given a native recipe on a 32-bit, x86 machine running Linux, the
+         value is "i686-linux".
+
+      -  Given a recipe being built for a little-endian, MIPS target
+         running Linux, the value might be "mipsel-linux".
+
+   TARGET_VENDOR
+      Specifies the name of the target vendor.
+
+   TCLIBC
+      Specifies the GNU standard C library (``libc``) variant to use during
+      the build process. This variable replaces ``POKYLIBC``, which is no
+      longer supported.
+
+      You can select "glibc", "musl", "newlib", or "baremetal"
+
+   TCLIBCAPPEND
+      Specifies a suffix to be appended onto the
+      :term:`TMPDIR` value. The suffix identifies the
+      ``libc`` variant for building. When you are building for multiple
+      variants with the same :term:`Build Directory`, this
+      mechanism ensures that output for different ``libc`` variants is kept
+      separate to avoid potential conflicts.
+
+      In the ``defaultsetup.conf`` file, the default value of
+      ``TCLIBCAPPEND`` is "-${TCLIBC}". However, distros such as poky,
+      which normally only support one ``libc`` variant, set
+      ``TCLIBCAPPEND`` to "" in their distro configuration file resulting
+      in no suffix being applied.
+
+   TCMODE
+      Specifies the toolchain selector. ``TCMODE`` controls the
+      characteristics of the generated packages and images by telling the
+      OpenEmbedded build system which toolchain profile to use. By default,
+      the OpenEmbedded build system builds its own internal toolchain. The
+      variable's default value is "default", which uses that internal
+      toolchain.
+
+      .. note::
+
+         If
+         TCMODE
+         is set to a value other than "default", then it is your
+         responsibility to ensure that the toolchain is compatible with the
+         default toolchain. Using older or newer versions of these
+         components might cause build problems. See the Release Notes for
+         the Yocto Project release for the specific components with which
+         the toolchain must be compatible. To access the Release Notes, go
+         to the
+         Downloads
+         page on the Yocto Project website and click on the "RELEASE
+         INFORMATION" link for the appropriate release.
+
+      The ``TCMODE`` variable is similar to :term:`TCLIBC`,
+      which controls the variant of the GNU standard C library (``libc``)
+      used during the build process: ``glibc`` or ``musl``.
+
+      With additional layers, it is possible to use a pre-compiled external
+      toolchain. One example is the Sourcery G++ Toolchain. The support for
+      this toolchain resides in the separate Mentor Graphics
+      ``meta-sourcery`` layer at
+      http://github.com/MentorEmbedded/meta-sourcery/.
+
+      The layer's ``README`` file contains information on how to use the
+      Sourcery G++ Toolchain as an external toolchain. In summary, you must
+      be sure to add the layer to your ``bblayers.conf`` file in front of
+      the ``meta`` layer and then set the ``EXTERNAL_TOOLCHAIN`` variable
+      in your ``local.conf`` file to the location in which you installed
+      the toolchain.
+
+      The fundamentals used for this example apply to any external
+      toolchain. You can use ``meta-sourcery`` as a template for adding
+      support for other external toolchains.
+
+   TEST_EXPORT_DIR
+      The location the OpenEmbedded build system uses to export tests when
+      the :term:`TEST_EXPORT_ONLY` variable is set
+      to "1".
+
+      The ``TEST_EXPORT_DIR`` variable defaults to
+      ``"${TMPDIR}/testimage/${PN}"``.
+
+   TEST_EXPORT_ONLY
+      Specifies to export the tests only. Set this variable to "1" if you
+      do not want to run the tests but you want them to be exported in a
+      manner that you to run them outside of the build system.
+
+   TEST_LOG_DIR
+      Holds the SSH log and the boot log for QEMU machines. The
+      ``TEST_LOG_DIR`` variable defaults to ``"${WORKDIR}/testimage"``.
+
+      .. note::
+
+         Actual test results reside in the task log (
+         log.do_testimage
+         ), which is in the
+         ${WORKDIR}/temp/
+         directory.
+
+   TEST_POWERCONTROL_CMD
+      For automated hardware testing, specifies the command to use to
+      control the power of the target machine under test. Typically, this
+      command would point to a script that performs the appropriate action
+      (e.g. interacting with a web-enabled power strip). The specified
+      command should expect to receive as the last argument "off", "on" or
+      "cycle" specifying to power off, on, or cycle (power off and then
+      power on) the device, respectively.
+
+   TEST_POWERCONTROL_EXTRA_ARGS
+      For automated hardware testing, specifies additional arguments to
+      pass through to the command specified in
+      :term:`TEST_POWERCONTROL_CMD`. Setting
+      ``TEST_POWERCONTROL_EXTRA_ARGS`` is optional. You can use it if you
+      wish, for example, to separate the machine-specific and
+      non-machine-specific parts of the arguments.
+
+   TEST_QEMUBOOT_TIMEOUT
+      The time in seconds allowed for an image to boot before automated
+      runtime tests begin to run against an image. The default timeout
+      period to allow the boot process to reach the login prompt is 500
+      seconds. You can specify a different value in the ``local.conf``
+      file.
+
+      For more information on testing images, see the
+      ":ref:`dev-manual/dev-manual-common-tasks:performing automated runtime testing`"
+      section in the Yocto Project Development Tasks Manual.
+
+   TEST_SERIALCONTROL_CMD
+      For automated hardware testing, specifies the command to use to
+      connect to the serial console of the target machine under test. This
+      command simply needs to connect to the serial console and forward
+      that connection to standard input and output as any normal terminal
+      program does.
+
+      For example, to use the Picocom terminal program on serial device
+      ``/dev/ttyUSB0`` at 115200bps, you would set the variable as follows:
+      ::
+
+         TEST_SERIALCONTROL_CMD = "picocom /dev/ttyUSB0 -b 115200"
+
+   TEST_SERIALCONTROL_EXTRA_ARGS
+      For automated hardware testing, specifies additional arguments to
+      pass through to the command specified in
+      :term:`TEST_SERIALCONTROL_CMD`. Setting
+      ``TEST_SERIALCONTROL_EXTRA_ARGS`` is optional. You can use it if you
+      wish, for example, to separate the machine-specific and
+      non-machine-specific parts of the command.
+
+   TEST_SERVER_IP
+      The IP address of the build machine (host machine). This IP address
+      is usually automatically detected. However, if detection fails, this
+      variable needs to be set to the IP address of the build machine (i.e.
+      where the build is taking place).
+
+      .. note::
+
+         The
+         TEST_SERVER_IP
+         variable is only used for a small number of tests such as the
+         "dnf" test suite, which needs to download packages from
+         WORKDIR/oe-rootfs-repo
+         .
+
+   TEST_TARGET
+      Specifies the target controller to use when running tests against a
+      test image. The default controller to use is "qemu":
+      ::
+
+         TEST_TARGET = "qemu"
+
+      A target controller is a class that defines how an image gets
+      deployed on a target and how a target is started. A layer can extend
+      the controllers by adding a module in the layer's
+      ``/lib/oeqa/controllers`` directory and by inheriting the
+      ``BaseTarget`` class, which is an abstract class that cannot be used
+      as a value of ``TEST_TARGET``.
+
+      You can provide the following arguments with ``TEST_TARGET``:
+
+      -  *"qemu":* Boots a QEMU image and runs the tests. See the
+         ":ref:`qemu-image-enabling-tests`" section
+         in the Yocto Project Development Tasks Manual for more
+         information.
+
+      -  *"simpleremote":* Runs the tests on target hardware that is
+         already up and running. The hardware can be on the network or it
+         can be a device running an image on QEMU. You must also set
+         :term:`TEST_TARGET_IP` when you use
+         "simpleremote".
+
+         .. note::
+
+            This argument is defined in
+            meta/lib/oeqa/controllers/simpleremote.py
+            .
+
+      For information on running tests on hardware, see the
+      ":ref:`hardware-image-enabling-tests`"
+      section in the Yocto Project Development Tasks Manual.
+
+   TEST_TARGET_IP
+      The IP address of your hardware under test. The ``TEST_TARGET_IP``
+      variable has no effect when :term:`TEST_TARGET` is
+      set to "qemu".
+
+      When you specify the IP address, you can also include a port. Here is
+      an example:
+      ::
+
+         TEST_TARGET_IP = "192.168.1.4:2201"
+
+      Specifying a port is
+      useful when SSH is started on a non-standard port or in cases when
+      your hardware under test is behind a firewall or network that is not
+      directly accessible from your host and you need to do port address
+      translation.
+
+   TEST_SUITES
+      An ordered list of tests (modules) to run against an image when
+      performing automated runtime testing.
+
+      The OpenEmbedded build system provides a core set of tests that can
+      be used against images.
+
+      .. note::
+
+         Currently, there is only support for running these tests under
+         QEMU.
+
+      Tests include ``ping``, ``ssh``, ``df`` among others. You can add
+      your own tests to the list of tests by appending ``TEST_SUITES`` as
+      follows:
+      ::
+
+         TEST_SUITES_append = " mytest"
+
+      Alternatively, you can
+      provide the "auto" option to have all applicable tests run against
+      the image.
+      ::
+
+         TEST_SUITES_append = " auto"
+
+      Using this option causes the
+      build system to automatically run tests that are applicable to the
+      image. Tests that are not applicable are skipped.
+
+      The order in which tests are run is important. Tests that depend on
+      another test must appear later in the list than the test on which
+      they depend. For example, if you append the list of tests with two
+      tests (``test_A`` and ``test_B``) where ``test_B`` is dependent on
+      ``test_A``, then you must order the tests as follows:
+      ::
+
+         TEST_SUITES = "test_A test_B"
+
+      For more information on testing images, see the
+      ":ref:`dev-manual/dev-manual-common-tasks:performing automated runtime testing`"
+      section in the Yocto Project Development Tasks Manual.
+
+   TESTIMAGE_AUTO
+      Automatically runs the series of automated tests for images when an
+      image is successfully built. Setting ``TESTIMAGE_AUTO`` to "1" causes
+      any image that successfully builds to automatically boot under QEMU.
+      Using the variable also adds in dependencies so that any SDK for
+      which testing is requested is automatically built first.
+
+      These tests are written in Python making use of the ``unittest``
+      module, and the majority of them run commands on the target system
+      over ``ssh``. You can set this variable to "1" in your ``local.conf``
+      file in the :term:`Build Directory` to have the
+      OpenEmbedded build system automatically run these tests after an
+      image successfully builds:
+
+         TESTIMAGE_AUTO = "1"
+
+      For more information
+      on enabling, running, and writing these tests, see the
+      ":ref:`dev-manual/dev-manual-common-tasks:performing automated runtime testing`"
+      section in the Yocto Project Development Tasks Manual and the
+      ":ref:`testimage*.bbclass <ref-classes-testimage*>`" section.
+
+   THISDIR
+      The directory in which the file BitBake is currently parsing is
+      located. Do not manually set this variable.
+
+   TIME
+      The time the build was started. Times appear using the hour, minute,
+      and second (HMS) format (e.g. "140159" for one minute and fifty-nine
+      seconds past 1400 hours).
+
+   TMPDIR
+      This variable is the base directory the OpenEmbedded build system
+      uses for all build output and intermediate files (other than the
+      shared state cache). By default, the ``TMPDIR`` variable points to
+      ``tmp`` within the :term:`Build Directory`.
+
+      If you want to establish this directory in a location other than the
+      default, you can uncomment and edit the following statement in the
+      ``conf/local.conf`` file in the :term:`Source Directory`:
+      ::
+
+         #TMPDIR = "${TOPDIR}/tmp"
+
+      An example use for this scenario is to set ``TMPDIR`` to a local disk,
+      which does not use NFS, while having the Build Directory use NFS.
+
+      The filesystem used by ``TMPDIR`` must have standard filesystem
+      semantics (i.e. mixed-case files are unique, POSIX file locking, and
+      persistent inodes). Due to various issues with NFS and bugs in some
+      implementations, NFS does not meet this minimum requirement.
+      Consequently, ``TMPDIR`` cannot be on NFS.
+
+   TOOLCHAIN_HOST_TASK
+      This variable lists packages the OpenEmbedded build system uses when
+      building an SDK, which contains a cross-development environment. The
+      packages specified by this variable are part of the toolchain set
+      that runs on the :term:`SDKMACHINE`, and each
+      package should usually have the prefix ``nativesdk-``. For example,
+      consider the following command when building an SDK:
+      ::
+
+         $ bitbake -c populate_sdk imagename
+
+      In this case, a default list of packages is
+      set in this variable, but you can add additional packages to the
+      list. See the
+      ":ref:`sdk-manual/sdk-appendix-customizing-standard:adding individual packages to the standard sdk`" section
+      in the Yocto Project Application Development and the Extensible
+      Software Development Kit (eSDK) manual for more information.
+
+      For background information on cross-development toolchains in the
+      Yocto Project development environment, see the
+      ":ref:`sdk-manual/sdk-intro:the cross-development toolchain`"
+      section in the Yocto Project Overview and Concepts Manual. For
+      information on setting up a cross-development environment, see the
+      :doc:`../sdk-manual/sdk-manual` manual.
+
+   TOOLCHAIN_OUTPUTNAME
+      This variable defines the name used for the toolchain output. The
+      :ref:`populate_sdk_base <ref-classes-populate-sdk-*>` class sets
+      the ``TOOLCHAIN_OUTPUTNAME`` variable as follows:
+      ::
+
+         TOOLCHAIN_OUTPUTNAME ?= "${SDK_NAME}-toolchain-${SDK_VERSION}"
+
+      See
+      the :term:`SDK_NAME` and
+      :term:`SDK_VERSION` variables for additional
+      information.
+
+   TOOLCHAIN_TARGET_TASK
+      This variable lists packages the OpenEmbedded build system uses when
+      it creates the target part of an SDK (i.e. the part built for the
+      target hardware), which includes libraries and headers. Use this
+      variable to add individual packages to the part of the SDK that runs
+      on the target. See the
+      ":ref:`sdk-manual/sdk-appendix-customizing-standard:adding individual packages to the standard sdk`" section
+      in the Yocto Project Application Development and the Extensible
+      Software Development Kit (eSDK) manual for more information.
+
+      For background information on cross-development toolchains in the
+      Yocto Project development environment, see the
+      ":ref:`sdk-manual/sdk-intro:the cross-development toolchain`"
+      section in the Yocto Project Overview and Concepts Manual. For
+      information on setting up a cross-development environment, see the
+      :doc:`../sdk-manual/sdk-manual` manual.
+
+   TOPDIR
+      The top-level :term:`Build Directory`. BitBake
+      automatically sets this variable when you initialize your build
+      environment using ````` <#structure-core-script>`__.
+
+   TRANSLATED_TARGET_ARCH
+      A sanitized version of :term:`TARGET_ARCH`. This
+      variable is used where the architecture is needed in a value where
+      underscores are not allowed, for example within package filenames. In
+      this case, dash characters replace any underscore characters used in
+      ``TARGET_ARCH``.
+
+      Do not edit this variable.
+
+   TUNE_ARCH
+      The GNU canonical architecture for a specific architecture (i.e.
+      ``arm``, ``armeb``, ``mips``, ``mips64``, and so forth). BitBake uses
+      this value to setup configuration.
+
+      ``TUNE_ARCH`` definitions are specific to a given architecture. The
+      definitions can be a single static definition, or can be dynamically
+      adjusted. You can see details for a given CPU family by looking at
+      the architecture's ``README`` file. For example, the
+      ``meta/conf/machine/include/mips/README`` file in the
+      :term:`Source Directory` provides information for
+      ``TUNE_ARCH`` specific to the ``mips`` architecture.
+
+      ``TUNE_ARCH`` is tied closely to
+      :term:`TARGET_ARCH`, which defines the target
+      machine's architecture. The BitBake configuration file
+      (``meta/conf/bitbake.conf``) sets ``TARGET_ARCH`` as follows:
+      ::
+
+         TARGET_ARCH = "${TUNE_ARCH}"
+
+      The following list, which is by no means complete since architectures
+      are configurable, shows supported machine architectures:
+
+      - arm
+      - i586
+      - x86_64
+      - powerpc
+      - powerpc64
+      - mips
+      - mipsel
+
+   TUNE_ASARGS
+      Specifies architecture-specific assembler flags for the target
+      system. The set of flags is based on the selected tune features.
+      ``TUNE_ASARGS`` is set using the tune include files, which are
+      typically under ``meta/conf/machine/include/`` and are influenced
+      through :term:`TUNE_FEATURES`. For example, the
+      ``meta/conf/machine/include/x86/arch-x86.inc`` file defines the flags
+      for the x86 architecture as follows:
+      ::
+
+         TUNE_ASARGS += "${@bb.utils.contains("TUNE_FEATURES", "mx32", "-x32", "", d)}"
+
+      .. note::
+
+         Board Support Packages (BSPs) select the tune. The selected tune,
+         in turn, affects the tune variables themselves (i.e. the tune can
+         supply its own set of flags).
+
+   TUNE_CCARGS
+      Specifies architecture-specific C compiler flags for the target
+      system. The set of flags is based on the selected tune features.
+      ``TUNE_CCARGS`` is set using the tune include files, which are
+      typically under ``meta/conf/machine/include/`` and are influenced
+      through :term:`TUNE_FEATURES`.
+
+      .. note::
+
+         Board Support Packages (BSPs) select the tune. The selected tune,
+         in turn, affects the tune variables themselves (i.e. the tune can
+         supply its own set of flags).
+
+   TUNE_LDARGS
+      Specifies architecture-specific linker flags for the target system.
+      The set of flags is based on the selected tune features.
+      ``TUNE_LDARGS`` is set using the tune include files, which are
+      typically under ``meta/conf/machine/include/`` and are influenced
+      through :term:`TUNE_FEATURES`. For example, the
+      ``meta/conf/machine/include/x86/arch-x86.inc`` file defines the flags
+      for the x86 architecture as follows:
+      ::
+
+         TUNE_LDARGS += "${@bb.utils.contains("TUNE_FEATURES", "mx32", "-m elf32_x86_64", "", d)}"
+
+      .. note::
+
+         Board Support Packages (BSPs) select the tune. The selected tune,
+         in turn, affects the tune variables themselves (i.e. the tune can
+         supply its own set of flags).
+
+   TUNE_FEATURES
+      Features used to "tune" a compiler for optimal use given a specific
+      processor. The features are defined within the tune files and allow
+      arguments (i.e. ``TUNE_*ARGS``) to be dynamically generated based on
+      the features.
+
+      The OpenEmbedded build system verifies the features to be sure they
+      are not conflicting and that they are supported.
+
+      The BitBake configuration file (``meta/conf/bitbake.conf``) defines
+      ``TUNE_FEATURES`` as follows:
+      ::
+
+         TUNE_FEATURES ??= "${TUNE_FEATURES_tune-${DEFAULTTUNE}}"
+
+      See the :term:`DEFAULTTUNE` variable for more information.
+
+   TUNE_PKGARCH
+      The package architecture understood by the packaging system to define
+      the architecture, ABI, and tuning of output packages. The specific
+      tune is defined using the "_tune" override as follows:
+      ::
+
+         TUNE_PKGARCH_tune-tune = "tune"
+
+      These tune-specific package architectures are defined in the machine
+      include files. Here is an example of the "core2-32" tuning as used in
+      the ``meta/conf/machine/include/tune-core2.inc`` file:
+      ::
+
+         TUNE_PKGARCH_tune-core2-32 = "core2-32"
+
+   TUNEABI
+      An underlying Application Binary Interface (ABI) used by a particular
+      tuning in a given toolchain layer. Providers that use prebuilt
+      libraries can use the ``TUNEABI``,
+      :term:`TUNEABI_OVERRIDE`, and
+      :term:`TUNEABI_WHITELIST` variables to check
+      compatibility of tunings against their selection of libraries.
+
+      If ``TUNEABI`` is undefined, then every tuning is allowed. See the
+      :ref:`sanity <ref-classes-sanity>` class to see how the variable is
+      used.
+
+   TUNEABI_OVERRIDE
+      If set, the OpenEmbedded system ignores the
+      :term:`TUNEABI_WHITELIST` variable.
+      Providers that use prebuilt libraries can use the
+      ``TUNEABI_OVERRIDE``, ``TUNEABI_WHITELIST``, and
+      :term:`TUNEABI` variables to check compatibility of a
+      tuning against their selection of libraries.
+
+      See the :ref:`sanity <ref-classes-sanity>` class to see how the
+      variable is used.
+
+   TUNEABI_WHITELIST
+      A whitelist of permissible :term:`TUNEABI` values. If
+      ``TUNEABI_WHITELIST`` is not set, all tunes are allowed. Providers
+      that use prebuilt libraries can use the ``TUNEABI_WHITELIST``,
+      :term:`TUNEABI_OVERRIDE`, and ``TUNEABI``
+      variables to check compatibility of a tuning against their selection
+      of libraries.
+
+      See the :ref:`sanity <ref-classes-sanity>` class to see how the
+      variable is used.
+
+   TUNECONFLICTS[feature]
+      Specifies CPU or Application Binary Interface (ABI) tuning features
+      that conflict with feature.
+
+      Known tuning conflicts are specified in the machine include files in
+      the :term:`Source Directory`. Here is an example from
+      the ``meta/conf/machine/include/mips/arch-mips.inc`` include file
+      that lists the "o32" and "n64" features as conflicting with the "n32"
+      feature:
+      ::
+
+         TUNECONFLICTS[n32] = "o32 n64"
+
+   TUNEVALID[feature]
+      Specifies a valid CPU or Application Binary Interface (ABI) tuning
+      feature. The specified feature is stored as a flag. Valid features
+      are specified in the machine include files (e.g.
+      ``meta/conf/machine/include/arm/arch-arm.inc``). Here is an example
+      from that file:
+      ::
+
+         TUNEVALID[bigendian] = "Enable big-endian mode."
+
+      See the machine include files in the :term:`Source Directory`
+      for these features.
+
+   UBOOT_CONFIG
+      Configures the :term:`UBOOT_MACHINE` and can
+      also define :term:`IMAGE_FSTYPES` for individual
+      cases.
+
+      Following is an example from the ``meta-fsl-arm`` layer. ::
+
+         UBOOT_CONFIG ??= "sd"
+         UBOOT_CONFIG[sd] = "mx6qsabreauto_config,sdcard"
+         UBOOT_CONFIG[eimnor] = "mx6qsabreauto_eimnor_config"
+         UBOOT_CONFIG[nand] = "mx6qsabreauto_nand_config,ubifs"
+         UBOOT_CONFIG[spinor] = "mx6qsabreauto_spinor_config"
+
+      In this example, "sd" is selected as the configuration of the possible four for the
+      ``UBOOT_MACHINE``. The "sd" configuration defines
+      "mx6qsabreauto_config" as the value for ``UBOOT_MACHINE``, while the
+      "sdcard" specifies the ``IMAGE_FSTYPES`` to use for the U-boot image.
+
+      For more information on how the ``UBOOT_CONFIG`` is handled, see the
+      :ref:`uboot-config <ref-classes-uboot-config>`
+      class.
+
+   UBOOT_DTB_LOADADDRESS
+      Specifies the load address for the dtb image used by U-boot. During FIT
+      image creation, the ``UBOOT_DTB_LOADADDRESS`` variable is used in
+      :ref:`kernel-fitimage <ref-classes-kernel-fitimage>` class to specify
+      the load address to be used in
+      creating the dtb sections of Image Tree Source for the FIT image.
+
+   UBOOT_DTBO_LOADADDRESS
+      Specifies the load address for the dtbo image used by U-boot.  During FIT
+      image creation, the ``UBOOT_DTBO_LOADADDRESS`` variable is used in
+      :ref:`kernel-fitimage <ref-classes-kernel-fitimage>` class to specify the load address to be used in
+      creating the dtbo sections of Image Tree Source for the FIT image.
+
+   UBOOT_ENTRYPOINT
+      Specifies the entry point for the U-Boot image. During U-Boot image
+      creation, the ``UBOOT_ENTRYPOINT`` variable is passed as a
+      command-line parameter to the ``uboot-mkimage`` utility.
+
+   UBOOT_LOADADDRESS
+      Specifies the load address for the U-Boot image. During U-Boot image
+      creation, the ``UBOOT_LOADADDRESS`` variable is passed as a
+      command-line parameter to the ``uboot-mkimage`` utility.
+
+   UBOOT_LOCALVERSION
+      Appends a string to the name of the local version of the U-Boot
+      image. For example, assuming the version of the U-Boot image built
+      was "2013.10", the full version string reported by U-Boot would be
+      "2013.10-yocto" given the following statement:
+      ::
+
+         UBOOT_LOCALVERSION = "-yocto"
+
+   UBOOT_MACHINE
+      Specifies the value passed on the ``make`` command line when building
+      a U-Boot image. The value indicates the target platform
+      configuration. You typically set this variable from the machine
+      configuration file (i.e. ``conf/machine/machine_name.conf``).
+
+      Please see the "Selection of Processor Architecture and Board Type"
+      section in the U-Boot README for valid values for this variable.
+
+   UBOOT_MAKE_TARGET
+      Specifies the target called in the ``Makefile``. The default target
+      is "all".
+
+   UBOOT_MKIMAGE_DTCOPTS
+      Options for the device tree compiler passed to mkimage '-D'
+      feature while creating FIT image in :ref:`kernel-fitimage <ref-classes-kernel-fitimage>` class.
+
+   UBOOT_RD_LOADADDRESS
+      Specifies the load address for the RAM disk image.
+      During FIT image creation, the
+      ``UBOOT_RD_LOADADDRESS`` variable is used
+      in :ref:`kernel-fitimage <ref-classes-kernel-fitimage>` class to specify the
+      load address to be used in creating the Image Tree Source for
+      the FIT image.
+
+   UBOOT_RD_ENTRYPOINT
+      Specifies the entrypoint for the RAM disk image.
+      During FIT image creation, the
+      ``UBOOT_RD_ENTRYPOINT`` variable is used
+      in :ref:`kernel-fitimage <ref-classes-kernel-fitimage>` class to specify the
+      entrypoint to be used in creating the Image Tree Source for
+      the FIT image.
+
+   UBOOT_SIGN_ENABLE
+      Enable signing of FIT image. The default value is "0".
+
+   UBOOT_SIGN_KEYDIR
+      Location of the directory containing the RSA key and
+      certificate used for signing FIT image.
+
+   UBOOT_SIGN_KEYNAME
+      The name of keys used for signing U-boot FIT image stored in
+      :term:`UBOOT_SIGN_KEYDIR` directory. For e.g. dev.key key and dev.crt
+      certificate stored in :term:`UBOOT_SIGN_KEYDIR` directory will have
+      :term:`UBOOT_SIGN_KEYNAME` set to "dev".
+
+   UBOOT_SUFFIX
+      Points to the generated U-Boot extension. For example, ``u-boot.sb``
+      has a ``.sb`` extension.
+
+      The default U-Boot extension is ``.bin``
+
+   UBOOT_TARGET
+      Specifies the target used for building U-Boot. The target is passed
+      directly as part of the "make" command (e.g. SPL and AIS). If you do
+      not specifically set this variable, the OpenEmbedded build process
+      passes and uses "all" for the target during the U-Boot building
+      process.
+
+   UNKNOWN_CONFIGURE_WHITELIST
+      Specifies a list of options that, if reported by the configure script
+      as being invalid, should not generate a warning during the
+      :ref:`ref-tasks-configure` task. Normally, invalid
+      configure options are simply not passed to the configure script (e.g.
+      should be removed from :term:`EXTRA_OECONF` or
+      :term:`PACKAGECONFIG_CONFARGS`).
+      However, common options, for example, exist that are passed to all
+      configure scripts at a class level that might not be valid for some
+      configure scripts. It follows that no benefit exists in seeing a
+      warning about these options. For these cases, the options are added
+      to ``UNKNOWN_CONFIGURE_WHITELIST``.
+
+      The configure arguments check that uses
+      ``UNKNOWN_CONFIGURE_WHITELIST`` is part of the
+      :ref:`insane <ref-classes-insane>` class and is only enabled if the
+      recipe inherits the :ref:`autotools <ref-classes-autotools>` class.
+
+   UPDATERCPN
+      For recipes inheriting the
+      :ref:`update-rc.d <ref-classes-update-rc.d>` class, ``UPDATERCPN``
+      specifies the package that contains the initscript that is enabled.
+
+      The default value is "${PN}". Given that almost all recipes that
+      install initscripts package them in the main package for the recipe,
+      you rarely need to set this variable in individual recipes.
+
+   UPSTREAM_CHECK_GITTAGREGEX
+      You can perform a per-recipe check for what the latest upstream
+      source code version is by calling ``bitbake -c checkpkg`` recipe. If
+      the recipe source code is provided from Git repositories, the
+      OpenEmbedded build system determines the latest upstream version by
+      picking the latest tag from the list of all repository tags.
+
+      You can use the ``UPSTREAM_CHECK_GITTAGREGEX`` variable to provide a
+      regular expression to filter only the relevant tags should the
+      default filter not work correctly.
+      ::
+
+         UPSTREAM_CHECK_GITTAGREGEX = "git_tag_regex"
+
+   UPSTREAM_CHECK_REGEX
+      Use the ``UPSTREAM_CHECK_REGEX`` variable to specify a different
+      regular expression instead of the default one when the package
+      checking system is parsing the page found using
+      :term:`UPSTREAM_CHECK_URI`.
+      ::
+
+         UPSTREAM_CHECK_REGEX = "package_regex"
+
+   UPSTREAM_CHECK_URI
+      You can perform a per-recipe check for what the latest upstream
+      source code version is by calling ``bitbake -c checkpkg`` recipe. If
+      the source code is provided from tarballs, the latest version is
+      determined by fetching the directory listing where the tarball is and
+      attempting to find a later tarball. When this approach does not work,
+      you can use ``UPSTREAM_CHECK_URI`` to provide a different URI that
+      contains the link to the latest tarball.
+      ::
+
+         UPSTREAM_CHECK_URI = "recipe_url"
+
+   USE_DEVFS
+      Determines if ``devtmpfs`` is used for ``/dev`` population. The
+      default value used for ``USE_DEVFS`` is "1" when no value is
+      specifically set. Typically, you would set ``USE_DEVFS`` to "0" for a
+      statically populated ``/dev`` directory.
+
+      See the ":ref:`selecting-dev-manager`" section in
+      the Yocto Project Development Tasks Manual for information on how to
+      use this variable.
+
+   USE_VT
+      When using
+      :ref:`SysVinit <new-recipe-enabling-system-services>`,
+      determines whether or not to run a
+      `getty <http://en.wikipedia.org/wiki/Getty_%28Unix%29>`__ on any
+      virtual terminals in order to enable logging in through those
+      terminals.
+
+      The default value used for ``USE_VT`` is "1" when no default value is
+      specifically set. Typically, you would set ``USE_VT`` to "0" in the
+      machine configuration file for machines that do not have a graphical
+      display attached and therefore do not need virtual terminal
+      functionality.
+
+   USER_CLASSES
+      A list of classes to globally inherit. These classes are used by the
+      OpenEmbedded build system to enable extra features (e.g.
+      ``buildstats``, ``image-mklibs``, and so forth).
+
+      The default list is set in your ``local.conf`` file:
+      ::
+
+         USER_CLASSES ?= "buildstats image-mklibs image-prelink"
+
+      For more information, see
+      ``meta-poky/conf/local.conf.sample`` in the :term:`Source Directory`.
+
+   USERADD_ERROR_DYNAMIC
+      If set to ``error``, forces the OpenEmbedded build system to produce
+      an error if the user identification (``uid``) and group
+      identification (``gid``) values are not defined in any of the files
+      listed in :term:`USERADD_UID_TABLES` and
+      :term:`USERADD_GID_TABLES`. If set to
+      ``warn``, a warning will be issued instead.
+
+      The default behavior for the build system is to dynamically apply
+      ``uid`` and ``gid`` values. Consequently, the
+      ``USERADD_ERROR_DYNAMIC`` variable is by default not set. If you plan
+      on using statically assigned ``gid`` and ``uid`` values, you should
+      set the ``USERADD_ERROR_DYNAMIC`` variable in your ``local.conf``
+      file as follows:
+      ::
+
+         USERADD_ERROR_DYNAMIC = "error"
+
+      Overriding the
+      default behavior implies you are going to also take steps to set
+      static ``uid`` and ``gid`` values through use of the
+      :term:`USERADDEXTENSION`,
+      :term:`USERADD_UID_TABLES`, and
+      :term:`USERADD_GID_TABLES` variables.
+
+      .. note::
+
+         There is a difference in behavior between setting
+         USERADD_ERROR_DYNAMIC
+         to
+         error
+         and setting it to
+         warn
+         . When it is set to
+         warn
+         , the build system will report a warning for every undefined
+         uid
+         and
+         gid
+         in any recipe. But when it is set to
+         error
+         , it will only report errors for recipes that are actually built.
+         This saves you from having to add static IDs for recipes that you
+         know will never be built.
+
+   USERADD_GID_TABLES
+      Specifies a password file to use for obtaining static group
+      identification (``gid``) values when the OpenEmbedded build system
+      adds a group to the system during package installation.
+
+      When applying static group identification (``gid``) values, the
+      OpenEmbedded build system looks in :term:`BBPATH` for a
+      ``files/group`` file and then applies those ``uid`` values. Set the
+      variable as follows in your ``local.conf`` file:
+      ::
+
+
+         USERADD_GID_TABLES = "files/group"
+
+      .. note::
+
+         Setting the
+         USERADDEXTENSION
+         variable to "useradd-staticids" causes the build system to use
+         static
+         gid
+         values.
+
+   USERADD_PACKAGES
+      When inheriting the :ref:`useradd <ref-classes-useradd>` class,
+      this variable specifies the individual packages within the recipe
+      that require users and/or groups to be added.
+
+      You must set this variable if the recipe inherits the class. For
+      example, the following enables adding a user for the main package in
+      a recipe:
+      ::
+
+         USERADD_PACKAGES = "${PN}"
+
+      .. note::
+
+         It follows that if you are going to use the
+         USERADD_PACKAGES
+         variable, you need to set one or more of the
+         USERADD_PARAM
+         ,
+         GROUPADD_PARAM
+         , or
+         GROUPMEMS_PARAM
+         variables.
+
+   USERADD_PARAM
+      When inheriting the :ref:`useradd <ref-classes-useradd>` class,
+      this variable specifies for a package what parameters should pass to
+      the ``useradd`` command if you add a user to the system when the
+      package is installed.
+
+      Here is an example from the ``dbus`` recipe:
+      ::
+
+         USERADD_PARAM_${PN} = "--system --home ${localstatedir}/lib/dbus \
+                                --no-create-home --shell /bin/false \
+                                --user-group messagebus"
+
+      For information on the
+      standard Linux shell command ``useradd``, see
+      http://linux.die.net/man/8/useradd.
+
+   USERADD_UID_TABLES
+      Specifies a password file to use for obtaining static user
+      identification (``uid``) values when the OpenEmbedded build system
+      adds a user to the system during package installation.
+
+      When applying static user identification (``uid``) values, the
+      OpenEmbedded build system looks in :term:`BBPATH` for a
+      ``files/passwd`` file and then applies those ``uid`` values. Set the
+      variable as follows in your ``local.conf`` file:
+      ::
+
+         USERADD_UID_TABLES = "files/passwd"
+
+      .. note::
+
+         Setting the
+         USERADDEXTENSION
+         variable to "useradd-staticids" causes the build system to use
+         static
+         uid
+         values.
+
+   USERADDEXTENSION
+      When set to "useradd-staticids", causes the OpenEmbedded build system
+      to base all user and group additions on a static ``passwd`` and
+      ``group`` files found in :term:`BBPATH`.
+
+      To use static user identification (``uid``) and group identification
+      (``gid``) values, set the variable as follows in your ``local.conf``
+      file: USERADDEXTENSION = "useradd-staticids"
+
+      .. note::
+
+         Setting this variable to use static
+         uid
+         and
+         gid
+         values causes the OpenEmbedded build system to employ the
+         useradd-staticids
+         class.
+
+      If you use static ``uid`` and ``gid`` information, you must also
+      specify the ``files/passwd`` and ``files/group`` files by setting the
+      :term:`USERADD_UID_TABLES` and
+      :term:`USERADD_GID_TABLES` variables.
+      Additionally, you should also set the
+      :term:`USERADD_ERROR_DYNAMIC` variable.
+
+   VOLATILE_LOG_DIR
+      Specifies the persistence of the target's ``/var/log`` directory,
+      which is used to house postinstall target log files.
+
+      By default, ``VOLATILE_LOG_DIR`` is set to "yes", which means the
+      file is not persistent. You can override this setting by setting the
+      variable to "no" to make the log directory persistent.
+
+   WARN_QA
+      Specifies the quality assurance checks whose failures are reported as
+      warnings by the OpenEmbedded build system. You set this variable in
+      your distribution configuration file. For a list of the checks you
+      can control with this variable, see the
+      ":ref:`insane.bbclass <ref-classes-insane>`" section.
+
+   WKS_FILE_DEPENDS
+      When placed in the recipe that builds your image, this variable lists
+      build-time dependencies. The ``WKS_FILE_DEPENDS`` variable is only
+      applicable when Wic images are active (i.e. when
+      :term:`IMAGE_FSTYPES` contains entries related
+      to Wic). If your recipe does not create Wic images, the variable has
+      no effect.
+
+      The ``WKS_FILE_DEPENDS`` variable is similar to the
+      :term:`DEPENDS` variable. When you use the variable in
+      your recipe that builds the Wic image, dependencies you list in the
+      ``WIC_FILE_DEPENDS`` variable are added to the ``DEPENDS`` variable.
+
+      With the ``WKS_FILE_DEPENDS`` variable, you have the possibility to
+      specify a list of additional dependencies (e.g. native tools,
+      bootloaders, and so forth), that are required to build Wic images.
+      Following is an example:
+      ::
+
+         WKS_FILE_DEPENDS = "some-native-tool"
+
+      In the
+      previous example, some-native-tool would be replaced with an actual
+      native tool on which the build would depend.
+
+   WKS_FILE
+      Specifies the location of the Wic kickstart file that is used by the
+      OpenEmbedded build system to create a partitioned image
+      (image\ ``.wic``). For information on how to create a partitioned
+      image, see the
+      ":ref:`dev-manual/dev-manual-common-tasks:creating partitioned images using wic`"
+      section in the Yocto Project Development Tasks Manual. For details on
+      the kickstart file format, see the ":doc:`../ref-manual/ref-kickstart`" Chapter.
+
+   WORKDIR
+      The pathname of the work directory in which the OpenEmbedded build
+      system builds a recipe. This directory is located within the
+      :term:`TMPDIR` directory structure and is specific to
+      the recipe being built and the system for which it is being built.
+
+      The ``WORKDIR`` directory is defined as follows:
+      ::
+
+         ${TMPDIR}/work/${MULTIMACH_TARGET_SYS}/${PN}/${EXTENDPE}${PV}-${PR}
+
+      The actual directory depends on several things:
+
+      -  TMPDIR
+         : The top-level build output directory
+      -  MULTIMACH_TARGET_SYS
+         : The target system identifier
+      -  PN
+         : The recipe name
+      -  EXTENDPE
+         : The epoch - (if
+         PE
+         is not specified, which is usually the case for most recipes, then
+         EXTENDPE
+         is blank)
+      -  PV
+         : The recipe version
+      -  PR
+         : The recipe revision
+
+      As an example, assume a Source Directory top-level folder name
+      ``poky``, a default Build Directory at ``poky/build``, and a
+      ``qemux86-poky-linux`` machine target system. Furthermore, suppose
+      your recipe is named ``foo_1.3.0-r0.bb``. In this case, the work
+      directory the build system uses to build the package would be as
+      follows:
+      ::
+
+         poky/build/tmp/work/qemux86-poky-linux/foo/1.3.0-r0
+
+   XSERVER
+      Specifies the packages that should be installed to provide an X
+      server and drivers for the current machine, assuming your image
+      directly includes ``packagegroup-core-x11-xserver`` or, perhaps
+      indirectly, includes "x11-base" in
+      :term:`IMAGE_FEATURES`.
+
+      The default value of ``XSERVER``, if not specified in the machine
+      configuration, is "xserver-xorg xf86-video-fbdev xf86-input-evdev".
+