poky/documentation/ref-manual/migration-2.3.rst - mdmillerii/openbmc - Gitiles

 Moving to the Yocto Project 2.3 Release
 =======================================

 This section provides migration information for moving to the Yocto
 Project 2.3 Release from the prior release.

 .. _migration-2.3-recipe-specific-sysroots:

 Recipe-specific Sysroots
 ------------------------

 The OpenEmbedded build system now uses one sysroot per recipe to resolve
 long-standing issues with configuration script auto-detection of
 undeclared dependencies. Consequently, you might find that some of your
 previously written custom recipes are missing declared dependencies,
 particularly those dependencies that are incidentally built earlier in a
 typical build process and thus are already likely to be present in the
 shared sysroot in previous releases.

 Consider the following:

 -  *Declare Build-Time Dependencies:* Because of this new feature, you
    must explicitly declare all build-time dependencies for your recipe.
    If you do not declare these dependencies, they are not populated into
    the sysroot for the recipe.

 -  *Specify Pre-Installation and Post-Installation Native Tool
    Dependencies:* You must specifically specify any special native tool
    dependencies of ``pkg_preinst`` and ``pkg_postinst`` scripts by using
    the :term:`PACKAGE_WRITE_DEPS` variable.
    Specifying these dependencies ensures that these tools are available
    if these scripts need to be run on the build host during the
    :ref:`ref-tasks-rootfs` task.

    As an example, see the ``dbus`` recipe. You will see that this recipe
    has a ``pkg_postinst`` that calls ``systemctl`` if "systemd" is in
    :term:`DISTRO_FEATURES`. In the example,
    ``systemd-systemctl-native`` is added to ``PACKAGE_WRITE_DEPS``,
    which is also conditional on "systemd" being in ``DISTRO_FEATURES``.

 -  Examine Recipes that Use ``SSTATEPOSTINSTFUNCS``: You need to
    examine any recipe that uses ``SSTATEPOSTINSTFUNCS`` and determine
    steps to take.

    Functions added to ``SSTATEPOSTINSTFUNCS`` are still called as they
    were in previous Yocto Project releases. However, since a separate
    sysroot is now being populated for every recipe and if existing
    functions being called through ``SSTATEPOSTINSTFUNCS`` are doing
    relocation, then you will need to change these to use a
    post-installation script that is installed by a function added to
    :term:`SYSROOT_PREPROCESS_FUNCS`.

    For an example, see the ``pixbufcache`` class in ``meta/classes/`` in
    the :ref:`overview-manual/development-environment:yocto project source repositories`.

    .. note::

       The
       SSTATEPOSTINSTFUNCS
       variable itself is now deprecated in favor of the
       do_populate_sysroot[postfuncs]
       task. Consequently, if you do still have any function or functions
       that need to be called after the sysroot component is created for
       a recipe, then you would be well advised to take steps to use a
       post installation script as described previously. Taking these
       steps prepares your code for when
       SSTATEPOSTINSTFUNCS
       is removed in a future Yocto Project release.

 -  *Specify the Sysroot when Using Certain External Scripts:* Because
    the shared sysroot is now gone, the scripts
    ``oe-find-native-sysroot`` and ``oe-run-native`` have been changed
    such that you need to specify which recipe's
    :term:`STAGING_DIR_NATIVE` is used.

 .. note::

    You can find more information on how recipe-specific sysroots work in
    the ":ref:`ref-classes-staging`" section.

 .. _migration-2.3-path-variable:

 ``PATH`` Variable
 -----------------

 Within the environment used to run build tasks, the environment variable
 ``PATH`` is now sanitized such that the normal native binary paths
 (``/bin``, ``/sbin``, ``/usr/bin`` and so forth) are removed and a
 directory containing symbolic links linking only to the binaries from
 the host mentioned in the :term:`HOSTTOOLS` and
 :term:`HOSTTOOLS_NONFATAL` variables is added
 to ``PATH``.

 Consequently, any native binaries provided by the host that you need to
 call needs to be in one of these two variables at the configuration
 level.

 Alternatively, you can add a native recipe (i.e. ``-native``) that
 provides the binary to the recipe's :term:`DEPENDS`
 value.

 .. note::

    PATH
    is not sanitized in the same way within ``devshell``.
    If it were, you would have difficulty running host tools for
    development and debugging within the shell.

 .. _migration-2.3-scripts:

 Changes to Scripts
 ------------------

 The following changes to scripts took place:

 -  ``oe-find-native-sysroot``: The usage for the
    ``oe-find-native-sysroot`` script has changed to the following:
    ::

       $ . oe-find-native-sysroot recipe

    You must now supply a recipe for recipe
    as part of the command. Prior to the Yocto Project 2.3 release, it
    was not necessary to provide the script with the command.

 -  ``oe-run-native``: The usage for the ``oe-run-native`` script has
    changed to the following:
    ::

       $ oe-run-native native_recipe tool

    You must
    supply the name of the native recipe and the tool you want to run as
    part of the command. Prior to the Yocto Project 2.3 release, it
    was not necessary to provide the native recipe with the command.

 -  ``cleanup-workdir``: The ``cleanup-workdir`` script has been
    removed because the script was found to be deleting files it should
    not have, which lead to broken build trees. Rather than trying to
    delete portions of :term:`TMPDIR` and getting it wrong,
    it is recommended that you delete ``TMPDIR`` and have it restored
    from shared state (sstate) on subsequent builds.

 -  ``wipe-sysroot``: The ``wipe-sysroot`` script has been removed as
    it is no longer needed with recipe-specific sysroots.

 .. _migration-2.3-functions:

 Changes to Functions
 --------------------

 The previously deprecated ``bb.data.getVar()``, ``bb.data.setVar()``,
 and related functions have been removed in favor of ``d.getVar()``,
 ``d.setVar()``, and so forth.

 You need to fix any references to these old functions.

 .. _migration-2.3-bitbake-changes:

 BitBake Changes
 ---------------

 The following changes took place for BitBake:

 -  *BitBake's Graphical Dependency Explorer UI Replaced:* BitBake's
    graphical dependency explorer UI ``depexp`` was replaced by
    ``taskexp`` ("Task Explorer"), which provides a graphical way of
    exploring the ``task-depends.dot`` file. The data presented by Task
    Explorer is much more accurate than the data that was presented by
    ``depexp``. Being able to visualize the data is an often requested
    feature as standard ``*.dot`` file viewers cannot usual cope with the
    size of the ``task-depends.dot`` file.

 -  *BitBake "-g" Output Changes:* The ``package-depends.dot`` and
    ``pn-depends.dot`` files as previously generated using the
    ``bitbake -g`` command have been removed. A ``recipe-depends.dot``
    file is now generated as a collapsed version of ``task-depends.dot``
    instead.

    The reason for this change is because ``package-depends.dot`` and
    ``pn-depends.dot`` largely date back to a time before task-based
    execution and do not take into account task-level dependencies
    between recipes, which could be misleading.

 -  *Mirror Variable Splitting Changes:* Mirror variables including
    :term:`MIRRORS`, :term:`PREMIRRORS`,
    and :term:`SSTATE_MIRRORS` can now separate
    values entirely with spaces. Consequently, you no longer need "\\n".
    BitBake looks for pairs of values, which simplifies usage. There
    should be no change required to existing mirror variable values
    themselves.

 -  *The Subversion (SVN) Fetcher Uses an "ssh" Parameter and Not an
    "rsh" Parameter:* The SVN fetcher now takes an "ssh" parameter
    instead of an "rsh" parameter. This new optional parameter is used
    when the "protocol" parameter is set to "svn+ssh". You can only use
    the new parameter to specify the ``ssh`` program used by SVN. The SVN
    fetcher passes the new parameter through the ``SVN_SSH`` environment
    variable during the :ref:`ref-tasks-fetch` task.

    See the ":ref:`bitbake:bitbake-user-manual/bitbake-user-manual-fetching:subversion (svn) fetcher (\`\`svn://\`\`)`"
    section in the BitBake
    User Manual for additional information.

 -  ``BB_SETSCENE_VERIFY_FUNCTION`` and ``BB_SETSCENE_VERIFY_FUNCTION2``
    Removed: Because the mechanism they were part of is no longer
    necessary with recipe-specific sysroots, the
    ``BB_SETSCENE_VERIFY_FUNCTION`` and ``BB_SETSCENE_VERIFY_FUNCTION2``
    variables have been removed.

 .. _migration-2.3-absolute-symlinks:

 Absolute Symbolic Links
 -----------------------

 Absolute symbolic links (symlinks) within staged files are no longer
 permitted and now trigger an error. Any explicit creation of symlinks
 can use the ``lnr`` script, which is a replacement for ``ln -r``.

 If the build scripts in the software that the recipe is building are
 creating a number of absolute symlinks that need to be corrected, you
 can inherit ``relative_symlinks`` within the recipe to turn those
 absolute symlinks into relative symlinks.

 .. _migration-2.3-gplv2-and-gplv3-moves:

 GPLv2 Versions of GPLv3 Recipes Moved
 -------------------------------------

 Older GPLv2 versions of GPLv3 recipes have moved to a separate
 ``meta-gplv2`` layer.

 If you use :term:`INCOMPATIBLE_LICENSE` to
 exclude GPLv3 or set :term:`PREFERRED_VERSION`
 to substitute a GPLv2 version of a GPLv3 recipe, then you must add the
 ``meta-gplv2`` layer to your configuration.

 .. note::

    You can ``find meta-gplv2`` layer in the OpenEmbedded layer index at
    https://layers.openembedded.org/layerindex/branch/master/layer/meta-gplv2/.

 These relocated GPLv2 recipes do not receive the same level of
 maintenance as other core recipes. The recipes do not get security fixes
 and upstream no longer maintains them. In fact, the upstream community
 is actively hostile towards people that use the old versions of the
 recipes. Moving these recipes into a separate layer both makes the
 different needs of the recipes clearer and clearly identifies the number
 of these recipes.

 .. note::

    The long-term solution might be to move to BSD-licensed replacements
    of the GPLv3 components for those that need to exclude GPLv3-licensed
    components from the target system. This solution will be investigated
    for future Yocto Project releases.

 .. _migration-2.3-package-management-changes:

 Package Management Changes
 --------------------------

 The following package management changes took place:

 -  Smart package manager is replaced by DNF package manager. Smart has
    become unmaintained upstream, is not ported to Python 3.x.
    Consequently, Smart needed to be replaced. DNF is the only feasible
    candidate.

    The change in functionality is that the on-target runtime package
    management from remote package feeds is now done with a different
    tool that has a different set of command-line options. If you have
    scripts that call the tool directly, or use its API, they need to be
    fixed.

    For more information, see the `DNF
    Documentation <http://dnf.readthedocs.io/en/latest/>`__.

 -  Rpm 5.x is replaced with Rpm 4.x. This is done for two major reasons:

    -  DNF is API-incompatible with Rpm 5.x and porting it and
       maintaining the port is non-trivial.

    -  Rpm 5.x itself has limited maintenance upstream, and the Yocto
       Project is one of the very few remaining users.

 -  Berkeley DB 6.x is removed and Berkeley DB 5.x becomes the default:

    -  Version 6.x of Berkeley DB has largely been rejected by the open
       source community due to its AGPLv3 license. As a result, most
       mainstream open source projects that require DB are still
       developed and tested with DB 5.x.

    -  In OE-core, the only thing that was requiring DB 6.x was Rpm 5.x.
       Thus, no reason exists to continue carrying DB 6.x in OE-core.

 -  ``createrepo`` is replaced with ``createrepo_c``.

    ``createrepo_c`` is the current incarnation of the tool that
    generates remote repository metadata. It is written in C as compared
    to ``createrepo``, which is written in Python. ``createrepo_c`` is
    faster and is maintained.

 -  Architecture-independent RPM packages are "noarch" instead of "all".

    This change was made because too many places in DNF/RPM4 stack
    already make that assumption. Only the filenames and the architecture
    tag has changed. Nothing else has changed in OE-core system,
    particularly in the :ref:`allarch.bbclass <ref-classes-allarch>`
    class.

 -  Signing of remote package feeds using ``PACKAGE_FEED_SIGN`` is not
    currently supported. This issue will be fully addressed in a future
    Yocto Project release. See :yocto_bugs:`defect 11209 </show_bug.cgi?id=11209>`
    for more information on a solution to package feed signing with RPM
    in the Yocto Project 2.3 release.

 -  OPKG now uses the libsolv backend for resolving package dependencies
    by default. This is vastly superior to OPKG's internal ad-hoc solver
    that was previously used. This change does have a small impact on
    disk (around 500 KB) and memory footprint.

    .. note::

       For further details on this change, see the
       :yocto_git:`commit message </poky/commit/?id=f4d4f99cfbc2396e49c1613a7d237b9e57f06f81>`.

 .. _migration-2.3-removed-recipes:

 Removed Recipes
 ---------------

 The following recipes have been removed:

 -  ``linux-yocto 4.8``: Version 4.8 has been removed. Versions 4.1
    (LTSI), 4.4 (LTS), 4.9 (LTS/LTSI) and 4.10 are now present.

 -  ``python-smartpm``: Functionally replaced by ``dnf``.

 -  ``createrepo``: Replaced by the ``createrepo-c`` recipe.

 -  ``rpmresolve``: No longer needed with the move to RPM 4 as RPM
    itself is used instead.

 -  ``gstreamer``: Removed the GStreamer Git version recipes as they
    have been stale. ``1.10.``\ x recipes are still present.

 -  ``alsa-conf-base``: Merged into ``alsa-conf`` since ``libasound``
    depended on both. Essentially, no way existed to install only one of
    these.

 -  ``tremor``: Moved to ``meta-multimedia``. Fixed-integer Vorbis
    decoding is not needed by current hardware. Thus, GStreamer's ivorbis
    plugin has been disabled by default eliminating the need for the
    ``tremor`` recipe in :term:`OpenEmbedded-Core (OE-Core)`.

 -  ``gummiboot``: Replaced by ``systemd-boot``.

 .. _migration-2.3-wic-changes:

 Wic Changes
 -----------

 The following changes have been made to Wic:

 .. note::

    For more information on Wic, see the
    ":ref:`dev-manual/common-tasks:creating partitioned images using wic`"
    section in the Yocto Project Development Tasks Manual.

 -  *Default Output Directory Changed:* Wic's default output directory is
    now the current directory by default instead of the unusual
    ``/var/tmp/wic``.

    The "-o" and "--outdir" options remain unchanged and are used to
    specify your preferred output directory if you do not want to use the
    default directory.

 -  *fsimage Plug-in Removed:* The Wic fsimage plugin has been removed as
    it duplicates functionality of the rawcopy plugin.

 .. _migration-2.3-qa-changes:

 QA Changes
 ----------

 The following QA checks have changed:

 -  ``unsafe-references-in-binaries``: The
    ``unsafe-references-in-binaries`` QA check, which was disabled by
    default, has now been removed. This check was intended to detect
    binaries in ``/bin`` that link to libraries in ``/usr/lib`` and have
    the case where the user has ``/usr`` on a separate filesystem to
    ``/``.

    The removed QA check was buggy. Additionally, ``/usr`` residing on a
    separate partition from ``/`` is now a rare configuration.
    Consequently, ``unsafe-references-in-binaries`` was removed.

 -  ``file-rdeps``: The ``file-rdeps`` QA check is now an error by
    default instead of a warning. Because it is an error instead of a
    warning, you need to address missing runtime dependencies.

    For additional information, see the
    :ref:`insane <ref-classes-insane>` class and the
    ":ref:`ref-manual/qa-checks:errors and warnings`" section.

 .. _migration-2.3-miscellaneous-changes:

 Miscellaneous Changes
 ---------------------

 The following miscellaneous changes have occurred:

 -  In this release, a number of recipes have been changed to ignore the
    ``largefile`` :term:`DISTRO_FEATURES` item,
    enabling large file support unconditionally. This feature has always
    been enabled by default. Disabling the feature has not been widely
    tested.

    .. note::

       Future releases of the Yocto Project will remove entirely the
       ability to disable the
       largefile
       feature, which would make it unconditionally enabled everywhere.

 -  If the :term:`DISTRO_VERSION` value contains
    the value of the :term:`DATE` variable, which is the
    default between Poky releases, the ``DATE`` value is explicitly
    excluded from ``/etc/issue`` and ``/etc/issue.net``, which is
    displayed at the login prompt, in order to avoid conflicts with
    Multilib enabled. Regardless, the ``DATE`` value is inaccurate if the
    ``base-files`` recipe is restored from shared state (sstate) rather
    than rebuilt.

    If you need the build date recorded in ``/etc/issue*`` or anywhere
    else in your image, a better method is to define a post-processing
    function to do it and have the function called from
    :term:`ROOTFS_POSTPROCESS_COMMAND`.
    Doing so ensures the value is always up-to-date with the created
    image.

 -  Dropbear's ``init`` script now disables DSA host keys by default.
    This change is in line with the systemd service file, which supports
    RSA keys only, and with recent versions of OpenSSH, which deprecates
    DSA host keys.

 -  The :ref:`buildhistory <ref-classes-buildhistory>` class now
    correctly uses tabs as separators between all columns in
    ``installed-package-sizes.txt`` in order to aid import into other
    tools.

 -  The ``USE_LDCONFIG`` variable has been replaced with the "ldconfig"
    ``DISTRO_FEATURES`` feature. Distributions that previously set:
    ::

       USE_LDCONFIG = "0"

    should now instead use the following:

    ::

       DISTRO_FEATURES_BACKFILL_CONSIDERED_append = " ldconfig"

 -  The default value of
    :term:`COPYLEFT_LICENSE_INCLUDE` now
    includes all versions of AGPL licenses in addition to GPL and LGPL.

    .. note::

       The default list is not intended to be guaranteed as a complete
       safe list. You should seek legal advice based on what you are
       distributing if you are unsure.

 -  Kernel module packages are now suffixed with the kernel version in
    order to allow module packages from multiple kernel versions to
    co-exist on a target system. If you wish to return to the previous
    naming scheme that does not include the version suffix, use the
    following:
    ::

       KERNEL_MODULE_PACKAGE_SUFFIX = ""

 -  Removal of ``libtool`` ``*.la`` files is now enabled by default. The
    ``*.la`` files are not actually needed on Linux and relocating them
    is an unnecessary burden.

    If you need to preserve these ``.la`` files (e.g. in a custom
    distribution), you must change
    :term:`INHERIT_DISTRO` such that
    "remove-libtool" is not included in the value.

 -  Extensible SDKs built for GCC 5+ now refuse to install on a
    distribution where the host GCC version is 4.8 or 4.9. This change
    resulted from the fact that the installation is known to fail due to
    the way the ``uninative`` shared state (sstate) package is built. See
    the :ref:`uninative <ref-classes-uninative>` class for additional
    information.

 -  All native and nativesdk recipes now use a separate
    ``DISTRO_FEATURES`` value instead of sharing the value used by
    recipes for the target, in order to avoid unnecessary rebuilds.

    The ``DISTRO_FEATURES`` for ``native`` recipes is
    :term:`DISTRO_FEATURES_NATIVE` added to
    an intersection of ``DISTRO_FEATURES`` and
    :term:`DISTRO_FEATURES_FILTER_NATIVE`.

    For nativesdk recipes, the corresponding variables are
    :term:`DISTRO_FEATURES_NATIVESDK`
    and
    :term:`DISTRO_FEATURES_FILTER_NATIVESDK`.

 -  The ``FILESDIR`` variable, which was previously deprecated and rarely
    used, has now been removed. You should change any recipes that set
    ``FILESDIR`` to set :term:`FILESPATH` instead.

 -  The ``MULTIMACH_HOST_SYS`` variable has been removed as it is no
    longer needed with recipe-specific sysroots.
	Moving to the Yocto Project 2.3 Release
	=======================================

	This section provides migration information for moving to the Yocto
	Project 2.3 Release from the prior release.

	.. _migration-2.3-recipe-specific-sysroots:

	Recipe-specific Sysroots
	------------------------

	The OpenEmbedded build system now uses one sysroot per recipe to resolve
	long-standing issues with configuration script auto-detection of
	undeclared dependencies. Consequently, you might find that some of your
	previously written custom recipes are missing declared dependencies,
	particularly those dependencies that are incidentally built earlier in a
	typical build process and thus are already likely to be present in the
	shared sysroot in previous releases.

	Consider the following:

	- Declare Build-Time Dependencies: Because of this new feature, you
	must explicitly declare all build-time dependencies for your recipe.
	If you do not declare these dependencies, they are not populated into
	the sysroot for the recipe.

	- *Specify Pre-Installation and Post-Installation Native Tool
	Dependencies:* You must specifically specify any special native tool
	dependencies of ``pkg_preinst`` and ``pkg_postinst`` scripts by using
	the :term:`PACKAGE_WRITE_DEPS` variable.
	Specifying these dependencies ensures that these tools are available
	if these scripts need to be run on the build host during the
	:ref:`ref-tasks-rootfs` task.

	As an example, see the ``dbus`` recipe. You will see that this recipe
	has a ``pkg_postinst`` that calls ``systemctl`` if "systemd" is in
	:term:`DISTRO_FEATURES`. In the example,
	``systemd-systemctl-native`` is added to ``PACKAGE_WRITE_DEPS``,
	which is also conditional on "systemd" being in ``DISTRO_FEATURES``.

	- Examine Recipes that Use ``SSTATEPOSTINSTFUNCS``: You need to
	examine any recipe that uses ``SSTATEPOSTINSTFUNCS`` and determine
	steps to take.

	Functions added to ``SSTATEPOSTINSTFUNCS`` are still called as they
	were in previous Yocto Project releases. However, since a separate
	sysroot is now being populated for every recipe and if existing
	functions being called through ``SSTATEPOSTINSTFUNCS`` are doing
	relocation, then you will need to change these to use a
	post-installation script that is installed by a function added to
	:term:`SYSROOT_PREPROCESS_FUNCS`.

	For an example, see the ``pixbufcache`` class in ``meta/classes/`` in
	the :ref:`overview-manual/development-environment:yocto project source repositories`.

	.. note::

	The
	SSTATEPOSTINSTFUNCS
	variable itself is now deprecated in favor of the
	do_populate_sysroot[postfuncs]
	task. Consequently, if you do still have any function or functions
	that need to be called after the sysroot component is created for
	a recipe, then you would be well advised to take steps to use a
	post installation script as described previously. Taking these
	steps prepares your code for when
	SSTATEPOSTINSTFUNCS
	is removed in a future Yocto Project release.

	- Specify the Sysroot when Using Certain External Scripts: Because
	the shared sysroot is now gone, the scripts
	``oe-find-native-sysroot`` and ``oe-run-native`` have been changed
	such that you need to specify which recipe's
	:term:`STAGING_DIR_NATIVE` is used.

	.. note::

	You can find more information on how recipe-specific sysroots work in
	the ":ref:`ref-classes-staging`" section.

	.. _migration-2.3-path-variable:

	``PATH`` Variable
	-----------------

	Within the environment used to run build tasks, the environment variable
	``PATH`` is now sanitized such that the normal native binary paths
	(``/bin``, ``/sbin``, ``/usr/bin`` and so forth) are removed and a
	directory containing symbolic links linking only to the binaries from
	the host mentioned in the :term:`HOSTTOOLS` and
	:term:`HOSTTOOLS_NONFATAL` variables is added
	to ``PATH``.

	Consequently, any native binaries provided by the host that you need to
	call needs to be in one of these two variables at the configuration
	level.

	Alternatively, you can add a native recipe (i.e. ``-native``) that
	provides the binary to the recipe's :term:`DEPENDS`
	value.

	.. note::

	PATH
	is not sanitized in the same way within ``devshell``.
	If it were, you would have difficulty running host tools for
	development and debugging within the shell.

	.. _migration-2.3-scripts:

	Changes to Scripts
	------------------

	The following changes to scripts took place:

	- ``oe-find-native-sysroot``: The usage for the
	``oe-find-native-sysroot`` script has changed to the following:
	::

	$ . oe-find-native-sysroot recipe

	You must now supply a recipe for recipe
	as part of the command. Prior to the Yocto Project 2.3 release, it
	was not necessary to provide the script with the command.

	- ``oe-run-native``: The usage for the ``oe-run-native`` script has
	changed to the following:
	::

	$ oe-run-native native_recipe tool

	You must
	supply the name of the native recipe and the tool you want to run as
	part of the command. Prior to the Yocto Project 2.3 release, it
	was not necessary to provide the native recipe with the command.

	- ``cleanup-workdir``: The ``cleanup-workdir`` script has been
	removed because the script was found to be deleting files it should
	not have, which lead to broken build trees. Rather than trying to
	delete portions of :term:`TMPDIR` and getting it wrong,
	it is recommended that you delete ``TMPDIR`` and have it restored
	from shared state (sstate) on subsequent builds.

	- ``wipe-sysroot``: The ``wipe-sysroot`` script has been removed as
	it is no longer needed with recipe-specific sysroots.

	.. _migration-2.3-functions:

	Changes to Functions
	--------------------

	The previously deprecated ``bb.data.getVar()``, ``bb.data.setVar()``,
	and related functions have been removed in favor of ``d.getVar()``,
	``d.setVar()``, and so forth.

	You need to fix any references to these old functions.

	.. _migration-2.3-bitbake-changes:

	BitBake Changes
	---------------

	The following changes took place for BitBake:

	- BitBake's Graphical Dependency Explorer UI Replaced: BitBake's
	graphical dependency explorer UI ``depexp`` was replaced by
	``taskexp`` ("Task Explorer"), which provides a graphical way of
	exploring the ``task-depends.dot`` file. The data presented by Task
	Explorer is much more accurate than the data that was presented by
	``depexp``. Being able to visualize the data is an often requested
	feature as standard ``*.dot`` file viewers cannot usual cope with the
	size of the ``task-depends.dot`` file.

	- BitBake "-g" Output Changes: The ``package-depends.dot`` and
	``pn-depends.dot`` files as previously generated using the
	``bitbake -g`` command have been removed. A ``recipe-depends.dot``
	file is now generated as a collapsed version of ``task-depends.dot``
	instead.

	The reason for this change is because ``package-depends.dot`` and
	``pn-depends.dot`` largely date back to a time before task-based
	execution and do not take into account task-level dependencies
	between recipes, which could be misleading.

	- Mirror Variable Splitting Changes: Mirror variables including
	:term:`MIRRORS`, :term:`PREMIRRORS`,
	and :term:`SSTATE_MIRRORS` can now separate
	values entirely with spaces. Consequently, you no longer need "\\n".
	BitBake looks for pairs of values, which simplifies usage. There
	should be no change required to existing mirror variable values
	themselves.

	- *The Subversion (SVN) Fetcher Uses an "ssh" Parameter and Not an
	"rsh" Parameter:* The SVN fetcher now takes an "ssh" parameter
	instead of an "rsh" parameter. This new optional parameter is used
	when the "protocol" parameter is set to "svn+ssh". You can only use
	the new parameter to specify the ``ssh`` program used by SVN. The SVN
	fetcher passes the new parameter through the ``SVN_SSH`` environment
	variable during the :ref:`ref-tasks-fetch` task.

	See the ":ref:`bitbake:bitbake-user-manual/bitbake-user-manual-fetching:subversion (svn) fetcher (\`\`svn://\`\`)`"
	section in the BitBake
	User Manual for additional information.

	- ``BB_SETSCENE_VERIFY_FUNCTION`` and ``BB_SETSCENE_VERIFY_FUNCTION2``
	Removed: Because the mechanism they were part of is no longer
	necessary with recipe-specific sysroots, the
	``BB_SETSCENE_VERIFY_FUNCTION`` and ``BB_SETSCENE_VERIFY_FUNCTION2``
	variables have been removed.

	.. _migration-2.3-absolute-symlinks:

	Absolute Symbolic Links
	-----------------------

	Absolute symbolic links (symlinks) within staged files are no longer
	permitted and now trigger an error. Any explicit creation of symlinks
	can use the ``lnr`` script, which is a replacement for ``ln -r``.

	If the build scripts in the software that the recipe is building are
	creating a number of absolute symlinks that need to be corrected, you
	can inherit ``relative_symlinks`` within the recipe to turn those
	absolute symlinks into relative symlinks.

	.. _migration-2.3-gplv2-and-gplv3-moves:

	GPLv2 Versions of GPLv3 Recipes Moved
	-------------------------------------

	Older GPLv2 versions of GPLv3 recipes have moved to a separate
	``meta-gplv2`` layer.

	If you use :term:`INCOMPATIBLE_LICENSE` to
	exclude GPLv3 or set :term:`PREFERRED_VERSION`
	to substitute a GPLv2 version of a GPLv3 recipe, then you must add the
	``meta-gplv2`` layer to your configuration.

	.. note::

	You can ``find meta-gplv2`` layer in the OpenEmbedded layer index at
	https://layers.openembedded.org/layerindex/branch/master/layer/meta-gplv2/.

	These relocated GPLv2 recipes do not receive the same level of
	maintenance as other core recipes. The recipes do not get security fixes
	and upstream no longer maintains them. In fact, the upstream community
	is actively hostile towards people that use the old versions of the
	recipes. Moving these recipes into a separate layer both makes the
	different needs of the recipes clearer and clearly identifies the number
	of these recipes.

	.. note::

	The long-term solution might be to move to BSD-licensed replacements
	of the GPLv3 components for those that need to exclude GPLv3-licensed
	components from the target system. This solution will be investigated
	for future Yocto Project releases.

	.. _migration-2.3-package-management-changes:

	Package Management Changes
	--------------------------

	The following package management changes took place:

	- Smart package manager is replaced by DNF package manager. Smart has
	become unmaintained upstream, is not ported to Python 3.x.
	Consequently, Smart needed to be replaced. DNF is the only feasible
	candidate.

	The change in functionality is that the on-target runtime package
	management from remote package feeds is now done with a different
	tool that has a different set of command-line options. If you have
	scripts that call the tool directly, or use its API, they need to be
	fixed.

	For more information, see the `DNF
	Documentation <http://dnf.readthedocs.io/en/latest/>`__.

	- Rpm 5.x is replaced with Rpm 4.x. This is done for two major reasons:

	- DNF is API-incompatible with Rpm 5.x and porting it and
	maintaining the port is non-trivial.

	- Rpm 5.x itself has limited maintenance upstream, and the Yocto
	Project is one of the very few remaining users.

	- Berkeley DB 6.x is removed and Berkeley DB 5.x becomes the default:

	- Version 6.x of Berkeley DB has largely been rejected by the open
	source community due to its AGPLv3 license. As a result, most
	mainstream open source projects that require DB are still
	developed and tested with DB 5.x.

	- In OE-core, the only thing that was requiring DB 6.x was Rpm 5.x.
	Thus, no reason exists to continue carrying DB 6.x in OE-core.

	- ``createrepo`` is replaced with ``createrepo_c``.

	``createrepo_c`` is the current incarnation of the tool that
	generates remote repository metadata. It is written in C as compared
	to ``createrepo``, which is written in Python. ``createrepo_c`` is
	faster and is maintained.

	- Architecture-independent RPM packages are "noarch" instead of "all".

	This change was made because too many places in DNF/RPM4 stack
	already make that assumption. Only the filenames and the architecture
	tag has changed. Nothing else has changed in OE-core system,
	particularly in the :ref:`allarch.bbclass <ref-classes-allarch>`
	class.

	- Signing of remote package feeds using ``PACKAGE_FEED_SIGN`` is not
	currently supported. This issue will be fully addressed in a future
	Yocto Project release. See :yocto_bugs:`defect 11209 </show_bug.cgi?id=11209>`
	for more information on a solution to package feed signing with RPM
	in the Yocto Project 2.3 release.

	- OPKG now uses the libsolv backend for resolving package dependencies
	by default. This is vastly superior to OPKG's internal ad-hoc solver
	that was previously used. This change does have a small impact on
	disk (around 500 KB) and memory footprint.

	.. note::

	For further details on this change, see the
	:yocto_git:`commit message </poky/commit/?id=f4d4f99cfbc2396e49c1613a7d237b9e57f06f81>`.

	.. _migration-2.3-removed-recipes:

	Removed Recipes
	---------------

	The following recipes have been removed:

	- ``linux-yocto 4.8``: Version 4.8 has been removed. Versions 4.1
	(LTSI), 4.4 (LTS), 4.9 (LTS/LTSI) and 4.10 are now present.

	- ``python-smartpm``: Functionally replaced by ``dnf``.

	- ``createrepo``: Replaced by the ``createrepo-c`` recipe.

	- ``rpmresolve``: No longer needed with the move to RPM 4 as RPM
	itself is used instead.

	- ``gstreamer``: Removed the GStreamer Git version recipes as they
	have been stale. ``1.10.``\ x recipes are still present.

	- ``alsa-conf-base``: Merged into ``alsa-conf`` since ``libasound``
	depended on both. Essentially, no way existed to install only one of
	these.

	- ``tremor``: Moved to ``meta-multimedia``. Fixed-integer Vorbis
	decoding is not needed by current hardware. Thus, GStreamer's ivorbis
	plugin has been disabled by default eliminating the need for the
	``tremor`` recipe in :term:`OpenEmbedded-Core (OE-Core)`.

	- ``gummiboot``: Replaced by ``systemd-boot``.

	.. _migration-2.3-wic-changes:

	Wic Changes
	-----------

	The following changes have been made to Wic:

	.. note::

	For more information on Wic, see the
	":ref:`dev-manual/common-tasks:creating partitioned images using wic`"
	section in the Yocto Project Development Tasks Manual.

	- Default Output Directory Changed: Wic's default output directory is
	now the current directory by default instead of the unusual
	``/var/tmp/wic``.

	The "-o" and "--outdir" options remain unchanged and are used to
	specify your preferred output directory if you do not want to use the
	default directory.

	- fsimage Plug-in Removed: The Wic fsimage plugin has been removed as
	it duplicates functionality of the rawcopy plugin.

	.. _migration-2.3-qa-changes:

	QA Changes
	----------

	The following QA checks have changed:

	- ``unsafe-references-in-binaries``: The
	``unsafe-references-in-binaries`` QA check, which was disabled by
	default, has now been removed. This check was intended to detect
	binaries in ``/bin`` that link to libraries in ``/usr/lib`` and have
	the case where the user has ``/usr`` on a separate filesystem to
	``/``.

	The removed QA check was buggy. Additionally, ``/usr`` residing on a
	separate partition from ``/`` is now a rare configuration.
	Consequently, ``unsafe-references-in-binaries`` was removed.

	- ``file-rdeps``: The ``file-rdeps`` QA check is now an error by
	default instead of a warning. Because it is an error instead of a
	warning, you need to address missing runtime dependencies.

	For additional information, see the
	:ref:`insane <ref-classes-insane>` class and the
	":ref:`ref-manual/qa-checks:errors and warnings`" section.

	.. _migration-2.3-miscellaneous-changes:

	Miscellaneous Changes
	---------------------

	The following miscellaneous changes have occurred:

	- In this release, a number of recipes have been changed to ignore the
	``largefile`` :term:`DISTRO_FEATURES` item,
	enabling large file support unconditionally. This feature has always
	been enabled by default. Disabling the feature has not been widely
	tested.

	.. note::

	Future releases of the Yocto Project will remove entirely the
	ability to disable the
	largefile
	feature, which would make it unconditionally enabled everywhere.

	- If the :term:`DISTRO_VERSION` value contains
	the value of the :term:`DATE` variable, which is the
	default between Poky releases, the ``DATE`` value is explicitly
	excluded from ``/etc/issue`` and ``/etc/issue.net``, which is
	displayed at the login prompt, in order to avoid conflicts with
	Multilib enabled. Regardless, the ``DATE`` value is inaccurate if the
	``base-files`` recipe is restored from shared state (sstate) rather
	than rebuilt.

	If you need the build date recorded in ``/etc/issue*`` or anywhere
	else in your image, a better method is to define a post-processing
	function to do it and have the function called from
	:term:`ROOTFS_POSTPROCESS_COMMAND`.
	Doing so ensures the value is always up-to-date with the created
	image.

	- Dropbear's ``init`` script now disables DSA host keys by default.
	This change is in line with the systemd service file, which supports
	RSA keys only, and with recent versions of OpenSSH, which deprecates
	DSA host keys.

	- The :ref:`buildhistory <ref-classes-buildhistory>` class now
	correctly uses tabs as separators between all columns in
	``installed-package-sizes.txt`` in order to aid import into other
	tools.

	- The ``USE_LDCONFIG`` variable has been replaced with the "ldconfig"
	``DISTRO_FEATURES`` feature. Distributions that previously set:
	::

	USE_LDCONFIG = "0"

	should now instead use the following:

	::

	DISTRO_FEATURES_BACKFILL_CONSIDERED_append = " ldconfig"

	- The default value of
	:term:`COPYLEFT_LICENSE_INCLUDE` now
	includes all versions of AGPL licenses in addition to GPL and LGPL.

	.. note::

	The default list is not intended to be guaranteed as a complete
	safe list. You should seek legal advice based on what you are
	distributing if you are unsure.

	- Kernel module packages are now suffixed with the kernel version in
	order to allow module packages from multiple kernel versions to
	co-exist on a target system. If you wish to return to the previous
	naming scheme that does not include the version suffix, use the
	following:
	::

	KERNEL_MODULE_PACKAGE_SUFFIX = ""

	- Removal of ``libtool`` ``*.la`` files is now enabled by default. The
	``*.la`` files are not actually needed on Linux and relocating them
	is an unnecessary burden.

	If you need to preserve these ``.la`` files (e.g. in a custom
	distribution), you must change
	:term:`INHERIT_DISTRO` such that
	"remove-libtool" is not included in the value.

	- Extensible SDKs built for GCC 5+ now refuse to install on a
	distribution where the host GCC version is 4.8 or 4.9. This change
	resulted from the fact that the installation is known to fail due to
	the way the ``uninative`` shared state (sstate) package is built. See
	the :ref:`uninative <ref-classes-uninative>` class for additional
	information.

	- All native and nativesdk recipes now use a separate
	``DISTRO_FEATURES`` value instead of sharing the value used by
	recipes for the target, in order to avoid unnecessary rebuilds.

	The ``DISTRO_FEATURES`` for ``native`` recipes is
	:term:`DISTRO_FEATURES_NATIVE` added to
	an intersection of ``DISTRO_FEATURES`` and
	:term:`DISTRO_FEATURES_FILTER_NATIVE`.

	For nativesdk recipes, the corresponding variables are
	:term:`DISTRO_FEATURES_NATIVESDK`
	and
	:term:`DISTRO_FEATURES_FILTER_NATIVESDK`.

	- The ``FILESDIR`` variable, which was previously deprecated and rarely
	used, has now been removed. You should change any recipes that set
	``FILESDIR`` to set :term:`FILESPATH` instead.

	- The ``MULTIMACH_HOST_SYS`` variable has been removed as it is no
	longer needed with recipe-specific sysroots.