poky: subtree update:0ac99625bf..796be0593a
Alexander Kanavin (31):
netbase: upgrade 6.1 -> 6.2
meson: upgrade 0.55.1 -> 0.56.0
vulkan-samples: update to latest revision
libcap: update 2.44 -> 2.45
bind: upgrade 9.16.7 -> 9.16.9
quota: upgrade 4.05 -> 4.06
pango: upgrade 1.46.2 -> 1.48.0
elfutils: upgrade 0.181 -> 0.182
ifupdown: upgrade 0.8.35 -> 0.8.36
createrepo-c: upgrade 0.16.1 -> 0.16.2
acpica: upgrade 20200925 -> 20201113
grep: upgrade 3.5 -> 3.6
man-pages: upgrade 5.08 -> 5.09
stress-ng: upgrade 0.11.23 -> 0.11.24
libhandy: upgrade 1.0.1 -> 1.0.2
piglit: upgrade to latest revision
xkbcomp: upgrade 1.4.3 -> 1.4.4
lz4: upgrade 1.9.2 -> 1.9.3
bison: upgrade 3.7.3 -> 3.7.4
python3-setuptools-scm: fix upstream version check
cantarell-fonts: update 0.0.25 -> 0.201
meta/lib/oe/reproducible.py: gitsm:// works just as fine as git:// for timestamps
llvm: fix reproducibility
ruby: fix reproducibility
webkitgtk: fix reproducibility
ffmpeg: fix reproducibility
piglit: fix reproducibility
serf: do not install the static library
llvm: sort the lists in generated source reproducibibly
kea: fix reproducibility
poky.conf: do not write current date into distro version, use git hash instead
Andrej Valek (1):
kernel-dummy: fix executing unexpected tasks
Anuj Mittal (1):
releases.rst: add gatesgarth to current releases
Brett Warren (1):
libffi: add patch to revert clang VFP workaround
Chandana kalluri (1):
populate_sdk_ext: use SDK_CUSTOM_TEPLATECONF variable to enable custom templateconf.cfg
Changqing Li (1):
buildtools-tarball: add wic dependency into extended buildtools
Diego Sueiro (2):
modutils-initscripts: Fix modules.dep creation when USE_DEPMOD="0"
initscripts: Change execution order between checkroot and modutils
Dmitry Baryshkov (2):
linux-firmware: upgrade 20201022 -> 20201118
linux-firmware: package ath11k firmware
Fabio Berton (1):
mesa: Update 20.2.1 -> 20.2.4
Gratian Crisan (1):
kernel-module-split.bbclass: fix kernel modules getting marked as CONFFILES
Jack Mitchell (3):
Revert "connman: set service to conflict with systemd-networkd"
systemd-conf: add PACKAGECONFIG to enable/disable auto ethernet DHCP
systemd-conf: match ethernet interfaces by type rather than globbing
Joshua Watt (2):
bitbake: hashserv: client: Fix AF_UNIX path length limits
bitbake: hashserv: Fix broken AF_UNIX path length limit
Kai Kang (2):
systemd-systemctl-native: capable to call without argument
systemd.bbclass: update command to check systemctl available
Kevin Hao (1):
tune-octeontx2.inc: Add tune for Marvell OCTEON TX2 core
Li Wang (2):
qemu: CVE-2020-29129 CVE-2020-29130
qemu: CVE-2020-25624
Luca Boccassi (1):
dbus: move messagebus user to dbus-common package
Michael Halstead (1):
releases: conf: add link to 3.1.4, update to include 3.1.4
Nicolas Dechesne (19):
sphinx: add .vscode in .gitignore
{dev,kernel,sdk}-manual: replace hardcoded release version with &DISTRO;
sphinx: replace bitbake labels with references to corresponding title
brief-yoctoprojectqs: replace labels with references to section title
dev-manual: replace labels with references to section title
ref-manual: replace labels with references to section title
sdk-manual: replace labels with references to section title
overview-manual: remove unused labels
dev-manual: remove unused labels
sphinx: rename top level document in each manual
sphinx: use absolute paths for :doc: references
test-manual: remove 'test-manual' from filenames
toaster-manual: remove 'toaster-manual' from filenames
dev-manual: remove 'dev-manual' from filenames
kernel-dev: remove 'kernel-dev' from filenames
profile-manual: remove 'profile-manual' from filenames
overview-manual: remove 'overview-manual' from filenames
sdk-manual: remove 'sdk' from filenames
ref-manual: remove 'ref' from filenames
Paul Barker (5):
documentation: Simplify yocto_wiki links
documentation: Simplify yocto_git links
ref-manual: Simplify oe_git links
poky.conf: Add opensuseleap-15.2 and fedora-33 to tested distros
poky.conf: Drop fedora-30 from tested distros
Peter Kjellerstedt (2):
pseudo: Simplify pseudo_client_ignore_path_chroot()
bitbake.conf: Add all layers (from BBLAYERS) to PSEUDO_IGNORE_PATHS
Richard Purdie (8):
lz4: Use the new branch naming from upstream
Revert "bitbake.conf: Add all layers (from BBLAYERS) to PSEUDO_IGNORE_PATHS"
build-appliance-image: Update to master head revision
bitbake: Revert "fetch2: use relative symlinks for anything pulled from PREMIRRORS"
build-appliance-image: Update to master head revision
metadata_scm: Fix signature handling of METADATA_REVISION and METADATA_BRANCH
poky: Set SDK_VERSION explicitly
build-appliance-image: Update to master head revision
Ross Burton (9):
oeqa/devtool: use Yocto mirror for pv-1.5.3 tarball
image_types: remove obsolete tar comment
image_types: sort tarball file listings
package_manager/ipk: neaten OPKGLIBDIR logic
ldconfig-native: don't write auxiliary cache
package_manager/ipk: improve remove_packaging_data
oeqa/selftest/containerimage: update for improved cleanup
coreutils: add SUSE-specific issues to CVE whitelist
bitbake: msg: use safe YAML loader
Sinan Kaya (1):
poky-tiny: enable section removal
Tomasz Dziendzielski (1):
pseudo: Update to print PSEUDO_LOGFILE in abort message on path mismatches
sangeeta jain (1):
meta/lib/oeqa/manual/oe-core.json: Update test_bitbake_devshell
zangrc (3):
libinput: upgrade 1.16.3 -> 1.16.4
lighttpd: upgrade 1.4.55 -> 1.4.56
sysstat: upgrade 12.4.0 -> 12.4.1
Signed-off-by: Andrew Geissler <geissonator@yahoo.com>
Change-Id: I65f2f1c9d44433f3e62609240012c42256679b51
diff --git a/poky/documentation/sdk-manual/extensible.rst b/poky/documentation/sdk-manual/extensible.rst
new file mode 100644
index 0000000..c94213d
--- /dev/null
+++ b/poky/documentation/sdk-manual/extensible.rst
@@ -0,0 +1,1312 @@
+.. SPDX-License-Identifier: CC-BY-SA-2.0-UK
+
+************************
+Using the Extensible SDK
+************************
+
+This chapter describes the extensible SDK and how to install it.
+Information covers the pieces of the SDK, how to install it, and
+presents a look at using the ``devtool`` functionality. The extensible
+SDK makes it easy to add new applications and libraries to an image,
+modify the source for an existing component, test changes on the target
+hardware, and ease integration into the rest of the
+:term:`OpenEmbedded Build System`.
+
+.. note::
+
+ For a side-by-side comparison of main features supported for an
+ extensible SDK as compared to a standard SDK, see the "
+ Introduction
+ " section.
+
+In addition to the functionality available through ``devtool``, you can
+alternatively make use of the toolchain directly, for example from
+Makefile and Autotools. See the "`Using the SDK Toolchain
+Directly <#sdk-working-projects>`__" chapter for more information.
+
+Why use the Extensible SDK and What is in It?
+=============================================
+
+The extensible SDK provides a cross-development toolchain and libraries
+tailored to the contents of a specific image. You would use the
+Extensible SDK if you want a toolchain experience supplemented with the
+powerful set of ``devtool`` commands tailored for the Yocto Project
+environment.
+
+The installed extensible SDK consists of several files and directories.
+Basically, it contains an SDK environment setup script, some
+configuration files, an internal build system, and the ``devtool``
+functionality.
+
+Installing the Extensible SDK
+=============================
+
+The first thing you need to do is install the SDK on your :term:`Build
+Host` by running the ``*.sh`` installation script.
+
+You can download a tarball installer, which includes the pre-built
+toolchain, the ``runqemu`` script, the internal build system,
+``devtool``, and support files from the appropriate
+:yocto_dl:`toolchain </releases/yocto/yocto-&DISTRO;/toolchain/>` directory within the Index of
+Releases. Toolchains are available for several 32-bit and 64-bit
+architectures with the ``x86_64`` directories, respectively. The
+toolchains the Yocto Project provides are based off the
+``core-image-sato`` and ``core-image-minimal`` images and contain
+libraries appropriate for developing against that image.
+
+The names of the tarball installer scripts are such that a string
+representing the host system appears first in the filename and then is
+immediately followed by a string representing the target architecture.
+An extensible SDK has the string "-ext" as part of the name. Following
+is the general form:
+::
+
+ poky-glibc-host_system-image_type-arch-toolchain-ext-release_version.sh
+
+ Where:
+ host_system is a string representing your development system:
+
+ i686 or x86_64.
+
+ image_type is the image for which the SDK was built:
+
+ core-image-sato or core-image-minimal
+
+ arch is a string representing the tuned target architecture:
+
+ aarch64, armv5e, core2-64, i586, mips32r2, mips64, ppc7400, or cortexa8hf-neon
+
+ release_version is a string representing the release number of the Yocto Project:
+
+ &DISTRO;, &DISTRO;+snapshot
+
+For example, the following SDK installer is for a 64-bit
+development host system and a i586-tuned target architecture based off
+the SDK for ``core-image-sato`` and using the current DISTRO snapshot:
+::
+
+ poky-glibc-x86_64-core-image-sato-i586-toolchain-ext-DISTRO.sh
+
+.. note::
+
+ As an alternative to downloading an SDK, you can build the SDK
+ installer. For information on building the installer, see the "
+ Building an SDK Installer
+ " section.
+
+The SDK and toolchains are self-contained and by default are installed
+into the ``poky_sdk`` folder in your home directory. You can choose to
+install the extensible SDK in any location when you run the installer.
+However, because files need to be written under that directory during
+the normal course of operation, the location you choose for installation
+must be writable for whichever users need to use the SDK.
+
+The following command shows how to run the installer given a toolchain
+tarball for a 64-bit x86 development host system and a 64-bit x86 target
+architecture. The example assumes the SDK installer is located in
+``~/Downloads/`` and has execution rights.
+
+.. note::
+
+ If you do not have write permissions for the directory into which you
+ are installing the SDK, the installer notifies you and exits. For
+ that case, set up the proper permissions in the directory and run the
+ installer again.
+
+::
+
+ $ ./Downloads/poky-glibc-x86_64-core-image-minimal-core2-64-toolchain-ext-2.5.sh
+ Poky (Yocto Project Reference Distro) Extensible SDK installer version 2.5
+ ==========================================================================
+ Enter target directory for SDK (default: ~/poky_sdk):
+ You are about to install the SDK to "/home/scottrif/poky_sdk". Proceed [Y/n]? Y
+ Extracting SDK..............done
+ Setting it up...
+ Extracting buildtools...
+ Preparing build system...
+ Parsing recipes: 100% |##################################################################| Time: 0:00:52
+ Initialising tasks: 100% |###############################################################| Time: 0:00:00
+ Checking sstate mirror object availability: 100% |#######################################| Time: 0:00:00
+ Loading cache: 100% |####################################################################| Time: 0:00:00
+ Initialising tasks: 100% |###############################################################| Time: 0:00:00
+ done
+ SDK has been successfully set up and is ready to be used.
+ Each time you wish to use the SDK in a new shell session, you need to source the environment setup script e.g.
+ $ . /home/scottrif/poky_sdk/environment-setup-core2-64-poky-linux
+
+Running the Extensible SDK Environment Setup Script
+===================================================
+
+Once you have the SDK installed, you must run the SDK environment setup
+script before you can actually use the SDK. This setup script resides in
+the directory you chose when you installed the SDK, which is either the
+default ``poky_sdk`` directory or the directory you chose during
+installation.
+
+Before running the script, be sure it is the one that matches the
+architecture for which you are developing. Environment setup scripts
+begin with the string "``environment-setup``" and include as part of
+their name the tuned target architecture. As an example, the following
+commands set the working directory to where the SDK was installed and
+then source the environment setup script. In this example, the setup
+script is for an IA-based target machine using i586 tuning:
+::
+
+ $ cd /home/scottrif/poky_sdk
+ $ source environment-setup-core2-64-poky-linux
+ SDK environment now set up; additionally you may now run devtool to perform development tasks.
+ Run devtool --help for further details.
+
+Running the setup script defines many environment variables needed in
+order to use the SDK (e.g. ``PATH``,
+:term:`CC`,
+:term:`LD`, and so forth). If you want to
+see all the environment variables the script exports, examine the
+installation file itself.
+
+Using ``devtool`` in Your SDK Workflow
+======================================
+
+The cornerstone of the extensible SDK is a command-line tool called
+``devtool``. This tool provides a number of features that help you
+build, test and package software within the extensible SDK, and
+optionally integrate it into an image built by the OpenEmbedded build
+system.
+
+.. note::
+
+ The use of
+ devtool
+ is not limited to the extensible SDK. You can use
+ devtool
+ to help you easily develop any project whose build output must be
+ part of an image built using the build system.
+
+The ``devtool`` command line is organized similarly to
+:ref:`overview-manual/development-environment:git` in that it has a number of
+sub-commands for each function. You can run ``devtool --help`` to see
+all the commands.
+
+.. note::
+
+ See the "
+ devtool
+ Quick Reference
+ " in the Yocto Project Reference Manual for a
+ devtool
+ quick reference.
+
+Three ``devtool`` subcommands exist that provide entry-points into
+development:
+
+- *devtool add*: Assists in adding new software to be built.
+
+- *devtool modify*: Sets up an environment to enable you to modify
+ the source of an existing component.
+
+- *devtool upgrade*: Updates an existing recipe so that you can
+ build it for an updated set of source files.
+
+As with the build system, "recipes" represent software packages within
+``devtool``. When you use ``devtool add``, a recipe is automatically
+created. When you use ``devtool modify``, the specified existing recipe
+is used in order to determine where to get the source code and how to
+patch it. In both cases, an environment is set up so that when you build
+the recipe a source tree that is under your control is used in order to
+allow you to make changes to the source as desired. By default, new
+recipes and the source go into a "workspace" directory under the SDK.
+
+The remainder of this section presents the ``devtool add``,
+``devtool modify``, and ``devtool upgrade`` workflows.
+
+Use ``devtool add`` to Add an Application
+-----------------------------------------
+
+The ``devtool add`` command generates a new recipe based on existing
+source code. This command takes advantage of the
+:ref:`devtool-the-workspace-layer-structure`
+layer that many ``devtool`` commands use. The command is flexible enough
+to allow you to extract source code into both the workspace or a
+separate local Git repository and to use existing code that does not
+need to be extracted.
+
+Depending on your particular scenario, the arguments and options you use
+with ``devtool add`` form different combinations. The following diagram
+shows common development flows you would use with the ``devtool add``
+command:
+
+.. image:: figures/sdk-devtool-add-flow.png
+ :align: center
+
+1. *Generating the New Recipe*: The top part of the flow shows three
+ scenarios by which you could use ``devtool add`` to generate a recipe
+ based on existing source code.
+
+ In a shared development environment, it is typical for other
+ developers to be responsible for various areas of source code. As a
+ developer, you are probably interested in using that source code as
+ part of your development within the Yocto Project. All you need is
+ access to the code, a recipe, and a controlled area in which to do
+ your work.
+
+ Within the diagram, three possible scenarios feed into the
+ ``devtool add`` workflow:
+
+ - *Left*: The left scenario in the figure represents a common
+ situation where the source code does not exist locally and needs
+ to be extracted. In this situation, the source code is extracted
+ to the default workspace - you do not want the files in some
+ specific location outside of the workspace. Thus, everything you
+ need will be located in the workspace:
+ ::
+
+ $ devtool add recipe fetchuri
+
+ With this command, ``devtool`` extracts the upstream
+ source files into a local Git repository within the ``sources``
+ folder. The command then creates a recipe named recipe and a
+ corresponding append file in the workspace. If you do not provide
+ recipe, the command makes an attempt to determine the recipe name.
+
+ - *Middle*: The middle scenario in the figure also represents a
+ situation where the source code does not exist locally. In this
+ case, the code is again upstream and needs to be extracted to some
+ local area - this time outside of the default workspace.
+
+ .. note::
+
+ If required,
+ devtool
+ always creates a Git repository locally during the extraction.
+
+ Furthermore, the first positional argument srctree in this case
+ identifies where the ``devtool add`` command will locate the
+ extracted code outside of the workspace. You need to specify an
+ empty directory:
+ ::
+
+ $ devtool add recipe srctree fetchuri
+
+ In summary,
+ the source code is pulled from fetchuri and extracted into the
+ location defined by srctree as a local Git repository.
+
+ Within workspace, ``devtool`` creates a recipe named recipe along
+ with an associated append file.
+
+ - *Right*: The right scenario in the figure represents a situation
+ where the srctree has been previously prepared outside of the
+ ``devtool`` workspace.
+
+ The following command provides a new recipe name and identifies
+ the existing source tree location:
+ ::
+
+ $ devtool add recipe srctree
+
+ The command examines the source code and creates a recipe named
+ recipe for the code and places the recipe into the workspace.
+
+ Because the extracted source code already exists, ``devtool`` does
+ not try to relocate the source code into the workspace - only the
+ new recipe is placed in the workspace.
+
+ Aside from a recipe folder, the command also creates an associated
+ append folder and places an initial ``*.bbappend`` file within.
+
+2. *Edit the Recipe*: You can use ``devtool edit-recipe`` to open up the
+ editor as defined by the ``$EDITOR`` environment variable and modify
+ the file:
+ ::
+
+ $ devtool edit-recipe recipe
+
+ From within the editor, you
+ can make modifications to the recipe that take affect when you build
+ it later.
+
+3. *Build the Recipe or Rebuild the Image*: The next step you take
+ depends on what you are going to do with the new code.
+
+ If you need to eventually move the build output to the target
+ hardware, use the following ``devtool`` command:
+ :;
+
+ $ devtool build recipe
+
+ On the other hand, if you want an image to contain the recipe's
+ packages from the workspace for immediate deployment onto a device
+ (e.g. for testing purposes), you can use the ``devtool build-image``
+ command:
+ ::
+
+ $ devtool build-image image
+
+4. *Deploy the Build Output*: When you use the ``devtool build`` command
+ to build out your recipe, you probably want to see if the resulting
+ build output works as expected on the target hardware.
+
+ .. note::
+
+ This step assumes you have a previously built image that is
+ already either running in QEMU or is running on actual hardware.
+ Also, it is assumed that for deployment of the image to the
+ target, SSH is installed in the image and, if the image is running
+ on real hardware, you have network access to and from your
+ development machine.
+
+ You can deploy your build output to that target hardware by using the
+ ``devtool deploy-target`` command: $ devtool deploy-target recipe
+ target The target is a live target machine running as an SSH server.
+
+ You can, of course, also deploy the image you build to actual
+ hardware by using the ``devtool build-image`` command. However,
+ ``devtool`` does not provide a specific command that allows you to
+ deploy the image to actual hardware.
+
+5. *Finish Your Work With the Recipe*: The ``devtool finish`` command
+ creates any patches corresponding to commits in the local Git
+ repository, moves the new recipe to a more permanent layer, and then
+ resets the recipe so that the recipe is built normally rather than
+ from the workspace.
+ ::
+
+ $ devtool finish recipe layer
+
+ .. note::
+
+ Any changes you want to turn into patches must be committed to the
+ Git repository in the source tree.
+
+ As mentioned, the ``devtool finish`` command moves the final recipe
+ to its permanent layer.
+
+ As a final process of the ``devtool finish`` command, the state of
+ the standard layers and the upstream source is restored so that you
+ can build the recipe from those areas rather than the workspace.
+
+ .. note::
+
+ You can use the
+ devtool reset
+ command to put things back should you decide you do not want to
+ proceed with your work. If you do use this command, realize that
+ the source tree is preserved.
+
+Use ``devtool modify`` to Modify the Source of an Existing Component
+--------------------------------------------------------------------
+
+The ``devtool modify`` command prepares the way to work on existing code
+that already has a local recipe in place that is used to build the
+software. The command is flexible enough to allow you to extract code
+from an upstream source, specify the existing recipe, and keep track of
+and gather any patch files from other developers that are associated
+with the code.
+
+Depending on your particular scenario, the arguments and options you use
+with ``devtool modify`` form different combinations. The following
+diagram shows common development flows for the ``devtool modify``
+command:
+
+.. image:: figures/sdk-devtool-modify-flow.png
+ :align: center
+
+1. *Preparing to Modify the Code*: The top part of the flow shows three
+ scenarios by which you could use ``devtool modify`` to prepare to
+ work on source files. Each scenario assumes the following:
+
+ - The recipe exists locally in a layer external to the ``devtool``
+ workspace.
+
+ - The source files exist either upstream in an un-extracted state or
+ locally in a previously extracted state.
+
+ The typical situation is where another developer has created a layer
+ for use with the Yocto Project and their recipe already resides in
+ that layer. Furthermore, their source code is readily available
+ either upstream or locally.
+
+ - *Left*: The left scenario in the figure represents a common
+ situation where the source code does not exist locally and it
+ needs to be extracted from an upstream source. In this situation,
+ the source is extracted into the default ``devtool`` workspace
+ location. The recipe, in this scenario, is in its own layer
+ outside the workspace (i.e. ``meta-``\ layername).
+
+ The following command identifies the recipe and, by default,
+ extracts the source files:
+ ::
+
+ $ devtool modify recipe
+
+ Once
+ ``devtool``\ locates the recipe, ``devtool`` uses the recipe's
+ :term:`SRC_URI` statements to
+ locate the source code and any local patch files from other
+ developers.
+
+ With this scenario, no srctree argument exists. Consequently, the
+ default behavior of the ``devtool modify`` command is to extract
+ the source files pointed to by the ``SRC_URI`` statements into a
+ local Git structure. Furthermore, the location for the extracted
+ source is the default area within the ``devtool`` workspace. The
+ result is that the command sets up both the source code and an
+ append file within the workspace while the recipe remains in its
+ original location.
+
+ Additionally, if you have any non-patch local files (i.e. files
+ referred to with ``file://`` entries in ``SRC_URI`` statement
+ excluding ``*.patch/`` or ``*.diff``), these files are copied to
+ an ``oe-local-files`` folder under the newly created source tree.
+ Copying the files here gives you a convenient area from which you
+ can modify the files. Any changes or additions you make to those
+ files are incorporated into the build the next time you build the
+ software just as are other changes you might have made to the
+ source.
+
+ - *Middle*: The middle scenario in the figure represents a situation
+ where the source code also does not exist locally. In this case,
+ the code is again upstream and needs to be extracted to some local
+ area as a Git repository. The recipe, in this scenario, is again
+ local and in its own layer outside the workspace.
+
+ The following command tells ``devtool`` the recipe with which to
+ work and, in this case, identifies a local area for the extracted
+ source files that exists outside of the default ``devtool``
+ workspace:
+ ::
+
+ $ devtool modify recipe srctree
+
+ .. note::
+
+ You cannot provide a URL for
+ srctree
+ using the
+ devtool
+ command.
+
+ As with all extractions, the command uses the recipe's ``SRC_URI``
+ statements to locate the source files and any associated patch
+ files. Non-patch files are copied to an ``oe-local-files`` folder
+ under the newly created source tree.
+
+ Once the files are located, the command by default extracts them
+ into srctree.
+
+ Within workspace, ``devtool`` creates an append file for the
+ recipe. The recipe remains in its original location but the source
+ files are extracted to the location you provide with srctree.
+
+ - *Right*: The right scenario in the figure represents a situation
+ where the source tree (srctree) already exists locally as a
+ previously extracted Git structure outside of the ``devtool``
+ workspace. In this example, the recipe also exists elsewhere
+ locally in its own layer.
+
+ The following command tells ``devtool`` the recipe with which to
+ work, uses the "-n" option to indicate source does not need to be
+ extracted, and uses srctree to point to the previously extracted
+ source files:
+ ::
+
+ $ devtool modify -n recipe srctree
+
+ If an ``oe-local-files`` subdirectory happens to exist and it
+ contains non-patch files, the files are used. However, if the
+ subdirectory does not exist and you run the ``devtool finish``
+ command, any non-patch files that might exist next to the recipe
+ are removed because it appears to ``devtool`` that you have
+ deleted those files.
+
+ Once the ``devtool modify`` command finishes, it creates only an
+ append file for the recipe in the ``devtool`` workspace. The
+ recipe and the source code remain in their original locations.
+
+2. *Edit the Source*: Once you have used the ``devtool modify`` command,
+ you are free to make changes to the source files. You can use any
+ editor you like to make and save your source code modifications.
+
+3. *Build the Recipe or Rebuild the Image*: The next step you take
+ depends on what you are going to do with the new code.
+
+ If you need to eventually move the build output to the target
+ hardware, use the following ``devtool`` command:
+ ::
+
+ $ devtool build recipe
+
+ On the other hand, if you want an image to contain the recipe's
+ packages from the workspace for immediate deployment onto a device
+ (e.g. for testing purposes), you can use the ``devtool build-image``
+ command: $ devtool build-image image
+
+4. *Deploy the Build Output*: When you use the ``devtool build`` command
+ to build out your recipe, you probably want to see if the resulting
+ build output works as expected on target hardware.
+
+ .. note::
+
+ This step assumes you have a previously built image that is
+ already either running in QEMU or running on actual hardware.
+ Also, it is assumed that for deployment of the image to the
+ target, SSH is installed in the image and if the image is running
+ on real hardware that you have network access to and from your
+ development machine.
+
+ You can deploy your build output to that target hardware by using the
+ ``devtool deploy-target`` command:
+ ::
+
+ $ devtool deploy-target recipe target
+
+ The target is a live target machine running as an SSH server.
+
+ You can, of course, use other methods to deploy the image you built
+ using the ``devtool build-image`` command to actual hardware.
+ ``devtool`` does not provide a specific command to deploy the image
+ to actual hardware.
+
+5. *Finish Your Work With the Recipe*: The ``devtool finish`` command
+ creates any patches corresponding to commits in the local Git
+ repository, updates the recipe to point to them (or creates a
+ ``.bbappend`` file to do so, depending on the specified destination
+ layer), and then resets the recipe so that the recipe is built
+ normally rather than from the workspace.
+ ::
+
+ $ devtool finish recipe layer
+
+ .. note::
+
+ Any changes you want to turn into patches must be staged and
+ committed within the local Git repository before you use the
+ devtool finish
+ command.
+
+ Because there is no need to move the recipe, ``devtool finish``
+ either updates the original recipe in the original layer or the
+ command creates a ``.bbappend`` file in a different layer as provided
+ by layer. Any work you did in the ``oe-local-files`` directory is
+ preserved in the original files next to the recipe during the
+ ``devtool finish`` command.
+
+ As a final process of the ``devtool finish`` command, the state of
+ the standard layers and the upstream source is restored so that you
+ can build the recipe from those areas rather than from the workspace.
+
+ .. note::
+
+ You can use the
+ devtool reset
+ command to put things back should you decide you do not want to
+ proceed with your work. If you do use this command, realize that
+ the source tree is preserved.
+
+Use ``devtool upgrade`` to Create a Version of the Recipe that Supports a Newer Version of the Software
+-------------------------------------------------------------------------------------------------------
+
+The ``devtool upgrade`` command upgrades an existing recipe to that of a
+more up-to-date version found upstream. Throughout the life of software,
+recipes continually undergo version upgrades by their upstream
+publishers. You can use the ``devtool upgrade`` workflow to make sure
+your recipes you are using for builds are up-to-date with their upstream
+counterparts.
+
+.. note::
+
+ Several methods exist by which you can upgrade recipes -
+ devtool upgrade
+ happens to be one. You can read about all the methods by which you
+ can upgrade recipes in the "
+ Upgrading Recipes
+ " section of the Yocto Project Development Tasks Manual.
+
+The ``devtool upgrade`` command is flexible enough to allow you to
+specify source code revision and versioning schemes, extract code into
+or out of the ``devtool``
+:ref:`devtool-the-workspace-layer-structure`,
+and work with any source file forms that the
+:ref:`fetchers <bitbake:bitbake-user-manual/bitbake-user-manual-fetching:fetchers>` support.
+
+The following diagram shows the common development flow used with the
+``devtool upgrade`` command:
+
+.. image:: figures/sdk-devtool-upgrade-flow.png
+ :align: center
+
+1. *Initiate the Upgrade*: The top part of the flow shows the typical
+ scenario by which you use the ``devtool upgrade`` command. The
+ following conditions exist:
+
+ - The recipe exists in a local layer external to the ``devtool``
+ workspace.
+
+ - The source files for the new release exist in the same location
+ pointed to by :term:`SRC_URI`
+ in the recipe (e.g. a tarball with the new version number in the
+ name, or as a different revision in the upstream Git repository).
+
+ A common situation is where third-party software has undergone a
+ revision so that it has been upgraded. The recipe you have access to
+ is likely in your own layer. Thus, you need to upgrade the recipe to
+ use the newer version of the software:
+ ::
+
+ $ devtool upgrade -V version recipe
+
+ By default, the ``devtool upgrade`` command extracts source
+ code into the ``sources`` directory in the
+ :ref:`devtool-the-workspace-layer-structure`.
+ If you want the code extracted to any other location, you need to
+ provide the srctree positional argument with the command as follows:
+ $ devtool upgrade -V version recipe srctree
+
+ .. note::
+
+ In this example, the "-V" option specifies the new version. If you
+ don't use "-V", the command upgrades the recipe to the latest
+ version.
+
+ If the source files pointed to by the ``SRC_URI`` statement in the
+ recipe are in a Git repository, you must provide the "-S" option and
+ specify a revision for the software.
+
+ Once ``devtool`` locates the recipe, it uses the ``SRC_URI`` variable
+ to locate the source code and any local patch files from other
+ developers. The result is that the command sets up the source code,
+ the new version of the recipe, and an append file all within the
+ workspace.
+
+ Additionally, if you have any non-patch local files (i.e. files
+ referred to with ``file://`` entries in ``SRC_URI`` statement
+ excluding ``*.patch/`` or ``*.diff``), these files are copied to an
+ ``oe-local-files`` folder under the newly created source tree.
+ Copying the files here gives you a convenient area from which you can
+ modify the files. Any changes or additions you make to those files
+ are incorporated into the build the next time you build the software
+ just as are other changes you might have made to the source.
+
+2. *Resolve any Conflicts created by the Upgrade*: Conflicts could exist
+ due to the software being upgraded to a new version. Conflicts occur
+ if your recipe specifies some patch files in ``SRC_URI`` that
+ conflict with changes made in the new version of the software. For
+ such cases, you need to resolve the conflicts by editing the source
+ and following the normal ``git rebase`` conflict resolution process.
+
+ Before moving onto the next step, be sure to resolve any such
+ conflicts created through use of a newer or different version of the
+ software.
+
+3. *Build the Recipe or Rebuild the Image*: The next step you take
+ depends on what you are going to do with the new code.
+
+ If you need to eventually move the build output to the target
+ hardware, use the following ``devtool`` command:
+ ::
+
+ $ devtool build recipe
+
+ On the other hand, if you want an image to contain the recipe's
+ packages from the workspace for immediate deployment onto a device
+ (e.g. for testing purposes), you can use the ``devtool build-image``
+ command:
+ ::
+
+ $ devtool build-image image
+
+4. *Deploy the Build Output*: When you use the ``devtool build`` command
+ or ``bitbake`` to build your recipe, you probably want to see if the
+ resulting build output works as expected on target hardware.
+
+ .. note::
+
+ This step assumes you have a previously built image that is
+ already either running in QEMU or running on actual hardware.
+ Also, it is assumed that for deployment of the image to the
+ target, SSH is installed in the image and if the image is running
+ on real hardware that you have network access to and from your
+ development machine.
+
+ You can deploy your build output to that target hardware by using the
+ ``devtool deploy-target`` command: $ devtool deploy-target recipe
+ target The target is a live target machine running as an SSH server.
+
+ You can, of course, also deploy the image you build using the
+ ``devtool build-image`` command to actual hardware. However,
+ ``devtool`` does not provide a specific command that allows you to do
+ this.
+
+5. *Finish Your Work With the Recipe*: The ``devtool finish`` command
+ creates any patches corresponding to commits in the local Git
+ repository, moves the new recipe to a more permanent layer, and then
+ resets the recipe so that the recipe is built normally rather than
+ from the workspace.
+
+ Any work you did in the ``oe-local-files`` directory is preserved in
+ the original files next to the recipe during the ``devtool finish``
+ command.
+
+ If you specify a destination layer that is the same as the original
+ source, then the old version of the recipe and associated files are
+ removed prior to adding the new version.
+ ::
+
+ $ devtool finish recipe layer
+
+ .. note::
+
+ Any changes you want to turn into patches must be committed to the
+ Git repository in the source tree.
+
+ As a final process of the ``devtool finish`` command, the state of
+ the standard layers and the upstream source is restored so that you
+ can build the recipe from those areas rather than the workspace.
+
+ .. note::
+
+ You can use the
+ devtool reset
+ command to put things back should you decide you do not want to
+ proceed with your work. If you do use this command, realize that
+ the source tree is preserved.
+
+A Closer Look at ``devtool add``
+================================
+
+The ``devtool add`` command automatically creates a recipe based on the
+source tree you provide with the command. Currently, the command has
+support for the following:
+
+- Autotools (``autoconf`` and ``automake``)
+
+- CMake
+
+- Scons
+
+- ``qmake``
+
+- Plain ``Makefile``
+
+- Out-of-tree kernel module
+
+- Binary package (i.e. "-b" option)
+
+- Node.js module
+
+- Python modules that use ``setuptools`` or ``distutils``
+
+Apart from binary packages, the determination of how a source tree
+should be treated is automatic based on the files present within that
+source tree. For example, if a ``CMakeLists.txt`` file is found, then
+the source tree is assumed to be using CMake and is treated accordingly.
+
+.. note::
+
+ In most cases, you need to edit the automatically generated recipe in
+ order to make it build properly. Typically, you would go through
+ several edit and build cycles until the recipe successfully builds.
+ Once the recipe builds, you could use possible further iterations to
+ test the recipe on the target device.
+
+The remainder of this section covers specifics regarding how parts of
+the recipe are generated.
+
+Name and Version
+----------------
+
+If you do not specify a name and version on the command line,
+``devtool add`` uses various metadata within the source tree in an
+attempt to determine the name and version of the software being built.
+Based on what the tool determines, ``devtool`` sets the name of the
+created recipe file accordingly.
+
+If ``devtool`` cannot determine the name and version, the command prints
+an error. For such cases, you must re-run the command and provide the
+name and version, just the name, or just the version as part of the
+command line.
+
+Sometimes the name or version determined from the source tree might be
+incorrect. For such a case, you must reset the recipe:
+::
+
+ $ devtool reset -n recipename
+
+After running the ``devtool reset`` command, you need to
+run ``devtool add`` again and provide the name or the version.
+
+Dependency Detection and Mapping
+--------------------------------
+
+The ``devtool add`` command attempts to detect build-time dependencies
+and map them to other recipes in the system. During this mapping, the
+command fills in the names of those recipes as part of the
+:term:`DEPENDS` variable within the
+recipe. If a dependency cannot be mapped, ``devtool`` places a comment
+in the recipe indicating such. The inability to map a dependency can
+result from naming not being recognized or because the dependency simply
+is not available. For cases where the dependency is not available, you
+must use the ``devtool add`` command to add an additional recipe that
+satisfies the dependency. Once you add that recipe, you need to update
+the ``DEPENDS`` variable in the original recipe to include the new
+recipe.
+
+If you need to add runtime dependencies, you can do so by adding the
+following to your recipe:
+::
+
+ RDEPENDS_${PN} += "dependency1 dependency2 ..."
+
+.. note::
+
+ The
+ devtool add
+ command often cannot distinguish between mandatory and optional
+ dependencies. Consequently, some of the detected dependencies might
+ in fact be optional. When in doubt, consult the documentation or the
+ configure script for the software the recipe is building for further
+ details. In some cases, you might find you can substitute the
+ dependency with an option that disables the associated functionality
+ passed to the configure script.
+
+License Detection
+-----------------
+
+The ``devtool add`` command attempts to determine if the software you
+are adding is able to be distributed under a common, open-source
+license. If so, the command sets the
+:term:`LICENSE` value accordingly.
+You should double-check the value added by the command against the
+documentation or source files for the software you are building and, if
+necessary, update that ``LICENSE`` value.
+
+The ``devtool add`` command also sets the
+:term:`LIC_FILES_CHKSUM`
+value to point to all files that appear to be license-related. Realize
+that license statements often appear in comments at the top of source
+files or within the documentation. In such cases, the command does not
+recognize those license statements. Consequently, you might need to
+amend the ``LIC_FILES_CHKSUM`` variable to point to one or more of those
+comments if present. Setting ``LIC_FILES_CHKSUM`` is particularly
+important for third-party software. The mechanism attempts to ensure
+correct licensing should you upgrade the recipe to a newer upstream
+version in future. Any change in licensing is detected and you receive
+an error prompting you to check the license text again.
+
+If the ``devtool add`` command cannot determine licensing information,
+``devtool`` sets the ``LICENSE`` value to "CLOSED" and leaves the
+``LIC_FILES_CHKSUM`` value unset. This behavior allows you to continue
+with development even though the settings are unlikely to be correct in
+all cases. You should check the documentation or source files for the
+software you are building to determine the actual license.
+
+Adding Makefile-Only Software
+-----------------------------
+
+The use of Make by itself is very common in both proprietary and
+open-source software. Unfortunately, Makefiles are often not written
+with cross-compilation in mind. Thus, ``devtool add`` often cannot do
+very much to ensure that these Makefiles build correctly. It is very
+common, for example, to explicitly call ``gcc`` instead of using the
+:term:`CC` variable. Usually, in a
+cross-compilation environment, ``gcc`` is the compiler for the build
+host and the cross-compiler is named something similar to
+``arm-poky-linux-gnueabi-gcc`` and might require arguments (e.g. to
+point to the associated sysroot for the target machine).
+
+When writing a recipe for Makefile-only software, keep the following in
+mind:
+
+- You probably need to patch the Makefile to use variables instead of
+ hardcoding tools within the toolchain such as ``gcc`` and ``g++``.
+
+- The environment in which Make runs is set up with various standard
+ variables for compilation (e.g. ``CC``, ``CXX``, and so forth) in a
+ similar manner to the environment set up by the SDK's environment
+ setup script. One easy way to see these variables is to run the
+ ``devtool build`` command on the recipe and then look in
+ ``oe-logs/run.do_compile``. Towards the top of this file, a list of
+ environment variables exists that are being set. You can take
+ advantage of these variables within the Makefile.
+
+- If the Makefile sets a default for a variable using "=", that default
+ overrides the value set in the environment, which is usually not
+ desirable. For this case, you can either patch the Makefile so it
+ sets the default using the "?=" operator, or you can alternatively
+ force the value on the ``make`` command line. To force the value on
+ the command line, add the variable setting to
+ :term:`EXTRA_OEMAKE` or
+ :term:`PACKAGECONFIG_CONFARGS`
+ within the recipe. Here is an example using ``EXTRA_OEMAKE``:
+ ::
+
+ EXTRA_OEMAKE += "'CC=${CC}' 'CXX=${CXX}'"
+
+ In the above example,
+ single quotes are used around the variable settings as the values are
+ likely to contain spaces because required default options are passed
+ to the compiler.
+
+- Hardcoding paths inside Makefiles is often problematic in a
+ cross-compilation environment. This is particularly true because
+ those hardcoded paths often point to locations on the build host and
+ thus will either be read-only or will introduce contamination into
+ the cross-compilation because they are specific to the build host
+ rather than the target. Patching the Makefile to use prefix variables
+ or other path variables is usually the way to handle this situation.
+
+- Sometimes a Makefile runs target-specific commands such as
+ ``ldconfig``. For such cases, you might be able to apply patches that
+ remove these commands from the Makefile.
+
+Adding Native Tools
+-------------------
+
+Often, you need to build additional tools that run on the :term:`Build
+Host` as opposed to
+the target. You should indicate this requirement by using one of the
+following methods when you run ``devtool add``:
+
+- Specify the name of the recipe such that it ends with "-native".
+ Specifying the name like this produces a recipe that only builds for
+ the build host.
+
+- Specify the "DASHDASHalso-native" option with the ``devtool add``
+ command. Specifying this option creates a recipe file that still
+ builds for the target but also creates a variant with a "-native"
+ suffix that builds for the build host.
+
+.. note::
+
+ If you need to add a tool that is shipped as part of a source tree
+ that builds code for the target, you can typically accomplish this by
+ building the native and target parts separately rather than within
+ the same compilation process. Realize though that with the
+ "DASHDASHalso-native" option, you can add the tool using just one
+ recipe file.
+
+Adding Node.js Modules
+----------------------
+
+You can use the ``devtool add`` command two different ways to add
+Node.js modules: 1) Through ``npm`` and, 2) from a repository or local
+source.
+
+Use the following form to add Node.js modules through ``npm``:
+::
+
+ $ devtool add "npm://registry.npmjs.org;name=forever;version=0.15.1"
+
+The name and
+version parameters are mandatory. Lockdown and shrinkwrap files are
+generated and pointed to by the recipe in order to freeze the version
+that is fetched for the dependencies according to the first time. This
+also saves checksums that are verified on future fetches. Together,
+these behaviors ensure the reproducibility and integrity of the build.
+
+.. note::
+
+ - You must use quotes around the URL. The ``devtool add`` does not
+ require the quotes, but the shell considers ";" as a splitter
+ between multiple commands. Thus, without the quotes,
+ ``devtool add`` does not receive the other parts, which results in
+ several "command not found" errors.
+
+ - In order to support adding Node.js modules, a ``nodejs`` recipe
+ must be part of your SDK.
+
+As mentioned earlier, you can also add Node.js modules directly from a
+repository or local source tree. To add modules this way, use
+``devtool add`` in the following form:
+::
+
+ $ devtool add https://github.com/diversario/node-ssdp
+
+In this example, ``devtool``
+fetches the specified Git repository, detects the code as Node.js code,
+fetches dependencies using ``npm``, and sets
+:term:`SRC_URI` accordingly.
+
+Working With Recipes
+====================
+
+When building a recipe using the ``devtool build`` command, the typical
+build progresses as follows:
+
+1. Fetch the source
+
+2. Unpack the source
+
+3. Configure the source
+
+4. Compile the source
+
+5. Install the build output
+
+6. Package the installed output
+
+For recipes in the workspace, fetching and unpacking is disabled as the
+source tree has already been prepared and is persistent. Each of these
+build steps is defined as a function (task), usually with a "do\_" prefix
+(e.g. :ref:`ref-tasks-fetch`,
+:ref:`ref-tasks-unpack`, and so
+forth). These functions are typically shell scripts but can instead be
+written in Python.
+
+If you look at the contents of a recipe, you will see that the recipe
+does not include complete instructions for building the software.
+Instead, common functionality is encapsulated in classes inherited with
+the ``inherit`` directive. This technique leaves the recipe to describe
+just the things that are specific to the software being built. A
+:ref:`base <ref-classes-base>` class exists that
+is implicitly inherited by all recipes and provides the functionality
+that most recipes typically need.
+
+The remainder of this section presents information useful when working
+with recipes.
+
+Finding Logs and Work Files
+---------------------------
+
+After the first run of the ``devtool build`` command, recipes that were
+previously created using the ``devtool add`` command or whose sources
+were modified using the ``devtool modify`` command contain symbolic
+links created within the source tree:
+
+- ``oe-logs``: This link points to the directory in which log files and
+ run scripts for each build step are created.
+
+- ``oe-workdir``: This link points to the temporary work area for the
+ recipe. The following locations under ``oe-workdir`` are particularly
+ useful:
+
+ - ``image/``: Contains all of the files installed during the
+ :ref:`ref-tasks-install` stage.
+ Within a recipe, this directory is referred to by the expression
+ ``${``\ :term:`D`\ ``}``.
+
+ - ``sysroot-destdir/``: Contains a subset of files installed within
+ ``do_install`` that have been put into the shared sysroot. For
+ more information, see the "`Sharing Files Between
+ Recipes <#sdk-sharing-files-between-recipes>`__" section.
+
+ - ``packages-split/``: Contains subdirectories for each package
+ produced by the recipe. For more information, see the
+ "`Packaging <#sdk-packaging>`__" section.
+
+You can use these links to get more information on what is happening at
+each build step.
+
+Setting Configure Arguments
+---------------------------
+
+If the software your recipe is building uses GNU autoconf, then a fixed
+set of arguments is passed to it to enable cross-compilation plus any
+extras specified by
+:term:`EXTRA_OECONF` or
+:term:`PACKAGECONFIG_CONFARGS`
+set within the recipe. If you wish to pass additional options, add them
+to ``EXTRA_OECONF`` or ``PACKAGECONFIG_CONFARGS``. Other supported build
+tools have similar variables (e.g.
+:term:`EXTRA_OECMAKE` for
+CMake, :term:`EXTRA_OESCONS`
+for Scons, and so forth). If you need to pass anything on the ``make``
+command line, you can use ``EXTRA_OEMAKE`` or the
+:term:`PACKAGECONFIG_CONFARGS`
+variables to do so.
+
+You can use the ``devtool configure-help`` command to help you set the
+arguments listed in the previous paragraph. The command determines the
+exact options being passed, and shows them to you along with any custom
+arguments specified through ``EXTRA_OECONF`` or
+``PACKAGECONFIG_CONFARGS``. If applicable, the command also shows you
+the output of the configure script's "DASHDASHhelp" option as a
+reference.
+
+Sharing Files Between Recipes
+-----------------------------
+
+Recipes often need to use files provided by other recipes on the
+:term:`Build Host`. For example,
+an application linking to a common library needs access to the library
+itself and its associated headers. The way this access is accomplished
+within the extensible SDK is through the sysroot. One sysroot exists per
+"machine" for which the SDK is being built. In practical terms, this
+means a sysroot exists for the target machine, and a sysroot exists for
+the build host.
+
+Recipes should never write files directly into the sysroot. Instead,
+files should be installed into standard locations during the
+:ref:`ref-tasks-install` task within
+the ``${``\ :term:`D`\ ``}`` directory. A
+subset of these files automatically goes into the sysroot. The reason
+for this limitation is that almost all files that go into the sysroot
+are cataloged in manifests in order to ensure they can be removed later
+when a recipe is modified or removed. Thus, the sysroot is able to
+remain free from stale files.
+
+Packaging
+---------
+
+Packaging is not always particularly relevant within the extensible SDK.
+However, if you examine how build output gets into the final image on
+the target device, it is important to understand packaging because the
+contents of the image are expressed in terms of packages and not
+recipes.
+
+During the :ref:`ref-tasks-package`
+task, files installed during the
+:ref:`ref-tasks-install` task are
+split into one main package, which is almost always named the same as
+the recipe, and into several other packages. This separation exists
+because not all of those installed files are useful in every image. For
+example, you probably do not need any of the documentation installed in
+a production image. Consequently, for each recipe the documentation
+files are separated into a ``-doc`` package. Recipes that package
+software containing optional modules or plugins might undergo additional
+package splitting as well.
+
+After building a recipe, you can see where files have gone by looking in
+the ``oe-workdir/packages-split`` directory, which contains a
+subdirectory for each package. Apart from some advanced cases, the
+:term:`PACKAGES` and
+:term:`FILES` variables controls
+splitting. The ``PACKAGES`` variable lists all of the packages to be
+produced, while the ``FILES`` variable specifies which files to include
+in each package by using an override to specify the package. For
+example, ``FILES_${PN}`` specifies the files to go into the main package
+(i.e. the main package has the same name as the recipe and
+``${``\ :term:`PN`\ ``}`` evaluates to the
+recipe name). The order of the ``PACKAGES`` value is significant. For
+each installed file, the first package whose ``FILES`` value matches the
+file is the package into which the file goes. Defaults exist for both
+the ``PACKAGES`` and ``FILES`` variables. Consequently, you might find
+you do not even need to set these variables in your recipe unless the
+software the recipe is building installs files into non-standard
+locations.
+
+Restoring the Target Device to its Original State
+=================================================
+
+If you use the ``devtool deploy-target`` command to write a recipe's
+build output to the target, and you are working on an existing component
+of the system, then you might find yourself in a situation where you
+need to restore the original files that existed prior to running the
+``devtool deploy-target`` command. Because the ``devtool deploy-target``
+command backs up any files it overwrites, you can use the
+``devtool undeploy-target`` command to restore those files and remove
+any other files the recipe deployed. Consider the following example:
+::
+
+ $ devtool undeploy-target lighttpd root@192.168.7.2
+
+If you have deployed
+multiple applications, you can remove them all using the "-a" option
+thus restoring the target device to its original state:
+::
+
+ $ devtool undeploy-target -a root@192.168.7.2
+
+Information about files deployed to
+the target as well as any backed up files are stored on the target
+itself. This storage, of course, requires some additional space on the
+target machine.
+
+.. note::
+
+ The
+ devtool deploy-target
+ and
+ devtool undeploy-target
+ commands do not currently interact with any package management system
+ on the target device (e.g. RPM or OPKG). Consequently, you should not
+ intermingle
+ devtool deploy-target
+ and package manager operations on the target device. Doing so could
+ result in a conflicting set of files.
+
+Installing Additional Items Into the Extensible SDK
+===================================================
+
+Out of the box the extensible SDK typically only comes with a small
+number of tools and libraries. A minimal SDK starts mostly empty and is
+populated on-demand. Sometimes you must explicitly install extra items
+into the SDK. If you need these extra items, you can first search for
+the items using the ``devtool search`` command. For example, suppose you
+need to link to libGL but you are not sure which recipe provides libGL.
+You can use the following command to find out:
+::
+
+ $ devtool search libGL mesa
+
+A free implementation of the OpenGL API Once you know the recipe
+(i.e. ``mesa`` in this example), you can install it:
+::
+
+ $ devtool sdk-install mesa
+
+By default, the ``devtool sdk-install`` command assumes
+the item is available in pre-built form from your SDK provider. If the
+item is not available and it is acceptable to build the item from
+source, you can add the "-s" option as follows:
+::
+
+ $ devtool sdk-install -s mesa
+
+It is important to remember that building the item from source
+takes significantly longer than installing the pre-built artifact. Also,
+if no recipe exists for the item you want to add to the SDK, you must
+instead add the item using the ``devtool add`` command.
+
+Applying Updates to an Installed Extensible SDK
+===============================================
+
+If you are working with an installed extensible SDK that gets
+occasionally updated (e.g. a third-party SDK), then you will need to
+manually "pull down" the updates into the installed SDK.
+
+To update your installed SDK, use ``devtool`` as follows:
+::
+
+ $ devtool sdk-update
+
+The previous command assumes your SDK provider has set the
+default update URL for you through the
+:term:`SDK_UPDATE_URL`
+variable as described in the "`Providing Updates to the Extensible SDK
+After
+Installation <#sdk-providing-updates-to-the-extensible-sdk-after-installation>`__"
+section. If the SDK provider has not set that default URL, you need to
+specify it yourself in the command as follows: $ devtool sdk-update
+path_to_update_directory
+
+.. note::
+
+ The URL needs to point specifically to a published SDK and not to an
+ SDK installer that you would download and install.
+
+Creating a Derivative SDK With Additional Components
+====================================================
+
+You might need to produce an SDK that contains your own custom
+libraries. A good example would be if you were a vendor with customers
+that use your SDK to build their own platform-specific software and
+those customers need an SDK that has custom libraries. In such a case,
+you can produce a derivative SDK based on the currently installed SDK
+fairly easily by following these steps:
+
+1. If necessary, install an extensible SDK that you want to use as a
+ base for your derivative SDK.
+
+2. Source the environment script for the SDK.
+
+3. Add the extra libraries or other components you want by using the
+ ``devtool add`` command.
+
+4. Run the ``devtool build-sdk`` command.
+
+The previous steps take the recipes added to the workspace and construct
+a new SDK installer that contains those recipes and the resulting binary
+artifacts. The recipes go into their own separate layer in the
+constructed derivative SDK, which leaves the workspace clean and ready
+for users to add their own recipes.