MIRRORS/poky
1
0
Fork 0
mirror of git://git.yoctoproject.org/poky.git synced 2025-07-19 21:09:03 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity
b80dfd18ae
poky/documentation/dev-manual/devtool.rst
Trevor Woerner ec53c91af0 sphinx-lint: various fixes 
A 'make sphinx-lint' pass found the following issues:
	trailing-whitespace
	missing-space-after-literal
	role-with-double-backticks
	missing-space-before-role (role missing opening tag colon)

(From yocto-docs rev: 6d4c67457e00a80dda4cd05bc5f05d8ebd8da5fc)

Signed-off-by: Trevor Woerner <twoerner@gmail.com>
Reviewed-by: Quentin Schulz <quentin.schulz@cherry.de>
Signed-off-by: Antonin Godard <antonin.godard@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
2025-05-19 15:54:10 +01:00

1323 lines
57 KiB
ReStructuredText
Raw Blame History

.. SPDX-License-Identifier: CC-BY-SA-2.0-UK
Using the ``devtool`` command-line tool
***************************************
The ``devtool`` command-line tool provides a number of features that
help you build, test, and package software. This command is available
alongside the ``bitbake`` command. Additionally, the ``devtool`` command
is a key part of the :term:`Extensible Software Development Kit (eSDK)`.
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/devtool-add-flow.png
:width: 100%
#. *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.
#. *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 effect when you build it later.
#. *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
#. *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.
#. *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/devtool-modify-flow.png
:width: 100%
#. *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, there is no ``srctree`` argument. Consequently, the
default behavior of the ``devtool modify`` command is to extract
the source files pointed to by the :term:`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 :term:`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 :term:`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.
#. *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.
#. *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
#. *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.
#. *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.
``devtool ide-sdk`` configures IDEs and bootstraps SDKs
=======================================================
The ``devtool ide-sdk`` command can provide an IDE configuration for IDEs when
working on the source code of one or more recipes.
Depending on the programming language, and the build system used by the recipe,
the tools required for cross-development and remote debugging are different.
For example:
- A C/C++ project usually uses CMake or Meson.
- A Python project uses setuptools or one of its successors.
- A Rust project uses Cargo.
Also, the IDE plugins needed for the integration of a build system with the
IDE and the corresponding settings are usually specific to these build-systems.
To hide all these details from the user, ``devtool ide-sdk`` does two things:
- It generates any kind of SDK needed for cross-development and remote
debugging of the specified recipes.
- It generates the configuration for the IDE (and the IDE plugins) for using
the cross-toolchain and remote debugging tools provided by the SDK directly
from the IDE.
For supported build systems the configurations generated by ``devtool ide-sdk``
combine the advantages of the ``devtool modify`` based workflow
(see :ref:`using_devtool`) with the advantages of the simple Environment Setup
script based workflow (see :ref:`running_the_ext_sdk_env`) provided by Yocto's
SDK or eSDK:
- The source code of the recipe is in the workspace created by
``devtool modify`` or ``devtool add``.
Using ``devtool build``, ``devtool build-image``,
``devtool deploy-target`` or ``bitbake`` is possible.
Also ``devtool ide-sdk`` can be used to update the SDK and the IDE
configuration at any time.
- ``devtool ide-sdk`` aims to support multiple programming languages and
multiple IDEs natively. "Natively" means that the IDE is configured to call
the build tool (e.g. ``cmake`` or ``meson``) directly. This has several
advantages.
First of all, it is usually much faster to call for example ``cmake`` than
``devtool build``.
It also allows to benefit from the very good integration that IDEs like
VSCode offer for tools like CMake or GDB.
However, supporting many programming languages and multiple
IDEs is quite an elaborate and constantly evolving thing. Support for IDEs
is therefore implemented as plugins. Plugins can also be provided by
optional layers.
So much about the introduction to the default mode of ``devtool sdk-ide`` which
is called the "modified" mode because it uses the workspace created by
``devtool modify`` and the per recipe :term:`Sysroots <Sysroot>` of BitBake.
For some recipes and use cases, this default behavior of ``devtool ide-sdk``
with full ``devtool`` and ``bitbake`` integration might not be suitable.
To offer full feature parity with the SDK and the eSDK, ``devtool ide-sdk`` has
a second mode called "shared" mode.
If ``devtool ide-sdk`` is called with the ``--mode=shared`` option, it
bootstraps an SDK directly from the BitBake environment, which offers the same
Environment Setup script as described in :ref:`running_the_ext_sdk_env`.
In addition to the (e)SDK installer-based setup, the IDE gets configured
to use the shared :term:`Sysroots <Sysroot>` and the tools from the SDK.
``devtool ide-sdk --mode=shared`` is basically a wrapper for the setup of the
extensible SDK as described in :ref:`setting_up_ext_sdk_in_build`.
The use of ``devtool ide-sdk`` is an alternative to using one of the SDK
installers.
``devtool ide-sdk`` allows the creation of SDKs that offer all the
functionality of the SDK and the eSDK installers. Compared to the installers,
however, the SDK created with ``devtool ide-sdk`` is much more flexible.
For example, it is very easy to change the :term:`MACHINE` in the
``local.conf`` file, update the layer meta data and then regenerate the SDK.
Let's take a look at an example of how to use ``devtool ide-sdk`` in each of
the two modes:
#. *Modified mode*:
In order to use the ``devtool ide-sdk``, a few settings are needed. As a
starting example, the following lines of code can be added to the
``local.conf`` file::
# Build the companion debug file system
IMAGE_GEN_DEBUGFS = "1"
# Optimize build time: with devtool ide-sdk the dbg tar is not needed
IMAGE_FSTYPES_DEBUGFS = ""
# Without copying the binaries into roofs-dbg, GDB does not find all source files.
IMAGE_CLASSES += "image-combined-dbg"
# SSH is mandatory, no password simplifies the usage
EXTRA_IMAGE_FEATURES += "\
ssh-server-openssh \
allow-empty-password \
allow-root-login \
empty-root-password \
"
# Remote debugging needs gdbserver on the target device
IMAGE_INSTALL:append = " gdbserver"
# Add the recipes which should be modified to the image
# Otherwise some dependencies might be missing.
IMAGE_INSTALL:append = " my-recipe"
Assuming the BitBake environment is set up correctly and a workspace has
been created for the recipe using ``devtool modify my-recipe`` or probably
even better by using ``devtool modify my-recipe --debug-build``, the
following command can create the SDK and the configuration for VSCode in
the recipe workspace::
$ devtool ide-sdk my-recipe core-image-minimal --target root@192.168.7.2
The command requires an image recipe (``core-image-minimal`` for this
example) that is used to create the SDK.
This firmware image should also be installed on the target device.
It is possible to pass multiple package recipes::
$ devtool ide-sdk my-recipe-1 my-recipe-2 core-image-minimal --target root@192.168.7.2
``devtool ide-sdk`` tries to create an IDE configuration for all package
recipes.
What this command does exactly depends on the recipe, more precisely on the
build tool used by the recipe. The basic idea is to configure the IDE so
that it calls the build tool exactly as ``bitbake`` does.
For example, a CMake preset is created for a recipe that inherits
:ref:`ref-classes-cmake`. In the case of VSCode, CMake presets are supported
by the CMake Tools plugin. This is an example of how the build configuration
used by ``bitbake`` is exported to an IDE configuration that gives exactly
the same build results.
Support for remote debugging with seamless integration into the IDE is
important for a cross-SDK. ``devtool ide-sdk`` automatically generates the
necessary helper scripts for deploying the compiled artifacts to the target
device as well as the necessary configuration for the debugger and the IDE.
.. note::
To ensure that the debug symbols on the build machine match the binaries
running on the target device, it is essential that the image built by
``devtool ide-sdk`` is running on the target device.
The default IDE is VSCode. Some hints about using VSCode:
- VSCode can be used to work on the BitBake recipes or the application
source code.
Usually there is one instance of VSCode running in the folder where the
BitBake recipes are. This instance has the
`Yocto Project BitBake plugin <https://marketplace.visualstudio.com/items?itemName=yocto-project.yocto-bitbake>`_
running.
.. warning::
Some VSCode plugins (Python, BitBake and others) need a reasonable
configuration to work as expected. Otherwise, some plugins try to
index the build directory of BitBake, which keeps your system quite
busy until an out of memory exception stops this nonsense.
Other plugins, such as the BitBake plugin, do not behave as expected.
To work around such issues, the ``oe-init-build-env`` script creates
an initial ``.vscode/settings.json`` file if ``code`` can be found
and the ``.vscode`` folder does not yet exist.
It is best to run ``oe-init-build-env`` once before starting VSCode.
An alternative approach is to use a build folder outside the layers,
e.g. ``oe-init-build-env ../build``.
The BitBake plugin also offers to create devtool workspaces and run
``devtool ide-sdk`` with a few mouse clicks.
Of course, issuing commands in the terminal works as well.
- To work on the source code of a recipe another instance of VSCode is
started in the recipe's workspace. Example::
code build/workspace/sources/my-recipe
This instance of VSCode uses plugins that are useful for the development
of the application. ``devtool ide-sdk`` generates the necessary
``extensions.json``, ``settings.json``, ``tasks.json`` and ``launch.json``
configuration files for all the involved plugins.
When the source code folder present in the workspace folder is opened in
VSCode for the first time, a pop-up message recommends installing the
required plugins.
After accepting the installation of the plugins, working with the source
code or some debugging tasks should work as usual with VSCode.
Starting the VSCode instances in the recipe workspace folders can also be
done by a mouse click on the recipe workspaces in the first VSCode
instance.
- To work with CMake press ``Ctrl + Shift + p``, type ``cmake``. This will
show some possible commands like selecting a CMake preset, compiling or
running CTest.
For recipes inheriting :ref:`ref-classes-cmake-qemu` rather than
:ref:`ref-classes-cmake`, executing cross-compiled unit tests on the host
can be supported transparently with QEMU user-mode.
- To work with Meson press ``Ctrl + Shift + p``, type ``meson``. This will
show some possible commands like compiling or executing the unit tests.
A note on running cross-compiled unit tests on the host: Meson enables
support for QEMU user mode by default. It is expected that the execution
of the unit tests from the IDE will work without any additional steps,
given that the code is suitable for the execution on the host machine.
- For the deployment to the target device, just press ``Ctrl + Shift + p``,
type ``task``. Select ``install && deploy-target``.
- For remote debugging, switch to the debugging view by pressing the "play"
button with the ``bug icon`` on the left side. This will provide a green
play button with a drop-down list where a debug configuration can be
selected. After selecting one of the generated configurations, press the
"play" button.
Starting a remote debugging session automatically initiates the
deployment to the target device. If this is not desired, the
``"dependsOn": ["install && deploy-target...]`` parameter of the tasks
with ``"label": "gdbserver start...`` can be removed from the
``tasks.json`` file.
VSCode supports GDB with many different setups and configurations for
many different use cases. However, most of these setups have some
limitations when it comes to cross-development, support only a few target
architectures or require a high performance target device. Therefore
``devtool ide-sdk`` supports the classic, generic setup with GDB on the
development host and gdbserver on the target device.
Roughly summarized, this means:
- The binaries are copied via SSH to the remote target device by a
script referred by ``tasks.json``.
- gdbserver is started on the remote target device via SSH by a script
referred by ``tasks.json``.
Changing the parameters that are passed to the debugging executable
requires modifying the generated script. The script is located at
``oe-scripts/gdbserver_*``. Defining the parameters in the ``args``
field in the ``launch.json`` file does not work.
- VSCode connects to gdbserver as documented in
`Remote debugging or debugging with a local debugger server
<https://code.visualstudio.com/docs/cpp/launch-json-reference#_remote-debugging-or-debugging-with-a-local-debugger-server>`__.
Additionally ``--ide=none`` is supported. With the ``none`` IDE parameter,
some generic configuration files like ``gdbinit`` files and some helper
scripts starting gdbserver remotely on the target device as well as the GDB
client on the host are generated.
Here is a usage example for the ``cmake-example`` recipe from the
``meta-selftest`` layer which inherits :ref:`ref-classes-cmake-qemu`:
.. code-block:: sh
# Create the SDK
devtool modify cmake-example --debug-build
devtool ide-sdk cmake-example core-image-minimal -c --ide=none
# Install the firmware on a target device or start QEMU
runqemu
# From exploring the workspace of cmake-example
cd build/workspace/sources/cmake-example
# Find cmake-native and save the path into a variable
# Note: using just cmake instead of $CMAKE_NATIVE would work in many cases
CMAKE_NATIVE="$(jq -r '.configurePresets[0] | "\(.cmakeExecutable)"' CMakeUserPresets.json)"
# List available CMake presets
"$CMAKE_NATIVE" --list-presets
Available configure presets:
"cmake-example-cortexa57" - cmake-example: cortexa57
# Re-compile the already compiled sources
"$CMAKE_NATIVE" --build --preset cmake-example-cortexa57
ninja: no work to do.
# Do a clean re-build
"$CMAKE_NATIVE" --build --preset cmake-example-cortexa57 --target clean
[1/1] Cleaning all built files...
Cleaning... 8 files.
"$CMAKE_NATIVE" --build --preset cmake-example-cortexa57 --target all
[7/7] Linking CXX executable cmake-example
# Run the cross-compiled unit tests with QEMU user-mode
"$CMAKE_NATIVE" --build --preset cmake-example-cortexa57 --target test
[0/1] Running tests...
Test project .../build/tmp/work/cortexa57-poky-linux/cmake-example/1.0/cmake-example-1.0
Start 1: test-cmake-example
1/1 Test #1: test-cmake-example ............... Passed 0.03 sec
100% tests passed, 0 tests failed out of 1
Total Test time (real) = 0.03 sec
# Using CTest directly is possible as well
CTEST_NATIVE="$(dirname "$CMAKE_NATIVE")/ctest"
# List available CMake presets
"$CTEST_NATIVE" --list-presets
Available test presets:
"cmake-example-cortexa57" - cmake-example: cortexa57
# Run the cross-compiled unit tests with QEMU user-mode
"$CTEST_NATIVE" --preset "cmake-example-cortexa57"
Test project ...build/tmp/work/cortexa57-poky-linux/cmake-example/1.0/cmake-example-1.0
Start 1: test-cmake-example
1/1 Test #1: test-cmake-example ............... Passed 0.03 sec
100% tests passed, 0 tests failed out of 1
Total Test time (real) = 0.03 sec
# Deploying the new build to the target device (default is QEUM at 192.168.7.2)
oe-scripts/install_and_deploy_cmake-example-cortexa57
# Start a remote debugging session with gdbserver on the target and GDB on the host
oe-scripts/gdbserver_1234_usr-bin-cmake-example_m
oe-scripts/gdb_1234_usr-bin-cmake-example
break main
run
step
stepi
continue
quit
# Stop gdbserver on the target device
oe-scripts/gdbserver_1234_usr-bin-cmake-example_m stop
#. *Shared sysroots mode*
Creating an SDK with shared :term:`Sysroots <Sysroot>` that contains all the
dependencies needed to work with ``my-recipe`` is possible with the following
example command::
$ devtool ide-sdk --mode=shared my-recipe
For VSCode the cross-toolchain is exposed as a CMake kit. CMake kits are
defined in ``~/.local/share/CMakeTools/cmake-tools-kits.json``.
The following example shows how the cross-toolchain can be selected in
VSCode. First of all we need a folder containing a CMake project.
For this example, let's create a CMake project and start VSCode::
mkdir kit-test
echo "project(foo VERSION 1.0)" > kit-test/CMakeLists.txt
code kit-test
If there is a CMake project in the workspace, cross-compilation is
supported:
- Press ``Ctrl + Shift + P``, type ``CMake: Scan for Kits``
- Press ``Ctrl + Shift + P``, type ``CMake: Select a Kit``
Finally most of the features provided by CMake and the IDE should be
available.
Other IDEs than VSCode are supported as well. However,
``devtool ide-sdk --mode=shared --ide=none my-recipe`` is currently
just a simple wrapper for the setup of the extensible SDK, as described in
:ref:`setting_up_ext_sdk_in_build`.
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
:ref:`dev-manual/upgrading-recipes: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:`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/devtool-upgrade-flow.png
:width: 100%
#. *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 :term:`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 :term:`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 :term:`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.
#. *Resolve any Conflicts created by the Upgrade*: Conflicts could happen
after upgrading the software to a new version. Conflicts occur
if your recipe specifies some patch files in :term:`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.
#. *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
#. *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.
#. *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 :term:`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 :term:`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 :term:`LIC_FILES_CHKSUM` variable to point to one or more of those
comments if present. Setting :term:`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 :term:`LICENSE` value to "CLOSED" and leaves the
:term:`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. :term:`CC`, :term:`CXX`, and so forth) in a
similar manner to the environment set up by an :ref:`SDK
<overview-manual/concepts:Application Development 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, there is
a list of environment variables that are 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 :term:`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 "--also-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
"--also-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: through ``npm`` or 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. ``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.
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:
#. Fetch the source
#. Unpack the source
#. Configure the source
#. Compile the source
#. Install the build output
#. 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. There is
a :ref:`ref-classes-base` class 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
:ref:`ref-tasks-install` that have been put into the shared sysroot. For
more information, see the
":ref:`dev-manual/new-recipe:sharing files between recipes`" section.
- ``packages-split/``: Contains subdirectories for each package
produced by the recipe. For more information, see the
":ref:`dev-manual/devtool: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 :term:`EXTRA_OECONF` or :term:`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 :term:`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 :term:`EXTRA_OECONF` or
:term:`PACKAGECONFIG_CONFARGS`. If applicable, the command also shows you
the output of the configure script's "--help" 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
is through the :term:`Sysroot`. There is a sysroot for the target machine, and a
sysroot 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
---------
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 :term:`PACKAGES` variable lists all of the packages to be
produced, while the :term:`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 :term:`PACKAGES` value is significant. For
each installed file, the first package whose :term:`FILES` value matches the
file is the package into which the file goes. Both the :term:`PACKAGES` and
:term:`FILES` variables have default values. 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.
Reference in New Issue View Git Blame Copy Permalink