doc/contribute/documentation/generation.rst
.. _zephyr_doc:
Documentation Generation ########################
These instructions will walk you through generating the Zephyr Project's documentation on your local system using the same documentation sources as we use to create the online documentation found at https://docs.zephyrproject.org
.. _documentation-overview:
Documentation overview
Zephyr Project content is written using the reStructuredText markup language (.rst file extension) with Sphinx extensions, and processed using Sphinx to create a formatted stand-alone website. Developers can view this content either in its raw form as .rst markup files, or you can generate the HTML content and view it with a web browser directly on your workstation. This same .rst content is also fed into the Zephyr Project's public website documentation area (with a different theme applied).
You can read details about reStructuredText, and Sphinx from
their respective websites.
The project's documentation contains the following items:
ReStructuredText source files used to generate documentation found at the
https://docs.zephyrproject.org website. Most of the reStructuredText sources
are found in the /doc directory, but others are stored within the
code source tree near their specific component (such as /samples and
/boards)
Doxygen-generated material used to create all API-specific documents also found at https://docs.zephyrproject.org
Script-generated material for kernel configuration options based on Kconfig files found in the source code tree
.. graphviz:: :caption: Schematic of the documentation build process
digraph { rankdir=LR
images [shape="rectangle" label=".png, .jpg\nimages"]
rst [shape="rectangle" label="restructuredText\nfiles"]
conf [shape="rectangle" label="conf.py\nconfiguration"]
rtd [shape="rectangle" label="read-the-docs\ntheme"]
header [shape="rectangle" label="c header\ncomments"]
xml [shape="rectangle" label="XML"]
html [shape="rectangle" label="HTML\nweb site"]
sphinx[shape="ellipse" label="sphinx +\ndocutils"]
images -> sphinx
rst -> sphinx
conf -> sphinx
header -> doxygen
doxygen -> xml
xml-> sphinx
rtd -> sphinx
sphinx -> html
}
The reStructuredText files are processed by the Sphinx documentation system, and make use of the doxygen-generated API material. Additional tools are required to generate the documentation locally, as described in the following sections.
.. _documentation-processors:
Installing the documentation processors
Our documentation processing has been tested to run with:
doc/requirements.txtIn order to install the documentation tools, first install Zephyr as
described in :ref:getting_started. Then install additional tools
that are only required to generate the documentation,
as described below:
.. doc_processors_installation_start
.. tabs::
.. group-tab:: Linux
Common to all Linux installations, install the Python dependencies
required to build the documentation:
.. code-block:: console
pip install -U -r ~/zephyrproject/zephyr/doc/requirements.txt
On Ubuntu Linux:
.. code-block:: console
sudo apt-get install --no-install-recommends doxygen graphviz librsvg2-bin \
texlive-latex-base texlive-latex-extra latexmk texlive-fonts-recommended imagemagick
On Fedora Linux:
.. code-block:: console
sudo dnf install doxygen graphviz texlive-latex latexmk \
texlive-collection-fontsrecommended librsvg2-tools ImageMagick
On Clear Linux:
.. code-block:: console
sudo swupd bundle-add texlive graphviz ImageMagick
On Arch Linux:
.. code-block:: console
sudo pacman -S graphviz doxygen librsvg texlive-core texlive-bin \
texlive-latexextra texlive-fontsextra imagemagick
.. group-tab:: macOS
Install the Python dependencies required to build the documentation:
.. code-block:: console
pip install -U -r ~/zephyrproject/zephyr/doc/requirements.txt
Use ``brew`` and ``tlmgr`` to install the tools:
.. code-block:: console
brew install doxygen graphviz mactex librsvg imagemagick
tlmgr install latexmk
tlmgr install collection-fontsrecommended
.. group-tab:: Windows
Install the Python dependencies required to build the documentation:
.. code-block:: console
pip install -U -r %HOMEPATH$\zephyrproject\zephyr\doc\requirements.txt
Open a ``cmd.exe`` window as **Administrator** and run the following command:
.. code-block:: console
choco install doxygen.install graphviz strawberryperl miktex rsvg-convert imagemagick
.. note::
On Windows, the Sphinx executable ``sphinx-build.exe`` is placed in
the ``Scripts`` folder of your Python installation path.
Depending on how you have installed Python, you might need to
add this folder to your ``PATH`` environment variable. Follow
the instructions in `Windows Python Path`_ to add those if needed.
.. doc_processors_installation_end
Documentation presentation theme
Sphinx supports easy customization of the generated documentation
appearance through the use of themes. Replace the theme files and do
another make html and the output layout and style is changed.
The read-the-docs theme is installed as part of the
:ref:install_py_requirements step you took in the getting started
guide.
Running the documentation processors
The /doc directory in your cloned copy of the Zephyr project git
repo has all the .rst source files, extra tools, and Makefile for
generating a local copy of the Zephyr project's technical documentation.
Assuming the local Zephyr project copy is in a folder zephyr in your home
folder, here are the commands to generate the html content locally:
.. code-block:: console
cd ~/zephyrproject/zephyr/doc
cd %userprofile%\zephyrproject\zephyr\doc
cmake -GNinja -B_build .
cd _build
ninja html
ninja html
ninja pdf
.. warning::
The documentation build system creates copies in the build directory of every .rst file used to generate the documentation, along with dependencies referenced by those .rst files.
This means that Sphinx warnings and errors refer to the copies, and not the version-controlled original files in Zephyr. Be careful to make sure you don't accidentally edit the copy of the file in an error message, as these changes will not be saved.
Depending on your development system, it will take up to 15 minutes to
collect and generate the HTML content. When done, you can view the HTML
output with your browser started at doc/_build/html/index.html and
if generated, the PDF file is available at doc/_build/latex/zephyr.pdf.
If you want to build the documentation from scratch just delete the contents
of the build folder and run cmake and then ninja again.
.. note::
If you add or remove a file from the documentation, you need to re-run CMake.
On Unix platforms a convenience :zephyr_file:doc/Makefile can be used to
build the documentation directly from there:
.. code-block:: console
cd ~/zephyrproject/zephyr/doc
make html
make pdf
Developer-mode Document Building
When making and testing major changes to the documentation, we provide an option to temporarily stub-out the auto-generated Devicetree bindings documentation so the doc build process runs faster.
To enable this mode, set the following option when invoking cmake::
-DDT_TURBO_MODE=1
Another step that typically takes a long time is the generation of the list of supported features for each board. This can be disabled by setting the following option when invoking cmake::
-DHW_FEATURES_TURBO_MODE=1
Invoking :command:make with the following target will build the documentation
without either of the aforementioned features::
cd ~/zephyrproject/zephyr/doc
make html-fast
When working with documentation for boards from a specific vendor, it is also possible to limit generation of the list of supported features to subset of board vendors. This can be done by setting the following option when invoking cmake::
-DHW_FEATURES_VENDOR_FILTER=vendor1,vendor2
This option can also be used with the :command:make wrapper::
cd ~/zephyrproject/zephyr/doc
make html HW_FEATURES_VENDOR_FILTER=vendor1,vendor2
Viewing generated documentation locally
The generated HTML documentation can be hosted locally with python for viewing with a web browser:
.. code-block:: console
$ python3 -m http.server -d _build/html
.. note::
WSL2 users may need to explicitly bind the address to 127.0.0.1 in order
to be accessible from the host machine:
.. code-block:: console
$ python3 -m http.server -d _build/html --bind 127.0.0.1
Alternatively, the documentation can be built with the make html-live
(or make html-live-fast) command, which will build the documentation, host
it locally, and watch the documentation directory for changes. When changes are
observed, it will automatically rebuild the documentation and refresh the hosted
files.
Linking external Doxygen projects against Zephyr
External projects that build upon Zephyr functionality and wish to refer to
Zephyr documentation in Doxygen (through the use of @ref), can utilize the
tag file exported at zephyr.tag <../../doxygen/html/zephyr.tag>_
Once downloaded, the tag file can be used in a custom doxyfile.in as follows::
TAGFILES = "/path/to/zephyr.tag=https://docs.zephyrproject.org/latest/doxygen/html/"
For additional information refer to Doxygen External Documentation_.
.. _reStructuredText: https://sphinx-doc.org/rest.html .. _Sphinx: https://sphinx-doc.org/ .. _Windows Python Path: https://docs.python.org/3/using/windows.html#finding-the-python-executable .. _Doxygen External Documentation: https://www.doxygen.nl/manual/external.html