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
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).
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
/docdirectory, but others are stored within the code source tree near their specific component (such as
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
The reStructuredText files are processed by the Sphinx documentation system, and make use of the breathe extension for including the doxygen-generated API material. Additional tools are required to generate the documentation locally, as described in the following sections.
Installing the documentation processors¶
Our documentation processing has been tested to run with:
Doxygen version 1.8.13
Latexmk version 4.56
All Python dependencies listed in the repository file
In order to install the documentation tools, first install Zephyr as described in Getting Started Guide. Then install additional tools that are only required to generate the documentation, as described below:
On Ubuntu Linux:
sudo apt-get install --no-install-recommends doxygen graphviz librsvg2-bin \ texlive-latex-base texlive-latex-extra latexmk texlive-fonts-recommended
On Fedora Linux:
sudo dnf install doxygen graphviz texlive-latex latexmk \ texlive-collection-fontsrecommended librsvg2-tools
On Clear Linux:
sudo swupd bundle-add texlive graphviz
On Arch Linux:
sudo pacman -S graphviz doxygen librsvg texlive-core texlive-bin
tlmgr to install the tools:
brew install doxygen graphviz mactex librsvg tlmgr install latexmk tlmgr install collection-fontsrecommended
cmd.exe window as Administrator and run the following command:
choco install doxygen.install graphviz strawberryperl miktex rsvg-convert
On Windows, the Sphinx executable
sphinx-build.exe is placed in
Scripts folder of your Python installation path.
Dependending 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.
Documentation presentation theme¶
Sphinx supports easy customization of the generated documentation
appearance through the use of themes. Replace the theme files and do
make htmldocs and the output layout and style is changed.
read-the-docs theme is installed as part of the
Get Zephyr and install Python dependencies step you took in the getting started
Running the documentation processors¶
/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:
# On Linux/macOS cd ~/zephyr/doc # On Windows cd %userprofile%\zephyr\doc # Use cmake to configure a Ninja-based build system: cmake -GNinja -B_build . # Enter the build directory cd _build # To generate HTML output, run ninja on the generated build system: ninja html # If you modify or add .rst files, run ninja again: ninja html # To generate PDF output, run ninja on the generated build system: ninja pdf
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
if generated, the PDF file is available at
If you want to build the documentation from scratch just delete the contents
of the build folder and run
cmake and then
If you add or remove a file from the documentation, you need to re-run CMake.
On Unix platforms a convenience Makefile at the
of the Zephyr repository can be used to build the documentation directly from
cd ~/zephyr/doc # To generate HTML output make html # To generate PDF output make pdf
Filtering expected warnings¶
There are some known issues with Sphinx/Breathe that generate Sphinx warnings
even though the input is valid C code. While these issues are being considered
for fixing we have created a Sphinx extension that allows to filter them out
based on a set of regular expressions. The extension is named
zephyr.warnings_filter and it is located at
doc/_extensions/zephyr/warnings_filter.py. The warnings to be filtered out
can be added to the
The most common warning reported by Sphinx/Breathe is related to duplicate C declarations. This warning may be caused by different Sphinx/Breathe issues:
Multiple declarations of the same object are not supported
Different objects (e.g. a struct and a function) can not share the same name
Nested elements (e.g. in a struct or union) can not share the same name
Developer-mode Document Building¶
Building the documentation for all the Kconfig options significantly adds to the total doc build time. When making and testing major changes to the documentation, we provide an option to temporarily stub-out the auto-generated configuration documentation so the doc build process runs much faster.
To enable this mode, set the following option when invoking cmake:
or invoke make with the following target:
cd ~/zephyr # To generate HTML output without detailed Kconfig make html-fast