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Welcome to Zephyr Kernel
########################

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   Find more information regarding the ReST markup in the
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Welcome to the Zephyr Project.

Thank you for your interest in the Zephyr Project. These instructions are
designed to walk you through generating the Zephyr Project's documentation.

Documentation Notes
*******************

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 workstations drive. 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 about Sphinx extensions from
their respective websites.

The project's documentation currently comprises the following items:

* ReStructuredText source files used to generate documentation found at
  https://zephyrproject.org/doc website. Most of the reStructuredText sources
  are found in the ``/doc`` directory, but there are others 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://zephyrproject.org/doc

* Script-generated material for kernel configuration options based on kconfig
  files found in the source code tree

* Additional material on https://wiki.zephyrproject.org

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 1.8.10 (and 1.8.11)
* Sphinx version 1.4.4 (but not with 1.5.1)
* Breathe version 4.4.0
* docutils version 0.12 (0.13 has issues with Sphinx 1.4.4)

Begin by cloning a copy of the git repository for the zephyr project and
setting up your development environment as described in :ref:`getting_started`
or specifically for Ubuntu in :ref:`installation_linux`.  (Be sure to
export the environment variables ``ZEPHYR_GCC_VARIANT`` and
``ZEPHYR_SDK_INSTALL_DIR`` as documented there.)

Here are a set of commands to install the documentation generations tools on
Ubuntu:

.. code-block:: bash

   $ sudo -E apt-get install python-pip
   $ pip install --upgrade pip
   $ sudo -E apt-get install doxygen
   $ pip install sphinx==1.4.4
   $ sudo -HE pip install breathe
   $ sudo -HE pip install sphinx-rtd-theme

There is a known issue that causes docutils version 0.13 to fail with sphinx
1.4.4.  Verify the version of docutils using:

.. code-block:: bash

   $ pip show docutils

If this shows you've got version 0.13 of docutils installed, you can install
the working version of docutils with:

.. code-block:: bash

   $ sudo -HE  pip install docutils==0.12


Running the Documentation Generators
************************************

The ``/doc`` directory in your cloned copy of 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 ``~/zephyr``, here are the commands to generate the html
content locally:

.. code-block:: bash

   $ cd ~/zephyr
   $ source zephyr-env.sh
   $ make htmldocs

The html output will be in ``~/zephyr/doc/_build/html/index.html``


.. _ReST documentation: http://sphinx-doc.org/rest.html