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1# coreboot documentation guidelines
2
3> Documentation is like sex: when it is good, it is very, very good;
4> and when it is bad, it is better than nothing.
5
6That said please always try to write documentation! One problem in the
7firmware development is the missing documentation. In this document
8you will get a brief introduction how to write, submit and publish
9documentation to coreboot.
10
11## Preparations
12
13coreboot uses [Sphinx] documentation tool. We prefer the markdown format
14over reStructuredText so only embedded ReST is supported. Checkout the
15[Markdown Guide] for more information.
16
17### option 1: Use the docker image
18
19The easiest way to build the documentation is using a docker image.
20To build the image run the following in the base directory:
21
22	make -C util/docker/ doc.coreboot.org
23
24Before building the documentation make sure the output directory is given
25the correct permissions before running docker.
26
27	mkdir -p Documentation/_build
28
29To build the documentation:
30
31	make -C util/docker docker-build-docs
32
33To have the documentation build and served over a web server live run:
34
35	make -C util/docker docker-livehtml-docs
36
37On the host machine, open a browser to the address <http://0.0.0.0:8000>.
38
39### option 2: Install Sphinx
40
41Please follow this official [guide] to install sphinx.
42You will also need python-recommonmark for sphinx to be able to handle
43markdown documentation.
44
45Since some Linux distributions don't package every needed sphinx extension,
46the installation via pip in a venv is recommended. You'll need these python3
47modules:
48
49* sphinx
50* recommonmark
51* sphinx_rtd_theme
52* sphinxcontrib-ditaa
53
54The following combination of versions has been tested: sphinx 2.3.1,
55recommonmark 0.6.0, sphinx_rtd_theme 0.4.3 and sphinxcontrib-ditaa 0.7.
56
57Now change into the `Documentation` folder in the coreboot directory and run
58this command in there
59
60	make sphinx
61
62If no error occurs, you can find the generated HTML documentation in
63`Documentation/_build` now.
64
65### Optional
66
67Install [sphinx-autobuild] for rebuilding markdown/rst sources on the fly!
68
69## Basic and simple rules
70
71The following rules should be followed in order to get it at least reviewed
72on [review.coreboot.org].
73
74Documentation:
75
761.  Must be written in **markdown** with **embedded reStructuredText**
77    format.
782.  Must be written in **English**.
793.  Must be placed into **Documentation/** directory subfolder.
804.  Should follow the same directory structure as **src/** when practical.
815.  Must be referenced from within other markdown files
826.  The commit must follow the [Gerrit Guidelines].
837.  Must have all **lowercase filenames**.
848.  Running text should have a visible width of about **72 chars**.
859.  Should not **duplicate** documentation, but reference it instead.
8610.  Must not include the same picture in multiple markdown files.
8711.  Images should be kept small. They should be under 700px in width, as
88     the current theme doesn't allow bigger images.
8912.  Shouldn't cover implementation details; for details, the code is the
90     reference.
91
92## Referencing markdown documents
93
94Starting with Sphinx 1.6 recommonmark's *auto_doc_ref* feature is broken.
95To reference documents use the TOC tree or inline RST code.
96
97## Markdown and Tables
98
99Under Sphinx markdown tables are not supported. Therefore you can use following
100code block to write tables in reStructuredText and embed them into the markdown:
101
102    ```{eval-rst}
103    +------------+------------+-----------+
104    | Header 1   | Header 2   | Header 3  |
105    +============+============+===========+
106    | body row 1 | column 2   | column 3  |
107    +------------+------------+-----------+
108    | body row 2 | Cells may span columns.|
109    +------------+------------+-----------+
110    | body row 3 | Cells may  | - Cells   |
111    +------------+ span rows. | - contain |
112    | body row 4 |            | - blocks. |
113    +------------+------------+-----------+
114    ``` #just a code block is enough
115
116## TocTree
117
118To make sure that all documents are included into the final documentation, you
119must reference each document from at least one *toctree*. The *toctree* must
120only reference files in the same folder or in subfolders !
121To create a toctree, simply use a bullet list or numbered list with a single
122reference. References in regular text aren't considered as *toctree* .
123This feature is enabled by recommonmark's *enable_auto_toc_tree* .
124
125**Example toctree:**
126
127```
128* [Chapter 1](chapter1.md)
129* [Chapter 2](chapter2.md)
130* [Subchapter](sub/index.md)
131```
132
133```
1341. [Chapter 1](chapter1.md)
1352. [Chapter 2](chapter2.md)
136```
137
138If you do only reference the document, but do not include it in any toctree,
139you'll see the following warning:
140**WARNING: document isn't included in any toctree**
141
142## CSV
143
144You can import CSV files and let sphinx automatically convert them to human
145readable tables, using the following reStructuredText snipped:
146
147    ```{eval-rst}
148    .. csv-table::
149       :header: "Key", "Value"
150       :file: keyvalues.csv
151    ```
152
153Of course this can only be done from a markdown file that is included in the
154TOC tree.
155
156[coreboot]: https://coreboot.org
157[Documentation]: https://review.coreboot.org/cgit/coreboot.git/tree/Documentation
158[sphinx-autobuild]: https://github.com/GaretJax/sphinx-autobuild
159[guide]: http://www.sphinx-doc.org/en/stable/install.html
160[Sphinx]: http://www.sphinx-doc.org/en/master/
161[Markdown Guide]: https://www.markdownguide.org/
162[Gerrit Guidelines]: ../contributing/gerrit_guidelines.md
163[review.coreboot.org]: https://review.coreboot.org
164