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Diffstat (limited to 'poky/documentation/README')
| -rw-r--r-- | poky/documentation/README | 308 |
1 files changed, 271 insertions, 37 deletions
diff --git a/poky/documentation/README b/poky/documentation/README index d64f2fd2f9..28d5c4be8e 100644 --- a/poky/documentation/README +++ b/poky/documentation/README @@ -34,22 +34,17 @@ Manual Organization Folders exist for individual manuals as follows: -* sdk-manual - The Yocto Project Software Development Kit (SDK) Developer's Guide. -* bsp-guide - The Yocto Project Board Support Package (BSP) Developer's Guide -* dev-manual - The Yocto Project Development Tasks Manual -* kernel-dev - The Yocto Project Linux Kernel Development Tasks Manual -* ref-manual - The Yocto Project Reference Manual -* yocto-project-qs - The Yocto Project Quick Start -* mega-manual - The Yocto Project Mega-Manual, which is an aggregated manual comprised - of all YP manuals and guides -* profile-manual - The Yocto Project Profile and Tracing Manual -* toaster-manual - The Toaster Manual - -Each folder is self-contained regarding content and figures. Note that there -is a sed file needed to process the links of the mega-manual. The sed file -is located in the tools directory. Also note that the figures folder in the -mega-manual directory contains duplicates of all the figures in the YP folders -directories for all YP manuals and guides. +* sdk-manual - The Yocto Project Software Development Kit (SDK) Developer's Guide. +* bsp-guide - The Yocto Project Board Support Package (BSP) Developer's Guide +* dev-manual - The Yocto Project Development Tasks Manual +* kernel-dev - The Yocto Project Linux Kernel Development Tasks Manual +* ref-manual - The Yocto Project Reference Manual +* brief-yoctoprojectqs - The Yocto Project Quick Start +* profile-manual - The Yocto Project Profile and Tracing Manual +* toaster-manual - The Toaster Manual +* test-manual - The Test Environment Manual + +Each folder is self-contained regarding content and figures. If you want to find HTML versions of the Yocto Project manuals on the web, go to http://www.yoctoproject.org and click on the "Documentation" tab. From @@ -60,34 +55,273 @@ currently being developed. In general, the Yocto Project site (http://www.yoctoproject.org) is a great reference for both information and downloads. -Makefile +poky.yaml +========= + +This file defines variables used for documentation production. The variables +are used to define release pathnames, URLs for the published manuals, etc. + +template ======== +Contains various templates, fonts, and some old PNG files. + +Sphinx +====== + +The Yocto Project documentation was migrated from the original DocBook +format to Sphinx based documentation for the Yocto Project 3.2 +release. This section will provide additional information related to +the Sphinx migration, and guidelines for developers willing to +contribute to the Yocto Project documentation. + + Sphinx is a tool that makes it easy to create intelligent and + beautiful documentation, written by Georg Brandl and licensed under + the BSD license. It was originally created for the Python + documentation. + +Extensive documentation is available on the Sphinx website: +https://www.sphinx-doc.org/en/master/. Sphinx is designed to be +extensible thanks to the ability to write our own custom extensions, +as Python modules, which will be executed during the generation of the +documentation. + +Yocto Project documentation website +=================================== + +A new website has been created to host the Yocto Project +documentation, it can be found at: https://docs.yoctoproject.org/. + +The entire Yocto Project documentation, as well as the BitBake manual +is published on this website, including all previously released +versions. A version switcher was added, as a drop-down menu on the top +of the page to switch back and forth between the various versions of +the current active Yocto Project releases. + +Transition pages have been added (as rst file) to show links to old +versions of the Yocto Project documentation with links to each manual +generated with DocBook. + +How to build the Yocto Project documentation +============================================ + +Sphinx is written in Python. While it might work with Python2, for +obvious reasons, we will only support building the Yocto Project +documentation with Python3. + +Sphinx might be available in your Linux distro packages repositories, +however it is not recommend using distro packages, as they might be +old versions, especially if you are using an LTS version of your +distro. The recommended method to install Sphinx and all required +dependencies is to use the Python Package Index (pip). -The Makefile processes manual directories to create HTML, PDF, -tarballs, etc. Details on how the Makefile work are documented -inside the Makefile. See that file for more information. +To install all required packages run: -To build a manual, you run the make command and pass it the name -of the folder containing the manual's contents. -For example, the following command run from the documentation directory -creates an HTML version of the SDK manual. -The DOC variable specifies the manual you are making: + $ pip3 install sphinx sphinx_rtd_theme pyyaml - $ make DOC=sdk-manual +To build the documentation locally, run: -poky.ent + $ cd documentation + $ make html + +The resulting HTML index page will be _build/html/index.html, and you +can browse your own copy of the locally generated documentation with +your browser. + +Alternatively, you can use Pipenv to automatically install all required +dependencies in a virtual environment: + + $ cd documentation + $ pipenv install + $ pipenv run make html + +Sphinx theme and CSS customization +================================== + +The Yocto Project documentation is currently based on the "Read the +Docs" Sphinx theme, with a few changes to make sure the look and feel +of the project documentation is preserved. + +Most of the theme changes can be done using the file +'sphinx-static/theme_overrides.css'. Most CSS changes in this file +were inherited from the DocBook CSS stylesheets. + +Sphinx design guidelines and principles +======================================= + +The initial Docbook to Sphinx migration was done with an automated +tool called Pandoc (https://pandoc.org/). The tool produced some clean +output markdown text files. After the initial automated conversion +additional changes were done to fix up headings, images and links. In +addition Sphinx has built in mechanisms (directives) which were used +to replace similar functions implemented in Docbook such as glossary, +variables substitutions, notes and references. + +Headings ======== -This file defines variables used for documentation production. The variables -are used to define release pathnames, URLs for the published manuals, etc. +The layout of the Yocto Project manuals is organized as follows -template + Book + Chapter + Section + Section + Section + +The following headings styles are defined in Sphinx: + + Book => overline === + Chapter => overline *** + Section => ==== + Section => ---- + Section => ^^^^ + Section => """" or ~~~~ + +With this proposal, we preserve the same TOCs between Sphinx and Docbook. + +Built-in glossary +================= + +Sphinx has a glossary directive. From +https://www.sphinx-doc.org/en/master/usage/restructuredtext/directives.html#glossary: + + This directive must contain a reST definition list with terms and + definitions. The definitions will then be referencable with the + [https://www.sphinx-doc.org/en/master/usage/restructuredtext/roles.html#role-term + 'term' role]. + +So anywhere in any of the Yocto Project manuals, :term:`VAR` can be +used to refer to an item from the glossary, and a link is created +automatically. A general index of terms is also generated by Sphinx +automatically. + +Global substitutions +==================== + +The Yocto Project documentation makes heavy use of global +variables. In Docbook these variables are stored in the file +poky.ent. This Docbook feature is not handled automatically with +Pandoc. Sphinx has builtin support for substitutions +(https://www.sphinx-doc.org/en/master/usage/restructuredtext/basics.html#substitutions), +however there are important shortcomings. For example they cannot be +used/nested inside code-block sections. + +A Sphinx extension was implemented to support variable substitutions +to mimic the DocBook based documentation behavior. Variabes +substitutions are done while reading/parsing the .rst files. The +pattern for variables substitutions is the same as with DocBook, +e.g. `&VAR;`. + +The implementation of the extension can be found here in the file +documentation/sphinx/yocto-vars.py, this extension is enabled by +default when building the Yocto Project documentation. All variables +are set in a file call poky.yaml, which was initially generated from +poky.ent. The file was converted into YAML so that it is easier to +process by the custom Sphinx extension (which is a Python module). + +For example, the following .rst content will produce the 'expected' +content: + + .. code-block:: + $ mkdir ~/poky-&DISTRO; + or + $ git clone &YOCTO_GIT_URL;/git/poky -b &DISTRO_NAME_NO_CAP; + +Variables can be nested, like it was the case for DocBook: + + YOCTO_HOME_URL : "http://www.yoctoproject.org" + YOCTO_DOCS_URL : "&YOCTO_HOME_URL;/docs" + +Note directive +============== + +Sphinx has a builtin 'note' directive that produces clean Note section +in the output file. There are various types of directives such as +"attention", "caution", "danger", "error", "hint", "important", "tip", +"warning", "admonition" that are supported, and additional directive +can be added as Sphinx extension if needed. + +Figures +======= + +The Yocto Project documentation has many figures/images. Sphinx has a +'figure' directive which is straight forward to use. To include a +figure in the body of the documentation: + + .. image:: figures/YP-flow-diagram.png + +Links and References +==================== + +The following types of links can be used: links to other locations in +the same document, to locations in other documents and to external +websites. + +More information can be found here: +https://sublime-and-sphinx-guide.readthedocs.io/en/latest/references.html. + +References +========== + +The following extension is enabed by default: +sphinx.ext.autosectionlabel +(https://www.sphinx-doc.org/en/master/usage/extensions/autosectionlabel.html). + +This extension allows you to refer sections by their titles. Note that +autosectionlabel_prefix_document is enabled by default, so that we can +insert references from any document. + +For example, to insert an HTML link to a section from +documentaion/manual/intro.rst, use: + + Please check this :ref:`manual/intro:Cross-References to Locations in the Same Document` + +Alternatively a custom text can be used instead of using the section +text: + + Please check this :ref:`section <manual/intro:Cross-References to Locations in the Same Document>` + +TIP: The following command can be used to dump all the references that + are defined in the project documentation: + + python -msphinx.ext.intersphinx <path to build folder>/html/objects.inv + +This dump contains all links and for each link it shows the default +"Link Text" that Sphinx would use. If the default link text is not +appropriate, a custom link text can be used in the ':ref:' directive. + +Extlinks ======== -Contains various templates, fonts, and some old PNG files. -tools -===== -Contains a tool to convert the DocBook files to PDF format. This folder also -contains the mega-manual.sed file, which is used by Makefile to process -cross-references from within the manual that normally go to an external -manual. +The sphinx.ext.extlinks extension is enabled by default +(https://sublime-and-sphinx-guide.readthedocs.io/en/latest/references.html#use-the-external-links-extension), +and it is configured with: + + 'yocto_home': ('https://yoctoproject.org%s', None), + 'yocto_wiki': ('https://wiki.yoctoproject.org%s', None), + 'yocto_dl': ('https://downloads.yoctoproject.org%s', None), + 'yocto_lists': ('https://lists.yoctoproject.org%s', None), + 'yocto_bugs': ('https://bugzilla.yoctoproject.org%s', None), + 'yocto_ab': ('https://autobuilder.yoctoproject.org%s', None), + 'yocto_docs': ('https://docs.yoctoproject.org%s', None), + 'yocto_git': ('https://git.yoctoproject.org%s', None), + 'oe_home': ('https://www.openembedded.org%s', None), + 'oe_lists': ('https://lists.openembedded.org%s', None), + +It creates convenient shortcuts which can be used throughout the +documentation rst files, as: + + Please check this :yocto_wiki:`wiki page </Weekly_Status>` + +Intersphinx links +================= + +The sphinx.ext.intersphinx extension is enabled by default +(https://www.sphinx-doc.org/en/master/usage/extensions/intersphinx.html), +so that we can cross reference content from other Sphinx based +documentation projects, such as the BitBake manual. + +References to the bitbake manual can be done like this: + + See the ":ref:`-D <bitbake:bitbake-user-manual/bitbake-user-manual-intro:usage and syntax>`" option +or + :term:`bitbake:BB_NUMBER_PARSE_THREADS` |