.. _doc_guidelines: Documentation Guidelines ######################## .. highlight:: rst .. note:: For instructions on building the documentation, see :ref:`zephyr_doc`. Zephyr Project content is written using the `reStructuredText`_ markup language (.rst file extension) with Sphinx extensions, and processed using Sphinx to create a formatted standalone website. Developers can view this content either in its raw form as .rst markup files, or (with Sphinx installed) they can :ref:`build the documentation ` locally to generate the documentation in HTML or PDF format. The HTML content can then be viewed using a web browser. This same .rst content is served by the `Zephyr documentation`_ website. You can read details about `reStructuredText`_ and about `Sphinx extensions`_ from their respective websites. .. _Sphinx extensions: http://www.sphinx-doc.org/en/stable/contents.html .. _reStructuredText: http://docutils.sourceforge.net/docs/ref/rst/restructuredtext.html .. _Sphinx Inline Markup: http://sphinx-doc.org/markup/inline.html#inline-markup .. _Zephyr documentation: https://docs.zephyrproject.org This document provides a quick reference for commonly used reST and Sphinx-defined directives and roles used to create the documentation you're reading. Content Structure ***************** Tabs, spaces, and indenting =========================== Indenting is significant in reST file content, and using spaces is preferred. Extra indenting can (unintentionally) change the way content is rendered too. For lists and directives, indent the content text to the first non-white space in the preceding line. For example:: * List item that spans multiple lines of text showing where to indent the continuation line. 1. And for numbered list items, the continuation line should align with the text of the line above. .. code-block:: The text within a directive block should align with the first character of the directive name. Refer to the Zephyr :ref:`coding_style` for additional requirements. Headings ======== While reST allows use of both an overline and matching underline to indicate a heading, we only use an underline indicator for headings. * Document title (h1) use ``#`` for the underline character * First section heading level (h2) use ``*`` * Second section heading level (h3) use ``=`` * Third section heading level (h4) use ``-`` The heading underline must be the same length as the heading text. For example:: This is a title heading ####################### some content goes here First section heading ********************* Lists ===== For bullet lists, place an asterisk (``*``) or hyphen (``-``) at the start of a paragraph and indent continuation lines with two spaces. The first item in a list (or sublist) must have a blank line before it and should be indented at the same level as the preceding paragraph (and not indented itself). For numbered lists start with a 1. or a. for example, and continue with autonumbering by using a ``#`` sign. Indent continuation lines with three spaces:: * This is a bulleted list. * It has two items, the second item and has more than one line of reST text. Additional lines are indented to the first character of the text of the bullet list. 1. This is a new numbered list. If the wasn't a blank line before it, it would be a continuation of the previous list (or paragraph). #. It has two items too. a. This is a numbered list using alphabetic list headings #. It has three items (and uses autonumbering for the rest of the list) #. Here's the third item #. This is an autonumbered list (default is to use numbers starting with 1). #. This is a second-level list under the first item (also autonumbered). Notice the indenting. #. And a second item in the nested list. #. And a second item back in the containing list. No blank line needed, but it wouldn't hurt for readability. Definition lists (with a term and its definition) are a convenient way to document a word or phrase with an explanation. For example this reST content:: The Makefile has targets that include: html Build the HTML output for the project clean Remove all generated output, restoring the folders to a clean state. Would be rendered as: The Makefile has targets that include: html Build the HTML output for the project clean Remove all generated output, restoring the folders to a clean state. Multi-column lists ================== If you have a long bullet list of items, where each item is short, you can indicate the list items should be rendered in multiple columns with a special ``.. rst-class:: rst-columns`` directive. The directive will apply to the next non-comment element (e.g., paragraph), or to content indented under the directive. For example, this unordered list:: .. rst-class:: rst-columns * A list of * short items * that should be * displayed * horizontally * so it doesn't * use up so much * space on * the page would be rendered as: .. rst-class:: rst-columns * A list of * short items * that should be * displayed * horizontally * so it doesn't * use up so much * space on * the page A maximum of three columns will be displayed, and change based on the available width of the display window, reducing to one column on narrow (phone) screens if necessary. We've deprecated use of the ``hlist`` directive because it misbehaves on smaller screens. Tables ====== There are a few ways to create tables, each with their limitations or quirks. `Grid tables `_ offer the most capability for defining merged rows and columns, but are hard to maintain:: +------------------------+------------+----------+----------+ | Header row, column 1 | Header 2 | Header 3 | Header 4 | | (header rows optional) | | | | +========================+============+==========+==========+ | body row 1, column 1 | column 2 | column 3 | column 4 | +------------------------+------------+----------+----------+ | body row 2 | ... | ... | you can | +------------------------+------------+----------+ easily + | body row 3 with a two column span | ... | span | +------------------------+------------+----------+ rows + | body row 4 | ... | ... | too | +------------------------+------------+----------+----------+ This example would render as: +------------------------+------------+----------+----------+ | Header row, column 1 | Header 2 | Header 3 | Header 4 | | (header rows optional) | | | | +========================+============+==========+==========+ | body row 1, column 1 | column 2 | column 3 | column 4 | +------------------------+------------+----------+----------+ | body row 2 | ... | ... | you can | +------------------------+------------+----------+ easily + | body row 3 with a two column span | ... | span | +------------------------+------------+----------+ rows + | body row 4 | ... | ... | too | +------------------------+------------+----------+----------+ `List tables `_ are much easier to maintain, but don't support row or column spans:: .. list-table:: Table title :widths: 15 20 40 :header-rows: 1 * - Heading 1 - Heading 2 - Heading 3 * - body row 1, column 1 - body row 1, column 2 - body row 1, column 3 * - body row 2, column 1 - body row 2, column 2 - body row 2, column 3 This example would render as: .. list-table:: Table title :widths: 15 20 40 :header-rows: 1 * - Heading 1 - Heading 2 - Heading 3 * - body row 1, column 1 - body row 1, column 2 - body row 1, column 3 * - body row 2, column 1 - body row 2, column 2 - body row 2, column 3 The ``:widths:`` parameter lets you define relative column widths. The default is equal column widths. If you have a three-column table and you want the first column to be half as wide as the other two equal-width columns, you can specify ``:widths: 1 2 2``. If you'd like the browser to set the column widths automatically based on the column contents, you can use ``:widths: auto``. Tabbed Content ============== As introduced in the :ref:`getting_started`, you can provide alternative content to the reader via a tabbed interface. When the reader clicks on a tab, the content for that tab is displayed, for example:: .. tabs:: .. tab:: Apples Apples are green, or sometimes red. .. tab:: Pears Pears are green. .. tab:: Oranges Oranges are orange. will display as: .. tabs:: .. tab:: Apples Apples are green, or sometimes red. .. tab:: Pears Pears are green. .. tab:: Oranges Oranges are orange. Tabs can also be grouped, so that changing the current tab in one area changes all tabs with the same name throughout the page. For example: .. tabs:: .. group-tab:: Linux Linux Line 1 .. group-tab:: macOS macOS Line 1 .. group-tab:: Windows Windows Line 1 .. tabs:: .. group-tab:: Linux Linux Line 2 .. group-tab:: macOS macOS Line 2 .. group-tab:: Windows Windows Line 2 In this latter case, we're using ``.. group-tab::`` instead of simply ``.. tab::``. Under the hood, we're using the `sphinx-tabs `_ extension that's included in the Zephyr setup. Within a tab, you can have most any content *other than a heading* (code-blocks, ordered and unordered lists, pictures, paragraphs, and such). You can read more about sphinx-tabs from the link above. Text Formatting *************** ReSTructuredText supports a variety of text formatting options. This section provides a quick reference for some of the most commonly used text formatting options in Zephyr documentation. For an exhaustive list, refer to the `reStructuredText Quick Reference`_, `reStructuredText Interpreted Text Roles`_ as well as the `additional roles provided by Sphinx`_. .. _reStructuredText Quick Reference: http://docutils.sourceforge.io/docs/user/rst/quickref.html .. _reStructuredText Interpreted Text Roles: https://docutils.sourceforge.io/docs/ref/rst/roles.html .. _additional roles provided by Sphinx: https://www.sphinx-doc.org/en/master/usage/restructuredtext/roles.html Content Highlighting ==================== Some common reST inline markup samples: * one asterisk: ``*text*`` for emphasis (*italics*), * two asterisks: ``**text**`` for strong emphasis (**boldface**), and * two backquotes: ````text```` for ``inline code`` samples. If asterisks or backquotes appear in running text and could be confused with inline markup delimiters, you can eliminate the confusion by adding a backslash (``\``) before it. File Names and Commands ======================= Sphinx extends reST by supporting additional inline markup elements (called "roles") used to tag text with special meanings and allow style output formatting. (You can refer to the `Sphinx Inline Markup`_ documentation for the full list). While double quotes can be used for rendering text as "code", you are encouraged to use the following roles for marking up file names, command names, and other "special" text. * :rst:role:`file` for file names, e.g., ``:file:`CMakeLists.txt``` will render as :file:`CMakeLists.txt` .. note:: In case you want to indicate a "variable" file path, you may use curly braces to enclose the variable part of the path, e.g., ``:file:`{boardname}_defconfig``` will render as :file:`{boardname}_defconfig`. * :rst:role:`command` for command names, e.g., ``:command:`make``` will render as :command:`make` * :rst:role:`envvar` for environment variables, e.g., ``:envvar:`ZEPHYR_BASE``` will render as :envvar:`ZEPHYR_BASE` For creating references to files that are hosted in the Zephyr organization on GitHub, refer to :ref:`linking_to_zephyr_files` section below. User Interaction ================ When documenting user interactions, such as key combinations or GUI interactions, use the following roles to highlight the commands in a meaningful way: * :rst:role:`kbd` for keyboard input, e.g., ``:kbd:`Ctrl-C``` will render as :kbd:`Ctrl-C` * :rst:role:`menuselection` for menu selections, e.g., ``:menuselection:`File --> Open``` will render as :menuselection:`File --> Open` * :rst:role:`guilabel` for GUI labels, e.g., ``:guilabel:`Cancel``` will render as :guilabel:`Cancel` Mathematical Formulas ===================== You can include mathematical formulas using either the :rst:role:`math` role or :rst:dir:`math` directive. The directive provides more flexibility in case you have a more complex formula. The input language for mathematics is LaTeX markup. Example:: The answer to life, the universe, and everything is :math:`30 + 2^2 + \sqrt{64} = 42`. This would render as: The answer to life, the universe, and everything is :math:`30 + 2^2 + \sqrt{64} = 42`. Non-ASCII Characters ==================== You can insert non-ASCII characters such as a Trademark symbol (|trade|), by using the notation ``|trade|``. Available replacement names are defined in an include file used during the Sphinx processing of the reST files. The names of these replacement characters are the same as used in HTML entities used to insert characters in HTML, e.g., ``\™`` and are defined in the file :zephyr_file:`doc/substitutions.txt` as listed below: .. literalinclude:: ../../substitutions.txt :language: rst We've kept the substitutions list small but others can be added as needed by submitting a change to the :zephyr_file:`doc/substitutions.txt` file. Code Blocks and Command Examples ================================ Use the reST :rst:dir:`code-block` directive to create a highlighted block of fixed-width text, typically used for showing formatted code or console commands and output. Smart syntax highlighting is also supported (using the Pygments package). You can also directly specify the highlighting language. For example:: .. code-block:: c struct k_object { char *name; uint8_t perms[CONFIG_MAX_THREAD_BYTES]; uint8_t type; uint8_t flags; uint32_t data; } __packed; Note the blank line between the :rst:dir:`code-block` directive and the first line of the code-block body, and the body content is indented three spaces (to the first non-white space of the directive name). This would be rendered as: .. code-block:: c struct k_object { char *name; uint8_t perms[CONFIG_MAX_THREAD_BYTES]; uint8_t type; uint8_t flags; uint32_t data; } __packed; Other languages are of course supported (see `languages supported by Pygments`_), and in particular, you are encouraged to make use of the following when appropriate: .. _`languages supported by Pygments`: http://pygments.org/languages/ * ``c`` for C code * ``cpp`` for C++ code * ``python`` for Python code * ``console`` for console output, i.e. interactive shell sessions where commands are prefixed by a prompt (ex. ``$`` for Linux, or ``uart:~$`` for Zephyr's shell), and where the output is also shown. The commands will be highlighted, and the output will not. What's more, copying code block using the "copy" button will automatically copy just the commands, excluding the prompt and the outputs of the commands. * ``shell`` or ``bash`` for shell commands. Both languages get highlighted the same but you may use ``bash`` for conveying that the commands are bash-specific, and ``shell`` for generic shell commands. .. note:: Do not use ``bash`` or ``shell`` if your code block includes a prompt, use ``console`` instead. Reciprocally, do not use ``console`` if your code block does not include a prompt and is not showcasing an interactive session with command(s) and their output. .. list-table:: When to use ``bash``/``shell`` vs. ``console`` :class: wrap-normal :header-rows: 1 :widths: 20,40,40 * - Use case - ``code-block`` snippet - Expected output * - One or several commands, no output - .. code-block:: rst .. code-block:: shell echo "Hello World!" - .. code-block:: shell echo "Hello World!" * - An interactive shell session with command(s) and their output - .. code-block:: rst .. code-block:: console $ echo "Hello World!" Hello World! - .. code-block:: console $ echo "Hello World!" Hello World! * - An interactive Zephyr shell session, with commands and their outputs - .. code-block:: rst .. code-block:: console uart:~$ version Zephyr version 3.5.99 uart:~$ kernel uptime Uptime: 20970 ms - .. code-block:: console uart:~$ version Zephyr version 3.5.99 uart:~$ kernel uptime Uptime: 20970 ms * ``bat`` for Windows batch files * ``cfg`` for config files with "KEY=value" entries (ex. Kconfig ``.conf`` files) * ``cmake`` for CMake * ``devicetree`` for Devicetree * ``kconfig`` for Kconfig * ``yaml`` for YAML * ``rst`` for reStructuredText When no language is specified, the language is set to ``none`` and the code block is not highlighted. You may also use ``none`` explicitly to achieve the same result; for example:: .. code-block:: none This would be a block of text styled with a background and box, but with no syntax highlighting. Would display as: .. code-block:: none This would be a block of text styled with a background and box, but with no syntax highlighting. There's a shorthand for writing code blocks too: end the introductory paragraph with a double colon (``::``) and indent the code block content that follows it by three spaces. On output, only one colon will be shown. The code block will have no highlighting (i.e. ``none``). You may however use the :rst:dir:`highlight` directive to customize the default language used in your document (see for example how this is done at the beginning of this very document). Links and Cross-References ************************** .. _internal-linking: Cross-referencing internal content ================================== Traditional ReST links are only supported within the current file using the notation:: Refer to the `internal-linking`_ page which renders as, Refer to the `internal-linking`_ page Note the use of a trailing underscore to indicate an outbound link. In this example, the label was added immediately before a heading, so the text that's displayed is the heading text itself. You can change the text that's displayed as the link writing this as:: Refer to the `show this text instead `_ page which renders as, Refer to the `show this text instead `_ page Cross-referencing external content ================================== With Sphinx's help, we can create link-references to any tagged text within the Zephyr Project documentation. Target locations in a document are defined with a label directive:: .. _my label name: Heading ======= Note the leading underscore indicating an inbound link. The content immediately following this label must be a heading, and is the target for a ``:ref:`my label name``` reference from anywhere within the Zephyr documentation. The heading text is shown when referencing this label. You can also change the text that's displayed for this link, such as:: :ref:`some other text ` To enable easy cross-page linking within the site, each file should have a reference label before its title so it can be referenced from another file. These reference labels must be unique across the whole site, so generic names such as "samples" should be avoided. For example the top of this document's .rst file is:: .. _doc_guidelines: Documentation Guidelines for the Zephyr Project ############################################### Other .rst documents can link to this document using the ``:ref:`doc_guidelines``` tag and it will show up as :ref:`doc_guidelines`. This type of internal cross reference works across multiple files, and the link text is obtained from the document source so if the title changes, the link text will update as well. You can also define links to any URL and then reference it in your document. For example, with this label definition in the document:: .. _Zephyr Wikipedia Page: https://en.wikipedia.org/wiki/Zephyr_(operating_system) you can reference it with:: Read the `Zephyr Wikipedia Page`_ for more information about the project. .. tip:: When a document contains many external links, it can be useful to list them in a single "References" section at the end of the document. This can be done using the :rst:dir:`target-notes` directive. Example:: References ========== .. target-notes:: .. _external_link1: https://example.com .. _external_link2: https://example.org Cross-referencing C documentation ================================= .. rst:role:: c:member c:data c:var c:func c:macro c:struct c:union c:enum c:enumerator c:type You may use these roles to cross-reference the Doxygen documentation of C functions, macros, types, etc. They are rendered in the HTML output as links to the corresponding Doxygen documentation for the item. For example:: Check out :c:function:`gpio_pin_configure` for more information. Will render as: Check out :c:func:`gpio_pin_configure` for more information. You may provide a custom link text, similar to the built-in :rst:role:`ref` role. Visual Elements *************** Images ====== Images are included in the documentation by using an :rst:dir:`image` directive:: .. image:: ../../images/doc-gen-flow.png :align: center :alt: alt text for the image or if you'd like to add an image caption, use:: .. figure:: ../../images/doc-gen-flow.png :alt: image description Caption for the figure The file name specified is relative to the document source file, and we recommend putting images into an ``images`` folder where the document source is found. The usual image formats handled by a web browser are supported: WebP, PNG, GIF, JPEG, and SVG. Keep the image size only as large as needed, generally at least 500 px wide but no more than 1000 px, and no more than 100 KB unless a particularly large image is needed for clarity. Recommended image formats based on content ------------------------------------------ * **Screenshots**: WebP or PNG. * **Diagrams**: Consider using Graphviz for simple diagrams (see `dedicated section `_ below. If using an external tool, SVG is preferred. * **Photos** (ex. boards): WebP. Use transparency if possible/available. .. _graphviz_diagrams: Graphviz ======== `Graphviz`_ is a tool for creating diagrams specified in a simple text language. As it's important to allow for diagrams used in the documentation to be easily maintained, we encourage the use of Graphviz for creating diagrams. Graphviz is particularly well suited for creating state diagrams, flow charts, and other types of diagrams that can be expressed as a graph. To include a Graphviz diagram in a document, use the :rst:dir:`graphviz` directive. For example:: .. graphviz:: digraph G { rankdir=LR; A -> B; B -> C; C -> D; } Would render as: .. graphviz:: digraph G { rankdir=LR; A -> B; B -> C; C -> D; } Please refer to the `Graphviz documentation`_ for more information on how to create diagrams using Graphviz's DOT language. .. _Graphviz: https://graphviz.org .. _Graphviz documentation: https://graphviz.org/documentation Custom Sphinx Roles and Directives ********************************** The Zephyr documentation uses custom Sphinx roles and directives to provide additional functionality and to make it easier to write and maintain consistent documentation. Application build commands ========================== .. rst:directive:: .. zephyr-app-commands:: Generate consistent documentation of the shell commands needed to manage (build, flash, etc.) an application For example, to generate commands to build ``samples/hello_world`` for ``qemu_x86`` use:: .. zephyr-app-commands:: :zephyr-app: samples/hello_world :board: qemu_x86 :goals: build This will render as: .. zephyr-app-commands:: :zephyr-app: samples/hello_world :board: qemu_x86 :goals: build .. rubric:: Options .. rst:directive:option:: tool :type: string Which tool to use. Valid options are currently ``cmake``, ``west`` and ``all``. The default is ``west``. .. rst:directive:option:: app :type: string Path to the application to build. .. rst:directive:option:: zephyr-app :type: string Path to the application to build, this is an app present in the upstream zephyr repository. Mutually exclusive with ``:app:``. .. rst:directive:option:: cd-into :type: no value If set, build instructions are given from within the ``:app:`` folder, instead of outside of it. .. rst:directive:option:: generator :type: string Which build system to generate. Valid options are currently ``ninja`` and ``make``. The default is ``ninja``. This option is not case sensitive. .. rst:directive:option:: host-os Which host OS the instructions are for. Valid options are ``unix``, ``win`` and ``all``. The default is ``all``. .. rst:directive:option:: board :type: string If set, build commands will target the given board. .. rst:directive:option:: shield :type: string If set, build commands will target the given shield. Multiple shields can be provided in a comma separated list. .. rst:directive:option:: conf If set, build commands will use the given configuration file(s). If multiple configuration files are provided, enclose the space-separated list of files with double quotes, e.g., `"a.conf b.conf"`. .. rst:directive:option:: gen-args :type: string If set, indicates additional arguments to the CMake invocation. .. rst:directive:option:: build-args :type: string If set, indicates additional arguments to the build invocation. .. rst:directive:option:: west-args :type: string If set, additional arguments to the west invocation (ignored for ``:tool: cmake``). .. rst:directive:option:: flash-args :type: string If set, additional arguments to the flash invocation. .. rst:directive:option:: snippets :type: string If set, indicates the application should be compiled with the listed snippets. Multiple snippets can be provided in a comma separated list. .. rst:directive:option:: build-dir :type: string If set, the application build directory will *APPEND* this relative, Unix-separated, path to the standard build directory. This is mostly useful for distinguishing builds for one application within a single page. .. rst:directive:option:: build-dir-fmt :type: string If set, assume that `west config build.dir-fmt`` has been set to this path. Exclusive with ``:build-dir:`` and depends on ``:tool: west``. .. rst:directive:option:: goals :type: string A whitespace-separated list of what to do with the app (any of ``build``, ``flash``, ``debug``, ``debugserver``, ``run``). Commands to accomplish these tasks will be generated in the right order. .. rst:directive:option:: maybe-skip-config :type: no value If set, this indicates the reader may have already created a build directory and changed there, and will tweak the text to note that doing so again is not necessary. .. rst:directive:option:: compact :type: no value If set, the generated output is a single code block with no additional comment lines. .. _linking_to_zephyr_files: Cross-referencing files in the Zephyr tree ========================================== Special roles are available to reference files in the Zephyr tree. For example, referencing this very file can be done using the :rst:role:`zephyr_file` role, like this:: Check out :zephyr_file:`doc/contribute/documentation/guidelines.rst` for more information. This would render as: Check out :zephyr_file:`doc/contribute/documentation/guidelines.rst` for more information. You may use the :rst:role:`zephyr_raw` role instead if you want to reference the "raw" content. .. rst:role:: zephyr_file This role is used to reference a file in the Zephyr tree. For example:: Check out :zephyr_file:`doc/contribute/documentation/guidelines.rst` for more information. Will render as: Check out :zephyr_file:`doc/contribute/documentation/guidelines.rst` for more information. .. rst:role:: zephyr_raw This role is used to reference the raw content of a file in the Zephyr tree. For example:: Check out :zephyr_raw:`doc/contribute/documentation/guidelines.rst` for more information. Will render as: Check out :zephyr_raw:`doc/contribute/documentation/guidelines.rst` for more information. .. rst:role:: module_file This role is used to reference a module in the Zephyr tree. For example:: Check out :module_file:`hal_stm32:CMakeLists.txt` for more information. Will render as: Check out :module_file:`hal_stm32:CMakeLists.txt` for more information. Cross-referencing GitHub issues and pull requests ================================================= .. rst:role:: github This role is used to reference a GitHub issue or pull request. For example, to reference issue #1234:: Check out :github:`1234` for more background about this known issue. This will render as: Check out :github:`1234` for more background about this known issue. Doxygen API documentation ========================= .. app.add_directive("doxygengroup", DoxygenGroupDirective) .. app.add_role_to_domain("c", "group", CXRefRole()) .. rst:directive:: .. doxygengroup:: name This directive is used to output a short description of a Doxygen group and a link to the corresponding Doxygen-generated documentation. All the code samples (declared using the :rst:dir:`zephyr:code-sample` directive) indicating the group as relevant will automatically be list and referenced in the rendered output. For example:: .. doxygengroup:: can_interface Will render as: .. doxygengroup:: can_interface .. rst:role:: c:group This role is used to reference a Doxygen group in the Zephyr tree. In the HTML documentation, they are rendered as links to the corresponding Doxygen-generated documentation for the group. For example:: Check out :c:group:`gpio_interface` for more information. Will render as: Check out :c:group:`gpio_interface` for more information. You may provide a custom link text, similar to the built-in :rst:role:`ref` role. Kconfig options =============== If you want to reference a Kconfig option from a document, you can use the :rst:role:`kconfig:option` role and provide the name of the option you want to reference. The role will automatically generate a link to the documentation of the Kconfig option when building HTML output. Make sure to use the full name of the Kconfig option, including the ``CONFIG_`` prefix. .. rst:role:: kconfig:option This role is used to reference a Kconfig option in the Zephyr tree. For example:: Check out :kconfig:option:`CONFIG_GPIO` for more information. Will render as: Check out :kconfig:option:`CONFIG_GPIO` for more information. Devicetree bindings =================== If you want to reference a Devicetree binding from a document, you can use the :rst:role:`dtcompatible` role and provide the compatible string of the binding you want to reference. The role will automatically generate a link to the documentation of the binding when building HTML output. .. rst:role:: dtcompatible This role can be used inline to make a reference to the generated documentation for the Devicetree compatible given as argument. There may be more than one page for a single compatible. For example, that happens if a binding behaves differently depending on the bus the node is on. If that occurs, the reference points at a "disambiguation" page which links out to all the possibilities, similarly to how Wikipedia disambiguation pages work. Example:: Check out :dtcompatible:`zephyr,input-longpress` for more information. Will render as: Check out :dtcompatible:`zephyr,input-longpress` for more information. Code samples ============ .. rst:directive:: .. zephyr:code-sample:: id This directive is used to describe a code sample, including which noteworthy APIs it may be exercising. For example:: .. zephyr:code-sample:: blinky :name: Blinky :relevant-api: gpio_interface Blink an LED forever using the GPIO API. The content of the directive is used as the description of the code sample. .. rubric:: Options .. rst:directive:option:: name :type: text Indicates the human-readable short name of the sample. .. rst:directive:option:: relevant-api :type: text Optional space-separated list of Doxygen group names that correspond to the APIs exercised by the code sample. .. rst:role:: zephyr:code-sample This role is used to reference a code sample described using :rst:dir:`zephyr:code-sample`. For example:: Check out :zephyr:code-sample:`blinky` for more information. Will render as: Check out :zephyr:code-sample:`blinky` for more information. This can be used exactly like the built-in :rst:role:`ref` role, i.e. you may provide a custom link text. For example:: Check out :zephyr:code-sample:`blinky code sample ` for more information. Will render as: Check out :zephyr:code-sample:`blinky code sample ` for more information. .. rst:directive:: .. zephyr:code-sample-category:: id This directive is used to define a category for grouping code samples. For example:: .. zephyr:code-sample-category:: gpio :name: GPIO :show-listing: Samples related to the GPIO subsystem. The contents of the directive is used as the description of the category. It can contain any valid reStructuredText content. .. rubric:: Options .. rst:directive:option:: name :type: text Indicates the human-readable name of the category. .. rst:directive:option:: show-listing :type: flag If set, a listing of code samples in the category will be shown. The listing is automatically generated based on all code samples found in the subdirectories of the current document. .. rst:directive:option:: glob :type: text A glob pattern to match the files to include in the listing. The default is `*/*` but it can be overridden e.g. when samples may be found in directories not sitting directly under the category directory. .. rst:role:: zephyr:code-sample-category This role is used to reference a code sample category described using :rst:dir:`zephyr:code-sample-category`. For example:: Check out :zephyr:code-sample-category:`cloud` samples for more information. Will render as: Check out :zephyr:code-sample-category:`cloud` samples for more information. .. rst:directive:: .. zephyr:code-sample-listing:: This directive is used to show a listing of all code samples found in one or more categories. For example:: .. zephyr:code-sample-listing:: :categories: cloud Will render as: .. zephyr:code-sample-listing:: :categories: cloud .. rubric:: Options .. rst:directive:option:: categories :type: text A space-separated list of category IDs for which to show the listing. .. rst:directive:option:: live-search :type: flag A flag to include a search box right above the listing. The search box allows users to filter the listing by code sample name/description, which can be useful for categories with a large number of samples. This option is only available in the HTML builder. Boards ====== .. rst:directive:: .. zephyr:board:: name This directive is used at the beginning of a document to indicate it is the main documentation page for a board whose name is given as the directive argument. For example:: .. zephyr:board:: wio_terminal The metadata for the board is read from various config files and used to automatically populate some sections of the board documentation. A board documentation page that uses this directive can be linked to using the :rst:role:`zephyr:board` role. .. rst:role:: zephyr:board This role is used to reference a board documented using :rst:dir:`zephyr:board`. For example:: Check out :zephyr:board:`wio_terminal` for more information. Will render as: Check out :zephyr:board:`wio_terminal` for more information. .. rst:directive:: .. zephyr:board-catalog:: This directive is used to generate a catalog of Zephyr-supported boards that can be used to quickly browse the list of all supported boards and filter them according to various criteria. References ********** .. target-notes::