sphinx: import docs

The Yocto Project docs was migrated from Docbook to Sphinx in YP
 3.2. This 3.1 is an LTS release, and since 3.1 docs are 'close to'
 the docs in 3.2, we agreed to backport sphinx docs onto 3.1.

This first patch brings all changes done in 3.2 until:
7f64574f7 README: include detailed information about sphinx

There are other changes after this commit, but they will be
 selectively backported in individual patches.

This patch was generated with the following command:

git cherry-pick -n \
 $(git log --reverse --oneline \
 ac352ad7f95db7eeacb53c2778caa31800bd7c26..7f64574f7 \
| cut -f1 -d' ')

The following commits were applies in the dunfell docs, but not in
master, so they were first reverted (and squashed into this change). A
commit will reintroduce the content from these patches in the Sphinx
files in a followup patch.

069c27574 Documenation: Prepared for the 3.1.1 release
bd140f0f9 Documentation: Add 3.1.1 version updates missing from previous commit
17cc71a8f Documenation: Prepared for the 3.1.2 release
1a69e2c02 Documenation: Prepared for the 3.1.3 release
8910ac1c7 Documenation: Prepared for the 3.1.4 release

(From yocto-docs rev: c25fe058b88b893b0d146f3ed27320b47cdec236)

Signed-off-by: Nicolas Dechesne <nicolas.dechesne@linaro.org>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

3 files changed, 397 insertions, 0 deletions

diff --git a/documentation/sphinx-static/YoctoProject_Logo_RGB.jpg b/documentation/sphinx-static/YoctoProject_Logo_RGB.jpg
new file mode 100644
index 0000000000..8ab47d49f7
--- /dev/null
+++ b/documentation/sphinx-static/YoctoProject_Logo_RGB.jpg
diff --git a/documentation/sphinx-static/switchers.js b/documentation/sphinx-static/switchers.js
new file mode 100644
index 0000000000..32113cfa96
--- /dev/null
+++ b/documentation/sphinx-static/switchers.js
@@ -0,0 +1,233 @@
+(function() {
+  'use strict';
+
+  var all_versions = {
+    'dev': 'dev (3.2)',
+    '3.1.2': '3.1.2',
+    '3.0.3': '3.0.3',
+    '2.7.4': '2.7.4',
+  };
+
+  var all_doctypes = {
+      'single': 'Individual Webpages',
+      'mega': "All-in-one 'Mega' Manual",
+  };
+
+  // Simple version comparision
+  // Return 1 if a > b
+  // Return -1 if a < b
+  // Return 0 if a == b
+  function ver_compare(a, b) {
+    if (a == "dev") {
+       return 1;
+    }
+
+    if (a === b) {
+       return 0;
+    }
+
+    var a_components = a.split(".");
+    var b_components = b.split(".");
+
+    var len = Math.min(a_components.length, b_components.length);
+
+    // loop while the components are equal
+    for (var i = 0; i < len; i++) {
+        // A bigger than B
+        if (parseInt(a_components[i]) > parseInt(b_components[i])) {
+            return 1;
+        }
+
+        // B bigger than A
+        if (parseInt(a_components[i]) < parseInt(b_components[i])) {
+            return -1;
+        }
+    }
+
+    // If one's a prefix of the other, the longer one is greater.
+    if (a_components.length > b_components.length) {
+        return 1;
+    }
+
+    if (a_components.length < b_components.length) {
+        return -1;
+    }
+
+    // Otherwise they are the same.
+    return 0;
+  }
+
+  function build_version_select(current_series, current_version) {
+    var buf = ['<select>'];
+
+    $.each(all_versions, function(version, title) {
+      var series = version.substr(0, 3);
+      if (series == current_series) {
+        if (version == current_version)
+            buf.push('<option value="' + version + '" selected="selected">' + title + '</option>');
+        else
+            buf.push('<option value="' + version + '">' + title + '</option>');
+
+        if (version != current_version)
+            buf.push('<option value="' + current_version + '" selected="selected">' + current_version + '</option>');
+      } else {
+        buf.push('<option value="' + version + '">' + title + '</option>');
+      }
+    });
+
+    buf.push('</select>');
+    return buf.join('');
+  }
+
+  function build_doctype_select(current_doctype) {
+    var buf = ['<select>'];
+
+    $.each(all_doctypes, function(doctype, title) {
+      if (doctype == current_doctype)
+        buf.push('<option value="' + doctype + '" selected="selected">' +
+                 all_doctypes[current_doctype] + '</option>');
+      else
+        buf.push('<option value="' + doctype + '">' + title + '</option>');
+    });
+    if (!(current_doctype in all_doctypes)) {
+        // In case we're browsing a doctype that is not yet in all_doctypes.
+        buf.push('<option value="' + current_doctype + '" selected="selected">' +
+                 current_doctype + '</option>');
+        all_doctypes[current_doctype] = current_doctype;
+    }
+    buf.push('</select>');
+    return buf.join('');
+  }
+
+  function navigate_to_first_existing(urls) {
+    // Navigate to the first existing URL in urls.
+    var url = urls.shift();
+
+    // Web browsers won't redirect file:// urls to file urls using ajax but
+    // its useful for local testing
+    if (url.startsWith("file://")) {
+      window.location.href = url;
+      return;
+    }
+
+    if (urls.length == 0) {
+      window.location.href = url;
+      return;
+    }
+    $.ajax({
+      url: url,
+      success: function() {
+        window.location.href = url;
+      },
+      error: function() {
+        navigate_to_first_existing(urls);
+      }
+    });
+  }
+
+  function get_docroot_url() {
+    var url = window.location.href;
+    var root = DOCUMENTATION_OPTIONS.URL_ROOT;
+
+    var urlarray = url.split('/');
+    // Trim off anything after '/'
+    urlarray.pop();
+    var depth = (root.match(/\.\.\//g) || []).length;
+    for (var i = 0; i < depth; i++) {
+      urlarray.pop();
+    }
+
+    return urlarray.join('/') + '/';
+  }
+
+  function on_version_switch() {
+    var selected_version = $(this).children('option:selected').attr('value');
+    var url = window.location.href;
+    var current_version = DOCUMENTATION_OPTIONS.VERSION;
+    var docroot = get_docroot_url()
+
+    var new_versionpath = selected_version + '/';
+    if (selected_version == "dev")
+        new_versionpath = '';
+
+    // dev versions have no version prefix
+    if (current_version == "dev") {
+        var new_url = docroot + new_versionpath + url.replace(docroot, "");
+        var fallback_url = docroot + new_versionpath;
+    } else {
+        var new_url = url.replace('/' + current_version + '/', '/' + new_versionpath);
+        var fallback_url = new_url.replace(url.replace(docroot, ""), "");
+    }
+
+    console.log(get_docroot_url())
+    console.log(url + " to url " + new_url);
+    console.log(url + " to fallback " + fallback_url);
+
+    if (new_url != url) {
+      navigate_to_first_existing([
+        new_url,
+        fallback_url,
+        'https://www.yoctoproject.org/docs/',
+      ]);
+    }
+  }
+
+  function on_doctype_switch() {
+    var selected_doctype = $(this).children('option:selected').attr('value');
+    var url = window.location.href;
+    if (selected_doctype == 'mega') {
+      var docroot = get_docroot_url()
+      var current_version = DOCUMENTATION_OPTIONS.VERSION;
+      // Assume manuals before 3.2 are using old docbook mega-manual
+      if (ver_compare(current_version, "3.2") < 0) {
+        var new_url = docroot + "mega-manual/mega-manual.html";
+      } else {
+        var new_url = docroot + "singleindex.html";
+      }
+    } else {
+      var new_url = url.replace("singleindex.html", "index.html")
+    }
+
+    if (new_url != url) {
+      navigate_to_first_existing([
+        new_url,
+        'https://www.yoctoproject.org/docs/',
+      ]);
+    }
+  }
+
+  // Returns the current doctype based upon the url
+  function doctype_segment_from_url(url) {
+    if (url.includes("singleindex") || url.includes("mega-manual"))
+      return "mega";
+    return "single";
+  }
+
+  $(document).ready(function() {
+    var release = DOCUMENTATION_OPTIONS.VERSION;
+    var current_doctype = doctype_segment_from_url(window.location.href);
+    var current_series = release.substr(0, 3);
+    var version_select = build_version_select(current_series, release);
+
+    $('.version_switcher_placeholder').html(version_select);
+    $('.version_switcher_placeholder select').bind('change', on_version_switch);
+
+    var doctype_select = build_doctype_select(current_doctype);
+
+    $('.doctype_switcher_placeholder').html(doctype_select);
+    $('.doctype_switcher_placeholder select').bind('change', on_doctype_switch);
+
+    if (ver_compare(release, "3.1") < 0) {
+      $('#outdated-warning').html('Version ' + release + ' of the project is now considered obsolete, please select and use a more recent version');
+      $('#outdated-warning').css('padding', '.5em');
+    } else if (release != "dev") {
+      $.each(all_versions, function(version, title) {
+        var series = version.substr(0, 3);
+        if (series == current_series && version != release) {
+          $('#outdated-warning').html('This document is for outdated version ' + release + ', you should select the latest release version in this series, ' + version + '.');
+          $('#outdated-warning').css('padding', '.5em');
+        }
+      });
+    }
+  });
+})();
diff --git a/documentation/sphinx-static/theme_overrides.css b/documentation/sphinx-static/theme_overrides.css
new file mode 100644
index 0000000000..55da38a2b8
--- /dev/null
+++ b/documentation/sphinx-static/theme_overrides.css
@@ -0,0 +1,164 @@
+/*
+    SPDX-License-Identifier: CC-BY-2.0-UK
+*/
+
+body {
+  font-family: Verdana, Sans, sans-serif;
+  margin:  0em auto;
+  color: #333;
+}
+
+h1,h2,h3,h4,h5,h6,h7 {
+  font-family: Arial, Sans;
+  color: #00557D;
+  clear: both;
+}
+
+h1 {
+  font-size: 2em;
+  text-align: left;
+  padding: 0em 0em 0em 0em;
+  margin: 2em 0em 0em 0em;
+}
+
+h2.subtitle {
+  margin: 0.10em 0em 3.0em 0em;
+  padding: 0em 0em 0em 0em;
+  font-size: 1.8em;
+  padding-left: 20%;
+  font-weight: normal;
+  font-style: italic;
+}
+
+h2 {
+  margin: 2em 0em 0.66em 0em;
+  padding: 0.5em 0em 0em 0em;
+  font-size: 1.5em;
+  font-weight: bold;
+}
+
+h3.subtitle {
+  margin: 0em 0em 1em 0em;
+  padding: 0em 0em 0em 0em;
+  font-size: 142.14%;
+  text-align: right;
+}
+
+h3 {
+  margin: 1em 0em 0.5em 0em;
+  padding: 1em 0em 0em 0em;
+  font-size: 140%;
+  font-weight: bold;
+}
+
+h4 {
+  margin: 1em 0em 0.5em 0em;
+  padding: 1em 0em 0em 0em;
+  font-size: 120%;
+  font-weight: bold;
+}
+
+h5 {
+  margin: 1em 0em 0.5em 0em;
+  padding: 1em 0em 0em 0em;
+  font-size: 110%;
+  font-weight: bold;
+}
+
+h6 {
+  margin: 1em 0em 0em 0em;
+  padding: 1em 0em 0em 0em;
+  font-size: 110%;
+  font-weight: bold;
+}
+
+em {
+  font-weight: bold;
+}
+
+.pre {
+  font-size: medium;
+  font-family: Courier, monospace;
+}
+
+.wy-nav-content a {
+  text-decoration: underline;
+  color: #444;
+  background: transparent;
+}
+
+.wy-nav-content a:hover {
+  text-decoration: underline;
+  background-color: #dedede;
+}
+
+.wy-nav-content a:visited {
+  color: #444;
+}
+
+[alt='Permalink'] { color: #eee; }
+[alt='Permalink']:hover { color: black; }
+
+@media screen {
+    /* content column
+     *
+     * RTD theme's default is 800px as max width for the content, but we have
+     * tables with tons of columns, which need the full width of the view-port.
+     */
+
+    .wy-nav-content{max-width: none; }
+
+    /* inline literal: drop the borderbox, padding and red color */
+    code, .rst-content tt, .rst-content code {
+        color: inherit;
+        border: none;
+        padding: unset;
+        background: inherit;
+        font-size: 85%;
+    }
+
+    .rst-content tt.literal,.rst-content tt.literal,.rst-content code.literal {
+        color: inherit;
+    }
+
+    /* Admonition should be gray, not blue or green */
+    .rst-content .note .admonition-title,
+    .rst-content .tip .admonition-title,
+    .rst-content .warning .admonition-title,
+    .rst-content .caution .admonition-title,
+    .rst-content .admonition-tying-it-together .admonition-title,
+    .rst-content .important .admonition-title {
+        background: #f0f0f2;
+        color: #00557D;
+
+    }
+
+    .rst-content .note,
+    .rst-content .tip,
+    .rst-content .important,
+    .rst-content .warning,
+    .rst-content .admonition-tying-it-together,
+    .rst-content .caution  {
+        background: #f0f0f2;
+    }
+
+    /* Remove the icon in front of note/tip element, and before the logo */
+    .icon-home:before, .rst-content .admonition-title:before {
+        display: none
+    }
+
+    /* a custom informalexample container is used in some doc */
+    .informalexample {
+        border: 1px solid;
+        border-color: #aaa;
+        margin: 1em 0em;
+        padding: 1em;
+        page-break-inside: avoid;
+    }
+
+    /* Remove the blue background in the top left corner, around the logo */
+    .wy-side-nav-search {
+        background: inherit;
+    }
+
+}