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Diffstat (limited to 'en/devices/architecture/vintf/match-rules.html')
| -rw-r--r-- | en/devices/architecture/vintf/match-rules.html | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/en/devices/architecture/vintf/match-rules.html b/en/devices/architecture/vintf/match-rules.html index dd79254b..b34b2190 100644 --- a/en/devices/architecture/vintf/match-rules.html +++ b/en/devices/architecture/vintf/match-rules.html @@ -4,6 +4,7 @@ <meta name="project_path" value="/_project.yaml" /> <meta name="book_path" value="/_book.yaml" /> </head> + {% include "_versions.html" %} <body> <!-- Copyright 2017 The Android Open Source Project @@ -390,6 +391,38 @@ ro.boot.avb_version == 2.3 && ro.boot.vbmeta.avb_version == 2.1 <font style="font-family: Roboto, Arial, Helvetica, sans-serif; background-color: green; color: white"> match </font> </pre> +<h3 id="avb-version-ota">Matching AVB version during OTA</h3> +<p>For devices launched with Android {{ androidPVersionNumber }} or lower, during OTA, the AVB +version requirements in framework compatibility matrix are matched against the current AVB version +on the device. If the AVB version has an major version upgrade during an OTA (for example, from +0.0 to 1.0), the check in OTA does not reflect the compatibility after the OTA.</p> +<p>To mitigate the issue, an OEM can place a fake AVB version in the OTA package +(<code>compatibility.zip</code>) to pass the check. To do so:</p> +<ol> +<li>Cherry-pick the following CLs to the Android {{ androidPVersionNumber }} source tree: +<ul> + <li><a href="https://android-review.googlesource.com/732261" class="external">CL 732261</a></li> + <li><a href="https://android-review.googlesource.com/732262" class="external">CL 732262</a></li> +</ul> +</li> +<li>Define <code>BOARD_OTA_FRAMEWORK_VBMETA_VERSION_OVERRIDE</code> for the device. Its value +should equal the AVB version before the OTA, i.e. the AVB version of the device when it was +launched.</li> +<li>Rebuild the OTA package.</li> +</ol> +<p>These changes automatically place +<code>BOARD_OTA_FRAMEWORK_VBMETA_VERSION_OVERRIDE</code> as +<code>compatibility-matrix.avb.vbmeta-version</code> in the following files: +<ul> + <li><code>/system/compatibility_matrix.xml</code> + (which is not used in Android {{ androidPVersionNumber }}) on the device</li> + <li><code>system_matrix.xml</code> in <code>compatibility.zip</code> in the OTA package</li> +</ul> +These changes do not affect other framework compatibility matrices, including +<code>/system/etc/vintf/compatibility_matrix.xml</code>. After the OTA, the new value in +<code>/system/etc/vintf/compatibility_matrix.xml</code> is used for compatibility checks instead. +</p> + <h2 id="vndk">VNDK version matches</h2> <p>The device compatibility matrix declares the required VNDK version in <code>compatibility-matrix.vendor-ndk.version</code>. If the device |