| commit | 0dd0aece5913ef64e2c877850b0ec4312c236ff0 | [log] [tgz] |
|---|---|---|
| author | Android Build Coastguard Worker <[email protected]> | Wed Apr 13 06:08:20 2022 +0000 |
| committer | Android Build Coastguard Worker <[email protected]> | Wed Apr 13 06:08:20 2022 +0000 |
| tree | 2d2c11c0d830194202c0443064930024bd04a58c | |
| parent | 796a085b0963b1d0321493d1e7606c617273b844 [diff] | |
| parent | 352f183dd9fd3ca54918f848ec6a16b5bc9ba650 [diff] |
Snap for 8446956 from 352f183dd9fd3ca54918f848ec6a16b5bc9ba650 to mainline-tethering-release Change-Id: Ic2c988271b1691cad806e645b48675bcc9f2104a
SdkExtensions module is responsible for:
The module is packaged in an apex, com.android.sdkext, and has several components:
bin/derive_classpath: a native binary that runs early in the device boot process. It reads individual classpath configs files from the system and other modules, merges them, and defines the definition of *CLASSPATH environ variables.bin/derive_sdk: native binary that runs early in the device boot process and reads metadata of other modules, to set system properties relating to the extension SDK (for instance build.version.extensions.r).javalib/framework-sdkextension.jar: this is a jar on the bootclasspath that exposes APIs to applications to query the extension SDK level.derive_sdk is a program that reads metadata stored in other apex modules, in the form of binary protobuf files in subpath etc/sdkinfo.pb inside each apex. The structure of this protobuf can be seen here. The exact steps for converting a set of metadata files to actual extension versions is likely to change over time, and should not be depended upon.
The module exposes a java class SdkExtensions in the package android.os.ext. The method getExtensionVersion(int) can be used to read the version of a particular sdk extension, e.g. getExtensionVersion(Build.VERSION_CODES.R).
derive_classpath service reads and merges individual config files in the /system/etc/classpaths/ and /apex/*/etc/classpaths. Each config stores protobuf message from classpaths.proto in a proto binary format. Exact merging algorithm that determines the order of the classpath entries is described in derive_classpath.cpp and may change over time.
For every new Android SDK level a new extension version should be defined. These are the steps necessary to do that:
derive_sdk.cpp by:GetSdkLevel with the new enum setderive_sdk_test.cpp verifying the new extensions worksSdkExtensions.getExtensionVersion API support the new extensions.