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android / platform / packages / modules / SdkExtensions / cda99fa5dbf7942fa227650ca9037f0cba3bbb13
commitcda99fa5dbf7942fa227650ca9037f0cba3bbb13[log] [tgz]
authorAnton Hansson <hansson@google.com>Fri Jan 15 08:15:57 2021 +0000
committerAnton Hansson <hansson@google.com>Mon Jan 18 12:51:18 2021 +0000
tree05c41fd984cb0448cbc85db429e1d0e1d5f623a4
parent16097eaa2166bff45370adbe4ad139f31e280d45 [diff]
Add ART module to extension SDKs

This is the only S module at the moment. Add a unit test to
derive_sdk_test to verify the multi-dessert logic works correctly.

Update the README with up-to-date instructions for adding new SDK
extensions.

Bug: 173188089
Test: atest derive_sdk_test
Change-Id: Id4fbbe13746d99d257342ff5d0dd17e6462d5336
4 files changed
tree: 05c41fd984cb0448cbc85db429e1d0e1d5f623a4
  1. derive_sdk/
  2. framework/
  3. gen_sdk/
  4. proto/
  5. testing/
  6. tests/
  7. Android.bp
  8. com.android.sdkext.avbpubkey
  9. com.android.sdkext.pem
  10. com.android.sdkext.pk8
  11. com.android.sdkext.x509.pem
  12. gen_sdkinfo.py
  13. manifest.json
  14. OWNERS
  15. PREUPLOAD.cfg
  16. README.md
  17. TEST_MAPPING
README.md

SdkExtensions module

SdkExtensions is a module that decides the extension SDK level of the device, and provides APIs for applications to query the extension SDK level.

General information

Structure

The module is packaged in an apex, com.android.sdkext, and has two components:

  • 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.

Deriving 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.binarypb 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.

Reading extension SDK level

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).

Developer information

Adding a new extension version

For every new Android SDK level a new extension version should be defined. These are the steps necessary to do that:

  • Add the new modules in this extension version to the SdkModule enum in sdk.proto.
  • Update derive_sdk.cpp by:
  • mapping the modules' package names to the new enum values
  • creating a new set with the new enum values
  • set a new sysprop to the value of GetSdkLevel with the new enum set
  • add a unit test to derive_sdk_test.cpp verifying the new extensions works
  • Make the SdkExtensions.getExtensionVersion API support the new extensions.
  • Extend the CTS test to verify the above two behaviors.
  • Update RollbackManagerServiceImpl#getExtensionVersions to account for the new extension version.