Google Git
Sign in
android / platform / packages / modules / SdkExtensions / 3982674
commit39826748e0edbfb8571b01bfd4dba86487985734[log] [tgz]
authorDaniel Chapin <chapin@google.com>Thu Mar 18 22:23:03 2021 +0000
committerandroid-build-team Robot <android-build-team-robot@google.com>Thu Mar 18 22:38:10 2021 +0000
tree375d2d38182fd682e763cd823cfd96c12f050db4
parent1058a69ae1be85822e05ea0886f73bd653d32b6c [diff]
resolve Coastguard cherrypick merge conflict for change: 13921408

Change-Id: If52355f0d00a4849836d3a47e63d1bb29401bc5e
(cherry picked from commit 8bc0918197b436ec2f72b839cd049450e61da9c4)
8 files changed
tree: 375d2d38182fd682e763cd823cfd96c12f050db4
  1. derive_classpath/
  2. derive_sdk/
  3. framework/
  4. gen_sdk/
  5. proto/
  6. testing/
  7. tests/
  8. Android.bp
  9. com.android.sdkext.avbpubkey
  10. com.android.sdkext.pem
  11. com.android.sdkext.pk8
  12. com.android.sdkext.x509.pem
  13. gen_sdkinfo.py
  14. manifest.json
  15. OWNERS
  16. PREUPLOAD.cfg
  17. README.md
  18. 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.