Add Legacy GSI R

Legacy GSIs named with the suffix _ab, ex. aosp_arm64_ab.
It contain some backward-compatible configurations for
devices upgraded from O/O-MR1.

The patch also addes legacy_gsi_release.mk for the special
configuretions of Legacy GSI.

Bug: 144742991
Test: boot aosp_arm64_ab-userdebug on a walleye P (with SPL)
Test: boot aosp_arm64_ab-userdebug on a walleye Q (with SPL)
Change-Id: I61c9e74abcc921ab2cb50bf6f6dce1097a8d6c77
10 files changed
tree: ec5fcb9bbe20929dc35f7e1371a9dcf2779a320e
  1. common/
  2. core/
  3. packaging/
  4. target/
  5. tests/
  6. tools/
  7. .gitignore
  8. buildspec.mk.default
  9. Changes.md
  10. CleanSpec.mk
  11. Deprecation.md
  12. envsetup.sh
  13. help.sh
  14. navbar.md
  15. OWNERS
  16. README.md
  17. tapasHelp.sh
  18. Usage.txt
README.md

Android Make Build System

This is the Makefile-based portion of the Android Build System.

For documentation on how to run a build, see Usage.txt

For a list of behavioral changes useful for Android.mk writers see Changes.md

For an outdated reference on Android.mk files, see build-system.html. Our Android.mk files look similar, but are entirely different from the Android.mk files used by the NDK build system. When searching for documentation elsewhere, ensure that it is for the platform build system -- most are not.

This Makefile-based system is in the process of being replaced with Soong, a new build system written in Go. During the transition, all of these makefiles are read by Kati, and generate a ninja file instead of being executed directly. That's combined with a ninja file read by Soong so that the build graph of the two systems can be combined and run as one.