Use deterministic salt for AVB footer of prebuilt boot img

When target specified a prebuilt boot.img, current build system will add
avb hash footer to it with a random salt. Use a deterministic salt
instead for more reproducible builds. To stay consistent with
non-prebuilt boot.img code path, we extract the kernel image from
prebuilt boot.img and uses sha256sum of kernel image as the salt.

Test: th
Bug: 293313353
Change-Id: I988999ddc4f18e0b8677b05a3165c847b6a11b52
3 files changed
tree: bdff6c2cfdf7cc7ea3f54617cf124f3e0d2bc1c7
  1. common/
  2. core/
  3. packaging/
  4. target/
  5. tests/
  6. tools/
  7. .gitignore
  8. banchanHelp.sh
  9. buildspec.mk.default
  10. Changes.md
  11. CleanSpec.mk
  12. cogsetup.sh
  13. Deprecation.md
  14. envsetup.sh
  15. help.sh
  16. METADATA
  17. navbar.md
  18. OWNERS
  19. PREUPLOAD.cfg
  20. rbesetup.sh
  21. README.md
  22. shell_utils.sh
  23. tapasHelp.sh
  24. 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For an outdated reference on Android.mk files, see build-system.html.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.