What's new in Q for Treble

Here is a quick and dirty list of what are the changes in master/Q that impacts Treble:

• logical volumes (like LVM2 but re-made from scratch)

  • fastbootd (a SECOND fastboot, which will run inside recovery)
  • dynamically resizable/deletable/creatable partitions
  • does it include userdata?

• gsid. Systems will be able to boot GSI instead of themselves

  • GSIs will be "flashable" from (rooted?) shell ( https://android-review.googlesource.com/c/platform/system/gsid/+/863812 )
  • there will be a separated userdata_gsi partition ( https://android-review.googlesource.com/c/platform/system/core/+/863889 )

• apex: loadable system modules, basically ext4 dm-verity loopback. Used for instance to have out-of-firmware upgradable libart

  • com.android.runtime (art)
  • com.android.resolv
  • com.android.conscrypt
  • com.android.tzdata

• dm-verity signed GSI? ( https://android-review.googlesource.com/c/platform/build/+/782877 )

• overlayfs

  • /system or /product can overlay /vendor ( https://android-review.googlesource.com/c/platform/system/core/+/804834 )

• SELinux policy read from /product and /odm additionally ( https://android-review.googlesource.com/c/platform/system/core/+/851068 )

• fastbootd: In addition to bootloader fastboot support, there is an additional fastboot support in recovery. Both are complementary and won't do the same things. fastbootd is meant to handle logical partitions