GSI vbmeta.img: set rollback_index to zero
The major purpose of vbmeta.img built on GSI targets (e.g., aosp_arm,
aosp_arm64, etc) is to disable AVB. We should also set the rollback
index to zero, to prevent the device bootloader from updating the
last seen rollback index in the tamper-evident storage.
Bug: 122583908
Test: build aosp_arm64, then `avbtool info_image --image $OUT/vbmeta.img`
Change-Id: I48a49957f8dd3169003b9507fe80e519f301d5b5
diff --git a/target/board/BoardConfigGsiCommon.mk b/target/board/BoardConfigGsiCommon.mk
index 88bc7da..68d29c8 100644
--- a/target/board/BoardConfigGsiCommon.mk
+++ b/target/board/BoardConfigGsiCommon.mk
@@ -34,11 +34,14 @@
# Android Verified Boot (AVB):
# Set AVB_VBMETA_IMAGE_FLAGS_VERIFICATION_DISABLED (--flags 2) in
-# vbmeta.img to disable AVB verification.
+# vbmeta.img to disable AVB verification. Also set the rollback index
+# to zero, to prevent the device bootloader from updating the last seen
+# rollback index in the tamper-evident storage.
#
# To disable AVB for GSI, use the vbmeta.img and the GSI together.
# To enable AVB for GSI, include the GSI public key into the device-specific
# vbmeta.img.
+BOARD_AVB_ROLLBACK_INDEX := 0
BOARD_AVB_MAKE_VBMETA_IMAGE_ARGS += --flags 2
# Enable chain partition for system.