fallback on older cow version
If a device's source or target cow version is specified at 2 (or
undefined) we should fallback on using the v2 writer.
e.g.
1. v3 -> v2 downgrade OTA
2. v2 -> v3
Bug: 322279333
Test: ota_from_target_files
Change-Id: I8c5139eceeb64ee255ddea66017b3e17bbdc44c0
diff --git a/tools/releasetools/ota_from_target_files.py b/tools/releasetools/ota_from_target_files.py
index dbbbca2..c0ff5d2 100755
--- a/tools/releasetools/ota_from_target_files.py
+++ b/tools/releasetools/ota_from_target_files.py
@@ -908,6 +908,16 @@
source_info.vabc_compression_param, target_info.vabc_compression_param, source_info.vabc_compression_param))
vabc_compression_param = source_info.vabc_compression_param
+ # Virtual AB Cow version 3 is introduced in Android U with improved memory
+ # and install time performance. All OTA's with
+ # both the source build and target build with VIRTUAL_AB_COW_VERSION = 3
+ # can support the new format. Otherwise, fallback on older versions
+ if not source_info.vabc_cow_version or not target_info.vabc_cow_version:
+ logger.info("Source or Target doesn't have VABC_COW_VERSION specified, default to version 2")
+ OPTIONS.vabc_cow_version = 2
+ elif source_info.vabc_cow_version != target_info.vabc_cow_version:
+ logger.info("Source and Target have different cow VABC_COW_VERSION specified, default to minimum version")
+ OPTIONS.vabc_cow_version = min(source_info.vabc_cow_version, target_info.vabc_cow_version)
# Virtual AB Compression was introduced in Androd S.
# Later, we backported VABC to Android R. But verity support was not
# backported, so if VABC is used and we are on Android R, disable