Andorid OTA A/B升级

参考 A/B（无缝）系统更新

升级后的显著变化是 ro.build.date.utc 、和版本号发生变化。

ro.odm_dlkm.build.date=Thu Mar 28 01:09:45 UTC 2024
ro.odm_dlkm.build.date.utc=1711588185ro.odm.build.date=Thu Mar 28 01:09:45 UTC 2024
ro.odm.build.date.utc=1711588185ro.product.build.date=Thu Mar 28 01:09:45 UTC 2024
ro.product.build.date.utc=1711588185ro.system_dlkm.build.date=Thu Mar 28 01:09:45 UTC 2024
ro.system_dlkm.build.date.utc=1711588185ro.system.build.date=Thu Mar 28 01:09:45 UTC 2024
ro.system.build.date.utc=1711588185ro.build.date=Thu Mar 28 01:09:45 UTC 2024
ro.build.date.utc=1711588185ro.system_ext.build.date=Thu Mar 28 01:09:45 UTC 2024
ro.system_ext.build.date.utc=1711588185ro.vendor_dlkm.build.date=Thu Mar 28 01:09:45 UTC 2024
ro.vendor_dlkm.build.date.utc=1711588185ro.vendor.build.date=Thu Mar 28 01:09:45 UTC 2024
ro.vendor.build.date.utc=1711588185

应用执行A/B申请流程

待续

Selinux 权限问题

A/B 升级会有 Selinux 权限问题，会需要修改 update_engine.te 。

调试导致校验失败

A/B升级关键的 TAG 是 update_engine 。

升级时校验失败，log

04-12 16:34:43.879   653   653 E update_engine: Cannot create update snapshots with overlayfs setup. Run `adb enable-verity`, reboot, then try again.
04-12 16:34:43.881   653   653 E update_engine: [ERROR:dynamic_partition_control_android.cc(971)] Cannot create update snapshots: Error
04-12 16:34:43.884   653   653 E update_engine: [ERROR:dynamic_partition_control_android.cc(516)] PrepareSnapshotPartitionsForUpdate failed in Android mode
04-12 16:34:43.886   653   653 E update_engine: [ERROR:delta_performer.cc(744)] Unable to initialize partition metadata for slot B
04-12 16:34:43.888   653   653 E update_engine: [ERROR:download_action.cc(227)] Error ErrorCode::kInstallDeviceOpenError (7) in DeltaPerformer's Write method when processing the received payload -- Terminating processing

很显眼的 adb enable-verity 。

为了方便调试，之前有进行 adb root 、adb remount ，所以检验失败。

执行 adb root 、adb enable-verity 后可以校验、升级成功。

谨记：测试OTA时，打底软件不要做调试操作。

调试操作包括但不限于：