updating the A/B-capable firmware or bootloader, preparing copies of databases for the new version, etc.).
The post-install step is not suitable for one-off bug fixes before reboot that require unforeseen permissions.
In addition, because the update runs in the background, users might not know an update is in progress.
All of this means the update process might be interrupted at any point due to policies, unexpected reboots, or user actions.
The partition, some users go without updates because the device has nowhere to store the update package.
To address this issue, Android 8.0 added support for streaming A/B updates that write blocks directly to the B partition as they are downloaded, without having to store the blocks on These patches are required to support streaming A/B updates in Android 7.1 and later whether using Google Mobile Services (GMS) or any other update client.
The current slot is bootable when the system is running, but the other slot may have an old (still correct) version of the system, a newer version, or invalid data.
Regardless of what the attribute set by the user space, which is relevant only if the slot is also bootable.
A successful slot should be able to boot, run, and update itself.
A bootable slot that was not marked as successful (after several attempts were made to boot from it) should be marked as unbootable by the bootloader, including changing the active slot to another bootable slot (normally to the slot running immediately before the attempt to boot into the new, active one).
A/B system updates, also known as seamless updates, ensure a workable booting system remains on the disk during an over-the-air (OTA) update.