Go to android update if it's update is available than the phone would have to be connected to a power source while it rebooted to recovery mode and actually flashed the update.All in, you're talking 30 minutes to an hour to install an update, and nobody has time for that. Even disregarding that hurdle, many users would just ignore the update out of fear for the bugs and UI changes it might bring, leaving their systems dangerously exposed to malware and hacks.
When you take a new phone out of its box, the operating system is installed on the first hard drive (partition "A"). When an update becomes available, it gets downloaded and installed to the second hard drive (partition "B").
The next time you restart your phone, it simply boots off of the "B" partition instead, which means you're now running the new Android update.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.
This reduces the likelihood of an inactive device afterward, which means fewer device replacements and device reflashes at repair and warranty centers. This approach is already explored successfully by other commercial-grade operating systems, such as ChromeOS, and Android 8.0 comes with the necessary platform changes to conduct streaming updates.
Allow to cancel a proxy resolution request
1 Fix terminating a transfer while resolving proxies
2 Add unittest for TerminateTrasnfer between ranges
3 Cleanup the RetryTimeoutCallback()
A/B system updates affect:
Interactions with the bootloader
The build process
OTA update package generation
The existing dm-verity feature guarantees the device will boot an uncorrupted image. If a device doesn't boot, because of a bad OTA or dm-verity issue, the device can reboot into an old image.