Understand Partitions, A/B Slots, Recovery and Verified Boot
Learn the storage and boot concepts that determine which images a device needs and how it can recover.
Learn the storage and boot concepts that determine which images a device needs and how it can recover.
Partitions are device-specific
Modern Android devices can use boot, init_boot, vendor_boot, recovery, system, vendor, product, vbmeta and dynamic super partitions. Never copy a flash command from a different model.
Some devices use dedicated recovery partitions; others boot recovery from boot or vendor_boot images.
A/B slots
Seamless-update devices maintain active and inactive slots. A ROM guide may require firmware on both slots, a specific active slot or a sideload process that changes slots.
Use only documented slot commands. Guessing can leave both slots unbootable.
Verified Boot
Android Verified Boot checks the integrity and authenticity of boot-critical partitions. Unlocking changes the trust state; some custom operating systems support relocking with their own verified-boot keys, while many community ROMs do not.
Relock only when the exact ROM documentation explicitly supports it and every required partition is stock or correctly signed.
Unlocking and flashing can erase data, weaken device security, disable protected services or make a phone unbootable. Use only your own device, exact model-specific instructions and a tested stock restore path.