Verified Boot (AVB — Android Verified Boot) is Android's cryptographic chain of trust. Every stage from the bootloader to system.img is signed and verified before it runs. If anything is tampered, the device shows a warning or refuses to boot.

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The chain of trust

  1. Hardware root — SoC's immutable ROM key
  2. Bootloader (LK) — signed by OEM
  3. vbmeta partition — hashes of boot/recovery/dtbo/vendor_boot/system
  4. boot.img — kernel + ramdisk
  5. system/vendor/product — dm-verity runtime verification

Boot states

  • GREEN — Locked, OEM-signed, verification passed
  • YELLOW — Locked but signed with user-provided key
  • ORANGE — Bootloader unlocked, no verification
  • RED — Locked but verification FAILED, won't boot

Most ART users will see ORANGE after unlocking the bootloader. It is harmless — the device still boots normally after a 5-second splash.

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