This bootloader, among other tasks, verifies and loads the Android Bootloader - 'aboot'. Next up in the boot-chain, the third and last secondary bootloader, SB元, is loaded. Their main responsibility is to boot up the various processors on the SoC and configure them so that they're ready to operate. Then, two secondary bootloaders are loaded, SBL1 ( Secondary Boot Loader), followed by SBL2.
As such, it only serves the very minimal purpose of allowing the device to boot, and authenticating and loading the next part of the boot-chain. Since the PBL is stored within an internal mask ROM, it cannot be modified or provisioned, and is therefore an intrinsic part of the device. Before we start our research, let's begin with a short introduction to the boot process - starting right at the point at which a device is powered on.įirst - the PBL ( Primary Boot Loader), also known as the 'BootROM' is executed.
