The boot image can contain address-data pairs that initialize control registers during the BootROM handover to user code. Unintended access to illegal addresses is enabled.
When a boot image address-data pair writes outside of its subset of addresses, the system generates a lockdown situation and a BootROM error code to generated.
The registers that are accessible during the handover depends on the boot mode (secure versus non-secure) and the device revision as shown in the table.
|Boot Mode||Allowed Addresses: |
|Allowed Addresses: |
|Non-Secure||E000_0000 to F800_6FFF|
E000_1000 to E000_1FFF
E010_0004 to E010_0FFF
F800_0100 to F800_01B0
|F800_8000 to FFEF_FFFF||F800_6000 to F800_6FFF|
|Secure||F800_0100 to F800_01B4||F800_0100 to F800_01AF|