7.4.1 Unlock, Load Program and Start Loaded Program

After Reset, the bootloader is locked and the host must send two frames as a password to unlock the bootloader. These frames are:


Order	Address	Command	Data
1	0x00000000	0xDE05	0x5345ACBA
2	0x00000000	0xDE05	0xACBA5345

At this point, the host sends commands to the bootloader and it can start loading the program to the PL460. The program must be loaded starting with address 0x00000000.

After loading the program, it must be started. Starting the loaded program requires clearing the CPUWAIT bit of the MSSC Miscellaneous register (Address 0x400E1800) and transferring control of the MISO signal to the M7-SPI peripheral:


Order	Address	Command	Data
1	0x400E1800	0x0000	0x00000000
2	0x00000000	0xA66A	0x00000000

If this action is not done, the MISO signal will remain controlled by the BOOTLOADER.