How can the ROM API feature be used to implement secondary stage booting? How can it be used to implement secure boot using custom keys?
The ROM API adi_rom_Boot() can be used to invoke one of the boot modes with options different from that during POR. For example, SPI2 is the default instance for SPI master boot, however with ROM API call, SPI0 or SPI1 instance can be used. Similarily, tThe DTR modes of the OSPI do not work by default. For these modes to work, the read delay values in the controller has to be updated using the ROM API.
ROM API can also be used to implement secure boot using custom keys. The secure keys can be passed via the hook routine.Hence the secure boot can be tested without/before programing the keys into the OTP locations.
The example codes for SSL for normal boot and secure boot are given here.