[U-Boot] Secure memory

Albert,

I am trying to separate secure memory and non-secure memory for ARMv8. Before I go too far, I'd like to check with you to see if there is already some code implemented.

Basically what I am trying to do is to mark most DDR memory non-secure because we have some non-secure masters such as SDHC DMA. I also want to reserve some memory for TrustZone application. In order to do that, I need to put the MMU tables in secure memory. I will need to modify common/board_f.c to process reserve_mmu() differently for secure and non-secure mode.

Please let me know if running u-boot in non-secure mode is a bad idea.

York