[U-Boot] Secure memory

[York Sun]

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