For testing adding a DCD Item, i modified flash_header.S to add one more DCD item to modify ENET_PALR, after the 83rd item (SabreSD, i.mx6Q):
MXC_DCD_ITEM(84, 0x021880E4, 0xFFFFFFFF)
I updated dcd_hdr and write_dcd_cmd as:
The u-boot now fails to boot up. If i modify the 84th DCD Item to be the same as the 83rd DCD item (i.e. configuring DDR) it works.
Are there limitations to what registers can be updated by the ROM from the DCD list, or am i missing something?