Scott Wood wrote:

0x2000 minus sizeof(...) would be a good default for CPM1 and CPM2
(8280 has its first chunk go up to 0x4000, but for some reason that
didn't get reflected in the dts for the one 8280 board in-tree).

Except that last time I tested it, it is not from 0 - 0x4000, but the
extra 0x2000 is added from offset 0x9000.....
So 8280 has available muram from 0 - 0x2000 and 0x9000 - 0xb000