MPC8360E Startup - CFG_INIT_RAM
Russell McGuire
rmcguire at uwbt.com
Tue Dec 12 10:05:42 EST 2006
Anybody,
I am porting U-boot to a new custom MPC8360E based board.
I have downloaded the GIT U-boot tree, and see that DENX has made an example
for the MPC8360E-MDS board, and it is an excellent start. <If anyone is
interested I have the new 83xx header files to support Rev 2.0 CPU's, only
about 10 extra lines>
My question lies with what value to place in the CFG_INIT_RAM address.
I see that the example board has this mapped to dcache? I think... If so how
does one calculate what address dcache sits at?
Or would I be able to use the internal IMMR space multi-user QE ram?
My question is without dissecting the assembly at startup, does the IMMR get
remapped before or after the CFG_INIT_RAM is used.
The board has no external memory other than DDR, so I am going to have to
use something in the CPU.
Due to the massive amount of flash on our board <128M>, I cannot leave the
.text space at 0xFE00000. So I would prefer the IMMR be located at
0xF0000000 and flash be at 0xE0000000, this would leave room for future
expansion <maybe up to 256M>, if this is even related to early startup.
-Russ
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