MPC8360E Startup - CFG_INIT_RAM

MPC8360E Startup - CFG_INIT_RAM

[Russell McGuire]

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

Re: MPC8360E Startup - CFG_INIT_RAM

[Wolfgang Denk]

Dear Russel,

in message <000801c71d78$e28cae60$6405a8c0@absolut> you wrote:
> 
> I am porting U-boot to a new custom MPC8360E based board.

You're off topic here. You should post such things on the
U-Bootmailing list instead.

> 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

No, the MPC8360EMDS was not done by us, but by Dave Liu; see the
MAINTAINERS file for details.

> My question lies with what value to place in the CFG_INIT_RAM address. 

See the "Note:" in the README...

> 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.

Even if you boot high you  can  easily  adjust  for  different  flash
sizes. This hase been done with other boards before. Just look around
a bit. Of course everything is much easier if you boot low.

Best regards,

Wolfgang Denk

-- 
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd@denx.de
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