Relocating PPCBoot into SRAM

[Wolfgang Denk]

In message <200302161254.35753.ADharankar at ATTBI.Com> you wrote:
>
> - On MPC75x and MPC7410 boards with MPC8260 in companion
>   mode, SRAM on 1M and 2M respectively are available.
>
> - Is it possible to relocate PPCBoot to this SRAM mapped
>   as private memory? Note that, this is a second relocation;
>   the first would already have occured when it is relocated
>   from Flash to SDRAM.

This makes little sense to me. If you want to run  U-Boot  /  PPCBoot
from SRAM, then relocate it to that memory in the first place.

> - And if this possible, a re-relocation from SRAM back to
>   SDRAM?

Well, _everything_ is possible. But it is not wise  to  do  (or  try)
everything.
>
> If this is possible, what needs to be done? The idea I
> would like to explore is to do a full memory test (walking
> bit, aligned/non-aligned access, refresh, alternating
> pattern, random pattern test - basically extensive testing)
> without executing PPCBoot in SDRAM.

You don't have to do is that complicated. There are many easier ways,
for ewxample: You can implement your memory  test  (which  should  be
non-destructive) as a U-Boot standalone application which gets loaded
into and started from SRAM. No nood to relocate U-Boot at all.

Best regards,

Wolfgang Denk

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