[U-Boot-Users] CPU (405ep) clock upgrade..

[Stefan Roese]

On Wednesday 02 July 2008, Yi-Neng Lin wrote:
>  This arises another question. Assume that both configurations (CPU and
> SDRAM) are obtained from the EEPROM, how can C program/function be adopted
> to use these parameters before CPU/memory is initiated? C
> programs/functions need memory space to setup the stacks, which means
> CPU/memory initialization should be done (via assembly) before any C
> programs/functions can be used.

All this is already taken care of. U-Boot uses a small area for initial RAM. 
Sometimes in D-cache, sometimes in onboard SRAM (SoC). IIRC, the 405EP has 
OCM, so this could be used here. You just need to configure this correctly in 
your board config file. Again I suggest you take a look at the zeus board as 
an example.

Best regards,
Stefan

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