[U-Boot-Users] Memory Banks & Flash Mapping

[Wolfgang Denk]

In message <20060217092048.GA4381 at false> you wrote:
> 
> "Because of the reset configuration for CS0# this is a mirror of the
> onboard Flash memory.  To be able to re-map memory U-Boot then jumps to
> its link address."
> 
> I don't get the second sentence. Flash is executed near the beginning of
> address space, exactly where the SDRAM shall get mapped. How is this
> possible ? 

How is what possible? Jumping to  the  link  addresses?  Because  the
flash  gets  mirrores many times. Mapping of SDRAM? Because we change
the flash mapping from the reset  configuration  via  a  pre,liminary
into the final mapping.

> As far as i understand my (working) u-boot code, relocation just works
> for my MPC875 board just because SDRAM is 64MB and Flash is 16MB in
> size. So when both are mapped to 0x0 just the first 16MB overlap and

RAM gets mapped only long after flash has been reconfigured, and then
it's out of the way.

> My concern was, if you are interested in my extensions.

Yes, of course.

Best regards,

Wolfgang Denk

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