[U-Boot-Users] yet another how-to-configure-RAM-in-u-boot question

Wolfgang Denk wd at denx.de
Mon May 30 20:58:27 CEST 2005


Hello,

in message <429B5AAE.2050002 at web.de> you wrote:
> 
> U-Boot maps memory banks using the preliminary mapping, tests RAM sizes, 
> then banks of the same are mapped from 0x0 on, starting with CS#2.

For completeness: the mapping starts at 0x0000 on PowerPC only; other
architectures use other memory maps.

> So my first question is: Am I in trouble for my SDRAM bank actually is 
> at CS #1? This seems to be what U-Boot expects, everything in the README 
> reads like no SDRAM should be at a bank below CS#2.

No, there is no such assumption - it is up to your hardware  (and  to
your code which supports your hardare) which chip select(s) are used.
The  description  in the README is just an example that shows what to
do in case of more than one flash bank and more than one RAM bank.

If you have only one bank of  flash  memopry  (at  CS0)  then  it  is
perfectly fine to use CS1 for RAM.

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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