[U-Boot-Users] SPI support in U-boot

Wolfgang Denk wd at denx.de
Wed Jan 25 12:16:51 CET 2006

Dear Vladimir,

in message <43D733BF.4030207 at paulidav.org> you wrote:
> I looked at the code for the boards that use this mechanism, and I can 
> see the array statically initialized, like (in board/sacsng/sacsng.c):
> My question is: where these addresses are relocated? My understanding is 
> that relocation for this type of data should be done manually, but 
> nowhere in the code can I see it. Not for a single board. That means 
> that if people got lucky, they execute the copy of the code from the 
> FLASH, not the relocated one.

Good catch!

> Is that OK? I also noticed the same mechanism being used in the 
> FPGA-related code.

I think your interpretation is correct.

> And another question. The current implementation(s) of the "eeprom" 
> command assume that there is only 1 SPI device and do not bothr 
> themselves with the chip selects at all. That means, that if you try to 
> execute "eeprom" command after you executed "sspi" (that will de-assert 
> the chip-select at the end or can choose a different one), the results 
> will be unpredictable. I have no problem modifying "eeprom" command for 
> my board, but this will force other people to do modifications as well, 
> so I am not sure what should we do.

It would be nice to preserve the currnt behaviour, so a patch  should
try  to  implement the required changes for all boiards. Testing will
have to be performed by the respective board maintainers, 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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then the world will somehow be better.
                                     - Terry Pratchett, _Men at Arms_

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