[U-Boot-Users] Big endian-ness - Config option?

[Wolfgang Denk]

In message <637EA992-FC18-11D8-9008-000393C7979E at student.unsw.edu.au> you wrote:
> 
> I've had two problems. The first has been that that the code uses the 
> get_timer(x) function, which is not implemented properly on ARM. (It 

Indeed, it seems to be broken.

> just returns the value of the OS counter, ignoring the value passed to 
> it. I had to replace the get_timer stuff with get_timer_masked and 
> reset_timer_masked. I could try fixing the arm implementation of 
> get_timer, but figured you guys wouldn't want me touching that bit of 
> code since other bits and pieces now depend on it. Is there some way of 
> doing this nicely?

There should be no software depending on  the  broken  behaviour.  If
there was any, it must be fixed, too.

> The second was that one part of the code munges some bytes into a word 
> to get them ready for writing. This is broken with respect to 
> endian-ness, and breaks on my XScale running in little-endian mode. Is 
> it possible (or appropriate?) to add a CFG_LITTLE_ENDIAN (or something 
> similar)? Is there a better way of switching between the two? It would 
> be nice if this code could be re-used without these sorts of problems.

If you use code from a board directory, no such endianess support  is
needed,  as the board will normally not change endianness (at least I
don't know of any of the supported boards  which  can  be  configured
both for BE or LE).

Endianess is considered an issue only in case you're using a  generic
driver  (like  drivers/cfi_flash.*);  but  AFAIK  the  cfi_flash code
already deals properly with the target byteorder.


Best regards,

Wolfgang Denk

-- 
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd at denx.de
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