[U-Boot] Performance problems with gunzip

A. Geisreiter ageisreiter at dh-electronics.de
Mon Jan 25 10:10:52 CET 2010


Hi Detlev,

thanks for the help. I have tried CONFIG_CMD_CACHE but this doesn't work,
because dcache_enable() is not implemented for PXA.

Then I tried to get the U-Boot source code for Gumstix verdex project, but I
can't find it. Where can I download this?

Regards,
Andreas

-----Ursprüngliche Nachricht-----
Von: Detlev Zundel [mailto:dzu at denx.de] 
Gesendet: Freitag, 22. Januar 2010 16:20
An: A. Geisreiter
Cc: u-boot at lists.denx.de
Betreff: Re: AW: [U-Boot] Performance problems with gunzip

Hi Andreas,

> thanks for the fast response. How do I enable data caches? 

I fear this is not as easy as flipping a bit in a register.  Depending
on the platform caches tend to be tied to the MMU, so enabling the
caches require setting up correct data structures for the MMU to work.
That's the non-trivial work.

Apart from that, there is CONFIG_CMD_CACHE which builds
common/cmd_cache.c.  I see that at least two PXA250 platforms enable
this, so maybe simply try that?

Moreover, a quick qoogle showed that the (non-mainline) Gumstix verdex
(PXA270) U-Boot port has a dcache command:

http://docwiki.gumstix.org/index.php/U-Boot

Maybe you can reap the code from their repository.  If you do, please
post it here ;)

Cheers
  Detlev

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