[U-Boot] [PATCH] atngw100: Use virtual address in CONFIG_ENV_ADDR

[Stefan Roese]

On Tuesday 01 September 2009 10:57:52 Haavard Skinnemoen wrote:
> > Well, usually we run with IC on and  with  DC  off,  usually  because
> > quite  a  number  of  drivers  and  other  code do not use proper I/O
> > accessors yet, and/or because it's easier and  nobody  really  cares.
> > For  example  on  PowerPC,  adding support for the data cache usually
> > gives only a minimal performance boost.  This  may  be  different  on
> > other architectures.
>
> Ok, so the code is broken and nobody else cares?

I wouldn't put it like this. The CFI driver assumes that the FLASH mapping is 
not cached. This makes perfect sense in my point of view.

> I suppose I could disable the DC (which is a bit complicated, but
> possible), but that would just add to the already high cost (in terms
> of both code size and performance) of using common code (i.e. the CFI
> driver), so I'm leaning towards a custom flash driver instead.

On some 440 platforms we configure the FLASH cached upon powerup, and disable 
the caching after relocating to SDRAM. So when the CFI driver is started, the 
FLASH is not cached any more, but we have the cache speedup upon relocation.

Cheers,
Stefan

--
DENX Software Engineering GmbH,      MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich,  Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-0 Fax: (+49)-8142-66989-80 Email: office at denx.de