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

Stefan Roese
2009-09-01T09:16:35Z

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

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