[U-Boot] [PATCH 2/8] armv7: cache maintenance operations for armv7

Wolfgang Denk
2011-01-09T22:41:43Z

Dear Albert ARIBAUD,

In message <4D286F58.9010605@free.fr> you wrote:
>
> I know we consider multi-board u-boot binaries when boards are variant
> of a given SoC, that's one reason why we wanted relocation. I'm not sure
> about multi-SoC when SoC is a variant of a given cpu, though. Wolfgang,
> your opinion?

Unless we see a specific example which uses this feature, we should
not add provisions that make the code more complicated than needed.

And when we start supporting such a feature, we should probably do
this based on a device tree approach.

> > Although this function is non-empty, flush_dcache_range() is in turn
> > empty. Effect will be the same, right?
>
> Yes the effect is the same, but your patch results in a non-trivially
> empty function; I'd prefer it to be visibly empty when we compile
> without cache support.

Yes, that's my opinion, too.

> Just because Linux uses armv7-a for a v7 arch does not mean we must have
> it for u-boot. For starters, U-boot does not always boot Linux. :)
>
> As for out-dated compilers, that's the question I'm asking: do we
> consider e.g. ELDK 4.2 as outdated or not? It won't accept armv7-a.

That's a catch question.

Yes, ELDK 4.2 is outdated. But it is still one of the most stable
versions of a tool chain known to me, especially when it comes to
using the very same tool versions across several architectures.

I cannot see any benefits of this code change that would justiify such
a breakage.

Best regards,

Wolfgang Denk

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