[U-Boot-Users] [Patch] Disable icache before call the firstline of kernel in do_bootelf().

[Wolfgang Denk]

In message <200708081147.09111.rgetz at blackfin.uclinux.org> you wrote:
>
> I think it is reasonable/prudent to turn off cache in all situations, on all 
> architectures.

No, it is not. Some architectures /  operating  systems  may  require
cache(s)  being on.  Some  others may not care, except for boot speed
which in turn is something some of the customers do care about.

Finally, I don't want to fix a prblem where non exists.

If we know for sure that certain systems require caches disabeled,
then let's provide them this environment; but please leave all the
rest unchanged.

> Instruction and data caches in U-Boot are a great thing, since it decreases 
> the time for a kernel or file system to be loaded, decompressed, but once 
> U-Boot looses control (the jump to the unknown application), it shouldn't 
> expect a return, or the hardware not to be changed by the app.

There is more than just Linux...

> go, bootm, boote, etc - should flush & turn off cache before the jump to the 
> application code (should also turn off what limited interrupts are enabled) 
> to be safe.

I disagree.


Best regards,

Wolfgang Denk

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