[U-Boot] Performance problems with gunzip

[Detlev Zundel <dzu@denx.de>]

Hi Alessandro,

>> 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.
>
> Not that difficult, either.

I never said it was difficult, only non-trivial :)

> You just need to fill the top-level page table for 1MB sections (4096
> sections = 16k bytes, which must be aligned on a 16k boundary).
>
>> 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?
>
> I think it's always disabled on arm, for the mmu reason.
>
>> Maybe you can reap the code from their repository.  If you do, please
>> post it here ;)
>
> Or I can cook an RFC patch later, after redoing the 8815 patches.
> I was just considering trying it these days, as I've done the same
> on another straight-on-iron project and it's not that difficult.

I am looking forward to something like this for a long time now and I'm
sure other people will value it too, so thanks in advance!
  Detlev

-- 
Sometimes I lie awake at night and I ask, "Why me?", then a voice
answers  "Nothing personal,  your name just happened to come up."
           -- Charlie Brown 
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