[coreboot] unrv2b delay (v2)

Arne Georg Gleditsch arne.gleditsch at numascale.com
Wed Oct 29 10:38:56 CET 2008


Peter Stuge <peter at stuge.se> writes:
> Arne Georg Gleditsch wrote:
>> The unrv2b uncompression algorithm appears to behave very badly in
>> the absence of a proper cache.
>
> But why does this improve when the algorithm runs out of RAM?
>
> Could ROM accesses be a factor?

Yes, at least in the sense that running from ROM means we're running
from an uncached memory region.  I assume you'd notice much the same
running from uncached DRAM as well.  copy_and_run is one of the few
things that run after cache-as-ram has been disabled but before our code
has been copied to proper DRAM, so it is especially sensitive regarding
code footprint.

-- 
								Arne.




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