[ECOS] MIPS cache or uncached memory

[Jimmy Zhang]

I know this question is not directly related to eCOS. However I can't
find a better place with this many gurus. Please let me finish my
question and then kick me out :-)

How can I make part of MIPS kseg0 memory uncached ? I must uncache that
region because it gives me too much trouble with DMA data, however, I
don't want to uncache the whole kseg0 segment in order to get better
performance.  Kseg0 is not mapped through TLB, so it seems I can't
achieve my goal through TLB. 

Cite from the book See Mips Run, "if you feel that your system needs to
make uncached references to cacheable memory, then I strongly recommand
that you divide memory into regions that are always accessed uncached
and regions that are always accessed through the cache - and don't let
them overlap. " But how ?

Thanks,

Jimmy



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