MTRR fixup?

Josh Carroll josh.carroll at
Wed Sep 3 21:58:24 UTC 2008

> You may be able to fix this by just using the memcontrol command -
> it already lets you program the MTRRs.

Yes, specifically:

memcontrol clear -b 0x... -l 0x....

Where the argument to -b is the first address listed from memcontrol
list, and the -l argument is the second address in the list.

E.g. for my ranges:

0xd0000000/0x10000000 BIOS uncacheable set-by-firmware active
0xe0000000/0x20000000 BIOS uncacheable set-by-firmware active

I used:

memcontrol clear -b 0xd0000000 -l 0x10000000
memcontrol clear -b 0xe0000000 -l 0x20000000

No adverse reaction so far...


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