[SeaBIOS] [PATCH] Add config option to disable MTRRinitialization.

Scott Duplichan scott at notabs.org
Tue Mar 15 01:29:09 CET 2011


Sebastian Herbszt wrote:

]>> >00034041578i[CPU0 ] 0x01fe28e9>> wrmsr  : 0F30
]>> >00034041578e[CPU0 ] exception(): 3rd (13) exception with no resolution, shutdown status is 00h,
]
]Stanislav, you happen to know why WRMSR is not recognized here?
]
]Sebastian

If it works like real hardware, it is exception 6 that would tell you the
instruction is not supporteed, not exception 13. Exception 13h during MTRR
initialization is most often because of too many mask bits set when writing
the mask part of a variable MTRR pair (ecx=201,203,...20Fh). Software
should call cpuid function 80000008h to find out how many bits can safely be
set in the variable MTRR mask. Setting reserved bits in the fixed MTRRs
might also be able to cause a GP fault.

Thanks,
Scott




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