[LinuxBIOS] epia memory issues

Ben Hewson ben at hewson-venieri.com
Sat Sep 9 12:16:48 CEST 2006

ok I after many attempts I think I am making some progress, but not to
sure why at the moment.
I will need to go back over the changes I have made and see if it is any
one thing that has made it work.

The memory check passes up until A0000. I am assuming as this is
resrvered for the VGA controller it is to be expected.

I have compared northbridge register dumps of both my epia boards, rev A
and D but can see no difference, so I don't think there have not been
any changes to the northbridge.

One difference between original bios and linuxbios is register 0x67.
According to the datasheet it is reserved. However booting with the
original bios this register contains 0xc4 and 0x00 with linuxbios. I am
currently setting it to 0xc4 but not sure yet if that is why I have some
success. I have made a few changes, while comparing the V2 to V1.

Anyway I am now getting as far as running filo but have another problem.
This is what I get

Setting fixed MTRRs(0-88) type:
Setting fixed MTRRs(0-88) Type:
DONE fixed
Setting variable MTRR 0, base:    0MB, range:  256MB, type

Unexpected Exception: 13 @ 10:00008891 -
Code: 0 eflags:
eax: 00000300 ebx: f0000800 ecx: 0000da00 edx:
edi: 0000da00 esi: 0000000f ebp: 00017ee0 esp: 00017ebc

Perhaps someone could explain this to me.

By booting from the original bios and resetting mid-boot and switching
to linuxbios filo has got to the stage of looking for my kernel image
although it couldn't find it (maybe bad typing on my part).

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