Geode LX DDC freeze in emulator when executing OUTW 0x20

[Alexander E. Patrakov]

I wrote:
> Bart Trojanowski wrote:
> 
>> We have no control over what the BIOS tries to execute but we can
>> prevent the emulator from causing bad things to happen when the BIOS
>> has bugs (or is expecting to be running only DOS).
>>
>> Under the belief that access to certain ports should not be permitted
>> under any circumstances I propose this patch:
>>
>> http://www.jukie.net/~bart/patches/xorg-server/20071222/0001-X86EMU-blacklist-I-O-port-20-for-INT-10-emulation.patch
> 
> While the blacklist is certainly useful, I am afraid it just hides the second
> bug: the BIOS chooses a different path under the emulator than without it (i.e.,
> through vm86). Access to port 20 is likely to crash Windows XP, too, and this
> simply cannot happen for marketing reasons.

To avoid misinterpretation: I don't have a Geode card, so the above is just a 
guess, not a bug report.

> Thus: could you please verify if the bug also exists with vm86-based int10 module?

And one more question: doesn't it make sense (if possible at all) to add the 
same port blacklist to the vm86-based int10 module?

-- 
Alexander E. Patrakov