epia m vga + memcpy update

Richard Smith rsmith at bitworks.com
Thu Sep 9 12:40:00 CEST 2004

Li-Ta Lo wrote:

>>>Did they do anything on the "core" x86emu? Last time I checked,
>>>XF86 4.4.0 has almost the same x86emu as testbios.
>>Something is differnt even with 4.3.  I can run my ATI M1 bios under 
>>testbios and it dosen't work but X with InitPrimary enabled works.
> Interesting. Do you have any idea why ?

Not really.  There's lots of variables.  I do have machines that 
testbios does work with my M1 bios.  But these machines boot a COTS bios 
rather than LB.

For one thing I think the emu in X handles the reads and writes to the 
timer rather than letting the bios get to the hardware.  The stock M1 
bios won't run under vgabios at all. The delay functions go into loops 
that only exit by chance.  The X emu will run that code fine.

I have a modified version of the M1 bios that works around the delay 
issue by effectively removing them so it runs under testbios but it 
still dosen't bring the card to life.  Its possible that my "fix" is 
part of the problem since timeing can be critical but I wouldn't expect 
the emulator to running too fast and I don't think too slow would be a 

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