epia m vga + memcpy update

Li-Ta Lo ollie at lanl.gov
Thu Sep 9 14:15:01 CEST 2004

On Thu, 2004-09-09 at 12:58, Richard Smith wrote:
> Li-Ta Lo wrote:
> > So you still think it is the timer ? 
> It may not be the only problem.  But its one problem.  The flaky results 
> I get seem to match up with wierd timeing problems.
> I haven't allocated a lot of time on this because we have found that 
> our board has hardware problems with the pci bus.  And it's difficult to 
> seperate out all the individual issues.
> But testbios dosen't work on an ASUS P2B booting LB or COTS and my 
> modified ATI vbios.  Nor does LB+ADLO+BOCHS with the original M1 vbios. 
>   X with InitPrimary works both under COTS and LB but that was using 
> using the orginal M1 bios not my "fixed" version.
> So see I still have a lot of apples->oranges comparisons.  I'll try to 
> scratch out sometime and build a consistent maxrix of everything that 
> works and what dosen't.
> This is where having that PCI expansion ROM stuff working would come in 
> _real_ handy.
> > Did you try to access the timer
> > HW in testbios ?
> I think HW access is what you _don't_ want to happen.  Rather than allow 
> the vbios to fiddle with the actuall timer hw it needs to provide a 
> software legacy timer interface that increments consistent with the emu 
> "clock".  The only hardware IO that should be allowed untrapped is the 
> IO range requested by the card and the Legacy VGA ranges.  Currently 
> testbios lets the vbios access any port it wishes.  The X emu must be 
> doing this or the ATI M1 bios would not work.

Do you mean the InitPrimary thing has software emulation for the timer ?


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