epia m vga + memcpy update

Richard Smith rsmith at bitworks.com
Thu Sep 9 13:40:00 CEST 2004

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.

This has to happen for non-x86 platform stuff as well which don't even 
have a x86 type timer.

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