Re: CVS updates/VGA mode setting

[Petr V. <VAN...@vc...>]

On 31 Aug 00 at 9:18, James Simmons wrote:
> > > Nice. Support even for Mode X :-) I will take a look at it in depth. The
> > 
> > Yes. And it even works...
> 
> Great. Will merge with CVS code soon. 

Thanks.
 
> > Problem is that for example Matrox devices are totaly dead after powerup.
> > And enabling framebuffer region and accessing it can cause PCI bus lockup,
> > because of memory clock (on old Millennium I) are programmed for 0Hz,
> > so PCI read cycle never finish.
> 
> What I mean is read the values from the vga hardware instead of from
> screeninfo which is provided by the firmware. 

If you want to support only standard modes (text, cfb8, vgaplanes, 
vga8planes), it is easy. But there is couple of more or less nonstandard
modes too. 2 (1plane) or 4-color (2planes) modes, alphanumeric mode with
character generator disabled (gives you `spectrum like' attribute + 8pixels).
What to do with them? Let them fall through and report something similar
for them?

If you are talking only about recognition of currently used videomode
at startup, it should be possible, and possibly trivial. I have
(in mgadump) code which adds `correct' constants and sums correct
bits together to get all picture sizes... Should I port that code
to Linux and send it to you?
                                                    Petr