On Fri, 2007-08-31 at 21:13 -0400, Timothy Normand Miller wrote: > > must reasonably expect to be able to access the card through the VGA > > registers, as it cannot know where the card's PCI resources have been > > mapped, right? Therefore, I guess that the X driver has to tell the card > > Check this out: > > http://en.wikipedia.org/wiki/VESA_BIOS
Heh, now that you mention it, I even remember it from writing protected mode DOS games many years ago. :) However, that does not seem to be the entire story, because I'm currently browsing through the X driver for S3 cards, and it definitely uses the real VGA ports to do things with the card. It's guarded by some functions that seem to be controlling access to VGA hardware inside the X server, but it in turn uses some very indirect calls to do the actual work, and I have yet to find where they are initialized and defined. I also found this: <http://www.x.org/wiki/PciReworkProposal> Point 7 under "Required Functionality" covers the fact that the X server hackers want VGA ownership arbitration, so there clearly is a need to turn VGA legacy decode on and off. I'll continue my research. Fredrik Tolf _______________________________________________ Open-graphics mailing list [email protected] http://lists.duskglow.com/mailman/listinfo/open-graphics List service provided by Duskglow Consulting, LLC (www.duskglow.com)
