Fabrice- Well, I've been assuming that the Windows driver doesn't call the BIOS to do a video mode switch (that seems like a silly thing to do and without sources I hate having to guess at things) but this is Windows so I guess it's possible. If you've got a BIOS patch I'd love to try it out when you're ready.
-- Don Dugger "Censeo Toto nos in Kansa esse decisse." - D. Gale [EMAIL PROTECTED] Ph: (303)440-1368 >-----Original Message----- >From: [EMAIL PROTECTED] >[mailto:[EMAIL PROTECTED] >] On Behalf Of Fabrice Bellard >Sent: Thursday, May 11, 2006 4:48 PM >To: qemu-devel@nongnu.org >Subject: Re: [Qemu-devel] [PATCH]Fix for minor video >corruption under Windows > >Hi, > >I think the proper fix must be done in the BIOS (set VRAM to 0xFF at >cirrus mode init). I made a patch for that but I must test it >a little more. > >Fabrice. > >Dugger, Donald D wrote: >> Leo- >> >> Yeah, I started there but it turns out there are multiple reasons why >> that is the wrong place to fix things: >> >> 1) `hw/vga.c' only knows about resolution changes, the bug >also appears >> if you change the pixel size, e.g. 24 bpp to 16 bpp. >> >> 2) Technically, because of the lazy screen update, your >change would be >> too late. To improve performance the vga code is only called >> periodically, not after every VRAM change. It is >theoretically possible >> for the target to change video mode, assume VRAM got reset, >do a bitblt >> from non-visible VRAM to visible VRAM and then have the >`hw/vga.c' code >> get called, overwriting the changes done to visible VRAM. >> >> -- >> Don Dugger >> "Censeo Toto nos in Kansa esse decisse." - D. Gale >> [EMAIL PROTECTED] >> Ph: (303)440-1368 >> >> >>>-----Original Message----- >>>From: [EMAIL PROTECTED] >>>[mailto:[EMAIL PROTECTED] >>>] On Behalf Of Leonardo E. Reiter >>>Sent: Tuesday, May 09, 2006 2:29 PM >>>To: qemu-devel@nongnu.org >>>Subject: Re: [Qemu-devel] [PATCH]Fix for minor video >>>corruption under Windows >>> >>>Donald... >>> >>>thanks... I actually posted a patch to fix this sometime >ago, but your >>>patch seems more thorough and probably more correct. Just FYI, I >>>attached my patch again. I will test your patch as well. >>> >>>Thanks again, >>> >>>Leo Reiter >>> >>>Donald D. Dugger wrote: >>> >>>>If you change the video resolution while running a Windows >>> >>>XP image such that >>> >>>>it uses fewer bytes of VRAM (either by using fewer bytes per >>> >>>pixel or by >>> >>>>lowering the resolution) then some window backgrounds will >>> >>>become corrupted. >>> >>>>This happens because the Windows XP Cirrus Logic driver >>> >>>assumes that VRAM is >>> >>>>initialized to 0xff whenever the video mode switches between >>> >>>VGA and SVGA. >>> >>>>This patch fixes this problem by resetting VRAM whenever a >>> >>>VGA/SVGA mode switch >>> >>>>occurs. >>>> >>>>Signed-off-by: [EMAIL PROTECTED] >>>> >>> >>>-- >>>Leonardo E. Reiter >>>Vice President of Product Development, CTO >>> >>>Win4Lin, Inc. >>>Virtual Computing that means Business >>>Main: +1 512 339 7979 >>>Fax: +1 512 532 6501 >>>http://www.win4lin.com >>> >> >> >> >> _______________________________________________ >> Qemu-devel mailing list >> Qemu-devel@nongnu.org >> http://lists.nongnu.org/mailman/listinfo/qemu-devel >> >> > > > >_______________________________________________ >Qemu-devel mailing list >Qemu-devel@nongnu.org >http://lists.nongnu.org/mailman/listinfo/qemu-devel > _______________________________________________ Qemu-devel mailing list Qemu-devel@nongnu.org http://lists.nongnu.org/mailman/listinfo/qemu-devel