recovering from the 6.3 xorg mess

[Warren Block]

On Wed, 19 Mar 2008, peter stern wrote:

> 14 found these disturbing entries in Xorg.0.log
>
> (--) MGA(0): BIOS at 0xF7000000
> Requesting insufficient memory window!: start: 0xf6800000 end: 0xf77fffff 
> size 0x2000000
> (EE) Cannot find empty range to map base to
> (WW) MGA(0): Video BIOS info block not detected!

It's a bug/problem with the way historical X tries to read the video 
BIOS.  In the past, it really didn't matter, everything still worked.
In fact, it still may work with the mga 1.4.7 driver in ports.

Newer versions of Xorg made more radical changes, and xorg-7.3 in 
particular.  Experimental versions of the latest mga driver (1.9.100) 
really want to read the BIOS in order to support features like dual 
monitors.  Based on how it works in Linux, and how it will be done in 
future versions of xorg, here's a patch for xorg-server under 6-STABLE:

http://wonkity.com/~wblock/mgapatch/xorg-patch.txt

If you only have one monitor, you can use the mga 1.4.7 driver from 
ports, which will also take modelines.  The 1.9.99 and 1.9.100 versions 
allow two monitors but apparently ignore modelines.

> Just how badly broken has the video-mga device gotten in FreeBSD.

Reading the video BIOS under FreeBSD can be fixed temporarily with the 
patch above.  Upcoming versions of xorg will fix it internally.

Otherwise, problems with the mga driver are probably not specific to 
FreeBSD.

-Warren Block * Rapid City, South Dakota USA