Subject: SiS X oddity...
To: None <port-i386@netbsd.org>
From: Mason Loring Bliss <mason@acheron.middleboro.ma.us>
List: current-users
Date: 06/14/1999 14:23:11
Hi, all.

A friend of mine got a new box the other day, and noted that it has on-
board SiS graphics. It's an i386 box - AMD K6-2/250, etc. He's got 1.4 on
it now, and is willing to run -current if needed. The box has a SiS 5595
chipset. XFree docs say nothing about this chipset, but it *almost* works.

The server starts and seems fully functional, albeit in 320x200x8 mode.

To wit:

XFree86 Version 3.3.3.1 / X Window System
(protocol Version 11, revision 0, vendor release 6300)
Release Date: January 4 1999
[...]
      sis5597, sis5598, sis6326, tvga8200lx, tvga8800cs, tvga8900b,
[...]
(--) SVGA: PCI: SiS Unknown chipset (0x6306) rev 162, Memory @ 0xfc800000, 0xfc100000, I/O @ 0x9000
(--) SVGA: chipset:  generic
(--) SVGA: videoram: 64k
(--) SVGA: clocks:  25.18
(**) SVGA: Using 8 bpp, Depth 8, Color weight: 666
(--) SVGA: Using builtin driver modes
(--) SVGA: Builtin Mode: 320x200
(--) SVGA: Virtual resolution set to 320x204
(--) SVGA: SpeedUp code selection modified because virtualX != 1024
[...]

So, the chipset can support XFree86, but it only sees 64K of video RAM. It
starts up, but in 320x200 mode, probably as a consequence of the video RAM
problem. (320x200 in eight bit mode is all that would fit into 64K of RAM,
so it makes some sense that way...)

The BIOS on this box allows the user to choose 2, 4, or 8 megs of video RAM,
which is evidently snagged from main RAM. We've told XF86Config that there's
different amounts of RAM, but this is seemingly ignored.

Can someone give me ideas as to how I could perhaps short-circuit the process
of determining the available video RAM? I'm going to try to dig around in the
X source to see if there's maybe a status word somewhere the server checks to
see how much video RAM is available, as it would make sense for that word to
be in a different location, perhaps...

Thanks in advance. :) I'd much rather help my friend get this chipset going
than have him have to snag still more hardware.

PS: The box is an HP Pavilion 44??.

-- 
    Mason Loring Bliss   mason@acheron.middleboro.ma.us   They also surf who
awake ? sleep : dream;   http://acheron.ne.mediaone.net   only stand on waves.