Re: 1.3.63 hung by vgalib program

Tony Nugent (tonyn@sctnugen.ppp.gu.edu.au)
Fri, 16 Feb 1996 22:52:45 +1000


On Thu, 15 Feb 1996, Dale Scheetz <dwarf@polaris.net> asked:

> Anyone know how to restore the graphics card to a 'normal' state?

The fact is that the kernel needs to have a basic video driver
compiled into it. It has drivers for all sorts of other hardware
devices, so why not the (graphics) video?

This issue has been bashed almost to death recently here, so I won't
go on too much at length about it, but this badly needs to happen and
it will be a major advance for linux (on pc's at least anyway:)

There is a group of people very actively working on a Generic Graphics
Device (there is a linux-ggi mailing list). Among other things, it
will allow the kernel to keep track of current video modes and allow some
sanity in situations like this, allow different modes in each console
(neat!:), as well as solve a lot of problems with having to suid
programs like X, ghostscript and svgalib that access the video
hardware. The idea is to have _very_ basic graphics functionality in
the kernel (and how to handle things like crashed graphics apps), and
then after then load modules for the added functionality for specific
cards. It will revolutionise svgalib and X in linux once it's up and
going.

But to answer the question...

There is something called a SAK patch that will allow you to regain
control in a console that's in raw keyboard mode with SysRq
(Ctrl-Print_Screen), and also Ctrl-Alt-Del:

http://www.ccs.neu.edu/home/albert/linux.html
http://www.ccs.neu.edu/home/albert/SAK.patch.gz

It works in the 1.2.13 kernel (but does give a compilation warning
that I've been meaning to check out). I've got no idea how the patch
applies to, or works in, the 1.3.x kernels.

Also, svgalib comes with some basic tools that allow you to (among
other things) record and restore video modes. They are:

savetextmode
fix132x43
textmode
dumpreg
restoretextmode
runx
restorepalette
restorefont

They all have man pages.

If you find yourself stuck in a graphics mode in a console, then
you'll have to type "restoretextmode" blind in order to get things
back to normal.

Cheers
Tony
-=*#*=-=*#*=-=*#*=-=*#*=-=*#*=-=*#*=-=*#*=-=*#*=-=*#*=-
T.Nugent@sct.gu.edu.au tonyn@sctnugen.ppp.gu.edu.au
Brisbane Queensland Australia
-=*#*=-=*#*=-=*#*=-=*#*=-=*#*=-=*#*=-=*#*=-=*#*=-=*#*=-
"I seem to be having tremendous difficulties with my lifestyle."
- Arthur (Monty Python's Holy Grail).