Re: 2.1.107: frame buffer problems (FYI)
Geert Uytterhoeven (Geert.Uytterhoeven@cs.kuleuven.ac.be)
Mon, 29 Jun 1998 00:32:32 +0200 (CEST)
On Sun, 28 Jun 1998, Adam J. Richter wrote:
> Geert Uytterhoeven writes, regarding console output not working
> in some cases when CONFIG_FB is defined:
> >Did you all enable vfb (the virtual frame buffer device)? That's meant for
> >testing only. Basically it allocates a large piece of memory and assumes it is
> >the frame buffer of a graphics board. Needless to say, this wastes a lot of
> >unswappable kernel memory if you don't want to use vfb.
>
> I had CONFIG_FB_VIRTUAL set to be a loadable module, not
> compiled into the kernel. The output stopped long before the
> root partition was mounted, so the vfb module could not possibly
> have been loaded at that point.
>
> I also tried rebuilding the kernel with CONFIG_FB_VIRTUAL=n,
> and got the same results. The output stops immediately after
> "uncompressing image..ok now booting kernel." The system comes up
> without any output to the console whatsoever, and I can telnet it.
> If I touch the console keyboard, the system crashes or freezes or at
> least drops off the network. I cannot determine what happens exactly,
> because there is no console output. All I know is that the system
> disappears from the network.
Because of a difference between Linus' tree and the vger tree, vgafb got a NULL
pointer for the video board address. Thus no characters on the screen, and
corruption of innocent memory. Fixed in the patches I posted a few hours ago.
> I have all of the other framebuffer devices activated, so
> I suspect that /dev/fb0 is being set to some other frame buffer
> device. Is there some file in /proc that I could examine to see
> what frame buffers the kernel thinks it has? (From a quick grep
> of linux/Documentation/fb/* and linux/drivers/video/*.c, I guess
> the answer is "no".)
| callisto$ cat /proc/fb
| 0 ATY Mach64GT
| callisto$
(on my CHRP/PPC box)
| cassandra$ cat /proc/fb
| 0 Amiga AGA
| cassandra$
(on my Amiga/m68k)
Greetings,
Geert
--
Geert Uytterhoeven Geert.Uytterhoeven@cs.kuleuven.ac.be
Wavelets, Linux/{m68k~Amiga,PPC~CHRP} http://www.cs.kuleuven.ac.be/~geert/
Department of Computer Science -- Katholieke Universiteit Leuven -- Belgium
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