Dan Malek wrote:

Kyle Harris wrote:

quoted

... I'm a little confused (not unusual :). Which device should
/dev/fb0 be? fbmem.c opens a device using major 29. But lcd823.c....

The confusion is probably not your fault this time :-).  Don't use
the old lcd driver that has my name in it.  That was just something
I hacked together one day for testing.  I posted it so someone that
knew something about frame buffers would really write one.

Fortunately, someone did.  I believe it was Joe Green from MontaVista
that did a real framebuffer driver.  Go to the MontaVista web site
and find the CDK 1.2 with the 2.2.14 kernel.

Thanks, this makes more sense. But I'm still having problems. I'm
running 2.2.13 on a TQM823 board. I updated lcd823.c and rebuilt the
kernel with fb and vt support. Now I get a kernel panic (listed below).

It appears to be related to the virtual console. If I run without the fb
(but keep vt) it also crashes.

I guess it's time to figure out how to interpret and debug kernel
panics. Any suggestions on where to start?

Thanks, Kyle.

Panic follows:

Linux version 2.2.13 (kyle@brdc01.nexus-tech.net) (gcc version 2.95.2
19991024
(release)) #53 Tue Nov 28 11:14:07 EST 2000
Boot arguments: root=/dev/nfs rw nfsroot=10.77.77.50:/LinuxPPC
nfsaddrs=10.77.77.20:10.77.77.50
LCD frame buffer 75 pages
time_init: decrementer frequency = 187500000/60
Calibrating delay loop... 49.87 BogoMIPS
Memory: 14760k available (780k kernel code, 792k data, 52k init)
[c0000000,c1000000]
Dentry hash table entries: 2048 (order 2, 16k)
Buffer-cache hash table entries: 32768 (order: 5, 131072 bytes)
Page-cache hash table entries: 4096 (order: 2, 16384 bytes)
POSIX conformance testing by UNIFIX
Linux NET4.0 for Linux 2.2
Based upon Swansea University Computer Society NET3.039
NET4: Unix domain sockets 1.0 for Linux NET4.0.
NET4: Linux TCP/IP 1.0 for NET4.0
IP Protocols: ICMP, UDP, TCP
TCP: Hash tables configured (ehash 16384 bhash 16384)
Starting kswapd v 1.5
Console: switching to frame buffer device
fb0:  MPC823 LCD frame buffer device
NIP: 00000000 XER: C000FA7F LR: C00F6BEC REGS: c0199df0 TRAP: 0400 DAR:
c00a3824
MSR: 08209032 EE: 1 PR: 0 FP: 0 ME: 1 IR/DR: 11
TASK = c0198000[1] 'swapper' mm->pgd c00db000 Last syscall: 120
last math 00000000
GPR00: 00000000 C0199EA0 C0198000 00000000 C00D3B21 C00E9324 C010901C
00000000
GPR08: 00000000 C0100000 00000000 C0110000 35FF5F33 02000130 00FFE500
C0FE0000
GPR16: 40800804 007FFF4F 0000000C 00000000 007FFF00 007FFEA0 00FBFFA0
00000002
GPR24: 00000000 00FFC76C 00000002 00000004 00000005 C0108F5C 00000001
C0108D10
Call backtrace:
C0108F5C C00F5DB0 C00F5E1C C00F4F50 C00F07A8 C0002B8C C0006E68
Kernel panic: kernel access of bad area pc 0 lr c00f6bec address 0 tsk
swapper/1

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