> > My question is ... what is signal 11 ? And how can I make sure that this
> > doesn't keep happening, because it is annoying.
> 
Signal 11 is an illegal memory access.

> This sounds like a revision J or K StrongARM SA-110. There is a bug in
> these that can lead to problems like this.
> 
Unless you have a tiny amount of memory I doubt that these random 
signal 11s are caused by this. It is much more likely that you have 
some slightly dodgy memory or your motherboards timings are slightly 
off. I had a fair few problems like this at one point which were fixed 
by replacing one of my SIMMs. This SIMM was a parity enabled SIMM and 
caused no problems at all until NetBSD started to really push the 
Risc PC hardware to it's limits. A this point the fact that the 
motherboard does not officially support parity SIMMs became a problem.

If you have 2 SIMMs try swapping them arround and each single SIMM on 
it's own to see if it makes any difference.

Random signal 11's are often the sign of faulty memory on i386 machines so
it seems likely that the signs are the same for ARM machines.

For reference I have a Rev K StrongARM Risc PC with 48MB RAM + 2MB VRAM 
which runs NetBSD 1.40 (current) without reliability problems. The machine 
does Web proxying IP NAT, News, mail. It also occasionally runs as an X 
workstation and I usually have a couple of xterms and an XEmacs running on it 
displaying to a FreeBSD/i386 machine. I did have a few problems with 
1.4 which where related to a bug in the rnd (random number generator) 
device but these were fixed in 1.4.1. 

> > Secondly ... after booting ... I get an error from kvm_read (?) with an
> > illegal address (0x0). Is this something I must worry about ? Is it connected
> > to the core dump problem ?
> 
Where in the boot process does it occur. Do you have a copy of the 
kernel you are booting as /netbsd ?

Mike