I wrote:

> I can't seem to get any useful information [out of the core file
> saved by savecore], eg:
> 
>   (gdb) backtrace
>   #0  0x0 in ?? ()
>   (gdb) info registers
>   d0             0x0      0
>   d1             0x0      0
>   d2             0x0      0
>   d3             0x0      0
>   d4             0x0      0
>   d5             0x0      0
>   d6             0x0      0
>   d7             0x0      0
[...]
>
> FYI, I'm in the process of updating the 1.3 DayStar '030 PowerCache
> kernel patch for 1.4. [...]  The only instability I've found
> so far is when I run perl (5.00404) which I compiled under 1.3, but
> core dumps under 1.4 (apparently due to a change in libc.so, even
> though the major version number on libc.so in 1.3 and 1.4 hasn't
> changed, suggesting that's they're compatible; hmmpf... ;) ).  When
> run under the 1.4 GENERIC kernel, perl core dumps; when run under my
> DayStar patched 1.4 kernel, the system panics w/ an MMU fault.

D'oh!  I just occurred to me that if the system can't create a core
file for the perl process but panics instead, then it would probably
be equally unable to create a core image of the kernel in swap, and so
the core file created by savecore is probably useless.

Oh, well; unless someone has another suggestion, it looks like I'm
stuck using the kernel debugger... (which actually isn't that bad;
it'd just be nice to be able to look at source code at the same
time). 

John