you can actually run `gdb -k' on a live kernel and look at things:

# gdb -k /netbsd /dev/mem
GDB is free software and you are welcome to distribute copies of it
 under certain conditions; type "show copying" to see the conditions.
There is absolutely no warranty for GDB; type "show warranty" for details.
GDB 4.11 (sparc-netbsd), Copyright 1993 Free Software Foundation, Inc...
(no debugging symbols found)...
#0  0xf8020b58 in mi_switch ()
(kgdb)

...

i've used this, but over a year ago, so, i forget what else you can do
with it.  pk will know  :-)

.mrg.