I have a sparc64, running NetBSD 4.0_RC1.  I'm working with  
RAIDframe, and while trying to familiarize myself with it, I'm trying  
to get it to make crash dumps I'll be able to recover.  So, to make  
it dump, I send a break to the serial console, and type "sync" (or  
"reboot 0x100", same result) and see:

NetBSD/sparc64 (host.distal.com) (console)

login: [halt sent]
cpu0: kdb breakpoint at 1297e20
Stopped at      netbsd:cpu_Debugger+0x4:        nop
db> reboot 0x100
syncing disks... done
unmounting file systems...panic: switch wchan
cpu0: kdb breakpoint at 1297e20
Stopped at      netbsd:cpu_Debugger+0x4:        nop
db>

   (as mentioned above, the outcome is the same with the "sync"  
command.)

   Does anyone know why this is happening?  That panic is inside of  
locore.s, so far as I can tell, so I'd need someone more familiar  
with the code to help me.  Martin?  ;-)

                             - Chris