Subject: Debugging Xen3 DOMU
To: None <>
From: Juraj Hercek <>
List: port-xen
Date: 12/21/2006 19:49:11

Is there a way to debug XEN3 DOMU kernel? Basically, my XEN3 DOMU kernel 
is crashing from time to time and I'd like to devote some time to find 
out the culprit of the crash. I think I know how to debug standard 
netbsd kernel using kgdb and two machines connected with null modem 
cable. Can I use same/similar idea to debug XEN3 DOMU? If so, what are 
the differences comparing to standard netbsd kernel debugging? Or is 
there a better way of debugging XEN3 DOMU?

Thanks in advance,

PS: I've compiled in ddb (kernel built from sources updated sometime at 
2006-12-17 afternoon) and this is a copy&paste from db at a quite a 
recent crash:
db> bt                     
cpu_Debugger(c046b805,ca6beca8,c0c38ee8,c04ecb40,5) at 
panic(c046a9a7,c04a0d20,1,c0a69644,0) at 
rtfree(c0a40f00,c0c79410,ca6becdc,c03c7921,c0c38ee8) at netbsd:rtfree+0xd2
in_rtflushall(2,c0c38ee8,ca6bedd4,c0c38ee8,c04bbce0) at 

rtrequest1(b,ca6bedd4,ca6bee7c,c0373f5d,ca6bedd4) at netbsd:rtrequest1+0x4ba
rtrequest(b,c04bfbd0,0,0,0) at netbsd:rtrequest+0x4b                       
rtalloc1(c04bfbd0,1,c03a4711,2e,ca6bef4c) at netbsd:rtalloc1+0x165
arplookup(0,0,2e,1,0) at netbsd:arplookup+0x53                   
in_arpinput(1,0,7ff0,100814,0) at netbsd:in_arpinput+0x372
arpintr(ca6befa8,0,7,ffffffc0,4) at netbsd:arpintr+0x1a8 
DDB lost frame for netbsd:Xsoftnet+0x47, trying 0xca6befa4
Xsoftnet() at netbsd:Xsoftnet+0x47                       
--- interrupt ---                
--- switch to interrupt stack ---
?(ca000031,11,11,0,0) at 0x1