Reproducable Kernel HARD lockup

[Rui Paulo]

On Fri, Apr 04, 2008 at 09:06:23AM -0400, Tuc at T-B-O-H.NET wrote:
> > 
> > On Fri, Apr 04, 2008 at 12:24:26AM -0400, Tuc at T-B-O-H.NET wrote:
> > > Hi,
> > > 
> > > 	LONG LONG LONG story made short.
> > > 
> > > 	Running Soekris 4801-60 previously on 5.5 . Would lock up
> > > every so often, then more often, then finally constantly. Shipped
> > > back to vendor, replaced, all good. Months later started to lock
> > > every few weeks, then every few hours. Replace CF with hard drive,
> > > locks in 10 minutes, etc.
> > > 
> > > 	Load OpenBSD on disk. Runs for days with no problem. 
> > > Decide I don't like OpenBSD ports system so decide to go FreeBSD
> > > 7. Glitch with memory stick, but otherwise system seems to run
> > > fine. Start SETI, system locks HARD. I have it set to be able
> > > to break to debugger with CR ~ ^b, but that just doesn't happen.
> > > (Previously tested it would in single user when system running
> > > fine).
> > > 
> > > 	Is there any way to debug a kernel lockup if you CAN'T
> > > break to debugger??
> > 
> > http://www.freebsd.org/doc/en_US.ISO8859-1/books/developers-handbook/kerneldebug.html
> > 
> > Hope this helps.
> >
> 	Unfortunately, not that I can see.
> 
> 	Kernel already had :
> 
> options         KDB
> options         KDB_TRACE
> options         KDB_UNATTENDED
> options         DDB
> #break on sequence CR ~ ^b
> options         ALT_BREAK_TO_DEBUGGER
> 
> 	And I couldn't break to the debugger for love nor money
> once it happens. I also can't remote debug due to my 7.0 system not
> having a serial port.
> 
> 			Thanks, Tuc

Do you have a firewire port?
See http://www.lemis.com/grog/Papers/Debug-tutorial/tutorial.pdf for
an explanation on how to setup firewire debugging.

Regards,
-- 
Rui Paulo