Subject: Re: Methods of debugging a locked-up/hung system that doesn't generate a kernel core dump?
To: None <>
From: Manuel Bouyer <>
List: tech-kern
Date: 04/13/2005 21:56:07
On Wed, Apr 13, 2005 at 03:42:35PM -0400, wrote:
> Yes, it's a i386.
> Problem is I don't know how to generate an NMI.
> Breaking into ddb using a keyboard sequence won't work if interrupts 
> are held off - correct?

Yes, or if the IPL is too high.
It looks like the pckbc driver interrupts at IPL_TTY. Using a serial console
may give interesting results, as the serial driver interrupt is at IPL_HIGH.

Manuel Bouyer <>
     NetBSD: 26 ans d'experience feront toujours la difference