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Date: Mon, 24 Nov 2008 13:56:22 -0800
From: Sam Leffler <sam@freebsd.org>
Organization: FreeBSD Project
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To: David Christensen <davidch@broadcom.com>
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Cc: "freebsd-net@FreeBSD.org" <freebsd-net@freebsd.org>,
	"freebsd-drivers@freebsd.org" <freebsd-drivers@freebsd.org>
Subject: Re: Gathering Hardware State During a Driver Initiated Kernel Panic
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David Christensen wrote:
> Is there a method or callback in FreeBSD where a driver can 
> be notified that it has caused a kernel panic in order to 
> generate a dump of internal hardware state information?  I've
> written a sysctl call for manual intervention and can handle
> some "expected" hardware events completely in the driver but
> I don't know of a way to get control again in cases where the 
> driver wasn't expecting a failure.
>   

Not sure how one can deduce a driver is at fault but you might define a 
ddb command for the driver and invoke that on panic using the ddb script 
mechanisms (see ddb(4)).

    Sam