From owner-freebsd-drivers@FreeBSD.ORG Sun Jan 29 19:26:23 2012 Return-Path: Delivered-To: freebsd-drivers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id D18EE106564A for ; Sun, 29 Jan 2012 19:26:23 +0000 (UTC) (envelope-from dieterbsd@engineer.com) Received: from mailout-us.gmx.com (mailout-us.gmx.com [74.208.5.67]) by mx1.freebsd.org (Postfix) with SMTP id 775958FC0A for ; Sun, 29 Jan 2012 19:26:23 +0000 (UTC) Received: (qmail 6504 invoked by uid 0); 29 Jan 2012 19:26:22 -0000 Received: from 67.206.161.175 by rms-us007.v300.gmx.net with HTTP Content-Type: text/plain; charset="utf-8" Date: Sun, 29 Jan 2012 14:26:19 -0500 From: "Dieter BSD" Message-ID: <20120129192621.300970@gmx.com> MIME-Version: 1.0 To: freebsd-drivers@freebsd.org X-Authenticated: #74169980 X-Flags: 0001 X-Mailer: GMX.com Web Mailer x-registered: 0 Content-Transfer-Encoding: 8bit X-GMX-UID: CvhXb/UU3zOlNR3dAHAhBrx+IGRvb4CQ Subject: Re: Introduction to writing kernel modules X-BeenThere: freebsd-drivers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Writing device drivers for FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 29 Jan 2012 19:26:23 -0000 > all it does is crash the kernel. Is there a way of debugging this > without going through reboot and fsck At the risk of pointing out the obvious, you can reduce/eliminate fsck by booting to single user mode, or you can umount or mount -u -r as many filesystems as possible before loading your module. > I can'T set up a virtual machine if a want to talk to > real hardware. It might be that the crash happens before it needs access to hardware? IIRC there is a way to allow bochs access to hardware, although I'd guess it is unlikely to have support for the device you're working on.