From owner-freebsd-hackers Wed May 10 14:10:12 2000 Delivered-To: freebsd-hackers@freebsd.org Received: from relay02.chello.nl (relay02.chello.nl [212.83.68.146]) by hub.freebsd.org (Postfix) with ESMTP id 0F2DC37B95E for ; Wed, 10 May 2000 14:10:07 -0700 (PDT) (envelope-from wkb@chello.nl) Received: from chello.nl ([213.46.78.184]) by relay02.chello.nl (InterMail vK.4.02.00.00 201-232-116 license eb4b2a5620dc3934c7c631b507644fb6) with ESMTP id <20000510210957.OXWV3505.relay02@chello.nl>; Wed, 10 May 2000 23:09:57 +0200 Received: (from wkb@localhost) by chello.nl (8.9.3/8.9.3) id XAA01891; Wed, 10 May 2000 23:10:04 +0200 (CEST) (envelope-from wkb) Date: Wed, 10 May 2000 23:10:04 +0200 From: Wilko Bulte To: Peter Jeremy Cc: imp@village.org, hackers@FreeBSD.ORG Subject: Re: Can NMI drop a hanging FreeBSD kernel into DDB? Message-ID: <20000510231004.A1871@jedi.wbnet> Reply-To: wc.bulte@chello.nl References: <00May11.070143est.115219@border.alcanet.com.au> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 1.0.1i In-Reply-To: <00May11.070143est.115219@border.alcanet.com.au>; from peter.jeremy@alcatel.com.au on Thu, May 11, 2000 at 07:01:43AM +1000 X-OS: FreeBSD 3.4-STABLE X-PGP: finger wilko@freebsd.org Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Thu, May 11, 2000 at 07:01:43AM +1000, Peter Jeremy wrote: > On Fri, 05 May 2000 22:56:42 -0600, Warner Losh wrote: > >In message <200005060453.WAA59241@harmony.village.org> Warner Losh writes: > >: However, it won't work if you are hacking pci hardware and manage to > >: hang the PCI bus. > > > >Unless, of course, the trap handler is in cache as well as the > >debugger routines you need. > > I thought the PCI bus was isolated from the CPU<->memory bus so this > couldn't occur. The trap handler should start OK, but just can't do > any I/O because the PCI bus is hung. And if you force the IOCHK* line on an AT slot to GND? Would that work on modern PCI machines? I used to do this on older EISA boxes. -- Wilko Bulte FreeBSD, the power to serve http://www.freebsd.org http://www.tcja.nl To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message