From owner-freebsd-hackers Wed May 10 19:38:11 2000 Delivered-To: freebsd-hackers@freebsd.org Received: from smtp02.teb1.iconnet.net (smtp02.teb1.iconnet.net [209.3.218.43]) by hub.freebsd.org (Postfix) with ESMTP id 721BF37BAD1 for ; Wed, 10 May 2000 19:38:07 -0700 (PDT) (envelope-from babkin@bellatlantic.net) Received: from bellatlantic.net (client-117-234.bellatlantic.net [151.198.117.234]) by smtp02.teb1.iconnet.net (8.9.1/8.9.1) with ESMTP id WAA19711; Wed, 10 May 2000 22:37:52 -0400 (EDT) Message-ID: <391A1F35.23F38D4A@bellatlantic.net> Date: Wed, 10 May 2000 22:47:17 -0400 From: Sergey Babkin X-Mailer: Mozilla 4.7 [en] (X11; U; FreeBSD 4.0-19990626-CURRENT i386) X-Accept-Language: ru, en MIME-Version: 1.0 To: Peter Jeremy Cc: wc.bulte@chello.nl, hackers@FreeBSD.ORG Subject: Re: Can NMI drop a hanging FreeBSD kernel into DDB? References: <00May11.070143est.115219@border.alcanet.com.au> <20000510231004.A1871@jedi.wbnet> <00May11.085127est.115442@border.alcanet.com.au> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG Peter Jeremy wrote: > > On 2000-May-11 07:10:27 +1000, Wilko Bulte wrote: > >And if you force the IOCHK* line on an AT slot to GND? Would that work > >on modern PCI machines? > > Grounding IOCHK* does cause an NMI on the only PCI machine I've tried > it on. It looks like this is maskable in the Intel PIIX3 (and > presumably later) chips, so it may depend on the BIOS. Seems like most of the modern machines just don't have that pin on the PCI bus connected anywhere. But on most of them (though not all) the pin on ISA works. Some high-end machines like Unisys or Compaq have an NMI button on the box (sometimes under the cover). > I don't know whether this will still work if the PCI bus is hung. I Most probably it won't. The keyboard is connected on most machines below PCI, so if PCI hangs you won't be able to do anything anyway. The same problem would be in the other direction, for PCI video card. -SB To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message