From owner-freebsd-hackers Sun Jun 30 14:20:22 2002 Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.FreeBSD.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id D244237B405 for ; Sun, 30 Jun 2002 14:20:11 -0700 (PDT) Received: from rwcrmhc52.attbi.com (rwcrmhc52.attbi.com [216.148.227.88]) by mx1.FreeBSD.org (Postfix) with ESMTP id 7638843E09 for ; Sun, 30 Jun 2002 14:20:11 -0700 (PDT) (envelope-from julian@elischer.org) Received: from InterJet.elischer.org ([12.232.206.8]) by rwcrmhc52.attbi.com (InterMail vM.4.01.03.27 201-229-121-127-20010626) with ESMTP id <20020630212011.BAQZ8262.rwcrmhc52.attbi.com@InterJet.elischer.org>; Sun, 30 Jun 2002 21:20:11 +0000 Received: from localhost (localhost.elischer.org [127.0.0.1]) by InterJet.elischer.org (8.9.1a/8.9.1) with ESMTP id OAA86771; Sun, 30 Jun 2002 14:17:24 -0700 (PDT) Date: Sun, 30 Jun 2002 14:17:21 -0700 (PDT) From: Julian Elischer To: Charles Sprickman Cc: "freebsd-hackers@freebsd.org" Subject: Re: getting a coredump before boot device found In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Sun, 30 Jun 2002, Charles Sprickman wrote: > On Sun, 30 Jun 2002, Julian Elischer wrote: > > > at that stage abut all you can do is live debugging.. > > Meaning boot kernel.debug directlly so I've got a kernel with symbols and > then get out the pen and paper? > > > do you have 2 machines you can link together? > > Oh yes. But I know nothing about remote gdb. it's not that difficult.. have the source and compile directory on the 2nd machine so gdb can access it. compile with debug symbols (config -g). Have the following .gdbinit in the compile/MYKENEL directory: file kernel.debug set remotebaud 9600 target remote /dev/cuaa1 then connect a null modem cable getween com2 of both machines. on the booting machine you need 'flags 0xc0 on sio1' in the config or from the kernel configurator when you boot. to tell the gdb stub that is where to go. when it crashes into the ddb type 'tr' to get a good backtrace, then type 'gdb' to set gdb mode then 's' to switch to it. on the compile machine, in the compile/MYKERN directory, type 'gdb' (you must have compiled with debug support.... "config -g") to go back to ddb 'det' to reboot from ddb: call boot 0 (you may need to do it more than once). > > Charles > > > > > On Sun, 30 Jun 2002, Charles Sprickman wrote: > > > > > Hi, > > > > > > I'm wondering if there's any way to get a coredump on a machine that's > > > panicing while probing ata-attached drives. I'd like to help someone fix > > > whatever this remaining ata bug is in 4.6 and -stable, but I'm stumped on > > > how to do this. I can break into the debugger, but my only option there > > > to write a core is to "panic" again, but since there's no dump device > > > configured yet... chicken and egg... > > > > > > Is this at all possible? I couldn't find anything in the DDB manpage, nor > > > in a quick google search. > > > > > > Thanks, > > > > > > CS > > > > > > > > > To Unsubscribe: send mail to majordomo@FreeBSD.org > > > with "unsubscribe freebsd-hackers" in the body of the message > > > > > > > > > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message