From owner-freebsd-hackers Mon May 20 14:19:27 1996 Return-Path: owner-hackers Received: (from root@localhost) by freefall.freebsd.org (8.7.3/8.7.3) id OAA18026 for hackers-outgoing; Mon, 20 May 1996 14:19:27 -0700 (PDT) Received: from irz301.inf.tu-dresden.de (irz301.inf.tu-dresden.de [141.76.1.11]) by freefall.freebsd.org (8.7.3/8.7.3) with SMTP id OAA18002 for ; Mon, 20 May 1996 14:19:16 -0700 (PDT) Received: from sax.sax.de by irz301.inf.tu-dresden.de (8.6.12/8.6.12-s1) with ESMTP id XAA14648; Mon, 20 May 1996 23:17:08 +0200 Received: by sax.sax.de (8.6.12/8.6.12-s1) with UUCP id XAA09363; Mon, 20 May 1996 23:17:08 +0200 Received: (from j@localhost) by uriah.heep.sax.de (8.7.5/8.6.9) id WAA06407; Mon, 20 May 1996 22:54:05 +0200 (MET DST) From: J Wunsch Message-Id: <199605202054.WAA06407@uriah.heep.sax.de> Subject: Re: Involking DDB To: freebsd-hackers@freebsd.org (FreeBSD hackers) Date: Mon, 20 May 1996 22:54:05 +0200 (MET DST) Cc: dennis@etinc.com (Dennis) Reply-To: joerg_wunsch@uriah.heep.sax.de (Joerg Wunsch) In-Reply-To: <199605201438.KAA21695@etinc.com> from Dennis at "May 20, 96 10:38:25 am" X-Phone: +49-351-2012 669 X-PGP-Fingerprint: DC 47 E6 E4 FF A6 E9 8F 93 21 E0 7D F9 12 D6 4E X-Mailer: ELM [version 2.4ME+ PL17 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-hackers@freebsd.org X-Loop: FreeBSD.org Precedence: bulk As Dennis wrote: > > Is there a way to start DDB without a system crash...ie run the kernel in > some sort of monitoring mode on demand? Several of them. Boot with `-d'. This drops you into DDB early in the game, so you can even trace the device probing. Since interrupts are not yet enabled, the ``hot keys'' described below won't work however. Hit the ``hot key'' on the PC keyboard. This is Ctrl-Alt-ESC by default, though i think some syscons keymaps tweak it onto another combination (which i forgot). Compile your kernel with option ``BREAK_TO_DEBUGGER'', use a serial console, and force a line break on the RS-232. This will drop you into DDB on the serial console. (If you've got a PC keyboard + driver as well, its ``hot key'' will do the same, even though the console is a serial one.) -- cheers, J"org joerg_wunsch@uriah.heep.sax.de -- http://www.sax.de/~joerg/ -- NIC: JW11-RIPE Never trust an operating system you don't have sources for. ;-)