From owner-freebsd-current@FreeBSD.ORG Wed Sep 17 06:36:02 2003 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 51C8316A4B3 for ; Wed, 17 Sep 2003 06:36:02 -0700 (PDT) Received: from mail.sandvine.com (sandvine.com [199.243.201.138]) by mx1.FreeBSD.org (Postfix) with ESMTP id 764F043F85 for ; Wed, 17 Sep 2003 06:36:01 -0700 (PDT) (envelope-from don@sandvine.com) Received: by mail.sandvine.com with Internet Mail Service (5.5.2653.19) id ; Wed, 17 Sep 2003 09:35:59 -0400 Message-ID: From: Don Bowman To: 'Terry Lambert' , Don Bowman Date: Wed, 17 Sep 2003 09:35:57 -0400 MIME-Version: 1.0 X-Mailer: Internet Mail Service (5.5.2653.19) Content-Type: text/plain; charset="iso-8859-1" cc: "'freebsd-current@freebsd.org'" Subject: RE: using tip on machine that has COMCONSOLE set to serial X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 17 Sep 2003 13:36:02 -0000 From: Terry Lambert [mailto:tlambert2@mindspring.com] > Don Bowman wrote: > > This may be a dumb question, but I have > > a situation where machine A and B both have > > enabled serial console. I'm ssh'ing into A to > > try and debug a problem on B. I'm trying to > > use tip, but am getting interference from the > > fact that A also has a serial console. > > > > If i disable the getty, its a bit better. > > > > Is there a way to make this work reliably, or > > am I SOL? > > Use or modify a getty to require multiple CR's to activate. Or > use one that only activates on a break. > > Best would be to use a getty that respected lock files, needed > 2 CR's to start after off-to-on DTR/DCD transition (you will be > using a NULL-modem cable), and your tip/cu/whatever program did > appropriate locking, and knew how to back off. > > Then you could put the getty's back-to-back and they would not > chat each other to death, and you could call out of the one > machine into the other, and your local getty would not eat half > the characters. > > See also "uugetty" and "mgetty" in ports. What i ended up doing which worked OK was to changed /etc/ttys on the machine i wanted to run tip on to comment out the 'ttyd0' line, and HUP init. I then installed 'minicom' port, and used it. The machine i was running it on has to be quiescent so no kernel printfs occur. minicom used /dev/cuaa0. Bruce Evans suggested using 'db' to poke a '0xc3' into the kernel printf start to make it return right away, if this were a bigger problem for me I would give that a try. --don