Date: Thu, 13 Apr 1995 08:58:24 -0400 (EDT) From: Peter Dufault <dufault@hda.com> To: joerg_wunsch@uriah.heep.sax.de Cc: bde@zeta.org.au, CVS-commiters@freefall.cdrom.com, cvs-sys@freefall.cdrom.com, phk@freefall.cdrom.com Subject: Re: cvs commit: src/sys/i386/isa sio.c Message-ID: <199504131258.IAA07400@hda.com> In-Reply-To: <199504130718.JAA12638@uriah.heep.sax.de> from "J Wunsch" at Apr 13, 95 09:18:42 am
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J Wunsch writes: > > As Poul-Henning Kamp wrote: > > > > > A magic sequence of chars would be a misfeature, as it would be for > > > syscons. The escape should be out of bounds (perhaps it should optionally > > > be break && some combination of the modem status lines). > > > > No, we want something you can send on a modem... > > Not really. Playing in DDB is likely to cause the machine hang, so > you need to hit the big red button. Real-life machines do not have > DDB. (It's also a security hole.) A modem console is useful for remote support. After supporting people with a console debugger (good old ddt; I wish we had that) over a modem I disagree with Joerg. The systems I worked with (Alliant) had ways to disable the modem; in the FreeBSD case it could be as simple as a physically secure system. Those Alliant systems, BTW, would "tee" the input and output to both the modem and the system console so that the people at both ends could watch what was going on. Of course you WOULD get broadcast messages in the middle of the night all over Alliant from a developer 100 miles away with a "SOMEBODY RESET MARLEY..." message As for getting in and out of ddb, you could have a protected /dev/ddb and cp /dev/null /dev/ddb. Peter -- Peter Dufault Real Time Machine Control and Simulation HD Associates, Inc. Voice: 508 433 6936 dufault@hda.com Fax: 508 433 5267
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