1.\" Copyright (c) 2003 Hidetoshi Shimokawa 2.\" All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 13.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 14.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 15.\" WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 16.\" DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, 17.\" INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 18.\" (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 19.\" SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 21.\" STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 22.\" ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 23.\" POSSIBILITY OF SUCH DAMAGE. 24.\" 25.\" $FreeBSD: src/share/man/man4/dcons.4,v 1.5 2004/06/17 19:51:17 ru Exp $ 26.\" $DragonFly: src/share/man/man4/dcons.4,v 1.3 2006/04/17 18:01:37 swildner Exp $ 27.\" 28.Dd February 11, 2003 29.Dt DCONS 4 30.Os 31.Sh NAME 32.Nm dcons 33.Nd dumb console device driver 34.Sh SYNOPSIS 35.Cd device dcons 36.Pp 37.Cd options DDB 38.Cd options ALT_BREAK_TO_DEBUGGER 39.Pp 40.Cd device firewire 41.Sh DESCRIPTION 42The 43.Nm 44device is a simple console device which just reads from and writes to 45an allocated buffer for input and output respectively. 46It is of no use by itself and it is supposed that the buffer is accessed 47via a bus like 48.Xr firewire 4 49or 50.Xr kvm 3 51for interaction. 52.Pp 53The buffer consists of 4 channels. 54There are 2 ports, one for the console TTY and another is GDB port, 55then each port has an input channel and an output channel. 56.Sh FILES 57.Bl -tag -width indent -compact 58.It Pa /dev/dcons 59.It Pa /etc/ttys 60.El 61.Sh EXAMPLES 62If you want to run 63.Xr getty 8 64on 65.Nm , 66insert the following line into 67.Pa /etc/ttys 68and send a 69.Dv HUP 70signal to 71.Xr init 8 72using 73.Xr kill 1 . 74.Bd -literal -offset indent 75dcons "/usr/libexec/getty std.9600" vt100 on secure 76.Ed 77.Pp 78Once the 79.Xr fwohci 4 80device is initialized to allow physical access, 81the buffer can be accessed from another host via a 82.Xr firewire 4 83bus using the 84.Xr dconschat 8 85application. 86See 87.Xr dconschat 8 88for more details. 89.Sh SEE ALSO 90.Xr dcons_crom 4 , 91.Xr ddb 4 , 92.Xr firewire 4 , 93.Xr fwohci 4 , 94.Xr ttys 5 , 95.Xr dconschat 8 , 96.Xr fwcontrol 8 97.Sh AUTHORS 98.An Hidetoshi Shimokawa Aq simokawa@FreeBSD.org 99.Sh BUGS 100This driver is 101.Ud . 102