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.\" $FreeBSD$ 26.\" 27.Dd January 26, 2008 28.Dt DCONS 4 29.Os 30.Sh NAME 31.Nm dcons 32.Nd dumb console device driver 33.Sh SYNOPSIS 34To compile this driver into the kernel, 35place the following lines in your kernel configuration file: 36.Bd -ragged -offset indent 37.Cd "options GDB" 38.Cd "device firewire" 39.Cd "device dcons" 40.Ed 41.Pp 42Alternatively, to load the driver as a module at boot time, 43place the following line in your kernel configuration file: 44.Bd -ragged -offset indent 45.Cd "options GDB" 46.Ed 47.Pp 48and in 49.Xr loader.conf 5 : 50.Bd -ragged -offset indent 51dcons_load="YES" 52.Ed 53.Sh DESCRIPTION 54The 55.Nm 56device is a simple console device which just reads from and writes to 57an allocated buffer for input and output respectively. 58It is of no use by itself and it is supposed that the buffer is accessed 59via a bus like 60.Xr firewire 4 61or 62.Xr kvm 3 63for interaction. 64.Pp 65The buffer consists of 4 channels. 66There are 2 ports, one for the console TTY and another is GDB port, 67then each port has an input channel and an output channel. 68.Sh FILES 69.Bl -tag -width indent -compact 70.It Pa /dev/dcons 71.It Pa /etc/ttys 72.El 73.Sh EXAMPLES 74If you want to run 75.Xr getty 8 76on 77.Nm , 78insert the following line into 79.Xr ttys 5 80and send a 81.Dv HUP 82signal to 83.Xr init 8 84using 85.Xr kill 1 . 86.Bd -literal -offset indent 87dcons "/usr/libexec/getty std.9600" vt100 on secure 88.Ed 89.Pp 90Once the 91.Xr fwohci 4 92device is initialized to allow physical access, 93the buffer can be accessed from another host via a 94.Xr firewire 4 95bus using the 96.Xr dconschat 8 97application. 98See 99.Xr dconschat 8 100for more details. 101.Pp 102If you want to use 103.Nm 104as a 105.Xr gdb 1 Pq Pa ports/devel/gdb 106port, add the following line into 107.Xr loader.conf 5 : 108.Bd -literal -offset indent 109dcons_gdb="1" 110.Ed 111.Sh SEE ALSO 112.Xr dcons_crom 4 , 113.Xr ddb 4 , 114.Xr firewire 4 , 115.Xr fwohci 4 , 116.Xr gdb 4 , 117.Xr ttys 5 , 118.Xr conscontrol 8 , 119.Xr dconschat 8 , 120.Xr fwcontrol 8 121.Sh AUTHORS 122.An Hidetoshi Shimokawa Aq Mt simokawa@FreeBSD.org 123.Sh BUGS 124This driver is 125.Ud 126