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.Dd January 26, 2008 26.Dt DCONS 4 27.Os 28.Sh NAME 29.Nm dcons 30.Nd dumb console device driver 31.Sh SYNOPSIS 32To compile this driver into the kernel, 33place the following lines in your kernel configuration file: 34.Bd -ragged -offset indent 35.Cd "options GDB" 36.Cd "device firewire" 37.Cd "device dcons" 38.Ed 39.Pp 40Alternatively, to load the driver as a module at boot time, 41place the following line in your kernel configuration file: 42.Bd -ragged -offset indent 43.Cd "options GDB" 44.Ed 45.Pp 46and in 47.Xr loader.conf 5 : 48.Bd -ragged -offset indent 49dcons_load="YES" 50.Ed 51.Sh DESCRIPTION 52The 53.Nm 54device is a simple console device which just reads from and writes to 55an allocated buffer for input and output respectively. 56It is of no use by itself and it is supposed that the buffer is accessed 57via a bus like 58.Xr firewire 4 59or 60.Xr kvm 3 61for interaction. 62.Pp 63The buffer consists of 4 channels. 64There are 2 ports, one for the console TTY and another is GDB port, 65then each port has an input channel and an output channel. 66.Sh FILES 67.Bl -tag -width indent -compact 68.It Pa /dev/dcons 69.It Pa /etc/ttys 70.El 71.Sh EXAMPLES 72If you want to run 73.Xr getty 8 74on 75.Nm , 76insert the following line into 77.Xr ttys 5 78and send a 79.Dv HUP 80signal to 81.Xr init 8 82using 83.Xr kill 1 . 84.Bd -literal -offset indent 85dcons "/usr/libexec/getty std.115200" vt100 on secure 86.Ed 87.Pp 88Once the 89.Xr fwohci 4 90device is initialized to allow physical access, 91the buffer can be accessed from another host via a 92.Xr firewire 4 93bus using the 94.Xr dconschat 8 95application. 96See 97.Xr dconschat 8 98for more details. 99.Pp 100If you want to use 101.Nm 102as a 103.Xr gdb 1 Pq Pa ports/devel/gdb 104port, add the following line into 105.Xr loader.conf 5 : 106.Bd -literal -offset indent 107dcons_gdb="1" 108.Ed 109.Sh SEE ALSO 110.Xr dcons_crom 4 , 111.Xr ddb 4 , 112.Xr firewire 4 , 113.Xr fwohci 4 , 114.Xr gdb 4 , 115.Xr ttys 5 , 116.Xr conscontrol 8 , 117.Xr dconschat 8 , 118.Xr fwcontrol 8 119.Sh AUTHORS 120.An Hidetoshi Shimokawa Aq Mt simokawa@FreeBSD.org 121.Sh BUGS 122This driver is 123.Ud 124