freebsd-dev/share/man/man4/dcons.4
Tom Rhodes c6eaff9892 Catch up with revision 1.18 of dcons_os.c and add an example of how to use
dcons(4) as a valid gdb port.

PR:             118490
Submitted by:   Alexandre Kovalenko <alex.kovalenko@verizon.net>
2008-01-26 06:50:14 +00:00

126 lines
3.2 KiB
Groff

.\" Copyright (c) 2003 Hidetoshi Shimokawa
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\" notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\" notice, this list of conditions and the following disclaimer in the
.\" documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
.\" WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
.\" DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
.\" INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
.\" (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
.\" SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
.\" STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
.\" ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
.\" POSSIBILITY OF SUCH DAMAGE.
.\"
.\" $FreeBSD$
.\"
.Dd January 26, 2008
.Dt DCONS 4
.Os
.Sh NAME
.Nm dcons
.Nd dumb console device driver
.Sh SYNOPSIS
To compile this driver into the kernel,
place the following lines in your kernel configuration file:
.Bd -ragged -offset indent
.Cd "options GDB"
.Cd "device firewire"
.Cd "device dcons"
.Ed
.Pp
Alternatively, to load the driver as a module at boot time,
place the following line in your kernel configuration file:
.Bd -ragged -offset indent
.Cd "options GDB"
.Ed
.Pp
and in
.Xr loader.conf 5 :
.Bd -ragged -offset indent
dcons_load="YES"
.Ed
.Sh DESCRIPTION
The
.Nm
device is a simple console device which just reads from and writes to
an allocated buffer for input and output respectively.
It is of no use by itself and it is supposed that the buffer is accessed
via a bus like
.Xr firewire 4
or
.Xr kvm 3
for interaction.
.Pp
The buffer consists of 4 channels.
There are 2 ports, one for the console TTY and another is GDB port,
then each port has an input channel and an output channel.
.Sh FILES
.Bl -tag -width indent -compact
.It Pa /dev/dcons
.It Pa /etc/ttys
.El
.Sh EXAMPLES
If you want to run
.Xr getty 8
on
.Nm ,
insert the following line into
.Xr ttys 5
and send a
.Dv HUP
signal to
.Xr init 8
using
.Xr kill 1 .
.Bd -literal -offset indent
dcons "/usr/libexec/getty std.9600" vt100 on secure
.Ed
.Pp
Once the
.Xr fwohci 4
device is initialized to allow physical access,
the buffer can be accessed from another host via a
.Xr firewire 4
bus using the
.Xr dconschat 8
application.
See
.Xr dconschat 8
for more details.
.Pp
If you want to use
.Xr dcons 4
as a
.Xr gdb 1
port, add the following line into
.Xr loader.conf 5
.Bd -literal -offset indent
dcons_gdb="1"
.Ed
.Sh SEE ALSO
.Xr dcons_crom 4 ,
.Xr ddb 4 ,
.Xr firewire 4 ,
.Xr fwohci 4 ,
.Xr gdb 4 ,
.Xr ttys 5 ,
.Xr conscontrol 8 ,
.Xr dconschat 8 ,
.Xr fwcontrol 8
.Sh AUTHORS
.An Hidetoshi Shimokawa Aq simokawa@FreeBSD.org
.Sh BUGS
This driver is
.Ud .