path: root/usr.sbin/dconschat/dconschat.8

.\" 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.
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.\" 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.
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.\" $FreeBSD$
.\"
.\"
.Dd February 11, 2003
.Dt DCONSCHAT 8
.Os
.Sh NAME
.Nm dconschat
.Nd user interface to dcons
.Sh SYNOPSIS
.Nm
.Op Fl brvwRT1
.Op Fl h Ar hz
.Op Fl C Ar console_port
.Op Fl G Ar gdb_port
.Op Fl M Ar core
.Op Fl N Ar system
.Nm
.Op Fl brvwR1
.Op Fl h Ar hz
.Op Fl C Ar console_port
.Op Fl G Ar gdb_port
.Op Fl a Ar address
.Op Fl u Ar bus_num
.Fl t Ar target_eui64
.Sh DESCRIPTION
The
.Nm
utility is designed to provide a way for users to access
.Xr dcons 4
(dumb console device) on a local or remote system.
The
.Nm
interacts with
.Xr dcons 4
using
.Xr kvm 3
or
.Xr firewire 4 
and interact with a user over tty or TCP/IP.
To access remote
.Xr dcons 4
using
.Xr firewire 4 ,
you have to specify target EUI64 address by
.Fl t
option.
.Pp
The
.Nm
and
.Xr dcons 4
communicate using 2 port, one for console port and the other for
remote gdb port.
Users are supposed to access
.Nm
using tty, telnet and gdb.
You can specify listen ports for console and gdb port by
.Fl C
and
.Fl G
options respectively. The port number 0 has special meaning that
current tty(stdin/out) is used instead of TCP/IP.
A negative port number will disable the port.
To quit dconschat, send a CR + '~' + '.' sequence to the console port
or send signal to the process.
.Pp
By analogy with
.Xr pty 4
device, the 
.Xr dcons 4
acts as a slave device and
.Nm
acts as a master device with
.Xr telnetd 8 .
.Pp
.Bl -tag -width indent 
.It Fl b
Translate Ctrl-C to ALT_BREAK(CR + '~' + Ctrl-B) on gdb port.
.It Fl r
Replay old buffer on connection.
.It Fl v
Verbose debug output. Multiple '-v' increase verbosity.
.It Fl w
Listen on wildcard address rather than localhost.
.It Fl R
Read-only. Don't write anything on dcons buffer.
.It Fl T
Enable ad hoc workaround for telnet protocol to
remove unnecessary byte sequences.
It should be set when you access dconschat using telnet.
.It Fl 1
One-Shot. Read available buffer then exit. This implies
.Fl r
option.
.It Fl h Ar hz
Specify polling rate. The default value is 100.
.It Fl C Ar console_port
Specify console port. The default value is 0(stdin/stdout).
.It Fl G Ar gdb_port
Specify gdb port.. The default value is -1(disabled).
.It Fl M Ar core
Specify core file.
.It Fl N Ar system
Specify system file such as /boot/kernel/kernel.
.It Fl t Ar target_eui64
Specify the 64bit extended unique identifier of the target and use FireWire to access remote
.Xr dcons 4 .
.It Fl a Ar address
Specify the physical/IO address of the dcons buffer. See
.Xr dcons 4
for details.
If this option is not specified,
.Nm
tries to get the address from the Configuration ROM on the target.
You are supposed to enable
.Xr dcons_crom 4
on the target to omit this option.
.It Fl u Ar bus_num
Specify FireWire bus number. The default is 0.
.El
.Sh EXAMPLE
To use
.Nm 
with FireWire for remote
.Xr dcons ,
you have to specify the eui64 of the target.
You can obtain EUI64 by running
.Xr fwcontorl 4
without options.
The first EUI64 is of the host running fwcontrol and others on the
bus follow.
.Bd -literal -offset indent
# fwcontrol
2 devices (info_len=2)
node        EUI64        status
   1  0x7766554433221100      0
   0  0x0011223344556677      1
.Ed
.Pp
The EUI64 doesn't change unless you change the hardware
as the ethernet address.
.Pp
Now we can run the
.Nm .
.Bd -literal -offset indent
# dconschat -br -G 12345 -t 0x00112233445566677
.Ed
.Pp
You'll get console output of the target and login prompt if a getty is
running on dcons. You can break to DDB with ALT_BREAK (CR + '~' + Ctrl-B)
if DDB and ALT_BREAK_TO_DEBUGGER is enabled in the target kernel.
To quit the session, type CR + '~' + '.' in the console port.
.Pp
Using gdb port is almost the same as remote gdb over serial line except
using TCP/IP instead of /dev/cu*. See 
"On-line Kernel Debugging Using Remote GDB"
section of The FreeBSD Developers Handbook and
.Xr gdb 4
for detail. 
.Bd -literal -offset indent
% gdb -k kernel.debug
(kgdb) target remote :12345
.Ed
.Pp
Once gdb is attached and you specified '-b' option to dconschat,
typing "Ctrl-C" on gdb causes break to debugger.
.Pp
The following command get console log from crash dump:
.Bd -literal -offset indent
# dconschat -1 -M vmcore.0 -N kernel.0
.Ed
.Pp
If you want access to the console using telnet, try the following:
.Bd -literal -offset indent
# dconschat -rTC 5555 &
# telnet localhost 5555
.Ed
.Pp
You may want to keep logging console output of several machines. Conserve-com
in the ports collection may help you. Insert the following lines
in the conserver.cf.
.Bd -literal -offset indent
console local {
	master localhost;
	type exec;
	exec /usr/sbin/dconschat -rh 25;
}
console remote {
	master localhost;
	type exec;
	exec /usr/sbin/dconschat -rh 25 -t 0x0011223344556677;
}
.Ed
.Sh FILES
.Bl -tag -width indent
.It Pa /dev/fwmem0.0
.It Pa /dev/mem
.It Pa /dev/kmem
.El
.Sh SEE ALSO
.Xr gdb 1 ,
.Xr telnet 1 ,
.Xr kvm 3 ,
.Xr dcons 4 ,
.Xr dcons_crom 4 ,
.Xr ddb 4 ,
.Xr firewire 4 ,
.Xr fwohci 4 ,
.Xr gdb 4 ,
.Xr fwcontrol 8
.Sh AUTHORS
.An Hidetoshi Shimokawa Aq simokawa@FreeBSD.org
.Sh BUGS
This utility is still under development.
.Pp