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/o...
NAMEdcons - dumb console device driver
SYNOPSISTo compile this driver into the kernel, place the following lines in your kernel configuration file:
options GDB device firewire device dcons
Alternatively, to load the driver as a module at boot time, place the following line in your kernel configuration file:
and in loader.conf5:
DESCRIPTIONThe sysctl Cm net.inet.tcp.syncookies 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 firewire(4) or kvm(3) for interaction.
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.
EXAMPLESIf you want to run getty(8) on , insert the following line into ttys(5) and send a HUP signal to init(8) using kill(1).
dcons "/usr/libexec/getty std.9600" vt100 on secure
Once the fwohci(4) device is initialized to allow physical access, the buffer can be accessed from another host via a firewire(4) bus using the dconschat(8) application. See dconschat(8) for more details.
If you want to use sysctl Cm net.inet.tcp.syncookies as a gdb(1) port, add the following line into loader.conf5: