1.\" $NetBSD: pcweasel.4,v 1.5 2009/05/18 12:31:01 wiz Exp $ 2.\" 3.\" Copyright (c) 2000 Zembu Labs, Inc. 4.\" All rights reserved. 5.\" 6.\" Author: Jason R. Thorpe <thorpej@zembu.com> 7.\" 8.\" Redistribution and use in source and binary forms, with or without 9.\" modification, are permitted provided that the following conditions 10.\" are met: 11.\" 1. Redistributions of source code must retain the above copyright 12.\" notice, this list of conditions and the following disclaimer. 13.\" 2. Redistributions in binary form must reproduce the above copyright 14.\" notice, this list of conditions and the following disclaimer in the 15.\" documentation and/or other materials provided with the distribution. 16.\" 3. All advertising materials mentioning features or use of this software 17.\" must display the following acknowledgement: 18.\" This product includes software developed by Zembu Labs, Inc. 19.\" 4. Neither the name of Zembu Labs nor the names of its employees may 20.\" be used to endorse or promote products derived from this software 21.\" without specific prior written permission. 22.\" 23.\" THIS SOFTWARE IS PROVIDED BY ZEMBU LABS, INC. ``AS IS'' AND ANY EXPRESS 24.\" OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WAR- 25.\" RANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DIS- 26.\" CLAIMED. IN NO EVENT SHALL ZEMBU LABS BE LIABLE FOR ANY DIRECT, INDIRECT, 27.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 28.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 29.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 30.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 31.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 32.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 33.\" 34.Dd November 23, 2007 35.Dt PCWEASEL 4 36.Os 37.Sh NAME 38.Nm pcweasel 39.Nd Support for the PC-Weasel serial console board 40.Sh SYNOPSIS 41.Cd "pseudo-device pcweasel" 42.Cd "weasel* at pci? dev ? function ?" 43.Pp 44Note that the appropriate display device must also be enabled. 45See 46.Xr pcdisplay 4 47for more information. 48.Sh DESCRIPTION 49The PC-Weasel is a serial console board for use primarily on 50Intel-based PC-class systems. 51It addresses a problem that nearly everyone who has deployed a 52PC-class server has experienced: the total lack of remote management 53capability on PC-class hardware. 54.Pp 55In addition to serial console support, the PC-Weasel provides the 56ability to remotely reset the system (by means of a hardware reset 57signal), and provides a watchdog timer function. 58.Pp 59The PC-Weasel works by emulating the original IBM Monochrome 60Display Adapter (MDA). 61Writes to the display's character cells are translated into ANSI 62terminal sequences which are then sent out the PC-Weasel's serial 63port. 64Incoming characters are translated into PC keyboard scan codes and 65then fed (by means of a cable) into the system's keyboard controller. 66The system believes it is using a display console. 67This is particularly important in the event that one needs access 68to BIOS configuration menus. 69.Pp 70The PC-Weasel also includes a ST16550 serial port, which may 71be configured as any one of the system's serial ports. 72Typical usage is to configure the port as 73.Em com0 74at ISA I/O address 0x3f8. 75When the PC-Weasel detects activity on the ST16550, the serial port 76is automatically connected to the ST16550 so that the serial port 77may be used as normal. 78When the PC-Weasel detects activity on the internal UART used for 79MDA emulation, the serial port is automatically reconnected to the 80emulation UART. 81This allows the boot program and kernel to be configured to use 82the serial port directly (which is more efficient than using the 83MDA emulation mode), yet allows the MDA emulation to be reestablished 84as soon as the kernel loses control of the system. 85.Pp 86The 87.Nm 88driver provides support for the additional features present on 89the PC-Weasel. 90At the moment, this includes support for the watchdog timer function. 91Use of the 92.Nm 93driver is not required in order for the system to function with 94a PC-Weasel installed so long as only the MDA emulation and 95ST16550 serial port functionality is required. 96.Sh SEE ALSO 97.Xr pcdisplay 4 , 98.Xr wdogctl 8 99.Sh HISTORY 100The 101.Nm 102driver first appeared in 103.Nx 1.5.1 . 104.Sh AUTHORS 105The PC-Weasel was invented by Herb Peyerl and Jonathan Levine 106at Canada Connect Corporation. 107It is now produced by Middle Digital, Inc., http://www.realweasel.com/ 108.Pp 109The 110.Nm 111driver was written by 112.An Jason R. Thorpe 113.Aq thorpej@zembu.com , 114and contributed by Zembu Labs, Inc. 115Herb Peyerl of Middle Digital, Inc. 116provided several firmware updates during the 117development of the driver. 118