1.\" $NetBSD: pcweasel.4,v 1.4 2007/11/23 11:40:50 xtraeme 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. See 45.Xr pcdisplay 4 46for more information. 47.Sh DESCRIPTION 48The PC-Weasel is a serial console board for use primarily on 49Intel-based PC-class systems. It addresses a problem that 50nearly everyone who has deployed a PC-class server has experienced: 51the total lack of remote management capability on PC-class hardware. 52.Pp 53In addition to serial console support, the PC-Weasel provides the 54ability to remotely reset the system (by means of a hardware reset 55signal), and provides a watchdog timer function. 56.Pp 57The PC-Weasel works by emulating the original IBM Monochrome 58Display Adapter (MDA). Writes to the display's character 59cells are translated into ANSI terminal sequences which are 60then sent out the PC-Weasel's serial port. Incoming characters 61are translated into PC keyboard scan codes and then fed (by means 62of a cable) into the system's keyboard controller. The system 63believes it is using a display console. This is particularly 64important in the event that one needs access to BIOS configuration 65menus. 66.Pp 67The PC-Weasel also includes a ST16550 serial port, which may 68be configured as any one of the system's serial ports. Typical 69usage is to configure the port as 70.Em com0 71at ISA I/O address 0x3f8. When the PC-Weasel detects activity 72on the ST16550, the serial port is automatically connected to 73the ST16550 so that the serial port may be used as normal. When 74the PC-Weasel detects activity on the internal UART used for MDA 75emulation, the serial port is automatically reconnected to the 76emulation UART. This allows the boot program and kernel to be 77configured to use the serial port directly (which is more efficient 78than using the MDA emulation mode), yet allows the MDA emulation 79to be reestablished as soon as the kernel loses control of the 80system. 81.Pp 82The 83.Nm 84driver provides support for the additional features present on 85the PC-Weasel. At the moment, this includes support for the 86watchdog timer function. Use of the 87.Nm 88driver is not required in order for the system to function with 89a PC-Weasel installed so long as only the MDA emulation and 90ST16550 serial port functionality is required. 91.Sh SEE ALSO 92.Xr pcdisplay 4 , 93.Xr wdogctl 8 94.Sh HISTORY 95The 96.Nm 97driver first appeared in 98.Nx 1.5.1 . 99.Sh AUTHORS 100The PC-Weasel was invented by Herb Peyerl and Jonathan Levine 101at Canada Connect Corporation. It is now produced by Middle 102Digital, Inc., http://www.realweasel.com/ 103.Pp 104The 105.Nm 106driver was written by 107.An Jason R. Thorpe 108.Aq thorpej@zembu.com , 109and contributed by Zembu Labs, Inc. 110Herb Peyerl of Middle Digital, Inc. 111provided several firmware updates during the 112development of the driver. 113