PCWEASEL(4)             NetBSD Kernel Interfaces Manual            PCWEASEL(4)

NAME
     pcweasel -- Support for the PC-Weasel serial console board

SYNOPSIS
     pseudo-device pcweasel
     weasel* at pci? dev ? function ?

     Note that the appropriate display device must also be enabled.  See
     pcdisplay(4) for more information.

DESCRIPTION
     The PC-Weasel is a serial console board for use primarily on Intel-based
     PC-class systems.  It addresses a problem that nearly everyone who has
     deployed a PC-class server has experienced: the total lack of remote man-
     agement capability on PC-class hardware.

     In addition to serial console support, the PC-Weasel provides the ability
     to remotely reset the system (by means of a hardware reset signal), and
     provides a watchdog timer function.

     The PC-Weasel works by emulating the original IBM Monochrome Display
     Adapter (MDA).  Writes to the display's character cells are translated
     into ANSI terminal sequences which are then sent out the PC-Weasel's
     serial port.  Incoming characters are translated into PC keyboard scan
     codes and then fed (by means of a cable) into the system's keyboard con-
     troller.  The system believes it is using a display console.  This is
     particularly important in the event that one needs access to BIOS config-
     uration menus.

     The PC-Weasel also includes a ST16550 serial port, which may be config-
     ured as any one of the system's serial ports.  Typical usage is to con-
     figure the port as com0 at ISA I/O address 0x3f8.  When the PC-Weasel
     detects activity on the ST16550, the serial port is automatically con-
     nected to the ST16550 so that the serial port may be used as normal.
     When the PC-Weasel detects activity on the internal UART used for MDA
     emulation, the serial port is automatically reconnected to the emulation
     UART.  This allows the boot program and kernel to be configured to use
     the serial port directly (which is more efficient than using the MDA emu-
     lation mode), yet allows the MDA emulation to be reestablished as soon as
     the kernel loses control of the system.

     The pcweasel driver provides support for the additional features present
     on the PC-Weasel.  At the moment, this includes support for the watchdog
     timer function.  Use of the pcweasel driver is not required in order for
     the system to function with a PC-Weasel installed so long as only the MDA
     emulation and ST16550 serial port functionality is required.

SEE ALSO
     pcdisplay(4), wdogctl(8)

HISTORY
     The pcweasel driver first appeared in NetBSD 1.5.1.

AUTHORS
     The PC-Weasel was invented by Herb Peyerl and Jonathan Levine at Canada
     Connect Corporation.  It is now produced by Middle Digital, Inc.,
     http://www.realweasel.com/

     The pcweasel driver was written by Jason R. Thorpe <thorpej@zembu.com>,
     and contributed by Zembu Labs, Inc.  Herb Peyerl of Middle Digital, Inc.
     provided several firmware updates during the development of the driver.

NetBSD 5.0_STABLE              November 23, 2007             NetBSD 5.0_STABLE
