1.\"- 2.\" Copyright (c) 2007 Dag-Erling Coïdan Smørgrav 3.\" All rights reserved. 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 8.\" 1. Redistributions of source code must retain the above copyright 9.\" notice, this list of conditions and the following disclaimer. 10.\" 2. Redistributions in binary form must reproduce the above copyright 11.\" notice, this list of conditions and the following disclaimer in the 12.\" documentation and/or other materials provided with the distribution. 13.\" 14.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24.\" SUCH DAMAGE. 25.\" 26.\" $FreeBSD$ 27.\" 28.Dd August 20, 2008 29.Dt ICHWD 4 30.Os 31.Sh NAME 32.Nm ichwd 33.Nd device driver for the Intel ICH watchdog interrupt timer 34.Sh SYNOPSIS 35To compile this driver into the kernel, 36place the following line in your 37kernel configuration file: 38.Bd -ragged -offset indent 39.Cd "device ichwd" 40.Ed 41.Pp 42Alternatively, to load the driver as a 43module at boot time, place the following line in 44.Xr loader.conf 5 : 45.Bd -literal -offset indent 46ichwd_load="YES" 47.Ed 48.Sh DESCRIPTION 49The 50.Nm 51driver provides 52.Xr watchdog 4 53support for the watchdog interrupt timer present on 54all Intel ICH motherboard chipsets. 55.Pp 56The ICH WDT counts down in ticks of approximately 0.6 seconds; the 57exact value depends on hardware quality and environmental factors. 58Supported watchdog intervals range from 2 to 63 ticks. 59.Pp 60Note that on some ICH-based systems, the WDT may be present but 61disabled, either in hardware or by the BIOS. 62The 63.Nm 64driver attempts to detect this condition and will refuse to attach if 65it believes the WDT is disabled. 66.Sh SEE ALSO 67.Xr watchdog 4 , 68.Xr watchdog 8 , 69.Xr watchdogd 8 , 70.Xr watchdog 9 71.Rs 72.%T Using the Intel ICH Family Watchdog Timer (WDT) 73.%R Intel Application Note AP-725 74.%O Document Number 292273-001 75.Re 76.Sh HISTORY 77The 78.Nm 79driver first appeared in 80.Fx 5.3 . 81.Sh AUTHORS 82.An -nosplit 83The 84.Nm 85driver was written by 86.An Wm. Daryl Hawkins Aq dhawkins@tamu.edu 87of Texas A&M University and 88.An Dag-Erling Sm\(/orgrav Aq des@FreeBSD.org . 89This manual page was written by 90.An Dag-Erling Sm\(/orgrav Aq des@FreeBSD.org . 91