Copyright (c) 2007 Dag-Erling Coïdan Smørgrav
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/or other materials provided with the distribution.
THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
SUCH DAMAGE.
$FreeBSD$
.Dd August 20, 2008 .Dt ICHWD 4 .Os .Sh NAME .Nm ichwd .Nd device driver for the Intel ICH watchdog interrupt timer .Sh SYNOPSIS To compile this driver into the kernel, place the following line in your kernel configuration file: d -ragged -offset indent .Cd "device ichwd" .Ed
p Alternatively, to load the driver as a module at boot time, place the following line in .Xr loader.conf 5 : d -literal -offset indent ichwd_load="YES" .Ed .Sh DESCRIPTION The .Nm driver provides .Xr watchdog 4 support for the watchdog interrupt timer present on all Intel ICH motherboard chipsets.
p The ICH WDT counts down in ticks of approximately 0.6 seconds; the exact value depends on hardware quality and environmental factors. Supported watchdog intervals range from 2 to 63 ticks.
p Note that on some ICH-based systems, the WDT may be present but disabled, either in hardware or by the BIOS. The .Nm driver attempts to detect this condition and will refuse to attach if it believes the WDT is disabled. .Sh SEE ALSO .Xr watchdog 4 , .Xr watchdog 8 , .Xr watchdogd 8 , .Xr watchdog 9 .Rs .%T Using the Intel ICH Family Watchdog Timer (WDT) .%R Intel Application Note AP-725 .%O Document Number 292273-001 .Re .Sh HISTORY The .Nm driver first appeared in .Fx 5.3 . .Sh AUTHORS .An -nosplit The .Nm driver was written by .An Wm. Daryl Hawkins Aq Mt dhawkins@tamu.edu of Texas A&M University and .An Dag-Erling Sm\(/orgrav Aq Mt des@FreeBSD.org . This manual page was written by .An Dag-Erling Sm\(/orgrav Aq Mt des@FreeBSD.org .