/share/man/man4/ichwd.4

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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 .