xref: /freebsd/share/man/man4/wdatwd.4 (revision 783d3ff6d7fae619db8a7990b8a6387de0c677b5)
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25.Dd November 18, 2022
26.Dt WDATWD 4
27.Os
28.Sh NAME
29.Nm wdatwd
30.Nd device driver for the ACPI WDAT based watchdog interrupt timer
31.Sh SYNOPSIS
32To compile this driver into the kernel,
33place the following line in your
34kernel configuration file:
35.Bd -ragged -offset indent
36.Cd "device wdatwd"
37.Ed
38.Pp
39Alternatively, to load the driver as a
40module at boot time, place the following line in
41.Xr loader.conf 5 :
42.Bd -literal -offset indent
43wdatwd_load="YES"
44.Ed
45.Sh DESCRIPTION
46The
47.Nm
48driver provides
49.Xr watchdog 4
50support for the watchdog interrupt timer in ACPI WDAT (Watchdog Action Table).
51.Pp
52Since WDAT itself is an abstraction for the real hardware such as ICH WDT, it
53must be noted that only one driver can be used at a time, either the real
54hardware specific driver or this driver.
55.Sh SYSCTL VARIABLES
56The following read-only
57.Xr sysctl 8
58variables are available:
59.Bl -tag -width indent
60.It Va dev.wdatwd.%d.running
61The status of the watchdog timer. 0 if not running, or 1 if running.
62.It Va dev.wdatwd.%d.timeout
63The current value of the watchdog timeout in millisecond.
64This can be 0 on some systems, and the zero value means that the default
65timeout is used.
66.It Va dev.wdatwd.%d.timeout_configurable
67Whether the timeout is configurable or not.
68It is 0 if configurable or any positive value if not.
69.It Va dev.wdatwd.%d.timeout_default
70The default value of the watchdog timeout in millisecond if any.
71.El
72.Sh SEE ALSO
73.Xr ichwd 4 ,
74.Xr watchdog 4 ,
75.Xr watchdog 8 ,
76.Xr watchdogd 8 ,
77.Xr watchdog 9
78.Rs
79.%T Hardware Watchdog Timers Design Specification
80.%R Requirements for Hardware Watchdog Timers Supported by Microsoft(R) Windows Vista(R) and Microsoft Windows Server(R) 2008 Operating Systems
81.%A Microsoft Corporation
82.%U http://msdn.microsoft.com/en-us/windows/hardware/gg463320.aspx
83.%D 2006
84.Re
85.Sh AUTHORS
86.An -nosplit
87The
88.Nm
89driver was written by
90.An Tetsuya Uemura Aq Mt t_uemura@macome.co.jp
91of MACOME, Corporation.
92