xref: /freebsd/share/man/man4/wdatwd.4 (revision 99aeb219cad9a5a0347ca3ffef963bb614c99eb9)
1.\"-
2.\" Copyright (c) 2022 Tetsuya Uemura <t_uemura@macome.co.jp>
3.\"
4.\" Redistribution and use in source and binary forms, with or without
5.\" modification, are permitted provided that the following conditions
6.\" are met:
7.\" 1. Redistributions of source code must retain the above copyright
8.\"    notice, this list of conditions and the following disclaimer.
9.\" 2. Redistributions in binary form must reproduce the above copyright
10.\"    notice, this list of conditions and the following disclaimer in the
11.\"    documentation and/or other materials provided with the distribution.
12.\"
13.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23.\" SUCH DAMAGE.
24.\"
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