1 .\" Copyright (c) 2004 Poul-Henning Kamp <phk@FreeBSD.org>
2 .\" Copyright (c) 2003, 2004 Sean M. Kelly <smkelly@FreeBSD.org>
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33 .Nd "hardware and software watchdog"
35 .Cd "options CPU_ELAN"
36 .Cd "options CPU_GEODE"
37 .Cd "options SW_WATCHDOG"
43 facility is used for controlling hardware and software watchdogs.
45 The interface is through a device
47 which responds to a single
52 The call takes a single argument which represents a timeout value
53 specified as an integer power of two nanoseconds.
60 timing out from userland, for instance by the
64 To disable the watchdogs, an argument of zero should be used.
68 call will return success if just one of the available
70 implementations support the request.
71 If the call fails, for instance if none of
73 implementations support the timeout
74 length, all watchdogs are disabled and must be explicitly re-enabled.
76 .\" XXX insert some descriptive text here
77 .Bd -literal -offset indent
78 u_int u = WD_ACTIVE | WD_TO_8SEC;
79 int fd = open("/dev/fido", O_RDWR);
81 ioctl(fd, WDIOCPATPAT, &u);
89 code first appeared in
95 facility was written by
96 .An Poul-Henning Kamp Aq phk@FreeBSD.org .
97 The software watchdog code
98 and this manual page were written by
99 .An Sean Kelly Aq smkelly@FreeBSD.org .
100 Some contributions were made by
101 .An Jeff Roberson Aq jeff@FreeBSD.org .