102 lines
3.0 KiB
Groff
102 lines
3.0 KiB
Groff
.\" Copyright (c) 2004 Poul-Henning Kamp <phk@FreeBSD.org>
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.\" Copyright (c) 2003, 2004 Sean M. Kelly <smkelly@FreeBSD.org>
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.\" All rights reserved.
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.\"
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.\" Redistribution and use in source and binary forms, with or without
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.\" modification, are permitted provided that the following conditions
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.\" are met:
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.\" 1. Redistributions of source code must retain the above copyright
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.\" notice, this list of conditions and the following disclaimer.
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" notice, this list of conditions and the following disclaimer in the
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.\" documentation and/or other materials provided with the distribution.
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.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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.\" SUCH DAMAGE.
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.\"
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.\" $FreeBSD$
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.\"
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.Dd June 25, 2003
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.Dt WATCHDOG 4
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.Os
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.Sh NAME
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.Nm watchdog
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.Nd "hardware and software watchdog"
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.Sh SYNOPSIS
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.Cd "options CPU_ELAN"
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.Cd "options CPU_GEODE"
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.Cd "options SW_WATCHDOG"
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.Pp
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.In sys/watchdog.h
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.Sh DESCRIPTION
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The
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.Nm
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facility is used for controlling hardware and software watchdogs.
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.Pp
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The interface is through a device
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.Pa /dev/fido
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which responds to a single
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.Xr ioctl 2
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call,
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.Dv WDIOCPATPAT .
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.Pp
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The call takes a single argument which represents a timeout value
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specified as an integer power of two nanoseconds.
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.Pp
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The
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.Dv WD_ACTIVE
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flag signals that the
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.Nm
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will be kept from
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timing out from userland, for instance by the
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.Xr watchdogd 8
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daemon.
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.Pp
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To disable the watchdogs, an argument of zero should be used.
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.Pp
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The
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.Xr ioctl 2
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call will return success if just one of the available
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.Xr watchdog 9
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implementations support the request.
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If the call fails, for instance if none of
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.Xr watchdog 9
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implementations support the timeout
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length, all watchdogs are disabled and must be explicitly re-enabled.
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.Sh EXAMPLES
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.\" XXX insert some descriptive text here
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.Bd -literal -offset indent
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u_int u = WD_ACTIVE | WD_TO_8SEC;
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int fd = open("/dev/fido", O_RDWR);
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ioctl(fd, WDIOCPATPAT, &u);
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.Ed
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.Sh SEE ALSO
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.Xr watchdogd 8 ,
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.Xr watchdog 9
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.Sh HISTORY
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The
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.Nm
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code first appeared in
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.Fx 5.1 .
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.Sh AUTHORS
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.An -nosplit
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The
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.Nm
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facility was written by
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.An Poul-Henning Kamp Aq phk@FreeBSD.org .
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The software watchdog code
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and this manual page were written by
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.An Sean Kelly Aq smkelly@FreeBSD.org .
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Some contributions were made by
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.An Jeff Roberson Aq jeff@FreeBSD.org .
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