Skip site navigation (1)Skip section navigation (2)

FreeBSD Man Pages

Man Page or Keyword Search:
Man Architecture
Apropos Keyword Search (all sections) Output format
home | help
WATCHDOG(4)	       FreeBSD Kernel Interfaces Manual		   WATCHDOG(4)

NAME
     watchdog -- hardware and software watchdog

SYNOPSIS
     options CPU_ELAN
     options CPU_GEODE
     options SW_WATCHDOG

     #include <sys/watchdog.h>

DESCRIPTION
     The watchdog facility is used for controlling hardware and	software
     watchdogs.

     The interface is through a	device named "/dev/" _PATH_WATCHDOG which
     responds to a single ioctl(2) call, WDIOCPATPAT.

     The call takes a single argument which represents a timeout value speci-
     fied as an	integer	power of two nanoseconds.

     The WD_ACTIVE flag	signals	that the watchdog will be kept from timing out
     from userland, for	instance by the	watchdogd(8) daemon.

     To	disable	the watchdogs, an argument of zero should be used.

     The ioctl(2) call will return success if just one of the available
     watchdog(9) implementations support the request.  If the call fails, for
     instance if none of watchdog(9) implementations support the timeout
     length, all watchdogs are disabled	and must be explicitly re-enabled.

EXAMPLES
	   u_int u = WD_ACTIVE | WD_TO_8SEC;
	   int fd = open("/dev/" _PATH_WATCHDOG, O_RDWR);

	   ioctl(fd, WDIOCPATPAT, &u);

SEE ALSO
     watchdogd(8), watchdog(9)

HISTORY
     The watchdog code first appeared in FreeBSD 5.1.

AUTHORS
     The watchdog facility was written by Poul-Henning Kamp <phk@FreeBSD.org>.
     The software watchdog code	and this manual	page were written by Sean
     Kelly <smkelly@FreeBSD.org>.  Some	contributions were made	by Jeff
     Roberson <jeff@FreeBSD.org>.

FreeBSD	10.1			 June 25, 2003			  FreeBSD 10.1

NAME | SYNOPSIS | DESCRIPTION | EXAMPLES | SEE ALSO | HISTORY | AUTHORS

Want to link to this manual page? Use this URL:
<https://www.freebsd.org/cgi/man.cgi?query=watchdog&sektion=4&manpath=FreeBSD+5.4-RELEASE>

home | help