swwdog(4) [netbsd man page]

SWWDOG(4)						   BSD Kernel Interfaces Manual 						 SWWDOG(4)

NAME

     swwdog -- software watchdog timer

SYNOPSIS

     pseudo-device swwdog

DESCRIPTION

     The swwdog driver provides a software watchdog timer that works with wdogctl(8).  If the timer expires, the system reboots if the boolean
     variable swwdog_reboot is true; otherwise, the system will panic.	swwdog_reboot is accessible as a sysctl(8) variable, hw.swwdog.reboot and
     defaults to false.

     The default period of swwdog is 60 seconds.

     As with other watchdog timers, the swwdog driver prevents a system from suspending when the watchdog is armed.

SEE ALSO

     sysctl(8), wdogctl(8)

HISTORY

     The swwdog driver was written by Steven M. Bellovin.

BUGS

     Only one watchdog timer can be active at any given time.  (Arguably, this is a bug in the watchdog timer framework.)  Therefore, only a sin-
     gle instance of the swwdog device can be created.

     Kernel tickle mode is useless with swwdog and arguably should be rejected, since both it and this driver rely on the same callout mechanism;
     if one is blocked, almost certainly the other is as well.

     The alarm option to wdogctl(8) isn't implemented.

BSD
								   June 8, 2011 							       BSD

ICHWD(4)						   BSD Kernel Interfaces Manual 						  ICHWD(4)

NAME

     ichwd -- device driver for the Intel ICH watchdog interrupt timer

SYNOPSIS

     To compile this driver into the kernel, place the following line in your kernel configuration file:

	   device ichwd

     Alternatively, to load the driver as a module at boot time, place the following line in loader.conf(5):

	   ichwd_load="YES"

DESCRIPTION

     The ichwd driver provides watchdog(4) support for the watchdog interrupt timer present on all Intel ICH motherboard chipsets.

     The ICH WDT counts down in ticks of approximately 0.6 seconds; the exact value depends on hardware quality and environmental factors.  Sup-
     ported watchdog intervals range from 2 to 63 ticks.

     Note that on some ICH-based systems, the WDT may be present but disabled, either in hardware or by the BIOS.  The ichwd driver attempts to
     detect this condition and will refuse to attach if it believes the WDT is disabled.

SEE ALSO

     watchdog(4), watchdog(8), watchdogd(8), watchdog(9)

     Using the Intel ICH Family Watchdog Timer (WDT), Intel Application Note AP-725, Document Number 292273-001.

HISTORY

     The ichwd driver first appeared in FreeBSD 5.3.

AUTHORS

     The ichwd driver was written by Wm. Daryl Hawkins <dhawkins@tamu.edu> of Texas A&M University and Dag-Erling Smorgrav <des@FreeBSD.org>.
     This manual page was written by Dag-Erling Smorgrav <des@FreeBSD.org>.

BSD
								  August 20, 2008							       BSD