ICHWD(4FREEBSD) - man page online | special files

Device driver for the Intel ICH watchdog interrupt timer.

August 20, 2008
ICHWD(4)                           BSD Kernel Interfaces Manual                          ICHWD(4)


ichwd — device driver for the Intel ICH watchdog interrupt timer


To compile this driver into the kernel, place the following line in your kernel configura‐ tion 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"


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. Supported 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.


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.


The ichwd driver first appeared in FreeBSD 5.3.


The ichwd driver was written by Wm. Daryl Hawkins <> of Texas A&M Univer‐ sity and Dag-Erling Smørgrav <>. This manual page was written by Dag-Erling Smørgrav <>.
BSD August 20, 2008 BSD
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ichwd(4freebsd) referred by
refer to watchdog(4freebsd) | watchdog(8) | watchdog(9freebsd)