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WBWD(4) FreeBSD Kernel Interfaces Manual WBWD(4)
NAME
wbwd - device driver for Winbond/Nuvoton Super I/O chips watchdog timer
SYNOPSIS
To compile this driver into the kernel, place the following lines in your
kernel configuration file:
device superio
device wbwd
Alternatively, to load the driver as a module at boot time, place the
following line in loader.conf(5):
wbwd_load="YES"
DESCRIPTION
The wbwd driver provides watchdog(4) support for the watchdog interrupt
timer present on at least the following Super I/O chips:
o Winbond 83627HF/F/HG/G
o Winbond 83627S
o Winbond 83697HF
o Winbond 83697UG
o Winbond 83637HF
o Winbond 83627THF
o Winbond 83687THF
o Winbond 83627EHF
o Winbond 83627DHG
o Winbond 83627UHG
o Winbond 83667HG
o Winbond 83627DHG-P
o Winbond 83667HG-B
o Nuvoton NCT6775
o Nuvoton NCT6776
o Nuvoton NCT6102
o Nuvoton NCT6779
o Nuvoton NCT6791
o Nuvoton NCT6792
SYSCTL VARIABLES
The wbwd driver provides the following options as sysctl(8) variables.
dev.wbwd.0.timeout_override
This variable allows to program the timer to a value independent
on the one provided by the watchdog(4) framework while still
relying on the regular updates from e.g. watchdogd(8). This is
particularly useful if your system provides multiple watchdogs
and you want them to fire in a special sequence to trigger an NMI
after a shorter period than the reset timeout for example. The
value set must not be lower than the sleep time of watchdogd(8).
A value of 0 disables this feature and the timeout value provided
by watchdog(4) will be used.
dev.wbwd.0.debug_verbose
If set this sysctl will tell the driver to log its current state
before and after the timer reset on each invocation from
watchdog(9) to the kernel message buffer for debugging.
SEE ALSO
superio(4), watchdog(4), device.hints(5), watchdog(8), watchdogd(8),
watchdog(9)
HISTORY
The wbwd driver first appeared in FreeBSD 10.0.
AUTHORS
This manual page was written by Bjoern A. Zeeb <bz@FreeBSD.org>.
FreeBSD 14.0-RELEASE-p6 October 16, 2019 FreeBSD 14.0-RELEASE-p6