wbwd — device driver for Winbond/Nuvoton Super I/O chips watchdog timer

       This manual page was written by Bjoern A. Zeeb <bz@FreeBSD.org>.

Debian                                          October 16, 2019                                         WBWD(4)

       The  wbwd  driver  provides  watchdog(4) support for the watchdog interrupt timer present on at least the
       following Super I/O chips:
       •   Winbond 83627HF/F/HG/G
       •   Winbond 83627S
       •   Winbond 83697HF
       •   Winbond 83697UG
       •   Winbond 83637HF
       •   Winbond 83627THF
       •   Winbond 83687THF
       •   Winbond 83627EHF
       •   Winbond 83627DHG
       •   Winbond 83627UHG
       •   Winbond 83667HG
       •   Winbond 83627DHG-P
       •   Winbond 83667HG-B
       •   Nuvoton NCT6775
       •   Nuvoton NCT6776
       •   Nuvoton NCT6102
       •   Nuvoton NCT6779
       •   Nuvoton NCT6791
       •   Nuvoton NCT6792

       The wbwd driver first appeared in FreeBSD 10.0.

       wbwd — device driver for Winbond/Nuvoton Super I/O chips watchdog timer

superio(4) watchdog(4), device.hints(5), watchdog(8), watchdogd(8), watchdog(9)

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

             devicesuperiodevicewbwd

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

             wbwd_load="YES"

       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.

       dev.wbwd.0.debug
               This read-only value gives the state of some registers on last update.

       The wbwd driver also provides further sysctl options that are hidden by default.  See the source code for
       more information.