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33 .Nd device driver for Winbond/Nuvoton Super I/O chips watchdog timer
35 To compile this driver into the kernel, place the following line in your
36 kernel configuration file:
37 .Bd -ragged -offset indent
41 Alternatively, to load the driver as a module at boot time, place the following
44 .Bd -literal -offset indent
52 support for the watchdog interrupt timer present on at least the following
56 Winbond 83627HF/F/HG/G
95 Driver may be forced to attach to unknown chips by adding to
96 .Pa /boot/device.hints :
97 .Cd hint.wbwd.0.at="isa"
101 driver provides the following options as
104 .Bl -tag -width "xxxxxx"
105 .It Va dev.wbwd.0.timeout_override
106 This variable allows to program the timer to a value independent on the one
109 framework while still relying on the regular updates from e.g.
111 This is particularly useful if your system provides multiple watchdogs and
112 you want them to fire in a special sequence to trigger an NMI after a shorter
113 period than the reset timeout for example.
114 The value set must not be lower than the sleep time of
116 A value of 0 disables this feature and the timeout value provided by
119 .It Va dev.wbwd.0.debug_verbose
120 If set this sysctl will tell the driver to log its current state before and
121 after the timer reset on each invocation from
123 to the kernel message buffer for debugging.
124 .It Va dev.wbwd.0.debug
125 This read-only value gives the state of some registers on last update.
130 driver also provides further sysctl options that are hidden by default.
131 See the source code for more information.
141 driver first appeared in
145 This manual page was written by
146 .An Bjoern A. Zeeb Aq Mt bz@FreeBSD.org .