AT Real-Time Clock (RTC) driver
This driver is a mandatory part of i386/amd64 kernels.
The following tunables are settable from the
- controls event timers functionality support. Setting to 0, disables it.
Default value is 1.
- Forces enabling or disabling of the device(s). Setting to 0 disables it,
setting to 1 enables it, bypassing any platform configuration hints.
Default value is -1 (autodetect).
This driver uses RTC hardware to supply kernel with time-of-day clock with 1
second resolution and one event timer. This hardware uses base frequency of
32768Hz for advancing time-of-day clock and generating periodic interrupts.
Interrupts could be generated with fixed number of frequencies, from 2Hz to
8192Hz, obtained by dividing base frequency by one of supported power-of-2
Event timer provided by the driver is irrelevant to CPU power states.