On Wed, Jan 10, 2018 at 01:23:19PM -0000, Christian Weisgerber wrote:
> On 2018-01-10, Maximilian Pichler <maxim.pich...@gmail.com> wrote:
>
> > * At boot the software clock (the value returned by gettimeofday) is
> > initialized from the hardware clock (the one with the coin-shaped
> > battery).
>
> ... from the RTC ("real-time clock"), yes.
>
> > My question is: Can OpenBSD be told initialize the software from the
> > hardware clock again after the system is booted?
>
> No.
>
This does occur on occasion; for example, when running an OpenBSD vmm(4)
guest, vmd(8) will notify the guest to resynch the clock from the RTC
after the host resumes from suspend/hibernate (actually, "any time
the host clock varies from more than 5s since it was last read by vmd(8"),
but that practically means "only during suspend/hibernate resumes").
If the OP was looking for code to do this for whatever reason, it's done
via vmmci(4).
-ml
> > (Also, is the hardware clock ever modified aside from explicit
> > invocations of date(1) or similar?)
>
> Yes,
> * when the system is properly shut down, and
> * periodically every 30 minutes, to prevent the RTC from drifting
> off during long uptimes.
>
> --
> Christian "naddy" Weisgerber na...@mips.inka.de
>
