On Wed, Jan 10, 2018 at 6:50 PM, Mike Larkin <mlar...@azathoth.net> wrote: >> > My question is: Can OpenBSD be told initialize the software from the >> > hardware clock again after the system is booted?
> 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). In fact this is precisely the use case I had in mind, except for that instead of inside vmm OpenBSD is running in Virtualbox on Mac OS. The clock seems to drift randomly and is off significantly after suspend/hibernate. Following your hint at vmmci and looking at https://cvsweb.openbsd.org/cgi-bin/cvsweb/src/sys/dev/pv/vmmci.c.diff?r1=1.2&r2=1.3&f=h it looks like inittodr(9) would reinitialize the software clock. However it seems to be available inside the kernel only. Is there no way to do this from userland? Thanks!
