rpi3 clock drift

[Bakul Shah]

On Tue, 26 Nov 2019 22:03:30 +0000 James Shuriff <james at opentech.cc> wrote:
> My Raspberry Pi 3 Model B is having some serious clock drift issues. Ntpd doe
> sn't function even with ntpd_sync_on_start, which calls ntpd with -g and allo
> ws the initial adjustment to exceed the panic threshold. This doesn't help me
>  much because the system will continue to drift very quickly and that option 
> only helps for the initial adjustment.
>
> I was thinking of ordering an I2C RTC but I'm unsure how to make FreeBSD awar
> e of the clock.
>
> There is a file in the Raspberry Pi firmware repo called i2c-rtc.dtbo and it 
> contains defs for clocks like DS1307 so I am assuming I can add this to confi
> g.txt, build U-Boot with CONFIG_RTC_DS1307 (or whatever model), and build the
>  kernel with device support for the clock but I'm not completely sure if I'm 
> going about this the right way. Beyond just getting FreeBSD to see the clock 
> I'm unsure how to tell FreeBSD to use it. Any advice?

Is the clock really drifting or is this due the initial time
being waaay off from the current time due to a lack of RTC? If
the latter do the initial time setup using ntpdate. Add

ntpdate_enable="YES"

to /etc/rc.conf.

If you can already use ntpd, there is not much point in using a local
rtc.