Re: Timekeeping problem in /usr/src on new RPI aarch64 snapshot

On Sat, Feb 25, 2023 at 12:21:09AM +0100, Ronald Klop wrote:
> 
> UFS stores the current timestamp in the superblock of the FS on clean
> shutdown/unmount. On boot it reads the time from the timestamp in the
> superblock of the root FS. Of coarse this timestamp is behind for the
> duration that the machine was off or rebooting so you need to adjust that
> using ntp. For ZFS root you can use the fakertc port to do something
> similar.
> 
> 
Mark Millard points out:
     /etc/localtime        Current zoneinfo file, see tzsetup(8) and zic(8).

     /etc/wall_cmos_clock  Empty file.  Its presence indicates that the
                           machine's CMOS clock is set to local time, while
                           its absence indicates a UTC CMOS clock.

Since there is no /etc/wall_cmos_clock on the newly-installed filesystem
it appears the superblock timestamp is then interpreted as UTC when a Pi
boots, using whatever happens to be set in /etc/localtime. My confusion
is reduced somewhat. On first boot, what is the state of /etc/localtime?

I've neglected to run tzsetup immediately on many previous installations
and not noticed any complaints about mis-set clocks in buildworld. Is this
new behavior?

Thanks to both Mark and Ronald!

bob prohaska