Re: Embedded linux: syncronizing system time w/o onboard HW clock

[Russell King - ARM Linux Admin]

Jim Fischer writes:
> Here's the problem: Once each day, Linux on the EBSA-285 resets the system
> clock back to the epoch date -- i.e., Jan 1, 1970.

Its not supposed to do that.  I don't see anything obvious in the code
that would cause that.  Have you checked the uptime on the machine as well?
Does this reset back to 0 each day?

> My guess is that the
> kernel is attempting to update the system clock based on the hardware clock,
> and since there is no hardware clock, the kernel simply resets the system
> clock to the epoch date/time.

Linux never re-synchronises with the RTC.  Its more the other way around.
If you're running something like NTP, then Linux re-synchronises the RTC
to its idea of time.

> Short of using something like NTP -- which seems excessively complex for
> this situation -- is there any other way to sync the system clock on the
> EBSA with a clock on one of the Win2K / Linux hosts on the LAN?

Look at the timed tools - in.timed.  It is a small server/client which will
synchronise time between machines.  RedHat have a separate .srpm in their
RH7.0 package set that you could use to compile it up (if you don't already
have it).  I'm not sure about Debian though.
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