TOD clock synchronization with NTP

[Till Straumann]

I'm thinking about how the RTEMS TOD clock could
be kept synchronous with NTP. Without ever
going back in time, of course. The best idea I
had so far, is introducing a 'slip_ticks' variable
that gets set by the NTP client thread if the local
clock needs to be adjusted backwards.
_TOD_Tickle_ticks() would then, once in a while,
decrement 'slip_ticks' and return without doing
nothing.

A better solution would be an adjustable hardware
clock rate but that's hardly portable.

Any other ideas?

-- Till