[ntp:questions] Simulate PPS devices

Maximilian Brehm maximilian.brehm at tu-ilmenau.de
Thu Apr 10 13:26:52 UTC 2014


so, I wrote a program to communicate with NTP via the shared
memory driver. It currently uses CLOCK_REALTIME and CLOCK_MONOTONIC to
simulate an offset and NTP wanders there correctly. 

Now I would like
to include support for PPS. I found gpsd (http://gpsd.berlios.de/) and
shmpps (thanks to William Unruh,
http://pkgs.fedoraproject.org/cgit/shmpps.git/) for reference. As far as
I see they both rely on hardware devices and connections via serial or
parallel port or USB. I also found an interesting hack of shmpps using
/dev/rtc at http://www.wraith.sf.ca.us/ntp/#parallel-port. As mentioned
in previous emails, I need the PPS signal to be simulated by analyzing
the timestamps of a packet stream from a reference system in a
destination system. The programs mentioned above use the Kernel-PPS
interface which relies on devices as far as I can see. So do you know a
proper way to approach this? Could I simulate a device similar to
/dev/rtc and make use of the hack? 

Is this still the correct mailing
list for this purpose? 




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