[ntp:questions] Implementing NTP in a legacy system

Chuck Swiger cswiger at mac.com
Wed Dec 12 18:45:51 UTC 2012

Hi, Andreas--

On Dec 12, 2012, at 10:12 AM, andreas.ames at de.transport.bombardier.com wrote:
[ ... ]
>> If you would be more forthcoming, people could probably give better
>> advice. 
> What I'm looking for is an API/other interface in NTPD to attach to a
> currently non-supported reference clock (most probably by writing the
> needed adapter code).  And this (adapted) NTPD shall run on the
> gateway device to feed the ntp clients in the new subsystem. 

There's a generic shared memory driver for NTPD documented here:


Using this API is probably the easiest way to get time from some
non-supported timesource into NTPD.  You can take a look at gpsd
as an example of how to populate and update the SHM time.

However, if you want to investigate writing a refclock driver, try:



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