In case you have some code ready for testing, the multi-clock MR [1]
now has a "clock" option in the refclock directive to specify the
target clock (by default it's the main system clock).
No code yet. Been busy getting 0.2 out the door.
For a direct synchronization of the PHC on eth0 using a SOCK refclock
chronyd can be configured like this:
clock PHC:eth0 main
refclock SOCK /var/run/refclock.sock clock PHC:eth0 poll 0
It seems to be working nicely with ptp4l as a SOCK source (clock_servo
set to refclock_sock).
This is very interesting. So the PHC-based refclock_sock output you were suggesting for SatPulse would be the same format as ptp4l produces with clock_servo as refclock_sock? That would be nicely uniform.
I am wondering whether using PHC as the main clock could result in more accurate time being served to clients compared to using the system clock as the main clock, assuming you had PHC-based refclock_sock input from SatPulse, hardware timestamping and no PTM, since you wouldn't have the inaccuracy from translating between PHC and system clocks.
James