Recommendation on chrony with 1pps

Hello,

What's the recommended way to use 1pps signals with chrony? I have two
options here:

1. I have a specialized Solarflare card that has a 1pps receiver on the
card itself and comes with sfptpd (PTP daemon for Solarflare cards and that
has support for chrony). So, I could run sfptpd (for 1pps) side-by-side
with chrony (for time of day).
2. Specify /dev/ppsX as a 1pps source in chrony configs and mention a ref
clock for time of day. Additional question here: Is it possible to specify
another NTP server (strat 1) as a ref clock here? Asking since the examples
are all targeted towards GPS ref clocks. If that's possible, could you
provide a sample config as well?

Additionally, for #2 above, do I have to recompile chrony from source with
additional arguments? I remember reading somewhere that by default chrony
doesn't support PPS. Alternatively, if it's possible to identify this via
something like `chronyd --version`, please let me know as well.


Thanks,
Abhijith