I'm trying to use ntp_adjtime() in nanokernel, but it was clear to me
that what to pass for the tick_update parameter.

nanokernel suggests that ntp_tick_adjust() to be called every tick for
precision time adjustment, so I hook ntp_tick_adjust() to the tick
interrupt function. The question I have now is what parameter to pass
to ntp_tick_adjust().

Here's the signature of ntp_tick_adjust()
void ntp_tick_adjust(struct timespec *tvp, int tick_update)

My question is what tick_update is.
On the source code that I found in nanokernel.tar.gz, I found this:
int tick_update; /* residual from adjtime()

I'm confused. Does that mean I will have to call adjtime() to give me
the residual first?

Thank you very much in advance