system info - NetBSD 1.3.3, i386

I've just obtained a WWVB receiver (an Ultralink M320 (www.ulio.com)), and
have started looking into running ntpd using it as the reference clock.

The ntpd distribution doesn't have a specific driver for it, but it's
pretty clear how to add a parse clock entry for it.

My problem is that the receiver also delivers a 1PPS signal to the DCD
pin on the serial port it is connected to, I'd like to use it, and I'm
having trouble figuring out how to enable the kernel support for PPS_SYNC.

Has anyone done this, with any clock, for NetBSD?  In particular, I can't
see in the kernel source where hardpps() ever gets called.  Do I need a
line discipline module or what?  There seems to be no way to tie the
hardpps() routine to the DCD signal on /dev/tty??.

On a slighly more general note, I can see the:

   options         NTP

line in the kernel configuration file, and I assume I can add an:

   options         PPS_SYNC

but I'm a little reluctant to just compile one up and try it without
knowing more about what I'm doing.  Do I need the EXT_CLOCK option as well?

Thanks in advance for any help or hints.

-- 
Tom Rushworth < tbr at acm dot org >