Here is what I did to get it to work:

http://www.febo.com/pipermail/time-nuts/2008-August/032726.html
http://www.febo.com/pipermail/time-nuts/2008-August/033106.html
http://www.febo.com/pipermail/time-nuts/2008-August/032803.html

I have a better patch for leap seconds that actually works correctly but have not had a chance to post it yet.

You need to make sure your kernel has the sysvshm option:
options         SYSVSHM                 # SYSV-style shared memory

then finally make sure that ntpd was compiled to support the SHM refclock.

I have a couple of thunderbolts working with net4501s using the TMR1IN
mod:  http://www.febo.com/pages/soekris/

I used a TAPR fatpps to stretch the pulse so the net4501 would be happy.

I start gpsd before ntpd

ntp.conf has:
server 127.127.28.0 minpoll 4 maxpoll 4 prefer
fudge 127.127.28.0 time1 -0.017 refid GPS

server 127.127.22.0 minpoll 4 maxpoll 4

tos mindist 0.050


        Scott

On 04/30/2009 08:50 PM, John Murphy wrote:
I'm trying to configure ntpd (4.2.4p5-a FreeBSD-7.1) to use the
shared memory driver to which gpsd should be writing timestamps.
All looks good on the gpsd side, after building it for 8N1, as
I can see what looks like ntpshm writing to shared memory:

gpsd: TSIP pkt_id = 0x41, packetlen= 14
gpsd: TSIP packet id 0x41 length 10: 48cf974905f941700000
gpsd: ntpshm_put: Clock: 1241129131 @ 1241129132.166348
gpsd: GPS Time 425146.281250 1529 15.000000

But, with ntp.conf entries like:

tos mindist 0.010
server 127.127.28.0 minpoll 4 maxpoll 4
fudge 127.127.28.0 time1 0.420 refid GPS
server 127.127.22.0 minpoll 4 maxpoll 4

The log shows:

ntpd 4.2.4p5-a Thu Jan  1 09:59:32 UTC 2009 (1)
refclock_newpeer: clock type 28 invalid
configuration of 127.127.28.0 failed

I'm also using the PPS output of the Thunderbolt, hence the
127.127.22.0 entry, and the 10MHz up converted to 33.333333MHz
for the soekris net4501 CPU clock. Both of those working well.

Do I need to initiate the shared memory some how? I feel I may
have missed something vital, which may be obvious to someone.


_______________________________________________
time-nuts mailing list -- [email protected]
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Reply via email to