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Re: [gpsd-dev] GPSd on FreeBSD

From: Hal Murray
Subject: Re: [gpsd-dev] GPSd on FreeBSD
Date: Tue, 10 Sep 2019 22:16:00 -0700

address@hidden said:
>> The stock FreeBSD kernel doesn't include PPS support.
> Why do you say that? 

Because I tried to use PPS on a FreeBSD/amd64 system and it didn't work and it 
started working after I built a kernel with
  include GENERIC
  options PPS_SYNC

>From kern/kern_ntptime.c
  #ifdef PPS_SYNC
  FEATURE(pps_sync, "Support usage of external PPS signal by kernel PLL");


Thanks for the poke.  Looks like I'm confusing things.

PPS is ambiguous in this context.  It can refer to either getting a time 
stamp, or to letting the kernel run a PLL that does all the work while ntpd 
just turns it on, then sits off on the side and does sanity checking.

Looks like I was remembering troubles with the kernel PLL.  I don't see any 
#ifdefs in the timestamp or ioctl area and the "kernel PLL" above is 

These are my opinions.  I hate spam.

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