[gpsd-dev] [PATCH] Time Service HOWTO: Clarify state of RFC2783 on NetBSD.

[Greg Troxel]

Note that RFC2783 support on serial is ancient, and works with ntpd,
but that gpsd's PPS code does not work with it.   Note the addition of
USB-serial RFC2783 support in NetBSD 7.

Add a missing "Linux" qualifier in discussion of Linux KPPS.
---
 www/gpsd-time-service-howto.txt | 21 ++++++++++++++-------
 1 file changed, 14 insertions(+), 7 deletions(-)

diff --git a/www/gpsd-time-service-howto.txt b/www/gpsd-time-service-howto.txt
index d66ffbb..18853b0 100644
--- a/www/gpsd-time-service-howto.txt
+++ b/www/gpsd-time-service-howto.txt
@@ -265,11 +265,12 @@ sources, make sure the build is with pps=yes and 
ntpshm=yes (the
 default).  The command "gpsd -L" should indicate that
 time-service features and PPS are enabled.
 
-If your kernel provides the RFC 2783 KPPS (kernel PPS) API, gpsd will
-use that for extra accuracy. Many Linux distributions have a package
-called "pps-tools" that will install KPPS support and the time_pps.h
-header file.  We recommend you do that.  If your kernel is built in
-the normal modular way, this package installation will suffice.
+If your Linux kernel provides the RFC 2783 KPPS (kernel PPS) API, gpsd
+will use that for extra accuracy. Many Linux distributions have a
+package called "pps-tools" that will install KPPS support and the
+time_pps.h header file.  We recommend you do that.  If your kernel is
+built in the normal modular way, this package installation will
+suffice.
 
 If you are scratch-building a Linux kernel, the configuration 
 must include either these two lines, or the same with "y" replaced
@@ -286,10 +287,16 @@ kernel).  This will have a list of the configuration 
options that were
 used to build the kernel.  You can check if the above options are
 set. Usually they will be set to "m", which is sufficient.
 
+NetBSD has included the RFC2783 Pulse Per Second API for real serial
+ports by default since before 2000, and it works with ntpd.  NetBSD 7
+(forthcoming) includes RFC2783 support for USB-serial devices, and
+this works with the GR601-W.  However, gpsd's code appears to rely on
+behavior beyond the standard, and gpsd RFC2783 PPS does not work on
+NetBSD (for serial or USB).
+
 Other OSes have different ways to enable KPPS in their kernels.
 When we learn what those are, we'll document them or point
-at references.  We can say that versions of NetBSD shipped after
-Juky 25 2014 have PPS support that is known to work with GPSD.
+at references.
 
 You will need to have either ntpd or chrony installed. If you are
 running a Unix variant with a package system, the packages will
-- 
1.9.4