Help needed to configure and compile gpsd to run on a Raspberry Pi 4 and NOT use systemd

[Mick Durkin]

Hi All,

First, some background.
=======================

My son wanted to have a timeserver on his internal network, so he
decided to go down the path of using a ublox type GPS module with a
serial interface and a PPS signal driving gpsd on a Raspberry Pi 4.

He installed the latest version of Raspbian and followed the
instructions in one of many YouTube tutorials
(https://youtu.be/7aTZ66ZL6Dk?si=4t6ErNw4Stdc6W4I) and successfully
got Chrony to supply time for him. All the tutorials online seem to go
down the same road and use the dreaded systemd. However, this means
electrically things are connected correctly and the Pi's configuration
(e.g. activating the UART and setting up the PPS pin) is good.

He then contacted me and told me what he had been able to do. As a
long time gpsd user (I have been tinkering with gpsd since about 2005,
when I wrote myself a driver for my Jupiter-T module and have made
minor contributions to the codebase over the years), I was not happy
that he was running gpsd under systemd. I pointed him to Gary's many
posts exhorting users not to use systemd with gpsd, but rather to
install cleanly from the source.

I am quite happy going down this path, so I persuaded him that this is
the way to go. I also said we might install NTPsec (from source)
rather than Chrony.



Now to the heart of my query.
=============================

Having never compiled gpsd for the Raspberry Pi, I dug into the
SConscript file to look at the "boolopts" table to see if there was
anything relevant.

The first area that seemed relevant was the "Export methods" section.
"shm_export" was set "True", so time can be sent to NTPsec, as we
want.

In "Other daemon options" "systemd" was set to "systemd". I wonder if
this should be changed to "False" if we don't want any systemd
"pollution"?

In "Build control" the "magic_hat" parameter had me mystified. As we
are using simple serial data + PPS into the Pi's UART port, we don't
have a hat. Should this be set to "False"?
Also, I think the "timeservice" flag should be changed to "True". The
instructions at
https://gpsd.gitlab.io/gpsd/gpsd-time-service-howto.html say "If you
do not use timeservice=yes, then make sure the build is with pps=yes
and ntpshm=yes (the defaults)." However, there does not seem to be
either a "pps" parameter or an "ntpshm" parameter in the latest code.
It might be the online document is out of date and I should simply set
"timeservice" to be "True"?


I would be grateful if members of the list could clarify these points for me.

BR

Mick