chrony bbappend: install config and patch for enable gpsd support

Example configuration for getting time from gnss signal provided
by gpsd (SHM 0) and NTP.

Chrony confilcts with others NTP daemons.

BugzID: 52095

Signed-off-by: Ramon Moesching <ramon.moesching@netmodule.com>

recipes-support/chrony/chrony_%.bbappend

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+# Copyright (C) 2020 Ramon Moesching <ramon.moesching@netmodule.com>
+# Released under the MIT license (see COPYING.MIT for the terms)
+FILESEXTRAPATHS_prepend:= "${THISDIR}/files:"
+
+# chrony needs continuously running nmea stream and for
+# thus gpsd daemon needs to start with -n paramteter.
+# Patching at installation time gpsd configuration file
+# to apply this parameter
+pkg_postinst_${PN}_prepend () {
+
+	GPSD_CONF=$D${sysconfdir}/default/gpsd.default
+	GPSD_OPS=$(awk /GPSD_OPTIONS/ "$GPSD_CONF" )
+	GPSD_OPSPARAM=$(echo "$GPSD_OPS" | awk /-n/)
+
+	if [ -e "$GPSD_CONF" ]; then
+		if [ -z  "$GPSD_OPSPARAM" ]; then
+			GPSD_OPSPARAM="${GPSD_OPS%\"} -n\""
+			sed  -i "s/$GPSD_OPS/$GPSD_OPSPARAM/g" "$GPSD_CONF"
+			echo "Patched $GPSD_CONF with -n"
+		fi
+		echo "Apply -n to GPSD_OPTIONS to use chrony "
+	else
+		echo "GPSD configuration file not at $GPSD_CONF "
+	fi
+
+}

recipes-support/chrony/files/chrony.conf

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+server 0.pool.ntp.org iburst
+server 1.pool.ntp.org iburst
+server 2.pool.ntp.org iburst
+
+#initstepslew 30 0.pool.ntp.org 1.pool.ntp.org 2.pool.ntp.org
+
+refclock SHM 0 poll 1 refid GPS offset 0.0 delay 2 filter 16
+
+
+rtcdevice /dev/rtc
+rtconutc
+
+logchange 0.5
+local stratum 10
+
+logdir /var/log/chrony
+
+keyfile /etc/chrony/chrony.keys
+commandkey 10
+
+dumpdir /var/log/chrony
+driftfile /var/log/chrony/chrony.drift
+
+makestep 10 -1
+maxdistance 3.0
+cmdallow 127.0.0.1