chrony: Versatile implementation of NTP

chrony is an alternative to ntpd.  In particular it may be useful
for quasi-realtime embedded systems that have a pulse-per-second
time reference available and need to rapidly synchronize to it after
boot, which appears to be unachievable with ntpd.

Signed-off-by: Henry Hallam <henry@pericynthion.org>
Reviewed-by: Koen Kooi <koen@dominion.thruhere.net>
Signed-off-by: Joe MacDonald <joe_macdonald@mentor.com>

1 files changed, 44 insertions, 0 deletions

diff --git a/meta-networking/recipes-support/chrony/chrony/chrony.conf b/meta-networking/recipes-support/chrony/chrony/chrony.conf
new file mode 100644
index 0000000000..8d226d31a5
--- /dev/null
+++ b/meta-networking/recipes-support/chrony/chrony/chrony.conf
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+# Use public NTP servers from the pool.ntp.org project.
+# Please consider joining the pool project if possible by running your own
+# server(s).
+# If you are a vendor distributing a product using chrony, you *MUST*
+# read and comply with http://www.pool.ntp.org/vendors.html
+pool 0.openembedded.pool.ntp.org iburst
+
+# Use a local timeserver in preference to the pool, if it's reachable.
+#server 192.168.22.22 iburst minpoll 2 prefer
+
+# Sync to pulse-per-second from an onboard GPS.
+#refclock PPS /dev/pps0 poll 0 prefer
+# You'll want to enable CONFIG_PPS and CONFIG_PPS_CLIENT_GPIO in your kernel,
+# and an entry something like this in your device tree:
+#	pps {
+#		compatible = "pps-gpio";
+#		gpios = <&ps7_gpio_0 56 0>;
+#	};
+
+# In first three updates step the system clock instead of slew
+# if the adjustment is larger than 1 second.
+makestep 1.0 3
+
+# Record the rate at which the system clock gains/loses time,
+# improving accuracy after reboot
+driftfile /var/lib/chrony/drift
+
+# Enable kernel synchronization of the hardware real-time clock (RTC).
+rtcsync
+
+# Allow NTP client access from local network.
+#allow 192.168/16
+
+# Serve time even if not synchronized to any NTP server.
+#local stratum 10
+
+# Specify file containing keys for NTP authentication.
+#keyfile /etc/chrony.keys
+
+# Specify directory for log files.
+logdir /var/log/chrony
+
+# Select which information is logged.
+#log measurements statistics tracking