From 2a1cf374b394acd2f579c47cc5a92b69e4d91b40 Mon Sep 17 00:00:00 2001
From: Joris van Rantwijk <joris@jorisvr.nl>
Date: Thu, 5 Feb 2026 22:26:10 +0100
Subject: [PATCH] Use static NTP server configuration

Ignore NTP servers provided via DHCP.
Enable real-time scheduling for Chrony.
---
 sw/buildroot_overlay/etc/chrony.conf          |  5 ++--
 sw/buildroot_overlay/etc/chrony_dhcp.conf     |  0
 .../udhcpc/default.script.d/ntp_chrony.script | 29 -------------------
 3 files changed, 3 insertions(+), 31 deletions(-)
 delete mode 100644 sw/buildroot_overlay/etc/chrony_dhcp.conf
 delete mode 100755 sw/buildroot_overlay/usr/share/udhcpc/default.script.d/ntp_chrony.script

diff --git a/sw/buildroot_overlay/etc/chrony.conf b/sw/buildroot_overlay/etc/chrony.conf
index 5eb2b54..213ebfd 100644
--- a/sw/buildroot_overlay/etc/chrony.conf
+++ b/sw/buildroot_overlay/etc/chrony.conf
@@ -1,3 +1,4 @@
-include /etc/chrony_dhcp.conf
-pool pool.ntp.org iburst
+sourcedir /etc/chrony/sources.d
 makestep 0.1 3
+sched_priority 1
+cmdport 0
diff --git a/sw/buildroot_overlay/etc/chrony_dhcp.conf b/sw/buildroot_overlay/etc/chrony_dhcp.conf
deleted file mode 100644
index e69de29..0000000
diff --git a/sw/buildroot_overlay/usr/share/udhcpc/default.script.d/ntp_chrony.script b/sw/buildroot_overlay/usr/share/udhcpc/default.script.d/ntp_chrony.script
deleted file mode 100755
index 46e75ef..0000000
--- a/sw/buildroot_overlay/usr/share/udhcpc/default.script.d/ntp_chrony.script
+++ /dev/null
@@ -1,29 +0,0 @@
-#!/bin/sh
-#
-# Configure chrony to use NTP server advertised by DHCP server.
-#
-
-configure_ntp() {
-
-    # Do nothing if the DHCP server does not advertise any NTP server.
-    [ -z "$ntpsrv" ] && return
-
-    # Write config snippet with NTP servers.
-    for srv in $ntpsrv ; do
-        echo "server $srv iburst"
-    done > /etc/chrony_dhcp.conf.new
-
-    # Compare to currently configured NTP servers.
-    if ! diff -q /etc/chrony_dhcp.conf /etc/chrony_dhcp.conf.new >/dev/null ; then
-        # Update configuration and restart Chrony.
-        mv /etc/chrony_dhcp.conf.new /etc/chrony_dhcp.conf
-        /etc/init.d/S49chrony reload
-    fi
-}
-
-case "$1" in
-    renew|bound)
-        configure_ntp
-        ;;
-esac
-