Add script to manage calibration file

Also rework the way config files are copied from SD card during boot.

sw/buildroot_overlay/etc/init.d/S03read_config.sh

@@ -0,0 +1,21 @@
+#!/bin/sh
+#
+# Read configuration files from SD card.
+#
+
+. /opt/puzzlefw/lib/functions.sh
+
+case "$1" in
+  start)
+    echo "Reading configuration files from SD card ..."
+    lock_config || exit 1
+    read_config || exit 1
+    ;;
+  stop|restart|reload)
+    true
+    ;;
+  *)
+    echo "Usage: $0 start"
+    exit 1
+esac
+

sw/buildroot_overlay/opt/puzzlefw/bin/puzzle-calibration

@@ -0,0 +1,46 @@
+#!/bin/sh
+#
+# Manage analog channel calibration.
+#
+
+. /opt/puzzlefw/lib/functions.sh
+
+# Copy calibration file to the SD card.
+cal_save() {
+
+    # Lock to avoid conflicting changes.
+    lock_config || exit 1
+
+    echo "Copying changed calibration to SD card ..."
+
+    sync_config calibration.conf || exit 1
+}
+
+case "$1" in
+  show)
+    cat ${CONFIG_DIR}/calibration.conf
+    ;;
+  save)
+    cal_save
+    ;;
+  *)
+    cat <<EOF
+Usage: $0 {show|save}
+
+Manage analog channel calibration.
+
+  $0 show
+    Display calibration.
+
+  $0 save
+    Copy a changed calibration file to the SD card.
+    Before running this command, the changed calibration must be written to
+    ${CONFIG_DIR}/calibration.conf.new.
+
+EOF
+    exit 1
+    ;;
+esac
+
+exit $?
+

sw/buildroot_overlay/opt/puzzlefw/bin/puzzle-ipcfg

@@ -86,12 +86,12 @@ EOF
 # Initialize configuration from SD card.
 ipcfg_init() {
 
-    echo "Loading IP address configuration from SD card ..."
+    echo "Activating saved IP address configuration ..."
 
-    # Copy configuration from SD card.
+    # Lock to avoid conflicting changes.
     lock_config || exit 1
-    read_config || exit 1
 
+    # Persistent configuration file has already been copied from SD card.
     # Copy persistent configuration to active configuration.
     cp -a ${CONFIG_DIR}/network.conf ${CONFIG_DIR}/network_active.conf
 
@@ -280,7 +280,7 @@ Usage: $0 {init|show|config|save|restart}
 Manage IP address configuration.
 
   $0 init
-    Initialize IP address from saved configuration on SD card.
+    Initialize IP address from saved configuration.
     This command is used during boot and should not be invoked manually.
 
   $0 show