ubuntu-touch: Add 03-etc-writable.chroot hook to move/symlink files in

/etc to /etc/writable/ that we need to update atomically. At the moment
these are adjtime, timezone, localtime. (LP: #1227520)

debian/changelog

@@ -1,3 +1,11 @@
+livecd-rootfs (2.190) UNRELEASED; urgency=low
+
+  * ubuntu-touch: Add 03-etc-writable.chroot hook to move/symlink files in
+    /etc to /etc/writable/ that we need to update atomically. At the moment
+    these are adjtime, timezone, localtime. (LP: #1227520)
+
+ -- Martin Pitt <martin.pitt@ubuntu.com>  Wed, 25 Sep 2013 11:06:03 +0200
+
 livecd-rootfs (2.189) saucy; urgency=low
 
   * Explicitly add the ubuntu-desktop task to Edubuntu builds, so that any

live-build/ubuntu-touch/hooks/03-etc-writable.chroot

@@ -0,0 +1,14 @@
+#!/bin/sh
+set -e
+set -x
+
+mkdir -p /etc/writable
+
+for f in adjtime timezone localtime; do
+    if [ -e /etc/$f ]; then
+        echo "I: Moving /etc/$f to /etc/writable/"
+        mv /etc/$f /etc/writable/$f
+    fi
+    echo "I: Linking /etc/$f to /etc/writable/"
+    ln -s /etc/writable/$f /etc/$f
+done