1 files changed, 63 insertions, 0 deletions
diff --git a/package/block-mount/files/55_determine_extroot_sysupgrade b/package/block-mount/files/55_determine_extroot_sysupgrade
new file mode 100644
index 0000000000..b0cd9036c2
--- /dev/null
+++ b/package/block-mount/files/55_determine_extroot_sysupgrade
@@ -0,0 +1,63 @@
+#!/bin/sh
+# Copyright (C) 2010 Daniel Dickinson
+# This is free software, licensed under the GNU General Public License v2.
+# See /LICENSE for more information.
+
+
+check_set_md5sum() {
+	local er_md5sum_file
+	er_md5sum_file="${ER_OVERLAY_PREFIX}/.extroot.md5sum"
+	local er_disabled
+	if [ "${ER_OVERLAY_ROM}" = "/rom" ]; then
+		er_disabled=/tmp/whole_root-disabled
+	else
+		er_disabled=/tmp${ER_OVERLAY_ROM}-disabled
+	fi
+
+	local er_extroot_md5sum
+	if [ -f $md5sum_file ]; then
+		er_extroot_md5sum="$(cat $er_md5sum_file)"
+	fi
+
+	local er_overlay_file="${ER_OVERLAY_ROM}/etc/extroot.md5sum"
+
+	local er_extroot_overlay_md5sum
+	if [ -f "$er_overlay_file" ]; then
+		er_extroot_overlay_md5sum="$(cat $er_overlay_file)"
+	fi
+
+	if [ -z "$er_extroot_overlay_md5sum" ]; then
+		cat $er_md5sum_file >$er_overlay_file
+	elif [ "$er_extroot_overlay_md5sum" != "$er_extroot_md5sum" ]; then
+		pi_extroot_mount_success="false"
+		mkdir -p $er_disabled
+		mount --move ${ER_OVERLAY_ROM} $er_disabled
+	fi
+}
+
+set_jffs_md5sum() {
+	# We do this anytime block-extroot exists, even on the first boot with
+	# no extroot defined.
+
+	local er_md5sum_file
+	er_md5sum_file="${ER_OVERLAY_PREFIX}/.extroot.md5sum"
+
+	local er_extroot_md5sum
+	if [ -f $er_md5sum_file ]; then
+		er_extroot_md5sum="$(cat $er_md5sum_file)"
+	fi
+	if [ -z "$er_extroot_md5sum" ]; then
+		dd if=/dev/urandom count=32 bs=1k 2>/dev/null | md5sum | cut -f1 -d\  >$er_md5sum_file
+	fi
+}
+
+determine_extroot_sysupgrade() {
+	check_skip || set_jffs_md5sum
+
+	check_skip || [ "$pi_extroot_mount_success" != "true" ] || {
+		check_set_md5sum
+	}
+}
+
+boot_hook_add preinit_mount_root determine_extroot_sysupgrade
+