[package] block-extroot: Added md5sum to extroot and underlying root filesystem. This is used to ensure that the extroot is not mounted as the rootfs after a sysupgrade *until the user deals with the extroot).

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@24230 3c298f89-4303-0410-b956-a3cf2f4a3e73

1 files changed, 55 insertions, 0 deletions

diff --git a/package/block-extroot/files/55_determine_extroot_sysupgrade b/package/block-extroot/files/55_determine_extroot_sysupgrade
new file mode 100644
index 0000000000..21af8b0180
--- /dev/null
+++ b/package/block-extroot/files/55_determine_extroot_sysupgrade
@@ -0,0 +1,55 @@
+#!/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_extroot_md5sum
+	if [ -f $md5sum_file ]; then
+		er_extroot_md5sum="$(cat $er_md5sum_file)"
+	fi
+
+	local er_extroot_overlay_md5sum
+	if [ -f "/overlay/etc/extroot.md5sum" ]; then
+		er_extroot_overlay_md5sum="$(cat /overlay/.extroot.md5sum)"
+	fi
+
+	if [ -z "$er_extroot_overlay_md5sum" ]; then
+		cat $er_md5sum_file >/overlay/.extroot.md5sum
+	elif [ "$er_extroot_overlay_md5sum" != "$er_extroot_md5sum" ]; then
+		pi_extroot_mount_success="false"
+		mkdir -p /tmp/overlay-disabled
+		mount --move /overlay /tmp/overlay-disabled
+	fi
+}
+
+set_jffs_md5sum() {
+	# We do this anytime block-extroot exists, even on the first boot with
+	# no extroot defined.
+
+	local er_md5sum_file
+	er_md5sum_file="${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
+