unified preinit environment

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@7173 3c298f89-4303-0410-b956-a3cf2f4a3e73

package/base-files/files/sbin/mount_root

@@ -3,9 +3,10 @@
 . /etc/functions.sh
 
 mount none /proc -t proc
-size=$(awk '/Mem:/ {l=5242880;print((s=$2/2)<l)?$2-l:s}' /proc/meminfo)
 
+size=$(awk '/MemTotal:/ {l=5242880;mt=($2*1024);print((s=mt/2)<l)?mt-l:s}' /proc/meminfo)
 mount none /tmp -t tmpfs -o size=$size,nosuid,nodev,mode=1777
+
 if grep devfs /proc/filesystems >/dev/null; then
 	mount none /dev -t devfs
 else
@@ -13,7 +14,9 @@ else
 	mknod /dev/console c 5 1
 	exec >/dev/console </dev/console 2>&1
 fi
+
 mkdir /dev/shm
+
 if grep sysfs /proc/filesystems >/dev/null; then
 	mount -t sysfs none /sys
 	HOTPLUG=""
@@ -27,14 +30,25 @@ echo "$HOTPLUG" > /proc/sys/kernel/hotplug
 mkdir -p /dev/pts
 mount none /dev/pts -t devpts
 
+jffs2_ready () {
+	mtdpart="$(find_mtd_part rootfs_data)"
+	magic=$(hexdump $mtdpart -n 4 -e '4/1 "%02x"')
+	[ "$magic" != "deadc0de" ]
+}
+
 [ failsafe != "$1" ] && {
 	grep rootfs /proc/mtd >/dev/null 2>/dev/null && {
 		mtd unlock rootfs
 		grep rootfs_data /proc/mtd >/dev/null 2>/dev/null && {
 			. /bin/firstboot
-			echo "switching to jffs2"
-			mount "$(find_mtd_part rootfs_data)" /jffs -t jffs2
-			fopivot /jffs /rom
+			jffs2_ready && {
+				echo "switching to jffs2"
+				mount "$(find_mtd_part rootfs_data)" /jffs -t jffs2
+				fopivot /jffs /rom
+			} || {
+				echo "jffs2 not ready yet; using ramdisk"
+				ramoverlay
+			}
 		}
 	} || mount -o remount,rw /dev/root /
 }