- Do this in sdcard or some writeable dir (in adb shell)
- mount -o remount,rw -t yaffs2 /dev/block/mtdblock4 /system
- echo "mount -o remount,rw -t yaffs2 /dev/block/mtdblock4 /system" >> mountrw
- echo "mount -o remount,ro -t yaffs2 /dev/block/mtdblock4 /system" >> mountro
- chmod 755 mountro mountrw
- cp mountro mountrw /system/xbin/
- now you can just type "mountrw" or "mountro" to remount
