add utils for image modify

README.md

@@ -38,3 +38,11 @@ on some system, qt5svg or qt5base will build failed on first build, please retry
 ```
 build_all
 ```
+
+# how to modify image after build:
+
+```
+./host/mount_image.sh install/xxxxxx/xxxx.img mountpoint
+cd mountpoint
+touch xxx
+```

host/mount_image.sh

@@ -0,0 +1,26 @@
+#!/bin/sh
+
+THISDIR=$(dirname $(realpath $0))
+
+if [ -z $2 ]
+then
+	echo "usage: $0 image dir"
+fi
+
+if [ ! -e $2 ]
+then
+	mkdir -pv $2
+fi
+
+set -eux
+
+PART=2
+
+PART_OFFSET=$(partx -s $1 | head -n 3 | tail -n 1 | awk '{print $2}')
+PART_OFFSET=$((PART_OFFSET * 512)) # sector size is 512
+
+echo "PART: $PART"
+echo "PART OFFSET: $PART_OFFSET"
+
+# some old version fuse2fs not support offset
+$THISDIR/fuse2fs -o fakeroot -o offset=$PART_OFFSET $1 $2