#!/bin/sh

switch_file=rfs.cpio.gz
target_file=cramfs.tar.gz

if [ "$1" == "" ]; then
	echo "Please input source file"
	exit
fi

if [ -f $1 ]; then
	echo "Decompress $1 rootfs file to $target_file"
else
	echo "Input source [$1] not exists"
	exit
fi

dd skip=1 if=$1 of=./$switch_file bs=64 > /dev/null

mkdir cramfs
cd cramfs
zcat ../$switch_file | cpio -idmv > /dev/null

cd ..

if [ -f $target_file ]; then
	echo "Remove old target file"
	rm $target_file
fi

tar -cvzf $target_file ./cramfs > /dev/null

rm cramfs -rf
rm $switch_file