https://qooah.com/2012/07/28/android-%e6%95%99%e5%ad%b8root%e6%a9%9f%e4%be%86%e5%81%9a%e7%94%9a%e9%ba%bc-%e6%88%91%e6%87%89%e8%a9%b2root-%e5%97%8e/