Upgrade or Install Samsung Galaxy J1 SM-J120G to Android 5.1.1 Lollipop. The firmware available for downloading http://www.sammobile.com/firmwares/database/SM-J120G/. You can download your Samsung Galaxy J1 SM-J120G firmware at the page, available for some countries. How to Root for Samsung Galaxy J1 SM-J120G is the separated post, this post only for upgrading to Android Lollipop.