Upgrade or Install Samsung Galaxy S6 SM-G920S to Android 6.0.1 Marshmallow. The Official firmware available for downloading http://www.sammobile.com/firmwares/database/SM-G920S. You can download your Samsung Galaxy S6 SM-G920S firmware at the page, available for some countries. How to Root for Samsung Galaxy S6 SM-G920S is the separated post, this post only for upgrading to Android 6.0.1 Marshmallow.