To build this project, import it into Eclipse Mars 2, select the desired configuration (SAM3X, SAM4E, etc.), and press Build. The build depends on the Eclipse workspace variable 'ArmGccPath" being set to the directory where your arm-none-eabi-g++ compiler resides. For example "C:\Program Files (x86)\GNU Tools ARM Embedded\7 2018-q2-update\bin" on Windows. To set it, go to Windows -> Preferences -> C/C++ -> Build -> Build Variables and click "Add..."