... firmware is contained in this repository. The main user code sits in the application.cpp file under firmware/user/src/ folder. Unless you know what you are doing, refrain from making changes to any other files. After you are done editing the files, you can rebuild the repository by running the make command in the firmware/main/ directory. If you have made changes to any of the other directories, make automatically determines which files need to be rebuilt and builds them for you.