Marlin is configured using C++ compiler directives. Hundreds of user-donated configurations are posted at the Configurations repository to get you started. Simply edit or replace these files, then build and upload Marlin to the board. h files contain all of Marlin’s build-time configuration options. See the Configuration with INI page for more information. config.ini may be included to modify the configuration at the start of a PlatformIO build.Configuration_adv.h contains more detailed customization options, add-ons, experimental features, and other esoteric settings.

Marlin is a huge C++ program composed of many files, but among the most important are the files that contain all of Marlin’s compile-time configuration options: