In the Build tab page, you can configure whether you want to use an external Makefile for your project. In that case, just tick the Use External Makefile checkbox and browse to select the correct path of makefile.
Build Commandline will be provided to the external makefile when build is invoked for the project. The default build target is 'all'.
Clean Commandline will be provided to the external makefile when clean is invoked for the project. The default clean target is 'clean'.
Besides the external makefile configuration, you can also specify the type of application to build. The options are Executable or Static Library, which can be selected using the Artifact Type combo box.