@albert said in Cant build RepRapFirmware:
Even though there was an error says that a .o file can not be found in the directory, it turns out that is because I did not match the configuration of CoreNG and RepRapFirmware ( I choose the SAM4E8E for CoreNG but Duet2_RTOS for ReprapFirmware). After I change the configuration of CoreNG to SAM4E8E_RTOS, everything is ok now.
That's correct. The SAM4E8E non-RTOS build of CoreNG is used by the DuetIAP project.