gistfile1.txt

#define RETRO_ENVIRONMENT_GET_SYSTEM_DIRECTORY 9
                                           // const char ** --
                                           // Returns the "system" directory of the frontend.
                                           // This directory can be used to store system specific ROMs such as BIOSes, configuration data, etc.
                                           // The returned value can be NULL.
                                           // If so, no such directory is defined,
                                           // and it's up to the implementation to find a suitable directory.