The f_mkdir function creates a new directory.
FRESULT f_mkdir ( const char* DirName /* Pointer to the directory name */ );
The f_mkdir function creates a new directory. This function is not supported in read-only configuration and minimization level of >= 1.
res = f_mkdir("sub1"); if (res) die(res); res = f_mkdir("sub1/sub2"); if (res) die(res); res = f_mkdir("sub1/sub2/sub3"); if (res) die(res);