The f_chdir function changes the current directory of a drive.
FRESULT f_chdir ( const TCHAR* path /* [IN] Path name */ );
FR_OK, FR_DISK_ERR, FR_INT_ERR, FR_NOT_READY, FR_NO_PATH, FR_INVALID_NAME, FR_INVALID_DRIVE, FR_NOT_ENABLED, FR_NO_FILESYSTEM, FR_TIMEOUT, FR_NOT_ENOUGH_CORE
The f_chdir() function changes the current directory of the logical drive. The current directory of a drive is initialized to the root directory when the drive is auto-mounted. Note that the current directory is retained in the each file system object so that it also affects other tasks that using the volume.
Available when _FS_RPATH >= 1.
/* Change current direcoty of the current drive (dir1 under root dir) */ f_chdir("/dir1"); /* Change current direcoty of drive 2 (parent dir) */ f_chdir("2:..");