Return Code of API Functions
Most of API functions return common result code in enum type FRESULT. When an API function succeeded, it returns zero (FR_OK), otherwise it returns non-zero value indicates type of error.
- FR_OK (0)
- The function succeeded.
- FR_DISK_ERR
- The lower layer, disk_read, disk_write or disk_ioctl function, reported that an unrecoverable hard error occured.
Note that if once this error occured at any operation to an open file, the file object is aborted and any operations to the file except for close will be rejected.
- FR_INT_ERR
- Assertion failed. An insanity is detected in the internal process. One of the following possibilities is suspected.
- Work area (file system object, file object or etc...) has been broken by stack overflow or any other tasks. This is the reason in most case.
- There is an error of the FAT structure on the volume.
- There is a bug in the FatFs module itself.
- Wrong lower layer implementation.
Note that if once this error occured at any operation to an open file, the file object is aborted and all operations to the file except for close will be rejected.
- FR_NOT_READY
- The lower layer, disk_initialize function, reported that the storage device could not be got ready to work. One of the following possibilities is suspected.
- No medium in the drive.
- Wrong lower layer implementation.
- Wrong hardware configuration.
- The storage device has broken.
- FR_NO_FILE
- Could not find the file in the directory.
- FR_NO_PATH
- Could not find the path. A directory in the path name could not be found.
- FR_INVALID_NAME
- The given string is invalid as the path name. One of the following possibilities is suspected.
- There is a character not allowed for the file name.
- The file name is out of 8.3 format. (at non-LFN cfg.)
- FF_MAX_LFN is insufficient for the file name. (at LFN cfg.)
- There is any character encoding error in the string.
- FR_DENIED
- The required access was denied due to one of the following reasons:
- Write mode open against the read-only file.
- Deleting the read-only file or directory.
- Deleting the non-empty directory or current directory.
- Reading the file opened without FA_READ flag.
- Any modification to the file opened without FA_WRITE flag.
- Could not create the object due to root directory full or disk full.
- Could not allocate a contiguous area to the file.
- FR_EXIST
- Name collision. An object with the same name is already existing in the directory.
- FR_INVALID_OBJECT
- The file/directory object is invalid or a null pointer is given. There are some reasons as follows:
- It has been closed, or the structure has been collapsed.
- It has been invalidated. Open objects on the volume are invalidated by voulme mount process.
- Physical drive is not ready to work due to a media removal.
- FR_WRITE_PROTECTED
- A write mode operation against the write-protected media.
- FR_INVALID_DRIVE
- Invalid drive number is specified in the path name or a null pointer is given as the path name. (Related option: FF_VOLUMES)
- FR_NOT_ENABLED
- Work area for the logical drive has not been registered by f_mount function.
- FR_NO_FILESYSTEM
- There is no valid FAT volume on the drive or wrong lower layer implementation.
- FR_MKFS_ABORTED
- The f_mkfs function aborted before start in format due to a reason as follows:
- It is impossible to format with the given parameters.
- The size of volume is too small. 128 sectors minimum with FM_SFD option.
- The partition bound to the logical drive coulud not be found. (Related option: FF_MULTI_PARTITION)
- FR_TIMEOUT
- The function was canceled due to a timeout of thread-safe control. (Related option: FF_TIMEOUT)
- FR_LOCKED
- The operation to the object was rejected by file sharing control. (Related option: FF_FS_LOCK)
- FR_NOT_ENOUGH_CORE
- Not enough memory for the operation. There is one of the following reasons:
- Could not allocate a memory for LFN working buffer. (Related option: FF_USE_LFN)
- Size of the given buffer is insufficient for the size required.
- FR_TOO_MANY_OPEN_FILES
- Number of open objects has been reached maximum value and no more object can be opened. (Related option: FF_FS_LOCK)
- FR_INVALID_PARAMETER
- The given parameter is invalid or there is an inconsistent for the volume.