ELM - FAT File System Module

FatFs is a generic FAT file system module for small embedded systems. The FatFs is written in compliance with ANSI C and completely separated from the disk I/O layer. Therefore it is independent of hardware architecture. It can be incorporated into cheap microcontrollers, such as 8051, PIC, AVR, SH, Z80, H8, ARM and etc..., without any change. Petit FatFs module is also available here.

Features

FAT12, FAT16 and FAT32.
Multiple volumes (physical drives and partitions).
Two partitioning rules: FDISK and Super-floppy.
Various configuration options:
- Long file name (LFN) support.
- Selectable code pages including DBCS.
- Multitask support.
- Multiple sector size support.
- Read-only, minimized API, buffer configuration and etc...

Application Interface

FatFs module provides following functions.

f_mount - Register/Unregister a Work Area
f_open - Open/Create a File
f_close - Close a File
f_read - Read File
f_write - Write File
f_lseek - Move R/W Pointer, Expand File Size
f_truncate - Truncate File Size
f_sync - Flush Cached Data
f_opendir - Open a Directory
f_readdir - Read a Directory Item
f_getfree - Get Free Clusters
f_stat - Get File Status
f_mkdir - Create a Directory
f_unlink - Remove a File or Directory
f_chmod - Change Attribute
f_utime - Change Timestamp
f_rename - Rename/Move a File or Directory
f_mkfs - Create a File System on the Drive
f_forward - Forward file data to the stream directly
f_chdir - Change current directory
f_chdrive - Change current drive
f_gets - Read a string
f_putc - Write a character
f_puts - Write a string
f_printf - Write a formatted string

Disk I/O Interface

Since the FatFs module is completely separated from disk I/O layer, it requires following functions to lower layer to read/write the physical disk and to get current time. The low level disk I/O module is not a part of FatFs module and it must be provided by user. The sample drivers are also available in the resources.

disk_initialize - Initialize disk drive
disk_status - Get disk status
disk_read - Read sector(s)
disk_write - Write sector(s)
disk_ioctl - Control device dependent features
get_fattime - Get current time

Resources

The FatFs module is a free software and is opened for education, research and development. You can use, modify and/or republish it for personal, non-profit or commercial use without any restriction under your responsibility.

FatFs User Forum
FatFs module application note Jun 21, 2009
ARM-Projects by Martin THOMAS (examples for LPC2000, AT91SAM and STM32)
FAT32 Specification by Microsoft (The reference document on FAT file system)
How to Use MMC/SDC
Benchmark 1 (ATmega64/9.2MHz with MMC via SPI, HDD/CFC via GPIO)
Benchmark 2 (LPC2368/72MHz with MMC via MCI)