FatFs - Generic FAT File System Module

FatFs is a generic FAT file system module for small embedded systems. The FatFs module is written in compliance with ANSI C (C89) and completely separated from the disk I/O layer. Therefore it is independent of the platform. It can be incorporated into small microcontrollers with limited resource, such as 8051, PIC, AVR, ARM, Z80, 78K and etc. Also Petit FatFs module for tiny microcontrollers is available here↗.

Features

Windows compatible FAT file system.
Platform independent. Easy to port.
Very small footprint for code and work area.
Various configuration options:
- Multiple volumes (physical drives and partitions).
- Multiple ANSI/OEM code pages including DBCS.
- Long file name support in ANSI/OEM or Unicode.
- RTOS support for multi-task operation.
- Multiple sector size support upto 4KB.
- Read-only, minimized API, I/O buffer and etc...

Application Interface

FatFs module provides following functions to the applications. In other words, this list describes what FatFs can do to access the FAT volumes.

f_mount - Register/Unregister a work area
f_open - Open/Create a file
f_close - Close an open file
f_read - Read file
f_write - Write file
f_lseek - Move read/write pointer, Expand file size
f_truncate - Truncate file size
f_sync - Flush cached data
f_forward - Forward file data to the stream
f_stat - Check existance of a file or sub-directory
f_opendir - Open a directory
f_closedir - Close an open directory
f_readdir - Read a directory item
f_mkdir - Create a sub-directory
f_unlink - Remove a file or sub-directory
f_chmod - Change attribute
f_utime - Change timestamp
f_rename - Rename/Move a file or sub-directory
f_chdir - Change current directory
f_chdrive - Change current drive
f_getcwd - Retrieve the current directory
f_getfree - Get free space on the volume
f_getlabel - Get volume label
f_setlabel - Set volume label
f_mkfs - Create a file system on the drive
f_fdisk - Divide a physical drive
f_gets - Read a string
f_putc - Write a character
f_puts - Write a string
f_printf - Write a formatted string
f_tell - Get current read/write pointer
f_eof - Test for end-of-file on a file
f_size - Get size of a file
f_error - Test for an error on a file

Device Control Interface

Since the FatFs module is a file system layer, it is completely separated from physical devices, such as memory card, harddisk and any type of storage devices. FatFs accesses the storage device via a simple interface described below. The low level device control module is not a part of FatFs module. It is provided by implementer. Also sample implementations for some platforms are available in the downloads.

disk_status - Get device status
disk_initialize - Initialize device
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 opened for education, research and development. You can use, modify and/or redistribute it for personal projects or commercial products without any restriction under your responsibility. For further information, refer to the application note.

FatFs Home Page↗
FatFs User Forum↗
Read first: FatFs module application note
Read SD card with FatFs on STM32F4xx devices by Tilen Majerle↗ (Quick and easy implementation for STM32F4-Discovery)
Nemuisan's Blog↗ (Well written implementations for STM32F/SDIO and LPC2300/MCI)
ARM-Projects by Martin THOMAS↗ (Examples for LPC2000, AT91SAM and STM32)
FAT32 Specification by Microsoft↗ (The authorized document on FAT file system)
The basics of FAT file system [ja]↗
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)