Petit FAT File System Module

Petit FatFs is a sub-set of FatFs module specifically designed for the systems with very tight code space and/or working memory. It is ideal for small gadgets with a tiny 8-bit microcontroller, bootstrap loaders in tight boot ROM and any sytem with limited memory.

Features

Very Small RAM Consumption (44 Bytes Work Area + Certain Stack).
Very Small Code Size (2K-4K bytes).
FAT12, FAT16 and FAT32.
Single Volume and Single File.
Streaming File Read.
File Write Function with Some Restrictions.

Application Interface

Petit FatFs module provides following functions.

pf_mount - Mount a Volume
pf_open - Open a File
pf_read - Read File
pf_write - Write File
pf_lseek - Move read/write Pointer
pf_opendir - Open a Directory
pf_readdir - Read a Directory Item

Disk I/O Interface

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

disk_initialize - Initialize storage device
disk_readp - Read a partial sector
disk_writep - Divided write to a sector

Resources

The Petit FatFs module is a free software and is opened for education, research and development. You can use, modify and/or redistribute it for personal, non-profit or commercial use without any restriction under your responsibility. For further information, refer to the application note.

Read first: Petit FatFs module application note January 30, 2019
Download: Petit FatFs R0.03a | Updates | Patches May 20, 2021
Download: Sample projects for various platforms January 30, 2019
Download: Previous Releases
Community: FatFs User Forum
FAT32 Specification by Microsoft↗ (The reference document on FAT file system)
How to Use MMC/SDC
Benchmark 3 (ATtiny85/8MHz with MMC via USI)