SPIFFS (SPI Flash File System)
V0.2

Copyright (c) 2013-2014 Peter Andersson (pelleplutt1976<at>gmail.com)

For legal stuff, see LICENCE in this directory. Basically, you may do whatever
you want with the source. Use, modify, sell, print it out, roll it and smoke it
 - as long as I won't be held responsible.

Love to hear feedback though!


* INTRODUCTION

Spiffs is a file system intended for SPI NOR flash devices on embedded targets.

Spiffs is designed with following characteristics in mind:
 - Small (embedded) targets, sparse RAM without heap
 - Only big areas of data (blocks) can be erased
 - An erase will reset all bits in block to ones
 - Writing pulls one to zeroes
 - Zeroes can only be pulled to ones by erase
 - Wear leveling


* FEATURES

What spiffs does:
 - Specifically designed for low ram usage
 - Uses statically sized ram buffers, independent of number of files
 - Posix-like api: open, close, read, write, seek, stat, etc
 - It can be run on any NOR flash, not only SPI flash - theoretically also on
   embedded flash of an microprocessor
 - Multiple spiffs configurations can be run on same target - and even on same
   SPI flash device
 - Implements static wear leveling 
 - Built in file system consistency checks
 
What spiffs does not:
 - Presently, spiffs does not support directories. It produces a flat
   structure. Creating a file with path "tmp/myfile.txt" will create a file 
   called "tmp/myfile.txt" instead of a "myfile.txt" under directory "tmp". 
 - It is not a realtime stack. One write operation might take much longer than
   another.
 - Poor scalability. Spiffs is intended for small memory devices - the normal
   sizes for SPI flashes. Going beyond ~128MB is probably a bad idea. This is
   a side effect of the design goal to use as little ram as possible.
 - Presently, it does not detect or handle bad blocks.

 
* MORE INFO 
 
For integration, see the docs/INTEGRATION file.

For use and design, see the docs/TECH_SPEC file.

For testing and contributions, see the docs/IMPLEMENTING file.