mirror of https://github.com/pellepl/spiffs
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
2.0 KiB
2.0 KiB
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.