RingFS, a small Flash-based ring buffer.

RingFS is a persistent, Flash-based ring buffer designed for embedded software. It's aimed at storing non-critical data that can be expunged on the FIFO basis as needed. Typical uses include:

telemetry data,
debug logs,
stack traces.

RingFS has been designed to run on NOR Flash memory, which exhibits the following semantics:

Bits are programmed by flipping them from 1 to 0 with byte granularity.
Bits are erased by flipping them from 0 to 1 with sector granularity.

Features

Designed and optimized for NOR Flash memory.
Stores fixed-size objects in a FIFO buffer.
Written in ISO C99.
No dynamic memory allocation.
Basic robustness features for error recovery.

Usage

Add ringfs.c and ringfs.h to your project.
Implement the required Flash ops (sector_erase, program, read).
Glue your Flash ops with ringfs using struct ringfs_flash_partition.

See example.c if this sounds complicated.

Documentation

See Doxygen-generated documentation at http://cloudyourcar.github.io/ringfs/.

Non-Features

The ring buffer has been designed to be as simple as possible. Therefore, the following are non-features that will not be implemented:

Variable object sizes (makes things much more complicated).
Complicated error recovery (we can lose data in edge cases).
Upgrades (complex, also unnecessary in our use cases).

Actually, on the second thought, I may consider adding support for variable object sizes some day.

License