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.
- 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.
- Add
ringfs.candringfs.hto 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.
See Doxygen-generated documentation at http://cloudyourcar.github.io/ringfs/.
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.
Copyright © 2014 Kosma Moczek <kosma@cloudyourcar.com>
This program is free software. It comes without any warranty, to the extent permitted by applicable law. You can redistribute it and/or modify it under the terms of the Do What The Fuck You Want To Public License, Version 2, as published by Sam Hocevar. See the COPYING file for more details.