Bestandssysteem – SPIFFS (SPI Flash File System)
Informatie (ENG):
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.
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## HISTORY ### 0.3.5 - Fixed a bug in fs check - API returns actual error codes #84) (thanks @Nails) - Fix compiler warnings for non-gcc #83 #81 (thanks @Nails) - Unable to recover from full fs #82 (thanks @rojer) - Define SPIFFS_O_* flags #80 - Problem with long filenames #79 (thanks @psjg) - Duplicate file name bug fix #74 (thanks @igrr) - SPIFFS_eof and SPIFFS_tell return wrong value #72 (thanks @ArtemPisarenko) - Bunch of testframe updates #77 #78 #86 (thanks @dpreussner, @psjg a.o) ### 0.3.4 - Added user callback file func. - Fixed a stat bug with obj id. - SPIFFS_probe_fs added - Add possibility to compile a read-only version of spiffs - Make magic dependent on fs length, if needed (see #59 & #66) (thanks @hreintke) - Exposed SPIFFS_open_by_page_function - Zero-size file cannot be seek #57 (thanks @lishen2) - Add tell and eof functions #54 (thanks @raburton) - Make api string params const #53 (thanks @raburton) - Preserve user_data during mount() #51 (thanks @rojer) New API functions: - `SPIFFS_set_file_callback_func` - register a callback informing about file events - `SPIFFS_probe_fs` - probe a spi flash trying to figure out size of fs - `SPIFFS_open_by_page` - open a file by page index - `SPIFFS_eof` - checks if end of file is reached - `SPIFFS_tell` - returns current file offset New config defines: - `SPIFFS_READ_ONLY` - `SPIFFS_USE_MAGIC_LENGTH` ### 0.3.3 **Might not be compatible with 0.3.2 structures. See issue #40** - Possibility to add integer offset to file handles - Truncate function presumes too few free pages #49 - Bug in truncate function #48 (thanks @PawelDefee) - Update spiffs_gc.c - remove unnecessary parameter (thanks @PawelDefee) - Update INTEGRATION docs (thanks @PawelDefee) - Fix pointer truncation in 64-bit platforms (thanks @igrr) - Zero-sized files cannot be read #44 (thanks @rojer) - (More) correct calculation of max_id in obj_lu_find #42 #41 (thanks @lishen2) - Check correct error code in obj_lu_find_free #41 (thanks @lishen2) - Moar comments for SPIFFS_lseek (thanks @igrr) - Fixed padding in spiffs_page_object_ix #40 (thanks @jmattsson @lishen2) - Fixed gc_quick test (thanks @jmattsson) - Add SPIFFS_EXCL flag #36 - SPIFFS_close may fail silently if cache is enabled #37 - User data in callbacks #34 - Ignoring SINGLETON build in cache setup (thanks Luca) - Compilation error fixed #32 (thanks @chotasanjiv) - Align cand_scores (thanks @hefloryd) - Fix build warnings when SPIFFS_CACHE is 0 (thanks @ajaybhargav) New config defines: - `SPIFFS_FILEHDL_OFFSET` ### 0.3.2 - Limit cache size if too much cache is given (thanks pgeiem) - New feature - Controlled erase. #23 - SPIFFS_rename leaks file descriptors #28 (thanks benpicco) - moved dbg print defines in test framework to params_test.h - lseek should return the resulting offset (thanks hefloryd) - fixed type on dbg ifdefs - silence warning about signed/unsigned comparison when spiffs_obj_id is 32 bit (thanks benpicco) - Possible error in test_spiffs.c #21 (thanks yihcdaso-yeskela) - Cache might writethrough too often #16 - even moar testrunner updates - Test framework update and some added tests - Some thoughts for next gen - Test sigsevs when having too many sectors #13 (thanks alonewolfx2) - GC might be suboptimal #11 - Fix eternal readdir when objheader at last block, last entry New API functions: - `SPIFFS_gc_quick` - call a nonintrusive gc - `SPIFFS_gc` - call a full-scale intrusive gc ### 0.3.1 - Removed two return warnings, was too triggerhappy on release ### 0.3.0 - Added existing namecheck when creating files - Lots of static analysis bugs #6 - Added rename func - Fix SPIFFS_read length when reading beyond file size - Added reading beyond file length testcase - Made build a bit more configurable - Changed name in spiffs from "errno" to "err_code" due to conflicts compiling in mingw - Improved GC checks, fixed an append bug, more robust truncate for very special case - GC checks preempts GC, truncate even less picky - Struct alignment needed for some targets, define in spiffs config #10 - Spiffs filesystem magic, definable in config New config defines: - `SPIFFS_USE_MAGIC` - enable or disable magic check upon mount - `SPIFFS_ALIGNED_OBJECT_INDEX_TABLES` - alignment for certain targets New API functions: - `SPIFFS_rename` - rename files - `SPIFFS_clearerr` - clears last errno - `SPIFFS_info` - returns info on used and total bytes in fs - `SPIFFS_format` - formats the filesystem - `SPIFFS_mounted` - checks if filesystem is mounte |