Add some easier util overrides: LFS_MALLOC/FREE/CRC #909
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Now you can override littlefs's malloc with some simple defines: -DLFS_MALLOC=my_malloc -DLFS_FREE=my_free This is probably what most users expected when wanting to override malloc/free in littlefs, but it hasn't been available, since instead littlefs provides a file-level override of builtin utils. The thinking was that there's just too many builtins that could be overriden, lfs_max/min/alignup/npw2/etc/etc/etc, so allowing users to just override the util file provides the best flexibility without a ton of ifdefs. But it's become clear this is awkward for users that just want to replace malloc. Maybe the original goal was too optimistic, maybe there's a better way to structure this file, or maybe the best API is just a bunch of ifdefs, I have no idea! This will hopefully continue to evolve.
Now you can override littlefs's CRC implementation with some simple defines: -DLFS_CRC=lfs_crc The motivation for this is the same for LFS_MALLOC/LFS_FREE. I think these are the main "system-level" utils that users want to override. Don't override with this something that's not CRC32! Your filesystem will no longer be compatible with other tools! This is only intended for provided hardware acceleration!
geky
added
enhancement
needs minor version
This was referenced Dec 19, 2023
Tests passed ✓, Code: 16820 B (+0.0%), Stack: 1448 B (+0.0%), Structs: 800 B (+0.0%)
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geky
added
next minor
and removed
needs minor version
Merged
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With this you can override littlefs's malloc/crc implementations with some simple defines:
I think these are the main "system-level" utils that users want to override, but am open to feedback.
Note on LFS_CRC:
Overriding LFS_CRC with something that's not CRC32 is discouraged. Your filesystem will no longer be compatible with other tools. This is only intended for providing hardware acceleration, etc.
These are probably what most users expected when wanting to override malloc/free/crc in littlefs, but they haven't been available, since instead littlefs provides a file-level override of builtin utils behind LFS_CONFIG.
The thinking was that there's just too many builtins that could be overriden, lfs_max/min/alignup/npw2/etc/etc/etc, so allowing users to just override the util file provides the best flexibility without a ton of ifdefs.
But it's become clear this is awkward for users that just want to replace malloc/crc.
Maybe the original goal was too optimistic, maybe there's a better way to structure this file, or maybe the best API is just a bunch of ifdefs, I have no idea. This will hopefully continue to evolve.