littlefs

https://github.com/ARMmbed/littlefs

Uses for loops with initialisation, so C99 is required. -std=c99 will need to be added to compiler options.

lfs_util.h contains a few debug/error macros, which utilise printf, so depending on whether your system has printf you may get warnings to deal with.

Suggested option in lfs_utils.h is to write your own config file and use -DLFS_CONFIG=lfs_config.h to have it included instead of lfs_utils.h, which means you need to copy and adjust anything needed.

If your compiler and associated system files does not have inttypes.h (see for example https://github.com/openbsd/src/blob/master/include/inttypes.h) you will need to add one or just define the following few which are needed by the debug macros.

#define PRIu16 "u" /* uint16_t */

#define PRIu32 "u" /* uint32_t */

If your system does not have printf, you can take the easy option at least initially and disable them using compiler defines (see lfs_util.h). LFS_NO_DEBUG, LFS_NO_WARN, LFS_NO_ERROR, LFS_NO_ASSERT Alternatively you need to provide a printf, or if you have created an lfs_config.h file replace printf with an appropriate debug print function on your system.

Additionally if you have a very restricted microcontroller, its likely you will want to set both or one of define LFS_NO_MALLOC, LFS_NO_ASSERT The first ensuring that memory allocation is not used, and the second if you do not want assert functionality.

If you want assert, then you will also need uintptr_t which is an optional C99 type, so may not exist in your system. Again you will need to typedef this yourself to the appropriate 'pointer size' for your system.