lib/littlefs: Reuse existing CRC32 function to save space.

Getting this to work required fixing a small issue in `lfs2_util.h`, which
has been submitted upstream.

Signed-off-by: Daniël van de Giessen <[email protected]>

Author: DvdGiessen

extmod/extmod.mk

@@ -206,7 +206,7 @@ endif
 
 ifeq ($(MICROPY_VFS_LFS2),1)
 CFLAGS_EXTMOD += -DMICROPY_VFS_LFS2=1
-CFLAGS_THIRDPARTY += -DLFS2_NO_MALLOC -DLFS2_NO_DEBUG -DLFS2_NO_WARN -DLFS2_NO_ERROR -DLFS2_NO_ASSERT
+CFLAGS_THIRDPARTY += -DLFS2_NO_MALLOC -DLFS2_NO_DEBUG -DLFS2_NO_WARN -DLFS2_NO_ERROR -DLFS2_NO_ASSERT -DLFS2_DEFINES=extmod/littlefs-include/lfs2_defines.h
 SRC_THIRDPARTY_C += $(addprefix $(LITTLEFS_DIR)/,\
 	lfs2.c \
 	lfs2_util.c \

extmod/littlefs-include/lfs2_defines.h

@@ -0,0 +1,12 @@
+#ifndef LFS2_DEFINES_H
+#define LFS2_DEFINES_H
+
+#include "py/mpconfig.h"
+
+#if MICROPY_PY_DEFLATE
+// We reuse the CRC32 implementation from uzlib to save a few bytes
+#include "lib/uzlib/uzlib.h"
+#define LFS2_CRC(crc, buffer, size) uzlib_crc32(buffer, size, crc)
+#endif
+
+#endif

lib/littlefs/lfs2_util.h

@@ -231,8 +231,8 @@ static inline uint32_t lfs2_tobe32(uint32_t a) {
 
 // Calculate CRC-32 with polynomial = 0x04c11db7
 #ifdef LFS2_CRC
-uint32_t lfs2_crc(uint32_t crc, const void *buffer, size_t size) {
-    return LFS2_CRC(crc, buffer, size)
+static inline uint32_t lfs2_crc(uint32_t crc, const void *buffer, size_t size) {
+    return LFS2_CRC(crc, buffer, size);
 }
 #else
 uint32_t lfs2_crc(uint32_t crc, const void *buffer, size_t size);