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/*
* lfs util functions
*
* Copyright (c) 2017 Christopher Haster
* Distributed under the MIT license
*/
#include "lfs_util.h"
uint32_t lfs_crc(uint32_t crc, lfs_size_t size, const void *buffer) {
static const uint32_t rtable[16] = {
0x00000000, 0x1db71064, 0x3b6e20c8, 0x26d930ac,
0x76dc4190, 0x6b6b51f4, 0x4db26158, 0x5005713c,
0xedb88320, 0xf00f9344, 0xd6d6a3e8, 0xcb61b38c,
0x9b64c2b0, 0x86d3d2d4, 0xa00ae278, 0xbdbdf21c,
};
const uint8_t *data = buffer;
for (lfs_size_t i = 0; i < size; i++) {
crc = (crc >> 4) ^ rtable[(crc ^ (data[i] >> 0)) & 0xf];
crc = (crc >> 4) ^ rtable[(crc ^ (data[i] >> 4)) & 0xf];
}
return crc;
}
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