managed_components/joltwallet__littlefs/src/lfs_config.c (perf_benchmark sample)

/* * lfs util functions * * Copyright (c) 2017, Arm Limited. All rights reserved. * SPDX-License-Identifier: BSD-3-Clause */ #include "lfs_config.h" const char ESP_LITTLEFS_TAG[] = "esp_littlefs"; // Software CRC implementation with small lookup table uint32_t lfs_crc(uint32_t crc, const void *buffer, size_t size) { 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 (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; }