lib/crc32c.c

   1 /*
   2  * Copied from Linux kernel crypto/crc32c.c
   3  * Copyright (c) 2004 Cisco Systems, Inc.
   4  * Copyright (c) 2008 Herbert Xu <herbert@gondor.apana.org.au>
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License as published by the Free
   8  * Software Foundation; either version 2 of the License, or (at your option)
   9  * any later version.
  10  * SPDX-License-Identifier:     GPL-2.0+
  11  */
  12
  13 #include <common.h>
  14 #include <compiler.h>
  15
  16 uint32_t crc32c_cal(uint32_t crc, const char *data, int length,
  17                     uint32_t *crc32c_table)
  18 {
  19         while (length--)
  20                 crc = crc32c_table[(u8)(crc ^ *data++)] ^ (crc >> 8);
  21
  22         return crc;
  23 }
  24
  25 void crc32c_init(uint32_t *crc32c_table, uint32_t pol)
  26 {
  27         int i, j;
  28         uint32_t v;
  29         const uint32_t poly = pol; /* Bit-reflected CRC32C polynomial */
  30
  31         for (i = 0; i < 256; i++) {
  32                 v = i;
  33                 for (j = 0; j < 8; j++)
  34                         v = (v >> 1) ^ ((v & 1) ? poly : 0);
  35
  36                 crc32c_table[i] = v;
  37         }
  38 }