blob: 6e6735acde326f128bc87d42d7197a86070297af [file] [log] [blame]
Charles Manningabbc67e2014-05-14 14:45:00 +12001/*
2 * Copyright 2012 Freescale Semiconductor, Inc.
3 *
4 * Cleaned up and refactored by Charles Manning.
5 *
6 * SPDX-License-Identifier: GPL-2.0+
7 */
8#include "pblimage.h"
9
10static uint32_t crc_table[256];
11static int crc_table_valid;
12
13static void make_crc_table(void)
14{
15 uint32_t mask;
16 int i, j;
17 uint32_t poly; /* polynomial exclusive-or pattern */
18
19 if (crc_table_valid)
20 return;
21
22 /*
23 * the polynomial used by PBL is 1 + x1 + x2 + x4 + x5 + x7 + x8 + x10
24 * + x11 + x12 + x16 + x22 + x23 + x26 + x32.
25 */
26 poly = 0x04c11db7;
27
28 for (i = 0; i < 256; i++) {
29 mask = i << 24;
30 for (j = 0; j < 8; j++) {
31 if (mask & 0x80000000)
32 mask = (mask << 1) ^ poly;
33 else
34 mask <<= 1;
35 }
36 crc_table[i] = mask;
37 }
38
39 crc_table_valid = 1;
40}
41
42uint32_t pbl_crc32(uint32_t in_crc, const char *buf, uint32_t len)
43{
44 uint32_t crc32_val;
45 int i;
46
47 make_crc_table();
48
49 crc32_val = ~in_crc;
50
51 for (i = 0; i < len; i++)
52 crc32_val = (crc32_val << 8) ^
53 crc_table[(crc32_val >> 24) ^ (*buf++ & 0xff)];
54
55 return crc32_val;
56}