1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Copyright 2012 Freescale Semiconductor, Inc.
4 *
5 * Cleaned up and refactored by Charles Manning.
6 */
7 #include "pblimage.h"
8 #include <u-boot/crc.h>
10 static uint32_t crc_table[256];
11 static int crc_table_valid;
13 static void make_crc_table(void)
14 {
15 uint32_t mask;
16 int i, j;
17 uint32_t poly; /* polynomial exclusive-or pattern */
19 if (crc_table_valid)
20 return;
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;
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 }
39 crc_table_valid = 1;
40 }
42 uint32_t pbl_crc32(uint32_t in_crc, const char *buf, uint32_t len)
43 {
44 uint32_t crc32_val;
45 int i;
47 make_crc_table();
49 crc32_val = ~in_crc;
51 for (i = 0; i < len; i++)
52 crc32_val = (crc32_val << 8) ^
53 crc_table[(crc32_val >> 24) ^ (*buf++ & 0xff)];
55 return crc32_val;
56 }