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>
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}
57