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/*
* Copyright 2012 Freescale Semiconductor, Inc.
*
* Cleaned up and refactored by Charles Manning.
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include "pblimage.h"
static uint32_t crc_table[256];
static int crc_table_valid;
static void make_crc_table(void)
{
uint32_t mask;
int i, j;
uint32_t poly; /* polynomial exclusive-or pattern */
if (crc_table_valid)
return;
/*
* the polynomial used by PBL is 1 + x1 + x2 + x4 + x5 + x7 + x8 + x10
* + x11 + x12 + x16 + x22 + x23 + x26 + x32.
*/
poly = 0x04c11db7;
for (i = 0; i < 256; i++) {
mask = i << 24;
for (j = 0; j < 8; j++) {
if (mask & 0x80000000)
mask = (mask << 1) ^ poly;
else
mask <<= 1;
}
crc_table[i] = mask;
}
crc_table_valid = 1;
}
uint32_t pbl_crc32(uint32_t in_crc, const char *buf, uint32_t len)
{
uint32_t crc32_val;
int i;
make_crc_table();
crc32_val = ~in_crc;
for (i = 0; i < len; i++)
crc32_val = (crc32_val << 8) ^
crc_table[(crc32_val >> 24) ^ (*buf++ & 0xff)];
return crc32_val;
}
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