55 lines
1,014 B
C
55 lines
1,014 B
C
// SPDX-License-Identifier: GPL-2.0+
|
|
/*
|
|
* Copyright 2012 Freescale Semiconductor, Inc.
|
|
*
|
|
* Cleaned up and refactored by Charles Manning.
|
|
*/
|
|
#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;
|
|
}
|