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iceman1001 2014-09-11 23:23:46 +02:00
commit f38a152863
103 changed files with 10544 additions and 508 deletions
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common/crc32.c Normal file
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#include <stdint.h>
#include <stddef.h>
#include "crc32.h"
#define htole32(x) (x)
#define CRC32_PRESET 0xFFFFFFFF
static void crc32_byte (uint32_t *crc, const uint8_t value);
static void crc32_byte (uint32_t *crc, const uint8_t value) {
/* x32 + x26 + x23 + x22 + x16 + x12 + x11 + x10 + x8 + x7 + x5 + x4 + x2 + x + 1 */
const uint32_t poly = 0xEDB88320;
*crc ^= value;
for (int current_bit = 7; current_bit >= 0; current_bit--) {
int bit_out = (*crc) & 0x00000001;
*crc >>= 1;
if (bit_out)
*crc ^= poly;
}
}
void crc32 (const uint8_t *data, const size_t len, uint8_t *crc) {
uint32_t desfire_crc = CRC32_PRESET;
for (size_t i = 0; i < len; i++) {
crc32_byte (&desfire_crc, data[i]);
}
*((uint32_t *)(crc)) = htole32 (desfire_crc);
}
void crc32_append (uint8_t *data, const size_t len) {
crc32 (data, len, data + len);
}