mirror of
https://github.com/DarkFlippers/unleashed-firmware.git
synced 2024-12-22 21:01:40 +03:00
37 lines
1.1 KiB
C
37 lines
1.1 KiB
C
/* Copyright (C) 2022-2023 Salvatore Sanfilippo -- All Rights Reserved
|
|
* See the LICENSE file for information about the license. */
|
|
|
|
#include <stdint.h>
|
|
#include <stddef.h>
|
|
|
|
/* CRC8 with the specified initialization value 'init' and
|
|
* polynomial 'poly'. */
|
|
uint8_t crc8(const uint8_t* data, size_t len, uint8_t init, uint8_t poly) {
|
|
uint8_t crc = init;
|
|
size_t i, j;
|
|
for(i = 0; i < len; i++) {
|
|
crc ^= data[i];
|
|
for(j = 0; j < 8; j++) {
|
|
if((crc & 0x80) != 0)
|
|
crc = (uint8_t)((crc << 1) ^ poly);
|
|
else
|
|
crc <<= 1;
|
|
}
|
|
}
|
|
return crc;
|
|
}
|
|
|
|
/* Sum all the specified bytes modulo 256.
|
|
* Initialize the sum with 'init' (usually 0). */
|
|
uint8_t sum_bytes(const uint8_t* data, size_t len, uint8_t init) {
|
|
for(size_t i = 0; i < len; i++) init += data[i];
|
|
return init;
|
|
}
|
|
|
|
/* Perform the bitwise xor of all the specified bytes.
|
|
* Initialize xor value with 'init' (usually 0). */
|
|
uint8_t xor_bytes(const uint8_t* data, size_t len, uint8_t init) {
|
|
for(size_t i = 0; i < len; i++) init ^= data[i];
|
|
return init;
|
|
}
|