| /* Copyright (c) 2013 The Chromium OS Authors. All rights reserved. |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #include "sysincludes.h" |
| |
| #include "crc8.h" |
| |
| /** |
| * Return CRC-8 of the data, using x^8 + x^2 + x + 1 polynomial. A table-based |
| * algorithm would be faster, but for only a few bytes it isn't worth the code |
| * size. */ |
| uint8_t Crc8(const void *vptr, int len) |
| { |
| const uint8_t *data = vptr; |
| unsigned crc = 0; |
| int i, j; |
| |
| for (j = len; j; j--, data++) { |
| crc ^= (*data << 8); |
| for(i = 8; i; i--) { |
| if (crc & 0x8000) |
| crc ^= (0x1070 << 3); |
| crc <<= 1; |
| } |
| } |
| |
| return (uint8_t)(crc >> 8); |
| } |
