1 /* Copyright (c) 2014 The Chromium OS Authors. All rights reserved. 2 * Use of this source code is governed by a BSD-style license that can be 3 * found in the LICENSE file. 4 */ 5 6 #include "2sysincludes.h" 7 #include "2crc8.h" 8 9 uint8_t vb2_crc8(const void *vptr, uint32_t size) 10 { 11 const uint8_t *data = vptr; 12 unsigned crc = 0; 13 uint32_t i, j; 14 15 /* 16 * Calculate CRC-8 directly. A table-based algorithm would be faster, 17 * but for only a few bytes it isn't worth the code size. 18 */ 19 for (j = size; j; j--, data++) { 20 crc ^= (*data << 8); 21 for(i = 8; i; i--) { 22 if (crc & 0x8000) 23 crc ^= (0x1070 << 3); 24 crc <<= 1; 25 } 26 } 27 28 return (uint8_t)(crc >> 8); 29 } 30
