1/*
2 * Copyright (c) 2001-2007 Apple Inc. All Rights Reserved.
3 *
4 * @APPLE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. Please obtain a copy of the License at
10 * http://www.opensource.apple.com/apsl/ and read it before using this
11 * file.
12 *
13 * The Original Code and all software distributed under the License are
14 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
15 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
16 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
18 * Please see the License for the specific language governing rights and
19 * limitations under the License.
20 *
21 * @APPLE_LICENSE_HEADER_END@
22 */
23/*
24 *  BLBlockChecksum.c
25 *  bless
26 *
27 *  Created by Shantonu Sen <ssen@apple.com> on Wed Feb 28 2002.
28 *  Copyright (c) 2002-2007 Apple Inc. All Rights Reserved.
29 *
30 *  $Id: BLBlockChecksum.c,v 1.8 2006/02/20 22:49:56 ssen Exp $
31 *
32 */
33
34#include <sys/types.h>
35
36#include "bless_private.h"
37
38/*
39 * Taken from MediaKit. Used to checksum secondary loader
40 * presently
41 */
42
43uint32_t BLBlockChecksum(const void *buf,uint32_t length)
44{
45  uint32_t          sum = 0;
46  uint32_t          *s = (uint32_t *) buf;
47  uint32_t          *t = s + length/4;
48
49  while (s < t) {
50    //      rotate 1 bit left and add bytes
51    sum = ((sum >> 31) | (sum << 1)) + *s++;
52  }
53  return sum;
54}
55
56