1 /* $NetBSD: cksum.c,v 1.3 2009/03/14 21:04:06 dsl Exp $ */
2
3 /*
4 * Copyright (c) 1999 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Julian Coleman, Waldi Ravens and Leo Weppelman.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 #include "privahdi.h"
33
34 /*
35 * Disklabel checksum.
36 */
37
38 int
dkcksum(struct disklabel * dl)39 dkcksum (struct disklabel *dl)
40 {
41 u_short *start, *end, sum = 0;
42
43 start = (u_short *)dl;
44 end = (u_short *)&dl->d_partitions[dl->d_npartitions];
45 while (start < end)
46 sum ^= *start++;
47 return (sum);
48 }
49
50 /*
51 * AHDI root sector checksum.
52 */
53
54 u_int16_t
ahdi_cksum(void * buf)55 ahdi_cksum (void *buf)
56 {
57 u_int16_t *p = (u_int16_t *)buf;
58 u_int16_t csum = 0;
59 int i;
60
61 for (i = 0; i < 256; i++)
62 csum += *p++;
63 return ((0x1234 - csum) & 0xffff);
64 }
65