1/* $OpenBSD: acpiutil.c,v 1.9 2020/06/17 16:16:05 deraadt Exp $ */
2/*
3 * Copyright (c) 2005 Thorsten Lockert <tholo@sigmasoft.com>
4 *
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 */
17
18#include <sys/param.h>
19#include <sys/systm.h>
20#include <sys/device.h>
21
22#include <dev/acpi/acpivar.h>
23
24u_int
25acpi_checksum(const void *v, size_t len)
26{
27	const u_char *p = v;
28	u_char s = 0;
29	int i;
30
31	for (i = 0; i < len; i++)
32		s += p[i];
33
34	if (s)
35		dnprintf(0,"\nacpi0: bad checksum at %p", v);
36
37	return (s);
38}
39