LibertyBSD_kernel/sys/dev/acpi/acpiutil.c

/* $OpenBSD: acpiutil.c,v 1.8 2015/03/14 03:38:47 jsg Exp $ */
/*
 * Copyright (c) 2005 Thorsten Lockert <tholo@sigmasoft.com>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/types.h>
#include <sys/systm.h>
#include <sys/device.h>

#include <dev/acpi/acpivar.h>

u_int
acpi_checksum(const void *v, size_t len)
{
	const u_char *p = v;
	u_char s = 0;
	int i;

	for (i = 0; i < len; i++)
		s += p[i];

	if (s)
		dnprintf(0,"\nacpi0: bad checksum at %p", v);

	return (s);
}