/*      $NetBSD: cksum.c,v 1.3 2009/03/14 21:04:06 dsl Exp $    */

/*
* Copyright (c) 1999 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Julian Coleman, Waldi Ravens and Leo Weppelman.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/

#include "privahdi.h"

/*
* Disklabel checksum.
*/

int
dkcksum (struct disklabel *dl)
{
       u_short *start, *end, sum = 0;

       start = (u_short *)dl;
       end   = (u_short *)&dl->d_partitions[dl->d_npartitions];
       while (start < end)
               sum ^= *start++;
       return (sum);
}

/*
* AHDI root sector checksum.
*/

u_int16_t
ahdi_cksum (void *buf)
{
       u_int16_t       *p = (u_int16_t *)buf;
       u_int16_t        csum = 0;
       int              i;

       for (i = 0; i < 256; i++)
               csum += *p++;
       return ((0x1234 - csum) & 0xffff);
}