usr.sbin/installboot/sum.c

   1 /*      $NetBSD: sum.c,v 1.3 2004/06/20 22:20:17 jmc Exp $      */
   2
   3 /*-
   4  * Copyright (c) 2002 The NetBSD Foundation, Inc.
   5  * All rights reserved.
   6  *
   7  * This code is derived from software contributed to The NetBSD Foundation
   8  * by Luke Mewburn of Wasabi Systems.
   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 /*
  33  * Copyright (c) 1999 Ross Harvey.  All rights reserved.
  34  *
  35  * Redistribution and use in source and binary forms, with or without
  36  * modification, are permitted provided that the following conditions
  37  * are met:
  38  * 1. Redistributions of source code must retain the above copyright
  39  *    notice, this list of conditions and the following disclaimer.
  40  * 2. Redistributions in binary form must reproduce the above copyright
  41  *    notice, this list of conditions and the following disclaimer in the
  42  *    documentation and/or other materials provided with the distribution.
  43  * 3. All advertising materials mentioning features or use of this software
  44  *    must display the following acknowledgement:
  45  *      This product includes software developed by Ross Harvey
  46  *      for the NetBSD Project.
  47  * 4. The name of the author may not be used to endorse or promote products
  48  *    derived from this software without specific prior written permission
  49  *
  50  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  51  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  52  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  53  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  54  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  55  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  56  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  57  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  58  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  59  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  60  */
  61
  62 #if HAVE_NBTOOL_CONFIG_H
  63 #include "nbtool_config.h"
  64 #endif
  65
  66 #include <sys/cdefs.h>
  67 #if defined(__RCSID) && !defined(__lint)
  68 __RCSID("$NetBSD: sum.c,v 1.3 2004/06/20 22:20:17 jmc Exp $");
  69 #endif  /* !__lint */
  70
  71 #include <sys/types.h>
  72
  73 #include <assert.h>
  74 #include <stdio.h>
  75
  76 #include "installboot.h"
  77
  78
  79 uint16_t
  80 compute_sunsum(const uint16_t *bb16)
  81 {
  82         uint16_t        i, s;
  83
  84         assert(bb16 != NULL);
  85
  86         s = 0;
  87         for (i = 0; i < 255; ++i)
  88                 s ^= bb16[i];
  89         return (s);
  90 }
  91
  92 int
  93 set_sunsum(ib_params *params, uint16_t *bb16, uint16_t sum)
  94 {
  95
  96         assert(params != NULL);
  97         assert(bb16 != NULL);
  98
  99 #define SUNSUM_OFFSET   255
 100         if (params->flags & IB_VERBOSE) {
 101                 printf("Old Sun checksum:          0x%04x\n",
 102                     be16toh(bb16[SUNSUM_OFFSET]));
 103                 printf("Recalculated Sun checksum: 0x%04x\n", be16toh(sum));
 104         }
 105                 // XXX: does this need to be big endian?
 106         bb16[SUNSUM_OFFSET] = sum;
 107         return (1);
 108 }