sys/arch/ofppc/stand/ofwboot/mbr.c

   1 /*      $NetBSD: ofdev.c,v 1.16 2009/01/12 07:49:57 tsutsui Exp $       */
   2
   3 /*
   4  * Copyright (C) 1995, 1996 Wolfgang Solfrank.
   5  * Copyright (C) 1995, 1996 TooLs GmbH.
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. All advertising materials mentioning features or use of this software
  17  *    must display the following acknowledgement:
  18  *      This product includes software developed by TooLs GmbH.
  19  * 4. The name of TooLs GmbH may not be used to endorse or promote products
  20  *    derived from this software without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
  23  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  24  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  25  * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  26  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  27  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
  28  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  29  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  30  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  31  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  32  */
  33
  34 #include <sys/param.h>
  35 #include <sys/bootblock.h>
  36
  37 #include <lib/libsa/byteorder.h>
  38 #include <lib/libsa/stand.h>
  39
  40 #include "mbr.h"
  41
  42
  43 static u_long
  44 get_long(const void *p)
  45 {
  46         const unsigned char *cp = p;
  47
  48         return cp[0] | (cp[1] << 8) | (cp[2] << 16) | (cp[3] << 24);
  49 }
  50
  51
  52 /*
  53  * Find a valid MBR disklabel.
  54  */
  55 int
  56 search_mbr_label(struct of_dev *devp, u_long off, char *buf,
  57     struct disklabel *lp, u_long off0)
  58 {
  59         size_t read;
  60         struct mbr_partition *p;
  61         int i;
  62         u_long poff;
  63         static int recursion;
  64
  65         if (strategy(devp, F_READ, off, DEV_BSIZE, buf, &read)
  66             || read != DEV_BSIZE)
  67                 return ERDLAB;
  68
  69         if (*(u_int16_t *)&buf[MBR_MAGIC_OFFSET] != sa_htole16(MBR_MAGIC))
  70                 return ERDLAB;
  71
  72         if (recursion++ <= 1)
  73                 off0 += off;
  74         for (p = (struct mbr_partition *)(buf + MBR_PART_OFFSET), i = 0;
  75              i < MBR_PART_COUNT; i++, p++) {
  76                 if (p->mbrp_type == MBR_PTYPE_NETBSD
  77 #ifdef COMPAT_386BSD_MBRPART
  78                     || (p->mbrp_type == MBR_PTYPE_386BSD &&
  79                         (printf("WARNING: old BSD partition ID!\n"), 1)
  80                         /* XXX XXX - libsa printf() is void */ )
  81 #endif
  82                     ) {
  83                         poff = get_long(&p->mbrp_start) + off0;
  84                         if (strategy(devp, F_READ, poff + LABELSECTOR,
  85                                      DEV_BSIZE, buf, &read) == 0
  86                             && read == DEV_BSIZE) {
  87                                 if (!getdisklabel(buf, lp)) {
  88                                         recursion--;
  89                                         return 0;
  90                                 }
  91                         }
  92                         if (strategy(devp, F_READ, off, DEV_BSIZE, buf, &read)
  93                             || read != DEV_BSIZE) {
  94                                 recursion--;
  95                                 return ERDLAB;
  96                         }
  97                 } else if (p->mbrp_type == MBR_PTYPE_EXT) {
  98                         poff = get_long(&p->mbrp_start);
  99                         if (!search_mbr_label(devp, poff, buf, lp, off0)) {
 100                                 recursion--;
 101                                 return 0;
 102                         }
 103                         if (strategy(devp, F_READ, off, DEV_BSIZE, buf, &read)
 104                             || read != DEV_BSIZE) {
 105                                 recursion--;
 106                                 return ERDLAB;
 107                         }
 108                 }
 109         }
 110
 111         recursion--;
 112         return ERDLAB;
 113 }