usr/src/cmd/boot/mbr/mbr.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25
  26 #include <stdio.h>
  27 #include <sys/types.h>
  28 #include <string.h>
  29 #include <fcntl.h>
  30 #include <libgen.h>
  31 #include <stdlib.h>
  32 #include <strings.h>
  33 #include <unistd.h>
  34 #include <sys/dktp/fdisk.h>
  35
  36 #define SECTOR_SIZE     512
  37 static char boot_sect[SECTOR_SIZE];
  38 static char new_mboot[SECTOR_SIZE];
  39
  40 static void
  41 usage(char *progname)
  42 {
  43         fprintf(stderr, "Usage: %s [ -d | -n | -o | -r ] <device> [<mboot>]\n",
  44             basename(progname));
  45         fprintf(stderr, "\t-n Set new Solaris partition magic 0xbf\n");
  46         fprintf(stderr, "\t-o Set old Solaris partition magic 0x82\n");
  47         fprintf(stderr, "\t-r Replace master boot program "
  48             "(/usr/lib/fs/ufs/mboot)\n");
  49         exit(-1);
  50 }
  51
  52 int
  53 main(int argc, char *argv[])
  54 {
  55         int c, fd, i, sol_part = -1;
  56         int setold = 0, setnew = 0, write_mboot = 0, list_hd = 0;
  57         char *device;
  58         struct mboot *mboot;
  59         char *mboot_file = "/usr/lib/fs/ufs/mboot";
  60
  61         while ((c = getopt(argc, argv, "dnor")) != EOF) {
  62                 switch (c) {
  63                 case 'd':
  64                         list_hd = 1;
  65                         continue;
  66                 case 'n':
  67                         setnew = 1;
  68                         continue;
  69                 case 'o':
  70                         setold = 1;
  71                         continue;
  72                 case 'r':
  73                         write_mboot = 1;
  74                         continue;
  75                 default:
  76                         usage(argv[0]);
  77                 }
  78         }
  79
  80         /* check arguments */
  81         if ((setnew && setold) || argc < optind + 1) {
  82                 usage(argv[0]);
  83         }
  84
  85         if (write_mboot && argc > optind + 1) {
  86                 mboot_file = strdup(argv[optind + 1]);
  87         }
  88         if (!mboot_file) {
  89                 usage(argv[0]);
  90         }
  91         fd = open(mboot_file, O_RDONLY);
  92         if (fd == -1 || read(fd, new_mboot, SECTOR_SIZE) != SECTOR_SIZE) {
  93                 fprintf(stderr, "cannot read file %s\n", mboot_file);
  94                 if (fd == -1)
  95                         perror("open");
  96                 else
  97                         perror("read");
  98                 exit(-1);
  99         }
 100         close(fd);
 101
 102         device = strdup(argv[optind]);
 103         if (!device) {
 104                 usage(argv[0]);
 105         }
 106         fd = open(device, O_RDWR);
 107         if (fd == -1 || read(fd, boot_sect, SECTOR_SIZE) != SECTOR_SIZE) {
 108                 fprintf(stderr, "cannot read MBR on %s\n", device);
 109                 if (fd == -1)
 110                         perror("open");
 111                 else
 112                         perror("read");
 113                 exit(-1);
 114         }
 115
 116         mboot = (struct mboot *)boot_sect;
 117         for (i = 0; i < FD_NUMPART; i++) {
 118                 struct ipart *part = (struct ipart *)mboot->parts + i;
 119                 if (!list_hd) {
 120                         if (part->bootid == 128)
 121                                 printf("active ");
 122                         else
 123                                 printf("       ");
 124                 }
 125                 if (setnew && part->systid == 0x82) {
 126                         part->systid = 0xbf;
 127                         sol_part = i;
 128                 } else if (setold && part->systid == 0xbf) {
 129                         part->systid = 0x82;
 130                         sol_part = i;
 131                 } else if (list_hd &&
 132                     (part->systid == 0x82 || part->systid == 0xbf)) {
 133                         sol_part = i;
 134                 }
 135                 if (!list_hd)
 136                         printf("%d (0x%2x): start_sect %u, size_sect %u\n",
 137                             i + 1, part->systid, part->relsect, part->numsect);
 138         }
 139
 140         if (list_hd) {
 141                 printf("(hd0,%d,a)\n", sol_part);
 142                 (void) close(fd);
 143                 return (0);
 144         }
 145
 146         /* write new mboot */
 147         if (write_mboot || sol_part != -1) {
 148                 if (write_mboot) {
 149                         /* copy over the new boot program */
 150                         bcopy((void *)new_mboot, (void *)boot_sect, BOOTSZ);
 151                 }
 152
 153                 if ((lseek(fd, 0, SEEK_SET) < 0) ||
 154                     (write(fd, (void *)boot_sect, SECTOR_SIZE) < 0)) {
 155                         perror("failed to update MBR");
 156                         exit(-1);
 157                 }
 158                 if (sol_part != -1) {
 159                         printf("Changed solaris partition %d", sol_part + 1);
 160                         if (setnew)
 161                                 printf("from 0x82 to 0xbf\n");
 162                         else
 163                                 printf("from 0xbf to 0x82\n");
 164                 }
 165                 if (write_mboot) {
 166                         printf("Replaced mboot program with %s\n", mboot_file);
 167                 }
 168         }
 169
 170         (void) close(fd);
 171         return (0);
 172 }