xref: /titanic_41/usr/src/cmd/boot/mbr/mbr.c (revision 1e49577a7fcde812700ded04431b49d67cc57d6d)
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 		if (setnew && part->systid == 0x82) {
125 			part->systid = 0xbf;
126 			sol_part = i;
127 		} else if (setold && part->systid == 0xbf) {
128 			part->systid = 0x82;
129 			sol_part = i;
130 		} else if (list_hd &&
131 		    (part->systid == 0x82 || part->systid == 0xbf)) {
132 			sol_part = i;
133 		}
134 		if (!list_hd)
135 			printf("%d (0x%2x): start_sect %u, size_sect %u\n",
136 			    i + 1, part->systid, part->relsect, part->numsect);
137 	}
138 
139 	if (list_hd) {
140 		printf("(hd0,%d,a)\n", sol_part);
141 		(void) close(fd);
142 		return (0);
143 	}
144 
145 	/* write new mboot */
146 	if (write_mboot || sol_part != -1) {
147 		if (write_mboot) {
148 			/* copy over the new boot program */
149 			bcopy((void *)new_mboot, (void *)boot_sect, BOOTSZ);
150 		}
151 
152 		if ((lseek(fd, 0, SEEK_SET) < 0) ||
153 		    (write(fd, (void *)boot_sect, SECTOR_SIZE) < 0)) {
154 			perror("failed to update MBR");
155 			exit(-1);
156 		}
157 		if (sol_part != -1) {
158 			printf("Changed solaris partition %d", sol_part + 1);
159 			if (setnew)
160 				printf("from 0x82 to 0xbf\n");
161 			else
162 				printf("from 0xbf to 0x82\n");
163 		}
164 		if (write_mboot) {
165 			printf("Replaced mboot program with %s\n", mboot_file);
166 		}
167 	}
168 
169 	(void) close(fd);
170 	return (0);
171 }
172