1 /* $OpenBSD: landisk_installboot.c,v 1.12 2022/12/28 21:30:16 jmc Exp $ */
2
3 /*
4 * Copyright (c) 2013 Joel Sing <jsing@openbsd.org>
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18
19 #include <sys/param.h> /* DEV_BSIZE */
20 #include <sys/disklabel.h>
21 #include <sys/dkio.h>
22 #include <sys/ioctl.h>
23 #include <sys/stat.h>
24
25 #include <ufs/ffs/fs.h>
26
27 #include <err.h>
28 #include <fcntl.h>
29 #include <stdio.h>
30 #include <stdlib.h>
31 #include <string.h>
32 #include <unistd.h>
33
34 #include "installboot.h"
35
36 void md_bootstrap(int, char *, char *);
37
38 char *bootldr;
39
40 void
md_init(void)41 md_init(void)
42 {
43 stages = 2;
44 stage1 = "/usr/mdec/xxboot";
45 stage2 = "/usr/mdec/boot";
46
47 bootldr = "/boot";
48 }
49
50 void
md_loadboot(void)51 md_loadboot(void)
52 {
53 }
54
55 void
md_prepareboot(int devfd,char * dev)56 md_prepareboot(int devfd, char *dev)
57 {
58 }
59
60 void
md_installboot(int devfd,char * dev)61 md_installboot(int devfd, char *dev)
62 {
63 /* XXX - is this necessary? */
64 sync();
65
66 bootldr = fileprefix(root, bootldr);
67 if (bootldr == NULL)
68 exit(1);
69 if (!nowrite)
70 if (filecopy(stage2, bootldr) == -1)
71 exit(1);
72
73 /*
74 * Write bootblock into the beginning of the OpenBSD partition or
75 * at the beginning of the disk.
76 */
77 md_bootstrap(devfd, dev, stage1);
78 }
79
80 void
md_bootstrap(int devfd,char * dev,char * bootfile)81 md_bootstrap(int devfd, char *dev, char *bootfile)
82 {
83 struct disklabel dl;
84 struct disklabel *lp;
85 struct partition *pp;
86 char *boot, *p, part;
87 size_t bootsize;
88 size_t bootsec;
89 struct stat sb;
90 daddr_t bootpos = 0;
91 int fd, i;
92
93 /*
94 * Install bootstrap code onto the given disk, preserving the
95 * existing disklabel.
96 */
97
98 /* Read disklabel from disk. */
99 if (ioctl(devfd, DIOCGDINFO, &dl) == -1)
100 err(1, "disklabel");
101 if (dl.d_secsize == 0) {
102 warnx("disklabel has sector size of 0, assuming %d", DEV_BSIZE);
103 dl.d_secsize = DEV_BSIZE;
104 }
105
106 /* Read bootstrap file. */
107 if (verbose)
108 fprintf(stderr, "reading bootstrap from %s\n", bootfile);
109 fd = open(bootfile, O_RDONLY);
110 if (fd == -1)
111 err(1, "open %s", bootfile);
112 if (fstat(fd, &sb) == -1)
113 err(1, "fstat %s", bootfile);
114 bootsec = howmany((ssize_t)sb.st_size, dl.d_secsize);
115 bootsize = bootsec * dl.d_secsize;
116 if (verbose)
117 fprintf(stderr, "bootstrap is %zu bytes "
118 "(%zu sectors @ %u bytes = %zu bytes)\n",
119 (ssize_t)sb.st_size, bootsec, dl.d_secsize, bootsize);
120 boot = calloc(1, bootsize);
121 if (boot == NULL)
122 err(1, "calloc");
123 if (read(fd, boot, bootsize) != (ssize_t)sb.st_size)
124 err(1, "read");
125 close(fd);
126
127 /*
128 * The landisk bootstrap can work when put either at the start of the
129 * disk, or at the start of an OpenBSD MBR partition, invoked from
130 * /usr/mdec/mbr.
131 * Check for a partition table in order to decide where to put the
132 * first-level bootstrap code.
133 */
134
135 if (dl.d_secsize >= sizeof(struct dos_mbr)) {
136 uint8_t *secbuf;
137 struct dos_mbr *mbr;
138
139 secbuf = malloc(dl.d_secsize);
140 if (secbuf == NULL)
141 err(1, "malloc");
142
143 /* Read MBR. */
144 if (pread(devfd, secbuf, dl.d_secsize, 0) != dl.d_secsize)
145 err(4, "can't read mbr");
146 mbr = (struct dos_mbr *)secbuf;
147 /* safe check because landisk is little endian */
148 if (mbr->dmbr_sign == DOSMBR_SIGNATURE) {
149 for (i = 0; i < NDOSPART; i++) {
150 if (mbr->dmbr_parts[i].dp_typ ==
151 DOSPTYP_OPENBSD) {
152 bootpos = mbr->dmbr_parts[i].dp_start;
153 break;
154 }
155 }
156 }
157
158 free(secbuf);
159 }
160
161 if (bootpos == 0) {
162 /*
163 * Installing at the start of the disk.
164 * Check that the bootstrap will fit - partitions must not
165 * overlap, or if they do, the partition type must be either
166 * FS_BOOT or FS_UNUSED. The 'c' partition will always overlap
167 * and is ignored.
168 */
169 if (verbose)
170 fprintf(stderr,
171 "ensuring used partitions do not overlap "
172 "with bootstrap sectors 0-%zu\n", bootsec);
173 for (i = 0; i < dl.d_npartitions; i++) {
174 part = 'a' + i;
175 pp = &dl.d_partitions[i];
176 if (i == RAW_PART)
177 continue;
178 if (DL_GETPSIZE(pp) == 0)
179 continue;
180 if (bootpos + (u_int64_t)bootsec <= DL_GETPOFFSET(pp))
181 continue;
182 switch (pp->p_fstype) {
183 case FS_BOOT:
184 break;
185 case FS_UNUSED:
186 warnx("bootstrap overlaps "
187 "with unused partition %c", part);
188 break;
189 default:
190 errx(1, "bootstrap overlaps with partition %c",
191 part);
192 }
193 }
194 } else {
195 /*
196 * Installing at the start of the OpenBSD partition.
197 * We only need to ensure the bootstrap code fits in the
198 * BBSIZE reserved area at the beginning of the file
199 * system.
200 */
201 if (bootsize > BBSIZE)
202 errx(1, "bootstrap is too large");
203 }
204
205 /*
206 * Make sure the bootstrap has left space for the disklabel.
207 * N.B.: LABELSECTOR *is* a DEV_BSIZE quantity!
208 */
209 lp = (struct disklabel *)(boot + (LABELSECTOR * DEV_BSIZE) +
210 LABELOFFSET);
211 for (i = 0, p = (char *)lp; i < (int)sizeof(*lp); i++)
212 if (p[i] != 0)
213 errx(1, "bootstrap has data in disklabel area");
214
215 /* Patch the disklabel into the bootstrap code. */
216 memcpy(lp, &dl, sizeof(dl));
217
218 /* Write the bootstrap out to the disk. */
219 bootpos *= dl.d_secsize;
220 if (verbose)
221 fprintf(stderr, "%s bootstrap to disk at offset %llx\n",
222 (nowrite ? "would write" : "writing"), bootpos);
223 if (nowrite)
224 return;
225 if (pwrite(devfd, boot, bootsize, bootpos) != (ssize_t)bootsize)
226 err(1, "pwrite");
227 }
228