2 * Copyright (c) 2008 Luigi Rizzo
3 * Copyright (c) 1999 Robert Nordier
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
18 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS
19 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
20 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
21 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
22 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
24 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
25 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
31 #include <sys/param.h>
32 #include <sys/disklabel.h>
33 #include <sys/diskmbr.h>
46 #define MBRSIZE 512 /* master boot record size */
48 #define OFF_VERSION 0x1b0 /* offset: version number, only boot0version */
49 #define OFF_SERIAL 0x1b8 /* offset: volume serial number */
50 #define OFF_PTBL 0x1be /* offset: partition table */
51 #define OFF_MAGIC 0x1fe /* offset: magic number */
53 * Offsets to the parameters of the 512-byte boot block.
54 * For historical reasons they are set as macros
63 struct opt_offsets b0_ofs[] = {
64 { 0x0, 0x0, 0x0, 0x0 }, /* no boot block */
65 { 0x1b9, 0x1ba, 0x1bb, 0x1bc }, /* original block */
66 { 0x1b5, 0x1b6, 0x1b7, 0x1bc }, /* NT_SERIAL block */
69 int b0_ver; /* boot block version set by boot0bs */
71 #define OFF_OPT (b0_ofs[b0_ver].opt) /* default boot option */
72 #define OFF_DRIVE (b0_ofs[b0_ver].drive) /* setdrv drive */
73 #define OFF_FLAGS (b0_ofs[b0_ver].flags) /* option flags */
74 #define OFF_TICKS (b0_ofs[b0_ver].ticks) /* clock ticks */
77 #define cv2(p) ((p)[0] | (p)[1] << 010)
80 (p)[0] = (u_int8_t)(x), \
81 (p)[1] = (u_int8_t)((x) >> 010)
91 static const int nopt = sizeof(opttbl) / sizeof(opttbl[0]);
93 static const char fmt0[] = "# flag start chs type"
94 " end chs offset size\n";
96 static const char fmt1[] = "%d 0x%02x %4u:%3u:%2u 0x%02x"
97 " %4u:%3u:%2u %10u %10u\n";
99 static int read_mbr(const char *, u_int8_t **, int);
100 static void write_mbr(const char *, int, u_int8_t *, int);
101 static void display_mbr(u_int8_t *);
102 static int boot0version(const u_int8_t *);
103 static int boot0bs(const u_int8_t *);
104 static void stropt(const char *, int *, int *);
105 static int argtoi(const char *, int, int, int);
106 static int set_bell(u_int8_t *, int, int);
107 static void usage(void);
109 unsigned vol_id[5]; /* 4 plus 1 for flag */
113 * Boot manager installation/configuration utility.
116 main(int argc, char *argv[])
118 u_int8_t *mbr, *boot0;
119 int boot0_size, mbr_size;
120 const char *bpath, *fpath;
123 int d_arg, m_arg, s_arg, t_arg;
124 int o_and, o_or, o_e = -1;
127 bpath = "/boot/boot0";
129 B_flag = v_flag = o_flag = 0;
130 d_arg = m_arg = s_arg = t_arg = -1;
133 while ((c = getopt(argc, argv, "Bvb:d:e:f:i:m:o:s:t:")) != -1)
145 d_arg = argtoi(optarg, 0, 0xff, 'd');
148 if (optarg[0] == '0' && optarg[1] == 'x')
149 sscanf(optarg, "0x%02x", &o_e);
157 if (sscanf(optarg, "%02x%02x-%02x%02x",
158 vol_id, vol_id+1, vol_id+2, vol_id+3) == 4)
161 errx(1, "bad argument %s", optarg);
164 m_arg = argtoi(optarg, 0, 0xf, 'm');
167 stropt(optarg, &o_and, &o_or);
171 if (strcasecmp(optarg, "pxe") == 0)
174 s_arg = argtoi(optarg, 1, 6, 's');
177 t_arg = argtoi(optarg, 1, 0xffff, 't');
186 disk = g_device_path(*argv);
188 errx(1, "Unable to get providername for %s\n", *argv);
189 up = B_flag || d_arg != -1 || m_arg != -1 || o_flag || s_arg != -1
192 /* open the disk and read in the existing mbr. Either here or
193 * when reading the block from disk, we do check for the version
194 * and abort if a suitable block is not found.
196 mbr_size = read_mbr(disk, &mbr, !B_flag);
198 /* save the existing MBR if we are asked to do so */
200 write_mbr(fpath, O_CREAT | O_TRUNC, mbr, mbr_size);
203 * If we are installing the boot loader, read it from disk and copy the
204 * slice table over from the existing MBR. If not, then point boot0
205 * back at the MBR we just read in. After this, boot0 is the data to
206 * write back to disk if we are going to do a write.
209 boot0_size = read_mbr(bpath, &boot0, 1);
210 memcpy(boot0 + OFF_PTBL, mbr + OFF_PTBL,
211 sizeof(struct dos_partition) * NDOSPART);
212 if (b0_ver == 2) /* volume serial number support */
213 memcpy(boot0 + OFF_SERIAL, mbr + OFF_SERIAL, 4);
216 boot0_size = mbr_size;
221 boot0[OFF_DRIVE] = d_arg;
223 /* set various flags */
225 boot0[OFF_FLAGS] &= 0xf0;
226 boot0[OFF_FLAGS] |= m_arg;
229 boot0[OFF_FLAGS] &= o_and;
230 boot0[OFF_FLAGS] |= o_or;
233 /* set the default boot selection */
235 boot0[OFF_OPT] = s_arg - 1;
237 /* set the timeout */
239 mk2(boot0 + OFF_TICKS, t_arg);
241 /* set the bell char */
242 if (o_e != -1 && set_bell(boot0, o_e, 0) != -1)
247 errx(1, "incompatible boot block, cannot set volume ID");
248 boot0[OFF_SERIAL] = vol_id[0];
249 boot0[OFF_SERIAL+1] = vol_id[1];
250 boot0[OFF_SERIAL+2] = vol_id[2];
251 boot0[OFF_SERIAL+3] = vol_id[3];
252 up = 1; /* force update */
254 /* write the MBR back to disk */
256 write_mbr(disk, 0, boot0, boot0_size);
258 /* display the MBR */
271 /* get or set the 'bell' character to be used in case of errors.
272 * Lookup for a certain code sequence, return -1 if not found.
275 set_bell(u_int8_t *mbr, int new_bell, int report)
277 /* lookup sequence: 0x100 means skip, 0x200 means done */
278 static unsigned seq[] =
279 { 0xb0, 0x100, 0xe8, 0x100, 0x100, 0x30, 0xe4, 0x200 };
281 for (ofs = 0x60; ofs < 0x180; ofs++) { /* search range */
282 if (mbr[ofs] != seq[0]) /* search initial pattern */
285 if (seq[i] == 0x200) { /* found */
288 mbr[ofs+1] = c = new_bell;
290 printf(" bell=%c (0x%x)",
291 (c >= ' ' && c < 0x7f) ? c : ' ', c);
294 if (seq[i] != 0x100 && seq[i] != mbr[ofs+i])
298 warn("bell not found");
302 * Read in the MBR of the disk. If it is boot0, then use the version to
303 * read in all of it if necessary. Use pointers to return a malloc'd
304 * buffer containing the MBR and then return its size.
307 read_mbr(const char *disk, u_int8_t **mbr, int check_version)
309 u_int8_t buf[MBRSIZE];
314 if ((fd = open(disk, O_RDONLY)) == -1)
315 err(1, "open %s", disk);
316 if ((n = read(fd, buf, MBRSIZE)) == -1)
317 err(1, "read %s", disk);
319 errx(1, "%s: short read", disk);
320 if (cv2(buf + OFF_MAGIC) != 0xaa55)
321 errx(1, "%s: bad magic", disk);
323 if (! (ver = boot0bs(buf))) {
325 errx(1, "%s: unknown or incompatible boot code", disk);
326 } else if (boot0version(buf) == 0x101) {
328 if ((*mbr = malloc(mbr_size)) == NULL)
329 errx(1, "%s: unable to allocate read buffer", disk);
330 if (lseek(fd, 0, SEEK_SET) == -1 ||
331 (n = read(fd, *mbr, mbr_size)) == -1)
334 errx(1, "%s: short read", disk);
337 *mbr = malloc(sizeof(buf));
338 memcpy(*mbr, buf, sizeof(buf));
344 * Write out the mbr to the specified file.
347 write_mbr(const char *fname, int flags, u_int8_t *mbr, int mbr_size)
353 struct gctl_req *grq;
355 fd = open(fname, O_WRONLY | flags, 0666);
357 n = write(fd, mbr, mbr_size);
360 errx(1, "%s: short write", fname);
365 * If we're called to write to a backup file, don't try to
366 * write through GEOM. It only generates additional errors.
371 /* Try open it read only. */
372 fd = open(fname, O_RDONLY);
374 warn("error opening %s", fname);
377 pname = g_providername(fd);
379 warn("error getting providername for %s", fname);
382 grq = gctl_get_handle();
383 gctl_ro_param(grq, "class", -1, "PART");
384 gctl_ro_param(grq, "arg0", -1, pname);
385 gctl_ro_param(grq, "verb", -1, "bootcode");
386 gctl_ro_param(grq, "bootcode", mbr_size, mbr);
387 gctl_ro_param(grq, "flags", -1, "C");
388 errmsg = gctl_issue(grq);
392 grq = gctl_get_handle();
393 gctl_ro_param(grq, "verb", -1, "write MBR");
394 gctl_ro_param(grq, "class", -1, "MBR");
395 gctl_ro_param(grq, "geom", -1, pname);
396 gctl_ro_param(grq, "data", mbr_size, mbr);
397 errmsg = gctl_issue(grq);
399 err(1, "write_mbr: %s", fname);
407 * Outputs an informative dump of the data in the MBR to stdout.
410 display_mbr(u_int8_t *mbr)
412 struct dos_partition *part;
415 part = (struct dos_partition *)(mbr + DOSPARTOFF);
417 for (i = 0; i < NDOSPART; i++)
419 printf(fmt1, 1 + i, part[i].dp_flag,
420 part[i].dp_scyl + ((part[i].dp_ssect & 0xc0) << 2),
421 part[i].dp_shd, part[i].dp_ssect & 0x3f, part[i].dp_typ,
422 part[i].dp_ecyl + ((part[i].dp_esect & 0xc0) << 2),
423 part[i].dp_ehd, part[i].dp_esect & 0x3f, part[i].dp_start,
426 version = boot0version(mbr);
427 printf("version=%d.%d drive=0x%x mask=0x%x ticks=%u",
428 version >> 8, version & 0xff, mbr[OFF_DRIVE],
429 mbr[OFF_FLAGS] & 0xf, cv2(mbr + OFF_TICKS));
431 printf("\noptions=");
432 for (i = 0; i < nopt; i++) {
435 if (!(mbr[OFF_FLAGS] & 1 << (7 - i)) ^ opttbl[i].def)
437 printf("%s", opttbl[i].tok);
441 printf("volume serial ID %02x%02x-%02x%02x\n",
442 mbr[OFF_SERIAL], mbr[OFF_SERIAL+1],
443 mbr[OFF_SERIAL+2], mbr[OFF_SERIAL+3]);
444 printf("default_selection=F%d (", mbr[OFF_OPT] + 1);
445 if (mbr[OFF_OPT] < 4)
446 printf("Slice %d", mbr[OFF_OPT] + 1);
447 else if (mbr[OFF_OPT] == 4)
455 * Return the boot0 version with the minor revision in the low byte, and
456 * the major revision in the next higher byte.
459 boot0version(const u_int8_t *bs)
461 /* Check for old version, and return 0x100 if found. */
466 /* We have a newer boot0, so extract the version number and return it. */
467 return *(const int *)(bs + OFF_VERSION) & 0xffff;
470 /* descriptor of a pattern to match.
471 * Start from the first entry trying to match the chunk of bytes,
472 * if you hit an entry with len=0 terminate the search and report
473 * off as the version. Otherwise skip to the next block after len=0
474 * An entry with len=0, off=0 is the end marker.
476 struct byte_pattern {
483 * Decide if we have valid boot0 boot code by looking for
484 * characteristic byte sequences at fixed offsets.
487 boot0bs(const u_int8_t *bs)
489 /* the initial code sequence */
490 static u_int8_t id0[] = {0xfc, 0x31, 0xc0, 0x8e, 0xc0, 0x8e, 0xd8,
491 0x8e, 0xd0, 0xbc, 0x00, 0x7c };
493 static u_int8_t id1[] = {'D', 'r', 'i', 'v', 'e', ' '};
494 static struct byte_pattern patterns[] = {
495 {0x0, sizeof(id0), id0},
496 {0x1b2, sizeof(id1), id1},
498 {0x0, sizeof(id0), id0}, /* version with NT support */
499 {0x1ae, sizeof(id1), id1},
503 struct byte_pattern *p = patterns;
505 for (; p->off || p->len; p++) {
508 if (!memcmp(bs + p->off, p->key, p->len)) /* match */
510 while (p->len) /* skip to next block */
513 b0_ver = p->off; /* XXX ugly side effect */
518 * Adjust "and" and "or" masks for a -o option argument.
521 stropt(const char *arg, int *xa, int *xo)
527 if (!(s = strdup(arg)))
529 for (s1 = s; (q = strtok(s1, ",")); s1 = NULL) {
530 if ((inv = !strncmp(q, "no", 2)))
532 for (i = 0; i < nopt; i++)
533 if (!strcmp(q, opttbl[i].tok))
536 errx(1, "%s: Unknown -o option", q);
549 * Convert and check an option argument.
552 argtoi(const char *arg, int lo, int hi, int opt)
558 x = strtol(arg, &s, 0);
559 if (errno || !*arg || *s || x < lo || x > hi)
560 errx(1, "%s: Bad argument to -%c option", arg, opt);
565 * Display usage information.
570 fprintf(stderr, "%s\n%s\n",
571 "usage: boot0cfg [-Bv] [-b boot0] [-d drive] [-f file] [-m mask]",
572 " [-o options] [-s slice] [-t ticks] disk");