2 * Copyright (c) 1999 Robert Nordier
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
17 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS
18 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
19 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
20 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
21 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
22 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
23 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
24 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 * $FreeBSD: src/usr.sbin/boot0cfg/boot0cfg.c,v 1.7.2.4 2002/03/16 01:06:51 mikeh Exp $
29 #include <sys/param.h>
30 #include <sys/diskmbr.h>
43 #define MBRSIZE 512 /* master boot record size */
45 #define OFF_VERSION 0x1b0 /* offset: version number */
46 #define OFF_OPT 0x1b9 /* offset: default boot option */
47 #define OFF_DRIVE 0x1ba /* offset: setdrv drive */
48 #define OFF_FLAGS 0x1bb /* offset: option flags */
49 #define OFF_TICKS 0x1bc /* offset: clock ticks */
50 #define OFF_PTBL 0x1be /* offset: partition table */
51 #define OFF_MAGIC 0x1fe /* offset: magic number */
53 #define cv2(p) ((p)[0] | (p)[1] << 010)
56 (p)[0] = (u_int8_t)(x), \
57 (p)[1] = (u_int8_t)((x) >> 010)
67 static const int nopt = sizeof(opttbl) / sizeof(opttbl[0]);
69 static const char fmt0[] = "# flag start chs type"
70 " end chs offset size\n";
72 static const char fmt1[] = "%d 0x%02x %4u:%3u:%2u 0x%02x"
73 " %4u:%3u:%2u %10u %10u\n";
75 static int read_mbr(const char *, u_int8_t **, int);
76 static void write_mbr(const char *, int, u_int8_t *, int);
77 static void display_mbr(u_int8_t *);
78 static int boot0version(const u_int8_t *);
79 static int boot0bs(const u_int8_t *);
80 static void stropt(const char *, int *, int *);
81 static int argtoi(const char *, int, int, int);
82 static void usage(void);
85 * Boot manager installation/configuration utility.
88 main(int argc, char *argv[])
90 u_int8_t *mbr, *boot0;
91 int boot0_size, mbr_size;
92 const char *bpath, *fpath;
94 int B_flag, v_flag, o_flag;
95 int d_arg, m_arg, s_arg, t_arg;
99 bpath = "/boot/boot0";
101 B_flag = v_flag = o_flag = 0;
102 d_arg = m_arg = s_arg = t_arg = -1;
105 while ((c = getopt(argc, argv, "Bvb:d:f:m:o:s:t:")) != -1)
117 d_arg = argtoi(optarg, 0, 0xff, 'd');
123 m_arg = argtoi(optarg, 0, 0xf, 'm');
126 stropt(optarg, &o_and, &o_or);
130 s_arg = argtoi(optarg, 1, 5, 's');
133 t_arg = argtoi(optarg, 1, 0xffff, 't');
143 disk = getdevpath(*argv, 0);
145 err(1, "cannot open disk %s", disk);
147 up = B_flag || d_arg != -1 || m_arg != -1 || o_flag || s_arg != -1
150 /* open the disk and read in the existing mbr */
151 mbr_size = read_mbr(disk, &mbr, !B_flag);
153 /* save the existing MBR if we are asked to do so */
155 write_mbr(fpath, O_CREAT | O_TRUNC, mbr, mbr_size);
158 * If we are installing the boot loader, read it from disk and copy the
159 * slice table over from the existing MBR. If not, then point boot0
160 * back at the MBR we just read in. After this, boot0 is the data to
161 * write back to disk if we are going to do a write.
164 boot0_size = read_mbr(bpath, &boot0, 1);
165 memcpy(boot0 + OFF_PTBL, mbr + OFF_PTBL,
166 sizeof(struct dos_partition) * NDOSPART);
169 boot0_size = mbr_size;
174 boot0[OFF_DRIVE] = d_arg;
176 /* set various flags */
178 boot0[OFF_FLAGS] &= 0xf0;
179 boot0[OFF_FLAGS] |= m_arg;
182 boot0[OFF_FLAGS] &= o_and;
183 boot0[OFF_FLAGS] |= o_or;
186 /* set the default boot selection */
188 boot0[OFF_OPT] = s_arg - 1;
190 /* set the timeout */
192 mk2(boot0 + OFF_TICKS, t_arg);
194 /* write the MBR back to disk */
196 write_mbr(disk, 0, boot0, boot0_size);
198 /* display the MBR */
212 * Read in the MBR of the disk. If it is boot0, then use the version to
213 * read in all of it if necessary. Use pointers to return a malloc'd
214 * buffer containing the MBR and then return its size.
217 read_mbr(const char *disk, u_int8_t **mbr, int check_version)
219 u_int8_t buf[MBRSIZE];
223 if ((fd = open(disk, O_RDONLY)) == -1)
224 err(1, "open %s", disk);
225 if ((n = read(fd, buf, MBRSIZE)) == -1)
226 err(1, "read %s", disk);
228 errx(1, "%s: short read", disk);
229 if (cv2(buf + OFF_MAGIC) != 0xaa55)
230 errx(1, "%s: bad magic", disk);
234 errx(1, "%s: unknown or incompatible boot code", disk);
235 } else if (boot0version(buf) == 0x101) {
237 if ((*mbr = malloc(mbr_size)) == NULL)
238 errx(1, "%s: unable to allocate read buffer", disk);
239 if (lseek(fd, 0, SEEK_SET) == -1 ||
240 (n = read(fd, *mbr, mbr_size)) == -1)
243 errx(1, "%s: short read", disk);
248 if ((*mbr = malloc(sizeof(buf))) == NULL)
249 errx(1, "%s: unable to allocate mbr buffer", disk);
250 memcpy(*mbr, buf, sizeof(buf));
256 * Write out the mbr to the specified file.
259 write_mbr(const char *fname, int flags, u_int8_t *mbr, int mbr_size)
264 fd = open(fname, O_WRONLY | flags, 0666);
266 n = write(fd, mbr, mbr_size);
269 errx(1, "%s: short write", fname);
274 err(1, "write_mbr: %s", fname);
278 * Outputs an informative dump of the data in the MBR to stdout.
281 display_mbr(u_int8_t *mbr)
283 struct dos_partition *part;
286 part = (struct dos_partition *)(mbr + DOSPARTOFF);
288 for (i = 0; i < NDOSPART; i++)
290 printf(fmt1, 1 + i, part[i].dp_flag,
291 part[i].dp_scyl + ((part[i].dp_ssect & 0xc0) << 2),
292 part[i].dp_shd, part[i].dp_ssect & 0x3f, part[i].dp_typ,
293 part[i].dp_ecyl + ((part[i].dp_esect & 0xc0) << 2),
294 part[i].dp_ehd, part[i].dp_esect & 0x3f, part[i].dp_start,
297 version = boot0version(mbr);
298 printf("version=%d.%d drive=0x%x mask=0x%x ticks=%u\noptions=",
299 version >> 8, version & 0xff, mbr[OFF_DRIVE],
300 mbr[OFF_FLAGS] & 0xf, cv2(mbr + OFF_TICKS));
301 for (i = 0; i < nopt; i++) {
304 if (!(mbr[OFF_FLAGS] & 1 << (7 - i)) ^ opttbl[i].def)
306 printf("%s", opttbl[i].tok);
309 printf("default_selection=F%d (", mbr[OFF_OPT] + 1);
310 if (mbr[OFF_OPT] < 4)
311 printf("Slice %d", mbr[OFF_OPT] + 1);
318 * Return the boot0 version with the minor revision in the low byte, and
319 * the major revision in the next higher byte.
322 boot0version(const u_int8_t *bs)
324 static u_int8_t idold[] = {0xfe, 0x45, 0xf2, 0xe9, 0x00, 0x8a};
326 /* Check for old version, and return 0x100 if found. */
327 if (memcmp(bs + 0x1c, idold, sizeof(idold)) == 0)
330 /* We have a newer boot0, so extract the version number and return it. */
331 return *(const int *)(bs + OFF_VERSION) & 0xffff;
335 * Decide if we have valid boot0 boot code by looking for
336 * characteristic byte sequences at fixed offsets.
339 boot0bs(const u_int8_t *bs)
341 static u_int8_t id0[] = {0xfc, 0x31, 0xc0, 0x8e, 0xc0, 0x8e, 0xd8,
342 0x8e, 0xd0, 0xbc, 0x00, 0x7c };
343 static u_int8_t id1[] = {0xfc, 0xb8, 0x00, 0x09, 0x8e, 0xc0, 0x8e,
344 0xd0, 0xbc, 0x00, 0x10 ,0x31 };
345 static u_int8_t id2[] = {'D', 'r', 'i', 'v', 'e', ' '};
351 {0x0, sizeof(id0), id0},
352 {0x0, sizeof(id1), id1},
353 {0x1b2, sizeof(id2), id2}
358 for (i = 0; i < sizeof(ident) / sizeof(ident[0]); i++) {
359 if (memcmp(bs + ident[i].off, ident[i].key, ident[i].len) == 0)
368 * Adjust "and" and "or" masks for a -o option argument.
371 stropt(const char *arg, int *xa, int *xo)
377 if (!(s = strdup(arg)))
379 for (s1 = s; (q = strtok(s1, ",")); s1 = NULL) {
380 if ((inv = !strncmp(q, "no", 2)))
382 for (i = 0; i < nopt; i++)
383 if (!strcmp(q, opttbl[i].tok))
386 errx(1, "%s: Unknown -o option", q);
399 * Convert and check an option argument.
402 argtoi(const char *arg, int lo, int hi, int opt)
408 x = strtol(arg, &s, 0);
409 if (errno || !*arg || *s || x < lo || x > hi)
410 errx(1, "%s: Bad argument to -%c option", arg, opt);
415 * Display usage information.
420 fprintf(stderr, "%s\n%s\n",
421 "usage: boot0cfg [-Bv] [-b boot0] [-d drive] [-f file] [-m mask]",
422 " [-o options] [-s slice] [-t ticks] disk");