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");