2 * Copyright (c) 1994 Bruce D. Evans.
5 * Copyright (c) 1982, 1986, 1988 Regents of the University of California.
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by the University of
19 * California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * from: @(#)ufs_disksubr.c 7.16 (Berkeley) 5/4/91
37 * from: ufs_disksubr.c,v 1.8 1994/06/07 01:21:39 phk Exp $
38 * $FreeBSD: src/sys/kern/subr_diskmbr.c,v 1.45 2000/01/28 10:22:07 bde Exp $
39 * $DragonFly: src/sys/kern/subr_diskmbr.c,v 1.24 2007/05/19 09:46:18 dillon Exp $
42 #include <sys/param.h>
43 #include <sys/systm.h>
46 #include <sys/diskslice.h>
47 #define DOSPTYP_EXTENDED 5
48 #define DOSPTYP_EXTENDEDX 15
49 #define DOSPTYP_ONTRACK 84
50 #include <sys/diskslice.h>
51 #include <sys/diskmbr.h>
53 #include <sys/malloc.h>
54 #include <sys/syslog.h>
55 #include <sys/device.h>
57 #define TRACE(str) do { if (dsi_debug) kprintf str; } while (0)
59 static volatile u_char dsi_debug
;
62 * This is what we have embedded in every boot1 for supporting the bogus
63 * "Dangerously Dedicated" mode. However, the old table is broken because
64 * it has an illegal geometry in it - it specifies 256 heads (heads = end
65 * head + 1) which causes nasty stuff when that wraps to zero in bios code.
66 * eg: divide by zero etc. This caused the dead-thinkpad problem, numerous
67 * SCSI bios crashes, EFI to crash, etc.
69 * We still have to recognize the old table though, even though we stopped
70 * inflicting it upon the world.
72 static struct dos_partition historical_bogus_partition_table
[NDOSPART
] = {
73 { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, },
74 { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, },
75 { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, },
76 { 0x80, 0, 1, 0, DOSPTYP_386BSD
, 255, 255, 255, 0, 50000, },
78 static struct dos_partition historical_bogus_partition_table_fixed
[NDOSPART
] = {
79 { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, },
80 { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, },
81 { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, },
82 { 0x80, 0, 1, 0, DOSPTYP_386BSD
, 254, 255, 255, 0, 50000, },
85 static int check_part (char *sname
, struct dos_partition
*dp
,
86 u_int64_t offset
, int nsectors
, int ntracks
,
87 u_int64_t mbr_offset
);
88 static void mbr_extended (cdev_t dev
, struct disk_info
*info
,
89 struct diskslices
*ssp
, u_int64_t ext_offset
,
90 u_int64_t ext_size
, u_int64_t base_ext_offset
,
91 int nsectors
, int ntracks
, u_int64_t mbr_offset
,
93 static int mbr_setslice (char *sname
, struct disk_info
*info
,
94 struct diskslice
*sp
, struct dos_partition
*dp
,
99 mbrinit(cdev_t dev
, struct disk_info
*info
, struct diskslices
**sspp
)
104 struct dos_partition
*dp
;
105 struct dos_partition
*dp0
;
106 struct dos_partition dpcopy
[NDOSPART
];
111 u_int64_t mbr_offset
;
115 struct diskslice
*sp
;
116 struct diskslices
*ssp
;
119 mbr_offset
= DOSBBSECTOR
;
121 if (info
->d_media_blksize
& DEV_BMASK
)
123 /* Read master boot record. */
124 wdev
= dkmodpart(dkmodslice(dev
, WHOLE_DISK_SLICE
), WHOLE_SLICE_PART
);
125 bp
= geteblk((int)info
->d_media_blksize
);
126 bp
->b_bio1
.bio_offset
= (off_t
)mbr_offset
* info
->d_media_blksize
;
127 bp
->b_bcount
= info
->d_media_blksize
;
128 bp
->b_cmd
= BUF_CMD_READ
;
129 dev_dstrategy(wdev
, &bp
->b_bio1
);
130 if (biowait(bp
) != 0) {
131 diskerr(&bp
->b_bio1
, wdev
,
132 "reading primary partition table: error",
139 /* Weakly verify it. */
141 sname
= dsname(dev
, dkunit(dev
), WHOLE_DISK_SLICE
, WHOLE_SLICE_PART
, partname
);
142 if (cp
[0x1FE] != 0x55 || cp
[0x1FF] != 0xAA) {
144 kprintf("%s: invalid primary partition table: no magic\n",
150 /* Make a copy of the partition table to avoid alignment problems. */
151 memcpy(&dpcopy
[0], cp
+ DOSPARTOFF
, sizeof(dpcopy
));
155 /* Check for "Ontrack Diskmanager". */
156 for (dospart
= 0, dp
= dp0
; dospart
< NDOSPART
; dospart
++, dp
++) {
157 if (dp
->dp_typ
== DOSPTYP_ONTRACK
) {
160 "%s: Found \"Ontrack Disk Manager\" on this disk.\n", sname
);
161 bp
->b_flags
|= B_INVAL
| B_AGE
;
168 if (bcmp(dp0
, historical_bogus_partition_table
,
169 sizeof historical_bogus_partition_table
) == 0 ||
170 bcmp(dp0
, historical_bogus_partition_table_fixed
,
171 sizeof historical_bogus_partition_table_fixed
) == 0) {
173 TRACE(("%s: invalid primary partition table: historical\n",
178 "%s: invalid primary partition table: Dangerously Dedicated (ignored)\n",
184 /* Guess the geometry. */
187 * Perhaps skip entries with 0 size.
188 * Perhaps only look at entries of type DOSPTYP_386BSD.
193 for (dospart
= 0, dp
= dp0
; dospart
< NDOSPART
; dospart
++, dp
++) {
198 ncyls
= DPCYL(dp
->dp_ecyl
, dp
->dp_esect
) + 1;
199 if (max_ncyls
< ncyls
)
201 nsectors
= DPSECT(dp
->dp_esect
);
202 if (max_nsectors
< nsectors
)
203 max_nsectors
= nsectors
;
204 ntracks
= dp
->dp_ehd
+ 1;
205 if (max_ntracks
< ntracks
)
206 max_ntracks
= ntracks
;
210 * Check that we have guessed the geometry right by checking the
216 * Check for overlaps.
217 * Check against d_secperunit if the latter is reliable.
220 for (dospart
= 0, dp
= dp0
; dospart
< NDOSPART
; dospart
++, dp
++) {
221 if (dp
->dp_scyl
== 0 && dp
->dp_shd
== 0 && dp
->dp_ssect
== 0
222 && dp
->dp_start
== 0 && dp
->dp_size
== 0)
224 sname
= dsname(dev
, dkunit(dev
), BASE_SLICE
+ dospart
,
225 WHOLE_SLICE_PART
, partname
);
228 * Temporarily ignore errors from this check. We could
229 * simplify things by accepting the table eariler if we
230 * always ignore errors here. Perhaps we should always
231 * accept the table if the magic is right but not let
232 * bad entries affect the geometry.
234 check_part(sname
, dp
, mbr_offset
, max_nsectors
, max_ntracks
,
241 * Accept the DOS partition table.
243 * Adjust the disk information structure with updated CHS
244 * conversion parameters, but only use values extracted from
245 * the primary partition table.
247 * NOTE! Regardless of our having to deal with this old cruft,
248 * we do not screw around with the info->d_media* parameters.
250 secpercyl
= (u_long
)max_nsectors
* max_ntracks
;
251 if (secpercyl
!= 0 && mbr_offset
== DOSBBSECTOR
) {
252 info
->d_secpertrack
= max_nsectors
;
253 info
->d_nheads
= max_ntracks
;
254 info
->d_secpercyl
= secpercyl
;
255 info
->d_ncylinders
= info
->d_media_blocks
/ secpercyl
;
259 * We are passed a pointer to a suitably initialized minimal
260 * slices "struct" with no dangling pointers in it. Replace it
261 * by a maximal one. This usually oversizes the "struct", but
262 * enlarging it while searching for logical drives would be
265 kfree(*sspp
, M_DEVBUF
);
266 ssp
= dsmakeslicestruct(MAX_SLICES
, info
);
269 /* Initialize normal slices. */
270 sp
= &ssp
->dss_slices
[BASE_SLICE
];
271 for (dospart
= 0, dp
= dp0
; dospart
< NDOSPART
; dospart
++, dp
++, sp
++) {
272 sname
= dsname(dev
, dkunit(dev
), BASE_SLICE
+ dospart
,
273 WHOLE_SLICE_PART
, partname
);
274 (void)mbr_setslice(sname
, info
, sp
, dp
, mbr_offset
);
276 ssp
->dss_nslices
= BASE_SLICE
+ NDOSPART
;
278 /* Handle extended partitions. */
280 for (dospart
= 0; dospart
< NDOSPART
; dospart
++, sp
++) {
281 if (sp
->ds_type
== DOSPTYP_EXTENDED
||
282 sp
->ds_type
== DOSPTYP_EXTENDEDX
) {
283 mbr_extended(wdev
, info
, ssp
,
284 sp
->ds_offset
, sp
->ds_size
, sp
->ds_offset
,
285 max_nsectors
, max_ntracks
, mbr_offset
, 1);
290 * mbr_extended() abuses ssp->dss_nslices for the number of slices
291 * that would be found if there were no limit on the number of slices
292 * in *ssp. Cut it back now.
294 if (ssp
->dss_nslices
> MAX_SLICES
)
295 ssp
->dss_nslices
= MAX_SLICES
;
298 bp
->b_flags
|= B_INVAL
| B_AGE
;
306 check_part(char *sname
, struct dos_partition
*dp
, u_int64_t offset
,
307 int nsectors
, int ntracks
, u_int64_t mbr_offset
)
320 secpercyl
= (u_long
)nsectors
* ntracks
;
321 chs_scyl
= DPCYL(dp
->dp_scyl
, dp
->dp_ssect
);
322 chs_ssect
= DPSECT(dp
->dp_ssect
);
323 ssector
= chs_ssect
- 1 + dp
->dp_shd
* nsectors
+ chs_scyl
* secpercyl
325 ssector1
= offset
+ dp
->dp_start
;
328 * If ssector1 is on a cylinder >= 1024, then ssector can't be right.
329 * Allow the C/H/S for it to be 1023/ntracks-1/nsectors, or correct
330 * apart from the cylinder being reduced modulo 1024. Always allow
331 * 1023/255/63, because this is the official way to represent
332 * pure-LBA for the starting position.
334 if ((ssector
< ssector1
335 && ((chs_ssect
== nsectors
&& dp
->dp_shd
== ntracks
- 1
338 && (ssector1
- ssector
) % (1024 * secpercyl
) == 0)))
339 || (dp
->dp_scyl
== 255 && dp
->dp_shd
== 255
340 && dp
->dp_ssect
== 255)) {
341 TRACE(("%s: C/H/S start %d/%d/%d, start %llu: allow\n",
342 sname
, chs_scyl
, dp
->dp_shd
, chs_ssect
, ssector1
));
346 chs_ecyl
= DPCYL(dp
->dp_ecyl
, dp
->dp_esect
);
347 chs_esect
= DPSECT(dp
->dp_esect
);
348 esector
= chs_esect
- 1 + dp
->dp_ehd
* nsectors
+ chs_ecyl
* secpercyl
350 esector1
= ssector1
+ dp
->dp_size
- 1;
353 * Allow certain bogus C/H/S values for esector, as above. However,
354 * heads == 255 isn't really legal and causes some BIOS crashes. The
355 * correct value to indicate a pure-LBA end is 1023/heads-1/sectors -
356 * usually 1023/254/63. "heads" is base 0, "sectors" is base 1.
358 if ((esector
< esector1
359 && ((chs_esect
== nsectors
&& dp
->dp_ehd
== ntracks
- 1
362 && (esector1
- esector
) % (1024 * secpercyl
) == 0)))
363 || (dp
->dp_ecyl
== 255 && dp
->dp_ehd
== 255
364 && dp
->dp_esect
== 255)) {
365 TRACE(("%s: C/H/S end %d/%d/%d, end %llu: allow\n",
366 sname
, chs_ecyl
, dp
->dp_ehd
, chs_esect
, esector1
));
370 error
= (ssector
== ssector1
&& esector
== esector1
) ? 0 : EINVAL
;
372 kprintf("%s: type 0x%x, start %llu, end = %llu, size %lu %s\n",
373 sname
, dp
->dp_typ
, ssector1
, esector1
,
374 (u_long
)dp
->dp_size
, error
? "" : ": OK");
375 if (ssector
!= ssector1
&& bootverbose
)
376 kprintf("%s: C/H/S start %d/%d/%d (%llu) != start %llu: invalid\n",
377 sname
, chs_scyl
, dp
->dp_shd
, chs_ssect
,
379 if (esector
!= esector1
&& bootverbose
)
380 kprintf("%s: C/H/S end %d/%d/%d (%llu) != end %llu: invalid\n",
381 sname
, chs_ecyl
, dp
->dp_ehd
, chs_esect
,
388 mbr_extended(cdev_t dev
, struct disk_info
*info
, struct diskslices
*ssp
,
389 u_int64_t ext_offset
, u_int64_t ext_size
, u_int64_t base_ext_offset
,
390 int nsectors
, int ntracks
, u_int64_t mbr_offset
, int level
)
395 struct dos_partition
*dp
;
396 struct dos_partition dpcopy
[NDOSPART
];
397 u_int64_t ext_offsets
[NDOSPART
];
398 u_int64_t ext_sizes
[NDOSPART
];
402 struct diskslice
*sp
;
406 "%s: excessive recursion in search for slices; aborting search\n",
411 /* Read extended boot record. */
412 bp
= geteblk((int)info
->d_media_blksize
);
413 bp
->b_bio1
.bio_offset
= (off_t
)ext_offset
* info
->d_media_blksize
;
414 bp
->b_bcount
= info
->d_media_blksize
;
415 bp
->b_cmd
= BUF_CMD_READ
;
416 dev_dstrategy(dev
, &bp
->b_bio1
);
417 if (biowait(bp
) != 0) {
418 diskerr(&bp
->b_bio1
, dev
,
419 "reading extended partition table: error",
425 /* Weakly verify it. */
427 if (cp
[0x1FE] != 0x55 || cp
[0x1FF] != 0xAA) {
428 sname
= dsname(dev
, dkunit(dev
), WHOLE_DISK_SLICE
, WHOLE_SLICE_PART
,
431 kprintf("%s: invalid extended partition table: no magic\n",
436 /* Make a copy of the partition table to avoid alignment problems. */
437 memcpy(&dpcopy
[0], cp
+ DOSPARTOFF
, sizeof(dpcopy
));
439 slice
= ssp
->dss_nslices
;
440 for (dospart
= 0, dp
= &dpcopy
[0]; dospart
< NDOSPART
;
442 ext_sizes
[dospart
] = 0;
443 if (dp
->dp_scyl
== 0 && dp
->dp_shd
== 0 && dp
->dp_ssect
== 0
444 && dp
->dp_start
== 0 && dp
->dp_size
== 0)
446 if (dp
->dp_typ
== DOSPTYP_EXTENDED
||
447 dp
->dp_typ
== DOSPTYP_EXTENDEDX
) {
450 sname
= dsname(dev
, dkunit(dev
), WHOLE_DISK_SLICE
,
451 WHOLE_SLICE_PART
, partname
);
452 ksnprintf(buf
, sizeof(buf
), "%s", sname
);
453 if (strlen(buf
) < sizeof buf
- 11)
454 strcat(buf
, "<extended>");
455 check_part(buf
, dp
, base_ext_offset
, nsectors
,
456 ntracks
, mbr_offset
);
457 ext_offsets
[dospart
] = base_ext_offset
+ dp
->dp_start
;
458 ext_sizes
[dospart
] = dp
->dp_size
;
460 sname
= dsname(dev
, dkunit(dev
), slice
, WHOLE_SLICE_PART
,
462 check_part(sname
, dp
, ext_offset
, nsectors
, ntracks
,
464 if (slice
>= MAX_SLICES
) {
465 kprintf("%s: too many slices\n", sname
);
469 sp
= &ssp
->dss_slices
[slice
];
470 if (mbr_setslice(sname
, info
, sp
, dp
, ext_offset
) != 0)
475 ssp
->dss_nslices
= slice
;
477 /* If we found any more slices, recursively find all the subslices. */
478 for (dospart
= 0; dospart
< NDOSPART
; dospart
++) {
479 if (ext_sizes
[dospart
] != 0) {
480 mbr_extended(dev
, info
, ssp
, ext_offsets
[dospart
],
481 ext_sizes
[dospart
], base_ext_offset
,
482 nsectors
, ntracks
, mbr_offset
, ++level
);
487 bp
->b_flags
|= B_INVAL
| B_AGE
;
492 mbr_setslice(char *sname
, struct disk_info
*info
, struct diskslice
*sp
,
493 struct dos_partition
*dp
, u_int64_t br_offset
)
498 offset
= br_offset
+ dp
->dp_start
;
499 if (offset
> info
->d_media_blocks
|| offset
< br_offset
) {
501 "%s: slice starts beyond end of the disk: rejecting it\n",
505 size
= info
->d_media_blocks
- offset
;
506 if (size
>= dp
->dp_size
)
510 "%s: slice extends beyond end of disk: truncating from %lu to %llu sectors\n",
511 sname
, (u_long
)dp
->dp_size
, size
);
512 sp
->ds_offset
= offset
;
514 sp
->ds_type
= dp
->dp_typ
;
517 * The first sector in each slice is reserved for a system boot
518 * sector. ds_skip_bsdlabel is always inclusive of ds_skip_platform,
519 * if they are the same then there is no label present (or yet
522 sp
->ds_skip_platform
= 1;
523 sp
->ds_skip_bsdlabel
= 1;