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 1.26 2007/06/19 06:07:57 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));
156 * Check for "Ontrack Diskmanager" or GPT. If a GPT is found in
157 * the first dos partition, ignore the rest of the MBR and go
160 for (dospart = 0, dp = dp0; dospart < NDOSPART; dospart++, dp++) {
162 (dp->dp_typ == DOSPTYP_PMBR || dp->dp_typ == DOSPTYP_GPT)) {
165 "%s: Found GPT in slice #%d\n", sname, dospart + 1);
166 error = gptinit(dev, info, sspp);
170 if (dp->dp_typ == DOSPTYP_ONTRACK) {
173 "%s: Found \"Ontrack Disk Manager\" on this disk.\n", sname);
174 bp->b_flags |= B_INVAL | B_AGE;
181 if (bcmp(dp0, historical_bogus_partition_table,
182 sizeof historical_bogus_partition_table) == 0 ||
183 bcmp(dp0, historical_bogus_partition_table_fixed,
184 sizeof historical_bogus_partition_table_fixed) == 0) {
186 TRACE(("%s: invalid primary partition table: historical\n",
191 "%s: invalid primary partition table: Dangerously Dedicated (ignored)\n",
197 /* Guess the geometry. */
200 * Perhaps skip entries with 0 size.
201 * Perhaps only look at entries of type DOSPTYP_386BSD.
206 for (dospart = 0, dp = dp0; dospart < NDOSPART; dospart++, dp++) {
211 ncyls = DPCYL(dp->dp_ecyl, dp->dp_esect) + 1;
212 if (max_ncyls < ncyls)
214 nsectors = DPSECT(dp->dp_esect);
215 if (max_nsectors < nsectors)
216 max_nsectors = nsectors;
217 ntracks = dp->dp_ehd + 1;
218 if (max_ntracks < ntracks)
219 max_ntracks = ntracks;
223 * Check that we have guessed the geometry right by checking the
229 * Check for overlaps.
230 * Check against d_secperunit if the latter is reliable.
233 for (dospart = 0, dp = dp0; dospart < NDOSPART; dospart++, dp++) {
234 if (dp->dp_scyl == 0 && dp->dp_shd == 0 && dp->dp_ssect == 0
235 && dp->dp_start == 0 && dp->dp_size == 0)
237 sname = dsname(dev, dkunit(dev), BASE_SLICE + dospart,
238 WHOLE_SLICE_PART, partname);
241 * Temporarily ignore errors from this check. We could
242 * simplify things by accepting the table eariler if we
243 * always ignore errors here. Perhaps we should always
244 * accept the table if the magic is right but not let
245 * bad entries affect the geometry.
247 check_part(sname, dp, mbr_offset, max_nsectors, max_ntracks,
254 * Accept the DOS partition table.
256 * Adjust the disk information structure with updated CHS
257 * conversion parameters, but only use values extracted from
258 * the primary partition table.
260 * NOTE! Regardless of our having to deal with this old cruft,
261 * we do not screw around with the info->d_media* parameters.
263 secpercyl = (u_long)max_nsectors * max_ntracks;
264 if (secpercyl != 0 && mbr_offset == DOSBBSECTOR) {
265 info->d_secpertrack = max_nsectors;
266 info->d_nheads = max_ntracks;
267 info->d_secpercyl = secpercyl;
268 info->d_ncylinders = info->d_media_blocks / secpercyl;
272 * We are passed a pointer to a suitably initialized minimal
273 * slices "struct" with no dangling pointers in it. Replace it
274 * by a maximal one. This usually oversizes the "struct", but
275 * enlarging it while searching for logical drives would be
278 kfree(*sspp, M_DEVBUF);
279 ssp = dsmakeslicestruct(MAX_SLICES, info);
282 /* Initialize normal slices. */
283 sp = &ssp->dss_slices[BASE_SLICE];
284 for (dospart = 0, dp = dp0; dospart < NDOSPART; dospart++, dp++, sp++) {
285 sname = dsname(dev, dkunit(dev), BASE_SLICE + dospart,
286 WHOLE_SLICE_PART, partname);
287 (void)mbr_setslice(sname, info, sp, dp, mbr_offset);
289 ssp->dss_nslices = BASE_SLICE + NDOSPART;
291 /* Handle extended partitions. */
293 for (dospart = 0; dospart < NDOSPART; dospart++, sp++) {
294 if (sp->ds_type == DOSPTYP_EXTENDED ||
295 sp->ds_type == DOSPTYP_EXTENDEDX) {
296 mbr_extended(wdev, info, ssp,
297 sp->ds_offset, sp->ds_size, sp->ds_offset,
298 max_nsectors, max_ntracks, mbr_offset, 1);
303 * mbr_extended() abuses ssp->dss_nslices for the number of slices
304 * that would be found if there were no limit on the number of slices
305 * in *ssp. Cut it back now.
307 if (ssp->dss_nslices > MAX_SLICES)
308 ssp->dss_nslices = MAX_SLICES;
311 bp->b_flags |= B_INVAL | B_AGE;
319 check_part(char *sname, struct dos_partition *dp, u_int64_t offset,
320 int nsectors, int ntracks, u_int64_t mbr_offset)
333 secpercyl = (u_long)nsectors * ntracks;
334 chs_scyl = DPCYL(dp->dp_scyl, dp->dp_ssect);
335 chs_ssect = DPSECT(dp->dp_ssect);
336 ssector = chs_ssect - 1 + dp->dp_shd * nsectors + chs_scyl * secpercyl
338 ssector1 = offset + dp->dp_start;
341 * If ssector1 is on a cylinder >= 1024, then ssector can't be right.
342 * Allow the C/H/S for it to be 1023/ntracks-1/nsectors, or correct
343 * apart from the cylinder being reduced modulo 1024. Always allow
344 * 1023/255/63, because this is the official way to represent
345 * pure-LBA for the starting position.
347 if ((ssector < ssector1
348 && ((chs_ssect == nsectors && dp->dp_shd == ntracks - 1
351 && (ssector1 - ssector) % (1024 * secpercyl) == 0)))
352 || (dp->dp_scyl == 255 && dp->dp_shd == 255
353 && dp->dp_ssect == 255)) {
354 TRACE(("%s: C/H/S start %d/%d/%d, start %llu: allow\n",
355 sname, chs_scyl, dp->dp_shd, chs_ssect, ssector1));
359 chs_ecyl = DPCYL(dp->dp_ecyl, dp->dp_esect);
360 chs_esect = DPSECT(dp->dp_esect);
361 esector = chs_esect - 1 + dp->dp_ehd * nsectors + chs_ecyl * secpercyl
363 esector1 = ssector1 + dp->dp_size - 1;
366 * Allow certain bogus C/H/S values for esector, as above. However,
367 * heads == 255 isn't really legal and causes some BIOS crashes. The
368 * correct value to indicate a pure-LBA end is 1023/heads-1/sectors -
369 * usually 1023/254/63. "heads" is base 0, "sectors" is base 1.
371 if ((esector < esector1
372 && ((chs_esect == nsectors && dp->dp_ehd == ntracks - 1
375 && (esector1 - esector) % (1024 * secpercyl) == 0)))
376 || (dp->dp_ecyl == 255 && dp->dp_ehd == 255
377 && dp->dp_esect == 255)) {
378 TRACE(("%s: C/H/S end %d/%d/%d, end %llu: allow\n",
379 sname, chs_ecyl, dp->dp_ehd, chs_esect, esector1));
383 error = (ssector == ssector1 && esector == esector1) ? 0 : EINVAL;
385 kprintf("%s: type 0x%x, start %llu, end = %llu, size %lu %s\n",
386 sname, dp->dp_typ, ssector1, esector1,
387 (u_long)dp->dp_size, error ? "" : ": OK");
388 if (ssector != ssector1 && bootverbose)
389 kprintf("%s: C/H/S start %d/%d/%d (%llu) != start %llu: invalid\n",
390 sname, chs_scyl, dp->dp_shd, chs_ssect,
392 if (esector != esector1 && bootverbose)
393 kprintf("%s: C/H/S end %d/%d/%d (%llu) != end %llu: invalid\n",
394 sname, chs_ecyl, dp->dp_ehd, chs_esect,
401 mbr_extended(cdev_t dev, struct disk_info *info, struct diskslices *ssp,
402 u_int64_t ext_offset, u_int64_t ext_size, u_int64_t base_ext_offset,
403 int nsectors, int ntracks, u_int64_t mbr_offset, int level)
408 struct dos_partition *dp;
409 struct dos_partition dpcopy[NDOSPART];
410 u_int64_t ext_offsets[NDOSPART];
411 u_int64_t ext_sizes[NDOSPART];
415 struct diskslice *sp;
419 "%s: excessive recursion in search for slices; aborting search\n",
424 /* Read extended boot record. */
425 bp = geteblk((int)info->d_media_blksize);
426 bp->b_bio1.bio_offset = (off_t)ext_offset * info->d_media_blksize;
427 bp->b_bcount = info->d_media_blksize;
428 bp->b_cmd = BUF_CMD_READ;
429 dev_dstrategy(dev, &bp->b_bio1);
430 if (biowait(bp) != 0) {
431 diskerr(&bp->b_bio1, dev,
432 "reading extended partition table: error",
438 /* Weakly verify it. */
440 if (cp[0x1FE] != 0x55 || cp[0x1FF] != 0xAA) {
441 sname = dsname(dev, dkunit(dev), WHOLE_DISK_SLICE, WHOLE_SLICE_PART,
444 kprintf("%s: invalid extended partition table: no magic\n",
449 /* Make a copy of the partition table to avoid alignment problems. */
450 memcpy(&dpcopy[0], cp + DOSPARTOFF, sizeof(dpcopy));
452 slice = ssp->dss_nslices;
453 for (dospart = 0, dp = &dpcopy[0]; dospart < NDOSPART;
455 ext_sizes[dospart] = 0;
456 if (dp->dp_scyl == 0 && dp->dp_shd == 0 && dp->dp_ssect == 0
457 && dp->dp_start == 0 && dp->dp_size == 0)
459 if (dp->dp_typ == DOSPTYP_EXTENDED ||
460 dp->dp_typ == DOSPTYP_EXTENDEDX) {
463 sname = dsname(dev, dkunit(dev), WHOLE_DISK_SLICE,
464 WHOLE_SLICE_PART, partname);
465 ksnprintf(buf, sizeof(buf), "%s", sname);
466 if (strlen(buf) < sizeof buf - 11)
467 strcat(buf, "<extended>");
468 check_part(buf, dp, base_ext_offset, nsectors,
469 ntracks, mbr_offset);
470 ext_offsets[dospart] = base_ext_offset + dp->dp_start;
471 ext_sizes[dospart] = dp->dp_size;
473 sname = dsname(dev, dkunit(dev), slice, WHOLE_SLICE_PART,
475 check_part(sname, dp, ext_offset, nsectors, ntracks,
477 if (slice >= MAX_SLICES) {
478 kprintf("%s: too many slices\n", sname);
482 sp = &ssp->dss_slices[slice];
483 if (mbr_setslice(sname, info, sp, dp, ext_offset) != 0)
488 ssp->dss_nslices = slice;
490 /* If we found any more slices, recursively find all the subslices. */
491 for (dospart = 0; dospart < NDOSPART; dospart++) {
492 if (ext_sizes[dospart] != 0) {
493 mbr_extended(dev, info, ssp, ext_offsets[dospart],
494 ext_sizes[dospart], base_ext_offset,
495 nsectors, ntracks, mbr_offset, ++level);
500 bp->b_flags |= B_INVAL | B_AGE;
505 mbr_setslice(char *sname, struct disk_info *info, struct diskslice *sp,
506 struct dos_partition *dp, u_int64_t br_offset)
511 offset = br_offset + dp->dp_start;
512 if (offset > info->d_media_blocks || offset < br_offset) {
514 "%s: slice starts beyond end of the disk: rejecting it\n",
518 size = info->d_media_blocks - offset;
519 if (size >= dp->dp_size)
523 "%s: slice extends beyond end of disk: truncating from %lu to %llu sectors\n",
524 sname, (u_long)dp->dp_size, size);
525 sp->ds_offset = offset;
527 sp->ds_type = dp->dp_typ;
528 bzero(&sp->ds_type_uuid, sizeof(sp->ds_type_uuid));
529 bzero(&sp->ds_stor_uuid, sizeof(sp->ds_type_uuid));
532 * Slices do not overlap with the parent (if any).