g_part_mbr.c revision 285830
1/*- 2 * Copyright (c) 2007, 2008 Marcel Moolenaar 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 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. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 */ 26 27#include <sys/cdefs.h> 28__FBSDID("$FreeBSD: releng/10.2/sys/geom/part/g_part_mbr.c 282861 2015-05-13 14:05:53Z ae $"); 29 30#include <sys/param.h> 31#include <sys/bio.h> 32#include <sys/diskmbr.h> 33#include <sys/endian.h> 34#include <sys/kernel.h> 35#include <sys/kobj.h> 36#include <sys/limits.h> 37#include <sys/lock.h> 38#include <sys/malloc.h> 39#include <sys/mutex.h> 40#include <sys/queue.h> 41#include <sys/sbuf.h> 42#include <sys/systm.h> 43#include <sys/sysctl.h> 44#include <geom/geom.h> 45#include <geom/geom_int.h> 46#include <geom/part/g_part.h> 47 48#include "g_part_if.h" 49 50FEATURE(geom_part_mbr, "GEOM partitioning class for MBR support"); 51 52SYSCTL_DECL(_kern_geom_part); 53static SYSCTL_NODE(_kern_geom_part, OID_AUTO, mbr, CTLFLAG_RW, 0, 54 "GEOM_PART_MBR Master Boot Record"); 55 56static u_int enforce_chs = 1; 57SYSCTL_UINT(_kern_geom_part_mbr, OID_AUTO, enforce_chs, 58 CTLFLAG_RWTUN, &enforce_chs, 1, "Enforce alignment to CHS addressing"); 59 60#define MBRSIZE 512 61 62struct g_part_mbr_table { 63 struct g_part_table base; 64 u_char mbr[MBRSIZE]; 65}; 66 67struct g_part_mbr_entry { 68 struct g_part_entry base; 69 struct dos_partition ent; 70}; 71 72static int g_part_mbr_add(struct g_part_table *, struct g_part_entry *, 73 struct g_part_parms *); 74static int g_part_mbr_bootcode(struct g_part_table *, struct g_part_parms *); 75static int g_part_mbr_create(struct g_part_table *, struct g_part_parms *); 76static int g_part_mbr_destroy(struct g_part_table *, struct g_part_parms *); 77static void g_part_mbr_dumpconf(struct g_part_table *, struct g_part_entry *, 78 struct sbuf *, const char *); 79static int g_part_mbr_dumpto(struct g_part_table *, struct g_part_entry *); 80static int g_part_mbr_modify(struct g_part_table *, struct g_part_entry *, 81 struct g_part_parms *); 82static const char *g_part_mbr_name(struct g_part_table *, struct g_part_entry *, 83 char *, size_t); 84static int g_part_mbr_probe(struct g_part_table *, struct g_consumer *); 85static int g_part_mbr_read(struct g_part_table *, struct g_consumer *); 86static int g_part_mbr_setunset(struct g_part_table *, struct g_part_entry *, 87 const char *, unsigned int); 88static const char *g_part_mbr_type(struct g_part_table *, struct g_part_entry *, 89 char *, size_t); 90static int g_part_mbr_write(struct g_part_table *, struct g_consumer *); 91static int g_part_mbr_resize(struct g_part_table *, struct g_part_entry *, 92 struct g_part_parms *); 93 94static kobj_method_t g_part_mbr_methods[] = { 95 KOBJMETHOD(g_part_add, g_part_mbr_add), 96 KOBJMETHOD(g_part_bootcode, g_part_mbr_bootcode), 97 KOBJMETHOD(g_part_create, g_part_mbr_create), 98 KOBJMETHOD(g_part_destroy, g_part_mbr_destroy), 99 KOBJMETHOD(g_part_dumpconf, g_part_mbr_dumpconf), 100 KOBJMETHOD(g_part_dumpto, g_part_mbr_dumpto), 101 KOBJMETHOD(g_part_modify, g_part_mbr_modify), 102 KOBJMETHOD(g_part_resize, g_part_mbr_resize), 103 KOBJMETHOD(g_part_name, g_part_mbr_name), 104 KOBJMETHOD(g_part_probe, g_part_mbr_probe), 105 KOBJMETHOD(g_part_read, g_part_mbr_read), 106 KOBJMETHOD(g_part_setunset, g_part_mbr_setunset), 107 KOBJMETHOD(g_part_type, g_part_mbr_type), 108 KOBJMETHOD(g_part_write, g_part_mbr_write), 109 { 0, 0 } 110}; 111 112static struct g_part_scheme g_part_mbr_scheme = { 113 "MBR", 114 g_part_mbr_methods, 115 sizeof(struct g_part_mbr_table), 116 .gps_entrysz = sizeof(struct g_part_mbr_entry), 117 .gps_minent = NDOSPART, 118 .gps_maxent = NDOSPART, 119 .gps_bootcodesz = MBRSIZE, 120}; 121G_PART_SCHEME_DECLARE(g_part_mbr); 122 123static struct g_part_mbr_alias { 124 u_char typ; 125 int alias; 126} mbr_alias_match[] = { 127 { DOSPTYP_386BSD, G_PART_ALIAS_FREEBSD }, 128 { DOSPTYP_EXT, G_PART_ALIAS_EBR }, 129 { DOSPTYP_NTFS, G_PART_ALIAS_MS_NTFS }, 130 { DOSPTYP_FAT16, G_PART_ALIAS_MS_FAT16 }, 131 { DOSPTYP_FAT32, G_PART_ALIAS_MS_FAT32 }, 132 { DOSPTYP_EXTLBA, G_PART_ALIAS_EBR }, 133 { DOSPTYP_LDM, G_PART_ALIAS_MS_LDM_DATA }, 134 { DOSPTYP_LINSWP, G_PART_ALIAS_LINUX_SWAP }, 135 { DOSPTYP_LINUX, G_PART_ALIAS_LINUX_DATA }, 136 { DOSPTYP_LINLVM, G_PART_ALIAS_LINUX_LVM }, 137 { DOSPTYP_LINRAID, G_PART_ALIAS_LINUX_RAID }, 138 { DOSPTYP_PPCBOOT, G_PART_ALIAS_PREP_BOOT }, 139 { DOSPTYP_VMFS, G_PART_ALIAS_VMFS }, 140 { DOSPTYP_VMKDIAG, G_PART_ALIAS_VMKDIAG }, 141 { DOSPTYP_APPLE_UFS, G_PART_ALIAS_APPLE_UFS }, 142 { DOSPTYP_APPLE_BOOT, G_PART_ALIAS_APPLE_BOOT }, 143 { DOSPTYP_HFS, G_PART_ALIAS_APPLE_HFS }, 144}; 145 146static int 147mbr_parse_type(const char *type, u_char *dp_typ) 148{ 149 const char *alias; 150 char *endp; 151 long lt; 152 int i; 153 154 if (type[0] == '!') { 155 lt = strtol(type + 1, &endp, 0); 156 if (type[1] == '\0' || *endp != '\0' || lt <= 0 || lt >= 256) 157 return (EINVAL); 158 *dp_typ = (u_char)lt; 159 return (0); 160 } 161 for (i = 0; 162 i < sizeof(mbr_alias_match) / sizeof(mbr_alias_match[0]); i++) { 163 alias = g_part_alias_name(mbr_alias_match[i].alias); 164 if (strcasecmp(type, alias) == 0) { 165 *dp_typ = mbr_alias_match[i].typ; 166 return (0); 167 } 168 } 169 return (EINVAL); 170} 171 172static int 173mbr_probe_bpb(u_char *bpb) 174{ 175 uint16_t secsz; 176 uint8_t clstsz; 177 178#define PO2(x) ((x & (x - 1)) == 0) 179 secsz = le16dec(bpb); 180 if (secsz < 512 || secsz > 4096 || !PO2(secsz)) 181 return (0); 182 clstsz = bpb[2]; 183 if (clstsz < 1 || clstsz > 128 || !PO2(clstsz)) 184 return (0); 185#undef PO2 186 187 return (1); 188} 189 190static void 191mbr_set_chs(struct g_part_table *table, uint32_t lba, u_char *cylp, u_char *hdp, 192 u_char *secp) 193{ 194 uint32_t cyl, hd, sec; 195 196 sec = lba % table->gpt_sectors + 1; 197 lba /= table->gpt_sectors; 198 hd = lba % table->gpt_heads; 199 lba /= table->gpt_heads; 200 cyl = lba; 201 if (cyl > 1023) 202 sec = hd = cyl = ~0; 203 204 *cylp = cyl & 0xff; 205 *hdp = hd & 0xff; 206 *secp = (sec & 0x3f) | ((cyl >> 2) & 0xc0); 207} 208 209static int 210mbr_align(struct g_part_table *basetable, uint32_t *start, uint32_t *size) 211{ 212 uint32_t sectors; 213 214 if (enforce_chs == 0) 215 return (0); 216 sectors = basetable->gpt_sectors; 217 if (*size < sectors) 218 return (EINVAL); 219 if (start != NULL && (*start % sectors)) { 220 *size += (*start % sectors) - sectors; 221 *start -= (*start % sectors) - sectors; 222 } 223 if (*size % sectors) 224 *size -= (*size % sectors); 225 if (*size < sectors) 226 return (EINVAL); 227 return (0); 228} 229 230static int 231g_part_mbr_add(struct g_part_table *basetable, struct g_part_entry *baseentry, 232 struct g_part_parms *gpp) 233{ 234 struct g_part_mbr_entry *entry; 235 uint32_t start, size; 236 237 if (gpp->gpp_parms & G_PART_PARM_LABEL) 238 return (EINVAL); 239 240 entry = (struct g_part_mbr_entry *)baseentry; 241 start = gpp->gpp_start; 242 size = gpp->gpp_size; 243 if (mbr_align(basetable, &start, &size) != 0) 244 return (EINVAL); 245 if (baseentry->gpe_deleted) 246 bzero(&entry->ent, sizeof(entry->ent)); 247 248 KASSERT(baseentry->gpe_start <= start, ("%s", __func__)); 249 KASSERT(baseentry->gpe_end >= start + size - 1, ("%s", __func__)); 250 baseentry->gpe_start = start; 251 baseentry->gpe_end = start + size - 1; 252 entry->ent.dp_start = start; 253 entry->ent.dp_size = size; 254 mbr_set_chs(basetable, baseentry->gpe_start, &entry->ent.dp_scyl, 255 &entry->ent.dp_shd, &entry->ent.dp_ssect); 256 mbr_set_chs(basetable, baseentry->gpe_end, &entry->ent.dp_ecyl, 257 &entry->ent.dp_ehd, &entry->ent.dp_esect); 258 return (mbr_parse_type(gpp->gpp_type, &entry->ent.dp_typ)); 259} 260 261static int 262g_part_mbr_bootcode(struct g_part_table *basetable, struct g_part_parms *gpp) 263{ 264 struct g_part_mbr_table *table; 265 uint32_t dsn; 266 267 if (gpp->gpp_codesize != MBRSIZE) 268 return (ENODEV); 269 270 table = (struct g_part_mbr_table *)basetable; 271 dsn = *(uint32_t *)(table->mbr + DOSDSNOFF); 272 bcopy(gpp->gpp_codeptr, table->mbr, DOSPARTOFF); 273 if (dsn != 0) 274 *(uint32_t *)(table->mbr + DOSDSNOFF) = dsn; 275 return (0); 276} 277 278static int 279g_part_mbr_create(struct g_part_table *basetable, struct g_part_parms *gpp) 280{ 281 struct g_provider *pp; 282 struct g_part_mbr_table *table; 283 284 pp = gpp->gpp_provider; 285 if (pp->sectorsize < MBRSIZE) 286 return (ENOSPC); 287 288 basetable->gpt_first = basetable->gpt_sectors; 289 basetable->gpt_last = MIN(pp->mediasize / pp->sectorsize, 290 UINT32_MAX) - 1; 291 292 table = (struct g_part_mbr_table *)basetable; 293 le16enc(table->mbr + DOSMAGICOFFSET, DOSMAGIC); 294 return (0); 295} 296 297static int 298g_part_mbr_destroy(struct g_part_table *basetable, struct g_part_parms *gpp) 299{ 300 301 /* Wipe the first sector to clear the partitioning. */ 302 basetable->gpt_smhead |= 1; 303 return (0); 304} 305 306static void 307g_part_mbr_dumpconf(struct g_part_table *table, struct g_part_entry *baseentry, 308 struct sbuf *sb, const char *indent) 309{ 310 struct g_part_mbr_entry *entry; 311 312 entry = (struct g_part_mbr_entry *)baseentry; 313 if (indent == NULL) { 314 /* conftxt: libdisk compatibility */ 315 sbuf_printf(sb, " xs MBR xt %u", entry->ent.dp_typ); 316 } else if (entry != NULL) { 317 /* confxml: partition entry information */ 318 sbuf_printf(sb, "%s<rawtype>%u</rawtype>\n", indent, 319 entry->ent.dp_typ); 320 if (entry->ent.dp_flag & 0x80) 321 sbuf_printf(sb, "%s<attrib>active</attrib>\n", indent); 322 } else { 323 /* confxml: scheme information */ 324 } 325} 326 327static int 328g_part_mbr_dumpto(struct g_part_table *table, struct g_part_entry *baseentry) 329{ 330 struct g_part_mbr_entry *entry; 331 332 /* Allow dumping to a FreeBSD partition or Linux swap partition only. */ 333 entry = (struct g_part_mbr_entry *)baseentry; 334 return ((entry->ent.dp_typ == DOSPTYP_386BSD || 335 entry->ent.dp_typ == DOSPTYP_LINSWP) ? 1 : 0); 336} 337 338static int 339g_part_mbr_modify(struct g_part_table *basetable, 340 struct g_part_entry *baseentry, struct g_part_parms *gpp) 341{ 342 struct g_part_mbr_entry *entry; 343 344 if (gpp->gpp_parms & G_PART_PARM_LABEL) 345 return (EINVAL); 346 347 entry = (struct g_part_mbr_entry *)baseentry; 348 if (gpp->gpp_parms & G_PART_PARM_TYPE) 349 return (mbr_parse_type(gpp->gpp_type, &entry->ent.dp_typ)); 350 return (0); 351} 352 353static int 354g_part_mbr_resize(struct g_part_table *basetable, 355 struct g_part_entry *baseentry, struct g_part_parms *gpp) 356{ 357 struct g_part_mbr_entry *entry; 358 struct g_provider *pp; 359 uint32_t size; 360 361 if (baseentry == NULL) { 362 pp = LIST_FIRST(&basetable->gpt_gp->consumer)->provider; 363 basetable->gpt_last = MIN(pp->mediasize / pp->sectorsize, 364 UINT32_MAX) - 1; 365 return (0); 366 } 367 size = gpp->gpp_size; 368 if (mbr_align(basetable, NULL, &size) != 0) 369 return (EINVAL); 370 /* XXX: prevent unexpected shrinking. */ 371 pp = baseentry->gpe_pp; 372 if ((g_debugflags & 0x10) == 0 && size < gpp->gpp_size && 373 pp->mediasize / pp->sectorsize > size) 374 return (EBUSY); 375 entry = (struct g_part_mbr_entry *)baseentry; 376 baseentry->gpe_end = baseentry->gpe_start + size - 1; 377 entry->ent.dp_size = size; 378 mbr_set_chs(basetable, baseentry->gpe_end, &entry->ent.dp_ecyl, 379 &entry->ent.dp_ehd, &entry->ent.dp_esect); 380 return (0); 381} 382 383static const char * 384g_part_mbr_name(struct g_part_table *table, struct g_part_entry *baseentry, 385 char *buf, size_t bufsz) 386{ 387 388 snprintf(buf, bufsz, "s%d", baseentry->gpe_index); 389 return (buf); 390} 391 392static int 393g_part_mbr_probe(struct g_part_table *table, struct g_consumer *cp) 394{ 395 char psn[8]; 396 struct g_provider *pp; 397 u_char *buf, *p; 398 int error, index, res, sum; 399 uint16_t magic; 400 401 pp = cp->provider; 402 403 /* Sanity-check the provider. */ 404 if (pp->sectorsize < MBRSIZE || pp->mediasize < pp->sectorsize) 405 return (ENOSPC); 406 if (pp->sectorsize > 4096) 407 return (ENXIO); 408 409 /* We don't nest under an MBR (see EBR instead). */ 410 error = g_getattr("PART::scheme", cp, &psn); 411 if (error == 0 && strcmp(psn, g_part_mbr_scheme.name) == 0) 412 return (ELOOP); 413 414 /* Check that there's a MBR. */ 415 buf = g_read_data(cp, 0L, pp->sectorsize, &error); 416 if (buf == NULL) 417 return (error); 418 419 /* We goto out on mismatch. */ 420 res = ENXIO; 421 422 magic = le16dec(buf + DOSMAGICOFFSET); 423 if (magic != DOSMAGIC) 424 goto out; 425 426 for (index = 0; index < NDOSPART; index++) { 427 p = buf + DOSPARTOFF + index * DOSPARTSIZE; 428 if (p[0] != 0 && p[0] != 0x80) 429 goto out; 430 } 431 432 /* 433 * If the partition table does not consist of all zeroes, 434 * assume we have a MBR. If it's all zeroes, we could have 435 * a boot sector. For example, a boot sector that doesn't 436 * have boot code -- common on non-i386 hardware. In that 437 * case we check if we have a possible BPB. If so, then we 438 * assume we have a boot sector instead. 439 */ 440 sum = 0; 441 for (index = 0; index < NDOSPART * DOSPARTSIZE; index++) 442 sum += buf[DOSPARTOFF + index]; 443 if (sum != 0 || !mbr_probe_bpb(buf + 0x0b)) 444 res = G_PART_PROBE_PRI_NORM; 445 446 out: 447 g_free(buf); 448 return (res); 449} 450 451static int 452g_part_mbr_read(struct g_part_table *basetable, struct g_consumer *cp) 453{ 454 struct dos_partition ent; 455 struct g_provider *pp; 456 struct g_part_mbr_table *table; 457 struct g_part_mbr_entry *entry; 458 u_char *buf, *p; 459 off_t chs, msize, first; 460 u_int sectors, heads; 461 int error, index; 462 463 pp = cp->provider; 464 table = (struct g_part_mbr_table *)basetable; 465 first = basetable->gpt_sectors; 466 msize = MIN(pp->mediasize / pp->sectorsize, UINT32_MAX); 467 468 buf = g_read_data(cp, 0L, pp->sectorsize, &error); 469 if (buf == NULL) 470 return (error); 471 472 bcopy(buf, table->mbr, sizeof(table->mbr)); 473 for (index = NDOSPART - 1; index >= 0; index--) { 474 p = buf + DOSPARTOFF + index * DOSPARTSIZE; 475 ent.dp_flag = p[0]; 476 ent.dp_shd = p[1]; 477 ent.dp_ssect = p[2]; 478 ent.dp_scyl = p[3]; 479 ent.dp_typ = p[4]; 480 ent.dp_ehd = p[5]; 481 ent.dp_esect = p[6]; 482 ent.dp_ecyl = p[7]; 483 ent.dp_start = le32dec(p + 8); 484 ent.dp_size = le32dec(p + 12); 485 if (ent.dp_typ == 0 || ent.dp_typ == DOSPTYP_PMBR) 486 continue; 487 if (ent.dp_start == 0 || ent.dp_size == 0) 488 continue; 489 sectors = ent.dp_esect & 0x3f; 490 if (sectors > basetable->gpt_sectors && 491 !basetable->gpt_fixgeom) { 492 g_part_geometry_heads(msize, sectors, &chs, &heads); 493 if (chs != 0) { 494 basetable->gpt_sectors = sectors; 495 basetable->gpt_heads = heads; 496 } 497 } 498 if (ent.dp_start < first) 499 first = ent.dp_start; 500 entry = (struct g_part_mbr_entry *)g_part_new_entry(basetable, 501 index + 1, ent.dp_start, ent.dp_start + ent.dp_size - 1); 502 entry->ent = ent; 503 } 504 505 basetable->gpt_entries = NDOSPART; 506 basetable->gpt_first = basetable->gpt_sectors; 507 basetable->gpt_last = msize - 1; 508 509 if (first < basetable->gpt_first) 510 basetable->gpt_first = 1; 511 512 g_free(buf); 513 return (0); 514} 515 516static int 517g_part_mbr_setunset(struct g_part_table *table, struct g_part_entry *baseentry, 518 const char *attrib, unsigned int set) 519{ 520 struct g_part_entry *iter; 521 struct g_part_mbr_entry *entry; 522 int changed; 523 524 if (baseentry == NULL) 525 return (ENODEV); 526 if (strcasecmp(attrib, "active") != 0) 527 return (EINVAL); 528 529 /* Only one entry can have the active attribute. */ 530 LIST_FOREACH(iter, &table->gpt_entry, gpe_entry) { 531 if (iter->gpe_deleted) 532 continue; 533 changed = 0; 534 entry = (struct g_part_mbr_entry *)iter; 535 if (iter == baseentry) { 536 if (set && (entry->ent.dp_flag & 0x80) == 0) { 537 entry->ent.dp_flag |= 0x80; 538 changed = 1; 539 } else if (!set && (entry->ent.dp_flag & 0x80)) { 540 entry->ent.dp_flag &= ~0x80; 541 changed = 1; 542 } 543 } else { 544 if (set && (entry->ent.dp_flag & 0x80)) { 545 entry->ent.dp_flag &= ~0x80; 546 changed = 1; 547 } 548 } 549 if (changed && !iter->gpe_created) 550 iter->gpe_modified = 1; 551 } 552 return (0); 553} 554 555static const char * 556g_part_mbr_type(struct g_part_table *basetable, struct g_part_entry *baseentry, 557 char *buf, size_t bufsz) 558{ 559 struct g_part_mbr_entry *entry; 560 int i; 561 562 entry = (struct g_part_mbr_entry *)baseentry; 563 for (i = 0; 564 i < sizeof(mbr_alias_match) / sizeof(mbr_alias_match[0]); i++) { 565 if (mbr_alias_match[i].typ == entry->ent.dp_typ) 566 return (g_part_alias_name(mbr_alias_match[i].alias)); 567 } 568 snprintf(buf, bufsz, "!%d", entry->ent.dp_typ); 569 return (buf); 570} 571 572static int 573g_part_mbr_write(struct g_part_table *basetable, struct g_consumer *cp) 574{ 575 struct g_part_entry *baseentry; 576 struct g_part_mbr_entry *entry; 577 struct g_part_mbr_table *table; 578 u_char *p; 579 int error, index; 580 581 table = (struct g_part_mbr_table *)basetable; 582 baseentry = LIST_FIRST(&basetable->gpt_entry); 583 for (index = 1; index <= basetable->gpt_entries; index++) { 584 p = table->mbr + DOSPARTOFF + (index - 1) * DOSPARTSIZE; 585 entry = (baseentry != NULL && index == baseentry->gpe_index) 586 ? (struct g_part_mbr_entry *)baseentry : NULL; 587 if (entry != NULL && !baseentry->gpe_deleted) { 588 p[0] = entry->ent.dp_flag; 589 p[1] = entry->ent.dp_shd; 590 p[2] = entry->ent.dp_ssect; 591 p[3] = entry->ent.dp_scyl; 592 p[4] = entry->ent.dp_typ; 593 p[5] = entry->ent.dp_ehd; 594 p[6] = entry->ent.dp_esect; 595 p[7] = entry->ent.dp_ecyl; 596 le32enc(p + 8, entry->ent.dp_start); 597 le32enc(p + 12, entry->ent.dp_size); 598 } else 599 bzero(p, DOSPARTSIZE); 600 601 if (entry != NULL) 602 baseentry = LIST_NEXT(baseentry, gpe_entry); 603 } 604 605 error = g_write_data(cp, 0, table->mbr, cp->provider->sectorsize); 606 return (error); 607} 608