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md.c revision 1.2.4.1
      1 /*	$NetBSD: md.c,v 1.2.4.1 2015/05/14 07:58:50 snj Exp $	*/
      2 
      3 /*
      4  * Copyright 1997 Piermont Information Systems Inc.
      5  * All rights reserved.
      6  *
      7  * Based on code written by Philip A. Nelson for Piermont Information
      8  * Systems Inc.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  * 3. The name of Piermont Information Systems Inc. may not be used to endorse
     19  *    or promote products derived from this software without specific prior
     20  *    written permission.
     21  *
     22  * THIS SOFTWARE IS PROVIDED BY PIERMONT INFORMATION SYSTEMS INC. ``AS IS''
     23  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     25  * ARE DISCLAIMED. IN NO EVENT SHALL PIERMONT INFORMATION SYSTEMS INC. BE
     26  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     27  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     28  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     29  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     30  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     31  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
     32  * THE POSSIBILITY OF SUCH DAMAGE.
     33  */
     34 
     35 /* md.c -- ofppc machine specific routines */
     36 
     37 #include <sys/param.h>
     38 #include <sys/sysctl.h>
     39 #include <sys/disklabel_rdb.h>
     40 #include <stdio.h>
     41 #include <util.h>
     42 #include <machine/cpu.h>
     43 
     44 #include "defs.h"
     45 #include "md.h"
     46 #include "msg_defs.h"
     47 #include "menu_defs.h"
     48 #include "endian.h"
     49 
     50 static int check_rdb(void);
     51 static uint32_t rdbchksum(void *);
     52 
     53 /* We use MBR_PTYPE_PREP like port-prep does. */
     54 static int nonewfsmsdos = 0, nobootfix = 0, noprepfix=0;
     55 static int bootpart_fat12 = PART_BOOT_FAT12;
     56 static int bootpart_binfo = PART_BOOT_BINFO;
     57 static int bootpart_prep = PART_BOOT_PREP;
     58 static int bootinfo_mbr = 1;
     59 static int rdb_found = 0;
     60 
     61 /* bootstart/bootsize are for the fat */
     62 int binfostart, binfosize, bprepstart, bprepsize;
     63 
     64 void
     65 md_init(void)
     66 {
     67 }
     68 
     69 void
     70 md_init_set_status(int flags)
     71 {
     72 
     73 	(void)flags;
     74 }
     75 
     76 int
     77 md_get_info(void)
     78 {
     79 
     80 	if (check_rdb())
     81 		return 1;
     82 
     83 	return set_bios_geom_with_mbr_guess();
     84 }
     85 
     86 /*
     87  * md back-end code for menu-driven BSD disklabel editor.
     88  */
     89 int
     90 md_make_bsd_partitions(void)
     91 {
     92 	int i;
     93 	int part;
     94 	int maxpart = getmaxpartitions();
     95 	int partstart;
     96 	int part_raw, part_bsd;
     97 	int ptend;
     98 	int no_swap = 0;
     99 	partinfo *p;
    100 
    101 	if (rdb_found) {
    102 		/*
    103 		 * We found RDB partitions on the disk, which cannot be
    104 		 * modified by rewriting the disklabel.
    105 		 * So just use what we have got.
    106 		 */
    107 		for (part = 0; part < maxpart; part++) {
    108 			if (PI_ISBSDFS(&pm->bsdlabel[part])) {
    109 				pm->bsdlabel[part].pi_flags |=
    110 				    PIF_NEWFS | PIF_MOUNT;
    111 
    112 				if (part == PART_A)
    113 					strcpy(pm->bsdlabel[part].pi_mount, "/");
    114 			}
    115 		}
    116 
    117 		part_bsd = part_raw = getrawpartition();
    118 		if (part_raw == -1)
    119 			part_raw = PART_C;	/* for sanity... */
    120 		pm->bsdlabel[part_raw].pi_offset = 0;
    121 		pm->bsdlabel[part_raw].pi_size = pm->dlsize;
    122 
    123 		set_sizemultname_meg();
    124 rdb_edit_check:
    125 		if (edit_and_check_label(pm->bsdlabel, maxpart, part_raw,
    126 		    part_bsd) == 0) {
    127 			msg_display(MSG_abort);
    128 			return 0;
    129 		}
    130 		if (md_check_partitions() == 0)
    131 			goto rdb_edit_check;
    132 
    133 		return 1;
    134 	}
    135 
    136 	/*
    137 	 * Initialize global variables that track space used on this disk.
    138 	 * Standard 4.4BSD 8-partition labels always cover whole disk.
    139 	 */
    140 	if (pm->ptsize == 0)
    141 		pm->ptsize = pm->dlsize - pm->ptstart;
    142 	if (pm->dlsize == 0)
    143 		pm->dlsize = pm->ptstart + pm->ptsize;
    144 
    145 	partstart = pm->ptstart;
    146 	ptend = pm->ptstart + pm->ptsize;
    147 
    148 	/* Ask for layout type -- standard or special */
    149 	msg_display(MSG_layout,
    150 		    pm->ptsize / (MEG / pm->sectorsize),
    151 		    DEFROOTSIZE + DEFSWAPSIZE + DEFUSRSIZE,
    152 		    DEFROOTSIZE + DEFSWAPSIZE + DEFUSRSIZE + XNEEDMB);
    153 
    154 	process_menu(MENU_layout, NULL);
    155 
    156 	/* Set so we use the 'real' geometry for rounding, input in MB */
    157 	pm->current_cylsize = pm->dlcylsize;
    158 	set_sizemultname_meg();
    159 
    160 	/* Build standard partitions */
    161 	memset(&pm->bsdlabel, 0, sizeof pm->bsdlabel);
    162 
    163 	/* Set initial partition types to unused */
    164 	for (part = 0 ; part < maxpart ; ++part)
    165 		pm->bsdlabel[part].pi_fstype = FS_UNUSED;
    166 
    167 	/* Whole disk partition */
    168 	part_raw = getrawpartition();
    169 	if (part_raw == -1)
    170 		part_raw = PART_C;	/* for sanity... */
    171 	pm->bsdlabel[part_raw].pi_offset = 0;
    172 	pm->bsdlabel[part_raw].pi_size = pm->dlsize;
    173 
    174 	if (part_raw == PART_D) {
    175 		/* Probably a system that expects an i386 style mbr */
    176 		part_bsd = PART_C;
    177 		pm->bsdlabel[PART_C].pi_offset = pm->ptstart;
    178 		pm->bsdlabel[PART_C].pi_size = pm->ptsize;
    179 	} else {
    180 		part_bsd = part_raw;
    181 	}
    182 
    183 	if (pm->bootsize != 0) {
    184 		pm->bsdlabel[PART_BOOT_FAT12].pi_fstype = FS_MSDOS;
    185 		pm->bsdlabel[PART_BOOT_FAT12].pi_size = pm->bootsize;
    186 		pm->bsdlabel[PART_BOOT_FAT12].pi_offset = pm->bootstart;
    187 		pm->bsdlabel[PART_BOOT_FAT12].pi_flags |= PART_BOOT_FAT12_PI_FLAGS;
    188 		strlcpy(pm->bsdlabel[PART_BOOT_FAT12].pi_mount,
    189 		    PART_BOOT_FAT12_PI_MOUNT,
    190 		    sizeof pm->bsdlabel[PART_BOOT_FAT12].pi_mount);
    191 	}
    192 	if (binfosize != 0) {
    193 		pm->bsdlabel[PART_BOOT_BINFO].pi_fstype = FS_OTHER;
    194 		pm->bsdlabel[PART_BOOT_BINFO].pi_size = binfosize;
    195 		pm->bsdlabel[PART_BOOT_BINFO].pi_offset = binfostart;
    196 	}
    197 	if (bprepsize != 0) {
    198 		pm->bsdlabel[PART_BOOT_PREP].pi_fstype = FS_BOOT;
    199 		pm->bsdlabel[PART_BOOT_PREP].pi_size = bprepsize;
    200 		pm->bsdlabel[PART_BOOT_PREP].pi_offset = bprepstart;
    201 	}
    202 
    203 #ifdef PART_REST
    204 	pm->bsdlabel[PART_REST].pi_offset = 0;
    205 	pm->bsdlabel[PART_REST].pi_size = pm->ptstart;
    206 #endif
    207 
    208 	/*
    209 	 * Save any partitions that are outside the area we are
    210 	 * going to use.
    211 	 * In particular this saves details of the other MBR
    212 	 * partitions on a multiboot i386 system.
    213 	 */
    214 	 for (i = maxpart; i--;) {
    215 		if (pm->bsdlabel[i].pi_size != 0)
    216 			/* Don't overwrite special partitions */
    217 			continue;
    218 		p = &pm->oldlabel[i];
    219 		if (p->pi_fstype == FS_UNUSED || p->pi_size == 0)
    220 			continue;
    221 		if (layoutkind == LY_USEEXIST) {
    222 			if (PI_ISBSDFS(p))
    223 				p->pi_flags |= PIF_MOUNT;
    224 		} else {
    225 			if (p->pi_offset < pm->ptstart + pm->ptsize &&
    226 			    p->pi_offset + p->pi_size > pm->ptstart)
    227 				/* Not outside area we are allocating */
    228 				continue;
    229 			if (p->pi_fstype == FS_SWAP)
    230 				no_swap = 1;
    231 		}
    232 		pm->bsdlabel[i] = pm->oldlabel[i];
    233 	 }
    234 
    235 	if (layoutkind == LY_USEEXIST) {
    236 		/* XXX Check we have a sensible layout */
    237 		;
    238 	} else
    239 		get_ptn_sizes(partstart, ptend - partstart, no_swap);
    240 
    241 	/*
    242 	 * OK, we have a partition table. Give the user the chance to
    243 	 * edit it and verify it's OK, or abort altogether.
    244 	 */
    245  edit_check:
    246 	if (edit_and_check_label(pm->bsdlabel, maxpart, part_raw, part_bsd) == 0) {
    247 		msg_display(MSG_abort);
    248 		return 0;
    249 	}
    250 	if (md_check_partitions() == 0)
    251 		goto edit_check;
    252 
    253 	/* Disk name */
    254 	msg_prompt(MSG_packname, pm->bsddiskname, pm->bsddiskname, sizeof pm->bsddiskname);
    255 
    256 	/* save label to disk for MI code to update. */
    257 	(void) savenewlabel(pm->bsdlabel, maxpart);
    258 
    259 	/* Everything looks OK. */
    260 	return 1;
    261 }
    262 
    263 /*
    264  * any additional partition validation
    265  */
    266 int
    267 md_check_partitions(void)
    268 {
    269 	int part, fprep=0, ffat=0;
    270 
    271 	if (rdb_found)
    272 		return 1;
    273 
    274 	/* we need to find a boot partition, otherwise we can't create
    275 	 * our msdos fs boot partition.  We make the assumption that
    276 	 * the user hasn't done something stupid, like move it away
    277 	 * from the MBR partition.
    278 	 */
    279 	for (part = PART_A; part < MAXPARTITIONS; part++) {
    280 		if (pm->bsdlabel[part].pi_fstype == FS_MSDOS) {
    281 			bootpart_fat12 = part;
    282 			ffat++;
    283 		} else if (pm->bsdlabel[part].pi_fstype == FS_BOOT) {
    284 			bootpart_prep = part;
    285 			fprep++;
    286 		} else if (pm->bsdlabel[part].pi_fstype == FS_OTHER) {
    287 			bootpart_binfo = part;
    288 			fprep++;
    289 		}
    290 	}
    291 	/* oh, the confusion */
    292 	if (ffat >= 1 && fprep < 2)
    293 		return 1;
    294 	if (ffat < 1 && fprep >= 2)
    295 		return 2;
    296 	if (ffat >=1 && fprep >= 2)
    297 		return 3;
    298 
    299 	msg_display(MSG_nobootpartdisklabel);
    300 	process_menu(MENU_ok, NULL);
    301 	return 0;
    302 }
    303 
    304 /*
    305  * hook called before writing new disklabel.
    306  */
    307 int
    308 md_pre_disklabel(void)
    309 {
    310 
    311 	if (rdb_found)
    312 		return 0;
    313 
    314 	msg_display(MSG_dofdisk);
    315 
    316 	/* write edited MBR onto disk. */
    317 	if (write_mbr(pm->diskdev, &mbr, 1) != 0) {
    318 		msg_display(MSG_wmbrfail);
    319 		process_menu(MENU_ok, NULL);
    320 		return 1;
    321 	}
    322 	return 0;
    323 }
    324 
    325 /*
    326  * hook called after writing disklabel to new target disk.
    327  */
    328 int
    329 md_post_disklabel(void)
    330 {
    331 	char bootdev[100];
    332 
    333 	if (pm->bootstart == 0 || pm->bootsize == 0 || rdb_found)
    334 		return 0;
    335 
    336 	snprintf(bootdev, sizeof bootdev, "/dev/r%s%c", pm->diskdev,
    337 	    'a'+bootpart_fat12);
    338 	run_program(RUN_DISPLAY, "/sbin/newfs_msdos %s", bootdev);
    339 
    340 	return 0;
    341 }
    342 
    343 /*
    344  * hook called after upgrade() or install() has finished setting
    345  * up the target disk but immediately before the user is given the
    346  * ``disks are now set up'' message.
    347  */
    348 int
    349 md_post_newfs(void)
    350 {
    351 
    352 	/* No bootblock. We use ofwboot from a partition visiable by OFW. */
    353 	return 0;
    354 }
    355 
    356 int
    357 md_post_extract(void)
    358 {
    359 	char bootdev[100], bootbdev[100], version[64];
    360 
    361 	/* if we can't make it bootable, just punt */
    362 	if ((nobootfix && noprepfix) || rdb_found)
    363 		return 0;
    364 
    365 	snprintf(version, sizeof version, "NetBSD/%s %s", MACH, REL);
    366 	run_program(RUN_DISPLAY, "/usr/mdec/mkbootinfo '%s' %d "
    367 	    "/tmp/bootinfo.txt", version, bootinfo_mbr);
    368 
    369 	if (!nobootfix) {
    370 		run_program(RUN_DISPLAY, "/bin/mkdir -p /%s/boot/ppc",
    371 		    target_prefix());
    372 		run_program(RUN_DISPLAY, "/bin/mkdir -p /%s/boot/netbsd",
    373 		    target_prefix());
    374 		run_program(RUN_DISPLAY, "/bin/cp /usr/mdec/ofwboot "
    375 		    "/%s/boot/netbsd", target_prefix());
    376 		run_program(RUN_DISPLAY, "/bin/cp /tmp/bootinfo.txt "
    377 		    "/%s/boot/ppc", target_prefix());
    378 		run_program(RUN_DISPLAY, "/bin/cp /usr/mdec/ofwboot "
    379 		    "/%s/boot/ofwboot", target_prefix());
    380 	}
    381 
    382 	if (!noprepfix) {
    383 		snprintf(bootdev, sizeof bootdev, "/dev/r%s%c", pm->diskdev,
    384 		    'a'+bootpart_prep);
    385 		snprintf(bootbdev, sizeof bootbdev, "/dev/%s%c", pm->diskdev,
    386 		    'a'+bootpart_prep);
    387 		run_program(RUN_DISPLAY, "/bin/dd if=/dev/zero of=%s bs=512",
    388 		    bootdev);
    389 		run_program(RUN_DISPLAY, "/bin/dd if=/usr/mdec/ofwboot "
    390 		    "of=%s bs=512", bootbdev);
    391 
    392 		snprintf(bootdev, sizeof bootdev, "/dev/r%s%c", pm->diskdev,
    393 		    'a'+bootpart_binfo);
    394 		snprintf(bootbdev, sizeof bootbdev, "/dev/%s%c", pm->diskdev,
    395 		    'a'+bootpart_binfo);
    396 		run_program(RUN_DISPLAY, "/bin/dd if=/dev/zero of=%s bs=512",
    397 		    bootdev);
    398 		run_program(RUN_DISPLAY, "/bin/dd if=/tmp/bootinfo.txt "
    399 		    "of=%s bs=512", bootbdev);
    400 	}
    401 
    402 	return 0;
    403 }
    404 
    405 void
    406 md_cleanup_install(void)
    407 {
    408 
    409 #ifndef DEBUG
    410 	enable_rc_conf();
    411 #endif
    412 }
    413 
    414 int
    415 md_pre_update(void)
    416 {
    417 	struct mbr_partition *part;
    418 	mbr_info_t *ext;
    419 	int i;
    420 
    421 	if (check_rdb())
    422 		return 1;
    423 
    424 	read_mbr(pm->diskdev, &mbr);
    425 	/* do a sanity check of the partition table */
    426 	for (ext = &mbr; ext; ext = ext->extended) {
    427 		part = ext->mbr.mbr_parts;
    428 		for (i = 0; i < MBR_PART_COUNT; part++, i++) {
    429 			if (part->mbrp_type == MBR_PTYPE_PREP &&
    430 			    part->mbrp_size > 50)
    431 				bootinfo_mbr = i+1;
    432 			if (part->mbrp_type == MBR_PTYPE_RESERVED_x21 &&
    433 			    part->mbrp_size < (MIN_FAT12_BOOT/512)) {
    434 				msg_display(MSG_boottoosmall);
    435 				msg_display_add(MSG_nobootpartdisklabel, 0);
    436 				if (!ask_yesno(NULL))
    437 					return 0;
    438 				nobootfix = 1;
    439 			}
    440 		}
    441 	}
    442 
    443 	i = md_check_partitions();
    444 	switch (i) {
    445 	case 0: nobootfix=1; noprepfix=1; break;
    446 	case 1: noprepfix=1; break;
    447 	case 2: nobootfix=1; break;
    448 	default: break;
    449 	}
    450 
    451 	return 1;
    452 }
    453 
    454 /* Upgrade support */
    455 int
    456 md_update(void)
    457 {
    458 
    459 	nonewfsmsdos = 1;
    460 	md_post_newfs();
    461 	return 1;
    462 }
    463 
    464 
    465 int
    466 md_check_mbr(mbr_info_t *mbri)
    467 {
    468 	mbr_info_t *ext;
    469 	struct mbr_partition *part;
    470 	int i;
    471 
    472 	for (ext = mbri; ext; ext = ext->extended) {
    473 		part = ext->mbr.mbr_parts;
    474 		for (i = 0; i < MBR_PART_COUNT; part++, i++) {
    475 			if (part->mbrp_type == MBR_PTYPE_FAT12) {
    476 				pm->bootstart = part->mbrp_start;
    477 				pm->bootsize = part->mbrp_size;
    478 			} else if (part->mbrp_type == MBR_PTYPE_PREP &&
    479 			    part->mbrp_size < 50) {
    480 				/* this is the bootinfo partition */
    481 				binfostart = part->mbrp_start;
    482 				binfosize = part->mbrp_size;
    483 				bootinfo_mbr = i+1;
    484 			} else if (part->mbrp_type == MBR_PTYPE_PREP &&
    485 			    part->mbrp_size > 50) {
    486 				bprepstart = part->mbrp_start;
    487 				bprepsize = part->mbrp_size;
    488 			}
    489 			break;
    490 		}
    491 	}
    492 
    493 	/* we need to either have a pair of prep partitions, or a single
    494 	 * fat.  if neither, things are broken. */
    495 	if (!(pm->bootsize >= (MIN_FAT12_BOOT/512) ||
    496 		(binfosize >= (MIN_BINFO_BOOT/512) &&
    497 		    bprepsize >= (MIN_PREP_BOOT/512)))) {
    498 		msg_display(MSG_bootnotright);
    499 		msg_display_add(MSG_reeditpart, 0);
    500 		if (!ask_yesno(NULL))
    501 			return 0;
    502 		return 1;
    503 	}
    504 
    505 	/* check the prep partitions */
    506 	if ((binfosize > 0 || bprepsize > 0) &&
    507 	    (binfosize < (MIN_BINFO_BOOT/512) ||
    508 		bprepsize < (MIN_PREP_BOOT/512))) {
    509 		msg_display(MSG_preptoosmall);
    510 		msg_display_add(MSG_reeditpart, 0);
    511 		if (!ask_yesno(NULL))
    512 			return 0;
    513 		return 1;
    514 	}
    515 
    516 	/* check the fat12 parititons */
    517 	if (pm->bootsize > 0 && pm->bootsize < (MIN_FAT12_BOOT/512)) {
    518 		msg_display(MSG_boottoosmall);
    519 		msg_display_add(MSG_reeditpart, 0);
    520 		if (!ask_yesno(NULL))
    521 			return 0;
    522 		return 1;
    523 	}
    524 
    525 	/* if both sets contain zero, thats bad */
    526 	if ((pm->bootstart == 0 || pm->bootsize == 0) &&
    527 	    (binfosize == 0 || binfostart == 0 ||
    528 		bprepsize == 0 || bprepstart == 0)) {
    529 		msg_display(MSG_nobootpart);
    530 		msg_display_add(MSG_reeditpart, 0);
    531 		if (!ask_yesno(NULL))
    532 			return 0;
    533 		return 1;
    534 	}
    535 	return 2;
    536 }
    537 
    538 /*
    539  * NOTE, we use a reserved partition type, because some RS/6000 machines hang
    540  * hard if they find a FAT12, and if we use type prep, that indicates that
    541  * it should be read raw.
    542  * One partition for FAT12 booting
    543  * One partition for NetBSD
    544  * One partition to hold the bootinfo.txt file
    545  * One partition to hold ofwboot
    546  */
    547 
    548 int
    549 md_mbr_use_wholedisk(mbr_info_t *mbri)
    550 {
    551 	struct mbr_sector *mbrs = &mbri->mbr;
    552 	mbr_info_t *ext;
    553 	struct mbr_partition *part;
    554 
    555 	part = &mbrs->mbr_parts[0];
    556 	/* Set the partition information for full disk usage. */
    557 	while ((ext = mbri->extended)) {
    558 		mbri->extended = ext->extended;
    559 		free(ext);
    560 	}
    561 	memset(part, 0, MBR_PART_COUNT * sizeof *part);
    562 
    563 	part[0].mbrp_type = MBR_PTYPE_RESERVED_x21;
    564 	part[0].mbrp_size = FAT12_BOOT_SIZE/512;
    565 	part[0].mbrp_start = bsec;
    566 	part[0].mbrp_flag = 0;
    567 
    568 	part[1].mbrp_type = MBR_PTYPE_NETBSD;
    569 	part[1].mbrp_size = pm->dlsize - (bsec + FAT12_BOOT_SIZE/512 +
    570 	    BINFO_BOOT_SIZE/512 + PREP_BOOT_SIZE/512);
    571 	part[1].mbrp_start = bsec + FAT12_BOOT_SIZE/512 + BINFO_BOOT_SIZE/512 +
    572 	    PREP_BOOT_SIZE/512;
    573 	part[1].mbrp_flag = MBR_PFLAG_ACTIVE;
    574 
    575 	part[2].mbrp_type = MBR_PTYPE_PREP;
    576 	part[2].mbrp_size = BINFO_BOOT_SIZE/512;
    577 	part[2].mbrp_start = bsec + FAT12_BOOT_SIZE/512;
    578 	part[2].mbrp_flag = 0;
    579 
    580 	part[3].mbrp_type = MBR_PTYPE_PREP;
    581 	part[3].mbrp_size = PREP_BOOT_SIZE/512;
    582 	part[3].mbrp_start = bsec + FAT12_BOOT_SIZE/512 + BINFO_BOOT_SIZE/512;
    583 	part[3].mbrp_flag = 0;
    584 
    585 	pm->ptstart = part[1].mbrp_start;
    586 	pm->ptsize = part[1].mbrp_size;
    587 	pm->bootstart = part[0].mbrp_start;
    588 	pm->bootsize = part[0].mbrp_size;
    589 	binfostart = part[2].mbrp_start;
    590 	binfosize= part[2].mbrp_size;
    591 	bprepstart = part[3].mbrp_start;
    592 	bprepsize = part[3].mbrp_size;
    593 	bootinfo_mbr = 4;
    594 
    595 	return 1;
    596 }
    597 
    598 const char *md_disklabel_cmd(void)
    599 {
    600 
    601 	/* we cannot rewrite an RDB disklabel */
    602 	if (rdb_found)
    603 		return "sync No disklabel";
    604 
    605 	return "disklabel -w -r";
    606 }
    607 
    608 static int
    609 check_rdb(void)
    610 {
    611 	char buf[512], diskpath[MAXPATHLEN];
    612 	struct rdblock *rdb;
    613 	off_t blk;
    614 	int fd;
    615 
    616 	/* Find out if this disk has a valid RDB, before continuing. */
    617 	rdb = (struct rdblock *)buf;
    618 	fd = opendisk(pm->diskdev, O_RDONLY, diskpath, sizeof(diskpath), 0);
    619 	if (fd < 0)
    620 		return 0;
    621 	for (blk = 0; blk < RDB_MAXBLOCKS; blk++) {
    622 		if (pread(fd, rdb, 512, blk * 512) != 512)
    623 			return 0;
    624 		if (rdb->id == RDBLOCK_ID && rdbchksum(rdb) == 0) {
    625 			rdb_found = 1;	/* do not repartition! */
    626 			return 1;
    627 		}
    628 	}
    629 	return 0;
    630 }
    631 
    632 static uint32_t
    633 rdbchksum(void *bdata)
    634 {
    635 	uint32_t *blp, cnt, val;
    636 
    637 	blp = bdata;
    638 	cnt = blp[1];
    639 	val = 0;
    640 	while (cnt--)
    641 		val += *blp++;
    642 	return val;
    643 }
    644 
    645 int
    646 md_pre_mount()
    647 {
    648 
    649 	return 0;
    650 }
    651