Change the kernel dev_t, representing a pointer to a specinfo structure,
[dragonfly.git] / sys / boot / i386 / libi386 / biosdisk.c
CommitLineData
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1/*-
2 * Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
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 * 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.
13 *
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 PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
c7e270b1 26 * $FreeBSD: src/sys/boot/i386/libi386/biosdisk.c,v 1.45 2004/09/21 06:46:44 wes Exp $
b13267a5 27 * $DragonFly: src/sys/boot/i386/libi386/Attic/biosdisk.c,v 1.10 2006/09/10 01:26:31 dillon Exp $
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28 */
29
30/*
31 * BIOS disk device handling.
32 *
33 * Ideas and algorithms from:
34 *
35 * - NetBSD libi386/biosdisk.c
36 * - FreeBSD biosboot/disk.c
37 *
38 */
39
40#include <stand.h>
41
42#include <sys/disklabel.h>
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43#include <sys/diskmbr.h>
44#include <machine/bootinfo.h>
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45
46#include <stdarg.h>
47
48#include <bootstrap.h>
49#include <btxv86.h>
50#include "libi386.h"
51
52#define BIOS_NUMDRIVES 0x475
53#define BIOSDISK_SECSIZE 512
54#define BUFSIZE (1 * BIOSDISK_SECSIZE)
55#define MAXBDDEV MAXDEV
56
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57#define DT_ATAPI 0x10 /* disk type for ATAPI floppies */
58#define WDMAJOR 0 /* major numbers for devices we frontend for */
59#define WFDMAJOR 1
60#define FDMAJOR 2
61#define DAMAJOR 4
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62
63#ifdef DISK_DEBUG
5ee58eed 64# define DEBUG(fmt, args...) printf("%s: " fmt "\n" , __func__ , ## args)
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65#else
66# define DEBUG(fmt, args...)
67#endif
68
69struct open_disk {
70 int od_dkunit; /* disk unit number */
71 int od_unit; /* BIOS unit number */
72 int od_cyl; /* BIOS geometry */
73 int od_hds;
74 int od_sec;
75 int od_boff; /* block offset from beginning of BIOS disk */
76 int od_flags;
77#define BD_MODEINT13 0x0000
78#define BD_MODEEDD1 0x0001
79#define BD_MODEEDD3 0x0002
80#define BD_MODEMASK 0x0003
81#define BD_FLOPPY 0x0004
82#define BD_LABELOK 0x0008
83#define BD_PARTTABOK 0x0010
84 struct disklabel od_disklabel;
85 int od_nslices; /* slice count */
5ee58eed 86 struct dos_partition od_slicetab[NEXTDOSPART];
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87};
88
89/*
90 * List of BIOS devices, translation from disk unit number to
91 * BIOS unit number.
92 */
93static struct bdinfo
94{
95 int bd_unit; /* BIOS unit number */
96 int bd_flags;
97 int bd_type; /* BIOS 'drive type' (floppy only) */
98} bdinfo [MAXBDDEV];
99static int nbdinfo = 0;
100
101static int bd_getgeom(struct open_disk *od);
102static int bd_read(struct open_disk *od, daddr_t dblk, int blks,
103 caddr_t dest);
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104static int bd_write(struct open_disk *od, daddr_t dblk, int blks,
105 caddr_t dest);
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106
107static int bd_int13probe(struct bdinfo *bd);
108
109static void bd_printslice(struct open_disk *od, struct dos_partition *dp,
110 char *prefix, int verbose);
111static void bd_printbsdslice(struct open_disk *od, daddr_t offset,
112 char *prefix, int verbose);
113
114static int bd_init(void);
115static int bd_strategy(void *devdata, int flag, daddr_t dblk,
116 size_t size, char *buf, size_t *rsize);
117static int bd_realstrategy(void *devdata, int flag, daddr_t dblk,
118 size_t size, char *buf, size_t *rsize);
119static int bd_open(struct open_file *f, ...);
120static int bd_close(struct open_file *f);
121static void bd_print(int verbose);
122
123struct devsw biosdisk = {
124 "disk",
125 DEVT_DISK,
126 bd_init,
127 bd_strategy,
128 bd_open,
129 bd_close,
130 noioctl,
131 bd_print,
132 NULL
133};
134
135static int bd_opendisk(struct open_disk **odp, struct i386_devdesc *dev);
136static void bd_closedisk(struct open_disk *od);
137static int bd_bestslice(struct open_disk *od);
7755d172 138static void bd_chainextended(struct open_disk *od, u_int32_t base, u_int32_t offset);
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139
140/*
141 * Translate between BIOS device numbers and our private unit numbers.
142 */
143int
144bd_bios2unit(int biosdev)
145{
146 int i;
147
148 DEBUG("looking for bios device 0x%x", biosdev);
149 for (i = 0; i < nbdinfo; i++) {
150 DEBUG("bd unit %d is BIOS device 0x%x", i, bdinfo[i].bd_unit);
151 if (bdinfo[i].bd_unit == biosdev)
152 return(i);
153 }
154 return(-1);
155}
156
157int
158bd_unit2bios(int unit)
159{
160 if ((unit >= 0) && (unit < nbdinfo))
161 return(bdinfo[unit].bd_unit);
162 return(-1);
163}
164
165/*
166 * Quiz the BIOS for disk devices, save a little info about them.
167 */
168static int
169bd_init(void)
170{
171 int base, unit, nfd = 0;
172
173 /* sequence 0, 0x80 */
174 for (base = 0; base <= 0x80; base += 0x80) {
175 for (unit = base; (nbdinfo < MAXBDDEV); unit++) {
176 /* check the BIOS equipment list for number of fixed disks */
177 if((base == 0x80) &&
178 (nfd >= *(unsigned char *)PTOV(BIOS_NUMDRIVES)))
179 break;
180
181 bdinfo[nbdinfo].bd_unit = unit;
182 bdinfo[nbdinfo].bd_flags = (unit < 0x80) ? BD_FLOPPY : 0;
183
184 if (!bd_int13probe(&bdinfo[nbdinfo]))
185 break;
186
187 /* XXX we need "disk aliases" to make this simpler */
188 printf("BIOS drive %c: is disk%d\n",
189 (unit < 0x80) ? ('A' + unit) : ('C' + unit - 0x80), nbdinfo);
190 nbdinfo++;
191 if (base == 0x80)
192 nfd++;
193 }
194 }
195 return(0);
196}
197
198/*
199 * Try to detect a device supported by the legacy int13 BIOS
200 */
201static int
202bd_int13probe(struct bdinfo *bd)
203{
204 v86.ctl = V86_FLAGS;
205 v86.addr = 0x13;
206 v86.eax = 0x800;
207 v86.edx = bd->bd_unit;
208 v86int();
209
210 if (!(v86.efl & 0x1) && /* carry clear */
211 ((v86.edx & 0xff) > ((unsigned)bd->bd_unit & 0x7f))) { /* unit # OK */
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212
213 /*
214 * Ignore devices with an absurd sector size.
215 */
216 if ((v86.ecx & 0x3f) == 0) {
217 DEBUG("Invalid geometry for unit %d", bd->bd_unit);
218 return(0);
219 }
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220 bd->bd_flags |= BD_MODEINT13;
221 bd->bd_type = v86.ebx & 0xff;
222
223 /* Determine if we can use EDD with this device. */
224 v86.eax = 0x4100;
225 v86.edx = bd->bd_unit;
226 v86.ebx = 0x55aa;
227 v86int();
228 if (!(v86.efl & 0x1) && /* carry clear */
229 ((v86.ebx & 0xffff) == 0xaa55) && /* signature */
230 (v86.ecx & 0x1)) { /* packets mode ok */
231 bd->bd_flags |= BD_MODEEDD1;
232 if((v86.eax & 0xff00) > 0x300)
233 bd->bd_flags |= BD_MODEEDD3;
234 }
235 return(1);
236 }
237 return(0);
238}
239
240/*
241 * Print information about disks
242 */
243static void
244bd_print(int verbose)
245{
246 int i, j;
247 char line[80];
248 struct i386_devdesc dev;
249 struct open_disk *od;
250 struct dos_partition *dptr;
251
252 for (i = 0; i < nbdinfo; i++) {
253 sprintf(line, " disk%d: BIOS drive %c:\n", i,
254 (bdinfo[i].bd_unit < 0x80) ? ('A' + bdinfo[i].bd_unit) : ('C' + bdinfo[i].bd_unit - 0x80));
255 pager_output(line);
256
257 /* try to open the whole disk */
258 dev.d_kind.biosdisk.unit = i;
259 dev.d_kind.biosdisk.slice = -1;
260 dev.d_kind.biosdisk.partition = -1;
261
262 if (!bd_opendisk(&od, &dev)) {
263
264 /* Do we have a partition table? */
265 if (od->od_flags & BD_PARTTABOK) {
266 dptr = &od->od_slicetab[0];
267
268 /* Check for a "dedicated" disk */
269 if ((dptr[3].dp_typ == DOSPTYP_386BSD) &&
270 (dptr[3].dp_start == 0) &&
271 (dptr[3].dp_size == 50000)) {
272 sprintf(line, " disk%d", i);
273 bd_printbsdslice(od, 0, line, verbose);
274 } else {
275 for (j = 0; j < od->od_nslices; j++) {
276 sprintf(line, " disk%ds%d", i, j + 1);
277 bd_printslice(od, &dptr[j], line, verbose);
278 }
279 }
280 }
281 bd_closedisk(od);
282 }
283 }
284}
285
286/*
287 * Print information about slices on a disk. For the size calculations we
288 * assume a 512 byte sector.
289 */
290static void
291bd_printslice(struct open_disk *od, struct dos_partition *dp, char *prefix,
292 int verbose)
293{
294 char line[80];
295
296 switch (dp->dp_typ) {
297 case DOSPTYP_386BSD:
298 bd_printbsdslice(od, (daddr_t)dp->dp_start, prefix, verbose);
299 return;
300 case DOSPTYP_LINSWP:
301 if (verbose)
302 sprintf(line, "%s: Linux swap %.6dMB (%d - %d)\n",
303 prefix, dp->dp_size / 2048,
304 dp->dp_start, dp->dp_start + dp->dp_size);
305 else
306 sprintf(line, "%s: Linux swap\n", prefix);
307 break;
308 case DOSPTYP_LINUX:
309 /*
310 * XXX
311 * read the superblock to confirm this is an ext2fs partition?
312 */
313 if (verbose)
314 sprintf(line, "%s: ext2fs %.6dMB (%d - %d)\n", prefix,
315 dp->dp_size / 2048, dp->dp_start,
316 dp->dp_start + dp->dp_size);
317 else
318 sprintf(line, "%s: ext2fs\n", prefix);
319 break;
320 case 0x00: /* unused partition */
321 case DOSPTYP_EXT:
322 return;
323 case 0x01:
324 if (verbose)
325 sprintf(line, "%s: FAT-12 %.6dMB (%d - %d)\n", prefix,
326 dp->dp_size / 2048, dp->dp_start,
327 dp->dp_start + dp->dp_size);
328 else
329 sprintf(line, "%s: FAT-12\n", prefix);
330 break;
331 case 0x04:
332 case 0x06:
333 case 0x0e:
334 if (verbose)
335 sprintf(line, "%s: FAT-16 %.6dMB (%d - %d)\n", prefix,
336 dp->dp_size / 2048, dp->dp_start,
337 dp->dp_start + dp->dp_size);
338 else
339 sprintf(line, "%s: FAT-16\n", prefix);
340 break;
341 case 0x0b:
342 case 0x0c:
343 if (verbose)
344 sprintf(line, "%s: FAT-32 %.6dMB (%d - %d)\n", prefix,
345 dp->dp_size / 2048, dp->dp_start,
346 dp->dp_start + dp->dp_size);
347 else
348 sprintf(line, "%s: FAT-32\n", prefix);
349 break;
350 default:
351 if (verbose)
352 sprintf(line, "%s: Unknown fs: 0x%x %.6dMB (%d - %d)\n",
353 prefix, dp->dp_typ, dp->dp_size / 2048,
354 dp->dp_start, dp->dp_start + dp->dp_size);
355 else
356 sprintf(line, "%s: Unknown fs: 0x%x\n", prefix,
357 dp->dp_typ);
358 }
359 pager_output(line);
360}
361
362/*
363 * Print out each valid partition in the disklabel of a FreeBSD slice.
364 * For size calculations, we assume a 512 byte sector size.
365 */
366static void
367bd_printbsdslice(struct open_disk *od, daddr_t offset, char *prefix,
368 int verbose)
369{
370 char line[80];
371 char buf[BIOSDISK_SECSIZE];
372 struct disklabel *lp;
373 int i;
374
375 /* read disklabel */
376 if (bd_read(od, offset + LABELSECTOR, 1, buf))
377 return;
378 lp =(struct disklabel *)(&buf[0]);
379 if (lp->d_magic != DISKMAGIC) {
380 sprintf(line, "%s: FFS bad disklabel\n", prefix);
381 pager_output(line);
382 return;
383 }
384
385 /* Print partitions */
386 for (i = 0; i < lp->d_npartitions; i++) {
387 /*
388 * For each partition, make sure we know what type of fs it is. If
389 * not, then skip it. However, since floppies often have bogus
390 * fstypes, print the 'a' partition on a floppy even if it is marked
391 * unused.
392 */
393 if ((lp->d_partitions[i].p_fstype == FS_BSDFFS) ||
394 (lp->d_partitions[i].p_fstype == FS_SWAP) ||
395 (lp->d_partitions[i].p_fstype == FS_VINUM) ||
396 ((lp->d_partitions[i].p_fstype == FS_UNUSED) &&
397 (od->od_flags & BD_FLOPPY) && (i == 0))) {
398
399 /* Only print out statistics in verbose mode */
400 if (verbose)
401 sprintf(line, " %s%c: %s %.6dMB (%d - %d)\n", prefix, 'a' + i,
402 (lp->d_partitions[i].p_fstype == FS_SWAP) ? "swap" :
403 (lp->d_partitions[i].p_fstype == FS_VINUM) ? "vinum" :
404 "FFS",
405 lp->d_partitions[i].p_size / 2048,
406 lp->d_partitions[i].p_offset,
407 lp->d_partitions[i].p_offset + lp->d_partitions[i].p_size);
408 else
409 sprintf(line, " %s%c: %s\n", prefix, 'a' + i,
410 (lp->d_partitions[i].p_fstype == FS_SWAP) ? "swap" :
411 (lp->d_partitions[i].p_fstype == FS_VINUM) ? "vinum" :
412 "FFS");
413 pager_output(line);
414 }
415 }
416}
417
418
419/*
420 * Attempt to open the disk described by (dev) for use by (f).
421 *
422 * Note that the philosophy here is "give them exactly what
423 * they ask for". This is necessary because being too "smart"
424 * about what the user might want leads to complications.
425 * (eg. given no slice or partition value, with a disk that is
426 * sliced - are they after the first BSD slice, or the DOS
427 * slice before it?)
428 */
429static int
430bd_open(struct open_file *f, ...)
431{
5ee58eed 432 va_list ap;
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433 struct i386_devdesc *dev;
434 struct open_disk *od;
435 int error;
436
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437 va_start(ap, f);
438 dev = va_arg(ap, struct i386_devdesc *);
439 va_end(ap);
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440 if ((error = bd_opendisk(&od, dev)))
441 return(error);
442
443 /*
444 * Save our context
445 */
446 ((struct i386_devdesc *)(f->f_devdata))->d_kind.biosdisk.data = od;
447 DEBUG("open_disk %p, partition at 0x%x", od, od->od_boff);
448 return(0);
449}
450
451static int
452bd_opendisk(struct open_disk **odp, struct i386_devdesc *dev)
453{
454 struct dos_partition *dptr;
455 struct disklabel *lp;
456 struct open_disk *od;
457 int sector, slice, i;
458 int error;
459 char buf[BUFSIZE];
460
461 if (dev->d_kind.biosdisk.unit >= nbdinfo) {
462 DEBUG("attempt to open nonexistent disk");
463 return(ENXIO);
464 }
465
466 od = (struct open_disk *)malloc(sizeof(struct open_disk));
467 if (!od) {
468 DEBUG("no memory");
469 return (ENOMEM);
470 }
471
472 /* Look up BIOS unit number, intialise open_disk structure */
473 od->od_dkunit = dev->d_kind.biosdisk.unit;
474 od->od_unit = bdinfo[od->od_dkunit].bd_unit;
475 od->od_flags = bdinfo[od->od_dkunit].bd_flags;
476 od->od_boff = 0;
477 od->od_nslices = 0;
478 error = 0;
479 DEBUG("open '%s', unit 0x%x slice %d partition %c",
480 i386_fmtdev(dev), dev->d_kind.biosdisk.unit,
481 dev->d_kind.biosdisk.slice, dev->d_kind.biosdisk.partition + 'a');
482
483 /* Get geometry for this open (removable device may have changed) */
484 if (bd_getgeom(od)) {
485 DEBUG("can't get geometry");
486 error = ENXIO;
487 goto out;
488 }
489
490 /*
491 * Following calculations attempt to determine the correct value
492 * for d->od_boff by looking for the slice and partition specified,
493 * or searching for reasonable defaults.
494 */
495
496 /*
497 * Find the slice in the DOS slice table.
498 */
499 if (bd_read(od, 0, 1, buf)) {
500 DEBUG("error reading MBR");
501 error = EIO;
502 goto out;
503 }
504
505 /*
506 * Check the slice table magic.
507 */
508 if (((u_char)buf[0x1fe] != 0x55) || ((u_char)buf[0x1ff] != 0xaa)) {
509 /* If a slice number was explicitly supplied, this is an error */
510 if (dev->d_kind.biosdisk.slice > 0) {
511 DEBUG("no slice table/MBR (no magic)");
512 error = ENOENT;
513 goto out;
514 }
515 sector = 0;
516 goto unsliced; /* may be a floppy */
517 }
518
519 /*
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520 * copy the partition table, then pick up any extended partitions. The
521 * base partition table always has four entries, even if some of them
522 * represented extended partitions. However, any additional sub-extended
523 * partitions will be silently recursed and not included in the slice
524 * table.
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525 */
526 bcopy(buf + DOSPARTOFF, &od->od_slicetab,
527 sizeof(struct dos_partition) * NDOSPART);
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528 od->od_nslices = NDOSPART;
529
530 dptr = &od->od_slicetab[0];
531 for (i = 0; i < NDOSPART; i++, dptr++) {
532 if ((dptr->dp_typ == DOSPTYP_EXT) || (dptr->dp_typ == DOSPTYP_EXTLBA))
533 bd_chainextended(od, dptr->dp_start, 0); /* 1st offset is zero */
534 }
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535 od->od_flags |= BD_PARTTABOK;
536 dptr = &od->od_slicetab[0];
537
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538 /*
539 * Overflow entries are not loaded into memory but we still keep
540 * track of the count. Fix it up now.
541 */
542 if (od->od_nslices > NEXTDOSPART)
543 od->od_nslices = NEXTDOSPART;
544
545 /*
546 * Is this a request for the whole disk?
547 */
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548 if (dev->d_kind.biosdisk.slice == -1) {
549 sector = 0;
550 goto unsliced;
551 }
552
553 /*
554 * if a slice number was supplied but not found, this is an error.
555 */
556 if (dev->d_kind.biosdisk.slice > 0) {
557 slice = dev->d_kind.biosdisk.slice - 1;
558 if (slice >= od->od_nslices) {
559 DEBUG("slice %d not found", slice);
560 error = ENOENT;
561 goto out;
562 }
563 }
564
565 /*
566 * Check for the historically bogus MBR found on true dedicated disks
567 */
568 if ((dptr[3].dp_typ == DOSPTYP_386BSD) &&
569 (dptr[3].dp_start == 0) &&
570 (dptr[3].dp_size == 50000)) {
571 sector = 0;
572 goto unsliced;
573 }
574
575 /* Try to auto-detect the best slice; this should always give a slice number */
576 if (dev->d_kind.biosdisk.slice == 0) {
577 slice = bd_bestslice(od);
578 if (slice == -1) {
579 error = ENOENT;
580 goto out;
581 }
582 dev->d_kind.biosdisk.slice = slice;
583 }
584
585 dptr = &od->od_slicetab[0];
586 /*
587 * Accept the supplied slice number unequivocally (we may be looking
588 * at a DOS partition).
589 */
590 dptr += (dev->d_kind.biosdisk.slice - 1); /* we number 1-4, offsets are 0-3 */
591 sector = dptr->dp_start;
592 DEBUG("slice entry %d at %d, %d sectors", dev->d_kind.biosdisk.slice - 1, sector, dptr->dp_size);
593
594 /*
595 * If we are looking at a BSD slice, and the partition is < 0, assume the 'a' partition
596 */
597 if ((dptr->dp_typ == DOSPTYP_386BSD) && (dev->d_kind.biosdisk.partition < 0))
598 dev->d_kind.biosdisk.partition = 0;
599
600 unsliced:
601 /*
602 * Now we have the slice offset, look for the partition in the disklabel if we have
603 * a partition to start with.
604 *
605 * XXX we might want to check the label checksum.
606 */
607 if (dev->d_kind.biosdisk.partition < 0) {
608 od->od_boff = sector; /* no partition, must be after the slice */
609 DEBUG("opening raw slice");
610 } else {
611
612 if (bd_read(od, sector + LABELSECTOR, 1, buf)) {
613 DEBUG("error reading disklabel");
614 error = EIO;
615 goto out;
616 }
617 DEBUG("copy %d bytes of label from %p to %p", sizeof(struct disklabel), buf + LABELOFFSET, &od->od_disklabel);
618 bcopy(buf + LABELOFFSET, &od->od_disklabel, sizeof(struct disklabel));
619 lp = &od->od_disklabel;
620 od->od_flags |= BD_LABELOK;
621
622 if (lp->d_magic != DISKMAGIC) {
623 DEBUG("no disklabel");
624 error = ENOENT;
625 goto out;
626 }
627 if (dev->d_kind.biosdisk.partition >= lp->d_npartitions) {
628 DEBUG("partition '%c' exceeds partitions in table (a-'%c')",
629 'a' + dev->d_kind.biosdisk.partition, 'a' + lp->d_npartitions);
630 error = EPART;
631 goto out;
632
633 }
634
635#ifdef DISK_DEBUG
636 /* Complain if the partition is unused unless this is a floppy. */
637 if ((lp->d_partitions[dev->d_kind.biosdisk.partition].p_fstype == FS_UNUSED) &&
638 !(od->od_flags & BD_FLOPPY))
639 DEBUG("warning, partition marked as unused");
640#endif
641
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642 od->od_boff =
643 lp->d_partitions[dev->d_kind.biosdisk.partition].p_offset -
644 lp->d_partitions[RAW_PART].p_offset +
645 sector;
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646 }
647
648 out:
649 if (error) {
650 free(od);
651 } else {
652 *odp = od; /* return the open disk */
653 }
654 return(error);
655}
656
7755d172 657
984263bc 658static void
7755d172 659bd_chainextended(struct open_disk *od, u_int32_t base, u_int32_t offset)
984263bc 660{
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661 char buf[BIOSDISK_SECSIZE];
662 struct dos_partition *dp1, *dp2;
663 int i;
664
665 if (bd_read(od, (daddr_t)(base + offset), 1, buf)) {
666 printf("\nerror reading extended partition table");
667 return;
984263bc 668 }
7755d172
MD
669
670 /*
671 * dp1 points to the first record in the on-disk XPT,
672 * dp2 points to the next entry in the in-memory parition table.
673 *
674 * NOTE: dp2 may be out of bounds if od_nslices >= NEXTDOSPART.
675 *
676 * NOTE: unlike the extended partitions in our primary dos partition
677 * table, we do not record recursed extended partitions themselves
678 * in our in-memory partition table.
679 *
680 * NOTE: recording within our in-memory table must be breadth first
681 * ot match what the kernel does. Thus, two passes are required.
682 *
683 * NOTE: partitioning programs which support extended partitions seem
684 * to always use the first entry for the user partition and the
685 * second entry to chain, and also appear to disallow more then one
686 * extended partition at each level. Nevertheless we make our code
687 * somewhat more generic (and the same as the kernel's own slice
688 * scan).
689 */
690 dp1 = (struct dos_partition *)(&buf[DOSPARTOFF]);
691 dp2 = &od->od_slicetab[od->od_nslices];
692
693 for (i = 0; i < NDOSPART; ++i, ++dp1) {
694 if (dp1->dp_scyl == 0 && dp1->dp_shd == 0 &&
695 dp1->dp_ssect == 0 && dp1->dp_start == 0 &&
696 dp1->dp_size == 0) {
984263bc 697 continue;
7755d172
MD
698 }
699 if ((dp1->dp_typ == DOSPTYP_EXT) ||
700 (dp1->dp_typ == DOSPTYP_EXTLBA)) {
701 /*
702 * breadth first traversal, must skip in the
703 * first pass
704 */
705 continue;
706 }
707
708 /*
709 * Only load up the in-memory data if we haven't overflowed
710 * our in-memory array.
711 */
712 if (od->od_nslices < NEXTDOSPART) {
713 dp2->dp_typ = dp1->dp_typ;
714 dp2->dp_start = base + offset + dp1->dp_start;
715 dp2->dp_size = dp1->dp_size;
716 }
717 ++od->od_nslices;
718 ++dp2;
984263bc 719 }
984263bc
MD
720
721 /*
7755d172
MD
722 * Pass 2 - handle extended partitions. Note that the extended
723 * slice itself is not stored in the slice array when we recurse,
724 * but any 'original' top-level extended slices are. This is to
725 * match what the kernel does.
984263bc 726 */
7755d172
MD
727 dp1 -= NDOSPART;
728 for (i = 0; i < NDOSPART; ++i, ++dp1) {
729 if (dp1->dp_scyl == 0 && dp1->dp_shd == 0 &&
730 dp1->dp_ssect == 0 && dp1->dp_start == 0 &&
731 dp1->dp_size == 0) {
732 continue;
733 }
734 if ((dp1->dp_typ == DOSPTYP_EXT) ||
735 (dp1->dp_typ == DOSPTYP_EXTLBA)) {
736 bd_chainextended(od, base, dp1->dp_start);
737 continue;
738 }
739 }
984263bc
MD
740}
741
742/*
743 * Search for a slice with the following preferences:
744 *
745 * 1: Active FreeBSD slice
746 * 2: Non-active FreeBSD slice
747 * 3: Active Linux slice
748 * 4: non-active Linux slice
749 * 5: Active FAT/FAT32 slice
750 * 6: non-active FAT/FAT32 slice
751 */
752#define PREF_RAWDISK 0
753#define PREF_FBSD_ACT 1
754#define PREF_FBSD 2
755#define PREF_LINUX_ACT 3
756#define PREF_LINUX 4
757#define PREF_DOS_ACT 5
758#define PREF_DOS 6
759#define PREF_NONE 7
760
761/*
762 * slicelimit is in the range 0 .. NDOSPART
763 */
764static int
765bd_bestslice(struct open_disk *od)
766{
767 struct dos_partition *dp;
768 int pref, preflevel;
769 int i, prefslice;
770
771 prefslice = 0;
772 preflevel = PREF_NONE;
773
774 dp = &od->od_slicetab[0];
775 for (i = 0; i < od->od_nslices; i++, dp++) {
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MD
776 switch (dp->dp_typ) {
777 case DOSPTYP_386BSD: /* FreeBSD */
778 pref = dp->dp_flag & 0x80 ? PREF_FBSD_ACT : PREF_FBSD;
779 break;
780
781 case DOSPTYP_LINUX:
782 pref = dp->dp_flag & 0x80 ? PREF_LINUX_ACT : PREF_LINUX;
783 break;
784
785 case 0x01: /* DOS/Windows */
786 case 0x04:
787 case 0x06:
788 case 0x0b:
789 case 0x0c:
790 case 0x0e:
791 pref = dp->dp_flag & 0x80 ? PREF_DOS_ACT : PREF_DOS;
792 break;
793
794 default:
795 pref = PREF_NONE;
796 }
797 if (pref < preflevel) {
798 preflevel = pref;
799 prefslice = i + 1;
800 }
801 }
802 return (prefslice);
803}
804
805static int
806bd_close(struct open_file *f)
807{
808 struct open_disk *od = (struct open_disk *)(((struct i386_devdesc *)(f->f_devdata))->d_kind.biosdisk.data);
809
810 bd_closedisk(od);
811 return(0);
812}
813
814static void
815bd_closedisk(struct open_disk *od)
816{
817 DEBUG("open_disk %p", od);
818#if 0
819 /* XXX is this required? (especially if disk already open...) */
820 if (od->od_flags & BD_FLOPPY)
821 delay(3000000);
822#endif
823 free(od);
824}
825
826static int
827bd_strategy(void *devdata, int rw, daddr_t dblk, size_t size, char *buf, size_t *rsize)
828{
829 struct bcache_devdata bcd;
830 struct open_disk *od = (struct open_disk *)(((struct i386_devdesc *)devdata)->d_kind.biosdisk.data);
831
832 bcd.dv_strategy = bd_realstrategy;
833 bcd.dv_devdata = devdata;
834 return(bcache_strategy(&bcd, od->od_unit, rw, dblk+od->od_boff, size, buf, rsize));
835}
836
837static int
838bd_realstrategy(void *devdata, int rw, daddr_t dblk, size_t size, char *buf, size_t *rsize)
839{
840 struct open_disk *od = (struct open_disk *)(((struct i386_devdesc *)devdata)->d_kind.biosdisk.data);
841 int blks;
842#ifdef BD_SUPPORT_FRAGS
843 char fragbuf[BIOSDISK_SECSIZE];
844 size_t fragsize;
845
846 fragsize = size % BIOSDISK_SECSIZE;
847#else
848 if (size % BIOSDISK_SECSIZE)
849 panic("bd_strategy: %d bytes I/O not multiple of block size", size);
850#endif
851
852 DEBUG("open_disk %p", od);
853
5644a38d
MD
854 switch(rw){
855 case F_READ:
856 blks = size / BIOSDISK_SECSIZE;
857 DEBUG("read %d from %d to %p", blks, dblk, buf);
984263bc 858
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MD
859 if (rsize)
860 *rsize = 0;
861 if (blks && bd_read(od, dblk, blks, buf)) {
862 DEBUG("read error");
863 return (EIO);
864 }
984263bc 865#ifdef BD_SUPPORT_FRAGS
5644a38d 866 DEBUG("bd_strategy: frag read %d from %d+%d to %p",
984263bc 867 fragsize, dblk, blks, buf + (blks * BIOSDISK_SECSIZE));
5644a38d
MD
868 if (fragsize && bd_read(od, dblk + blks, 1, fragsize)) {
869 DEBUG("frag read error");
870 return(EIO);
871 }
872 bcopy(fragbuf, buf + (blks * BIOSDISK_SECSIZE), fragsize);
984263bc 873#endif
5644a38d
MD
874 if (rsize)
875 *rsize = size;
876 return (0);
877 case F_WRITE :
878 blks = size / BIOSDISK_SECSIZE;
879 DEBUG("write %d from %d to %p", blks, dblk, buf);
880
881 if (rsize)
882 *rsize = 0;
883 if (blks && bd_write(od, dblk, blks, buf)) {
884 DEBUG("write error");
885 return (EIO);
886 }
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MD
887#ifdef BD_SUPPORT_FRAGS
888 if(fragsize) {
5644a38d
MD
889 DEBUG("Attempted to write a frag");
890 return (EIO);
5ee58eed
MD
891 }
892#endif
5644a38d
MD
893 if (rsize)
894 *rsize = size;
895 return (0);
896 default:
897 break; /* DO NOTHING */
898 }
899 return EROFS;
984263bc
MD
900}
901
902/* Max number of sectors to bounce-buffer if the request crosses a 64k boundary */
903#define FLOPPY_BOUNCEBUF 18
904
905static int
906bd_read(struct open_disk *od, daddr_t dblk, int blks, caddr_t dest)
907{
908 u_int x, bpc, cyl, hd, sec, result, resid, retry, maxfer;
909 caddr_t p, xp, bbuf, breg;
910
911 /* Just in case some idiot actually tries to read -1 blocks... */
912 if (blks < 0)
913 return (-1);
914
915 bpc = (od->od_sec * od->od_hds); /* blocks per cylinder */
916 resid = blks;
917 p = dest;
918
919 /* Decide whether we have to bounce */
920 if ((od->od_unit < 0x80) &&
921 ((VTOP(dest) >> 16) != (VTOP(dest + blks * BIOSDISK_SECSIZE) >> 16))) {
922
923 /*
924 * There is a 64k physical boundary somewhere in the destination buffer, so we have
925 * to arrange a suitable bounce buffer. Allocate a buffer twice as large as we
926 * need to. Use the bottom half unless there is a break there, in which case we
927 * use the top half.
928 */
929 x = min(FLOPPY_BOUNCEBUF, (unsigned)blks);
930 bbuf = malloc(x * 2 * BIOSDISK_SECSIZE);
c7e270b1 931 if (((u_int32_t)VTOP(bbuf) & 0xffff0000) == ((u_int32_t)VTOP(bbuf + x * BIOSDISK_SECSIZE) & 0xffff0000)) {
984263bc
MD
932 breg = bbuf;
933 } else {
934 breg = bbuf + x * BIOSDISK_SECSIZE;
935 }
936 maxfer = x; /* limit transfers to bounce region size */
937 } else {
938 breg = bbuf = NULL;
939 maxfer = 0;
940 }
941
942 while (resid > 0) {
943 x = dblk;
944 cyl = x / bpc; /* block # / blocks per cylinder */
945 x %= bpc; /* block offset into cylinder */
946 hd = x / od->od_sec; /* offset / blocks per track */
947 sec = x % od->od_sec; /* offset into track */
948
949 /* play it safe and don't cross track boundaries (XXX this is probably unnecessary) */
950 x = min(od->od_sec - sec, resid);
951 if (maxfer > 0)
952 x = min(x, maxfer); /* fit bounce buffer */
953
954 /* where do we transfer to? */
955 xp = bbuf == NULL ? p : breg;
956
957 /* correct sector number for 1-based BIOS numbering */
958 sec++;
959
ed987dc9
MD
960 /*
961 * Loop retrying the operation a couple of times. The BIOS may also
962 * retry.
963 */
984263bc 964 for (retry = 0; retry < 3; retry++) {
ed987dc9
MD
965 /*
966 * If retrying, reset the drive.
967 */
984263bc
MD
968 if (retry > 0) {
969 v86.ctl = V86_FLAGS;
970 v86.addr = 0x13;
971 v86.eax = 0;
972 v86.edx = od->od_unit;
973 v86int();
974 }
975
ed987dc9
MD
976 /*
977 * Always use EDD if the disk supports it, otherwise fall back
978 * to CHS mode (returning an error if the cylinder number is
979 * too large).
980 */
981 if (od->od_flags & BD_MODEEDD1) {
982 static unsigned short packet[8];
983
984 packet[0] = 0x10;
985 packet[1] = x;
986 packet[2] = VTOPOFF(xp);
987 packet[3] = VTOPSEG(xp);
988 packet[4] = dblk & 0xffff;
989 packet[5] = dblk >> 16;
990 packet[6] = 0;
991 packet[7] = 0;
992 v86.ctl = V86_FLAGS;
993 v86.addr = 0x13;
994 v86.eax = 0x4200;
995 v86.edx = od->od_unit;
996 v86.ds = VTOPSEG(packet);
997 v86.esi = VTOPOFF(packet);
998 v86int();
999 result = (v86.efl & 0x1);
1000 if (result == 0)
984263bc 1001 break;
ed987dc9 1002 } else if (cyl < 1024) {
984263bc
MD
1003 /* Use normal CHS addressing */
1004 v86.ctl = V86_FLAGS;
1005 v86.addr = 0x13;
1006 v86.eax = 0x200 | x;
1007 v86.ecx = ((cyl & 0xff) << 8) | ((cyl & 0x300) >> 2) | sec;
1008 v86.edx = (hd << 8) | od->od_unit;
1009 v86.es = VTOPSEG(xp);
1010 v86.ebx = VTOPOFF(xp);
1011 v86int();
1012 result = (v86.efl & 0x1);
1013 if (result == 0)
ed987dc9
MD
1014 break;
1015 } else {
1016 result = 1;
1017 break;
984263bc
MD
1018 }
1019 }
1020
1021 DEBUG("%d sectors from %d/%d/%d to %p (0x%x) %s", x, cyl, hd, sec - 1, p, VTOP(p), result ? "failed" : "ok");
1022 /* BUG here, cannot use v86 in printf because putchar uses it too */
1023 DEBUG("ax = 0x%04x cx = 0x%04x dx = 0x%04x status 0x%x",
1024 0x200 | x, ((cyl & 0xff) << 8) | ((cyl & 0x300) >> 2) | sec, (hd << 8) | od->od_unit, (v86.eax >> 8) & 0xff);
1025 if (result) {
1026 if (bbuf != NULL)
1027 free(bbuf);
1028 return(-1);
1029 }
1030 if (bbuf != NULL)
1031 bcopy(breg, p, x * BIOSDISK_SECSIZE);
1032 p += (x * BIOSDISK_SECSIZE);
1033 dblk += x;
1034 resid -= x;
1035 }
1036
1037/* hexdump(dest, (blks * BIOSDISK_SECSIZE)); */
1038 if (bbuf != NULL)
1039 free(bbuf);
1040 return(0);
1041}
1042
5ee58eed
MD
1043
1044static int
1045bd_write(struct open_disk *od, daddr_t dblk, int blks, caddr_t dest)
1046{
1047 u_int x, bpc, cyl, hd, sec, result, resid, retry, maxfer;
1048 caddr_t p, xp, bbuf, breg;
1049
1050 /* Just in case some idiot actually tries to read -1 blocks... */
1051 if (blks < 0)
1052 return (-1);
1053
1054 bpc = (od->od_sec * od->od_hds); /* blocks per cylinder */
1055 resid = blks;
1056 p = dest;
1057
1058 /* Decide whether we have to bounce */
1059 if ((od->od_unit < 0x80) &&
1060 ((VTOP(dest) >> 16) != (VTOP(dest + blks * BIOSDISK_SECSIZE) >> 16))) {
1061
1062 /*
1063 * There is a 64k physical boundary somewhere in the destination buffer, so we have
1064 * to arrange a suitable bounce buffer. Allocate a buffer twice as large as we
1065 * need to. Use the bottom half unless there is a break there, in which case we
1066 * use the top half.
1067 */
1068
1069 x = min(FLOPPY_BOUNCEBUF, (unsigned)blks);
1070 bbuf = malloc(x * 2 * BIOSDISK_SECSIZE);
c7e270b1 1071 if (((u_int32_t)VTOP(bbuf) & 0xffff0000) == ((u_int32_t)VTOP(bbuf + x * BIOSDISK_SECSIZE) & 0xffff0000)) {
5ee58eed
MD
1072 breg = bbuf;
1073 } else {
1074 breg = bbuf + x * BIOSDISK_SECSIZE;
1075 }
1076 maxfer = x; /* limit transfers to bounce region size */
1077 } else {
1078 breg = bbuf = NULL;
1079 maxfer = 0;
1080 }
1081
1082 while (resid > 0) {
1083 x = dblk;
1084 cyl = x / bpc; /* block # / blocks per cylinder */
1085 x %= bpc; /* block offset into cylinder */
1086 hd = x / od->od_sec; /* offset / blocks per track */
1087 sec = x % od->od_sec; /* offset into track */
1088
1089 /* play it safe and don't cross track boundaries (XXX this is probably unnecessary) */
1090 x = min(od->od_sec - sec, resid);
1091 if (maxfer > 0)
1092 x = min(x, maxfer); /* fit bounce buffer */
1093
1094 /* where do we transfer to? */
1095 xp = bbuf == NULL ? p : breg;
1096
1097 /* correct sector number for 1-based BIOS numbering */
1098 sec++;
1099
1100
1101 /* Put your Data In, Put your Data out,
1102 Put your Data In, and shake it all about
1103 */
1104 if (bbuf != NULL)
1105 bcopy(p, breg, x * BIOSDISK_SECSIZE);
1106 p += (x * BIOSDISK_SECSIZE);
1107 dblk += x;
1108 resid -= x;
1109
ed987dc9
MD
1110 /*
1111 * Loop retrying the operation a couple of times. The BIOS may also
1112 * retry.
1113 */
5ee58eed 1114 for (retry = 0; retry < 3; retry++) {
ed987dc9
MD
1115 /*
1116 * If retrying, reset the drive.
1117 */
5ee58eed
MD
1118 if (retry > 0) {
1119 v86.ctl = V86_FLAGS;
1120 v86.addr = 0x13;
1121 v86.eax = 0;
1122 v86.edx = od->od_unit;
1123 v86int();
1124 }
ed987dc9
MD
1125
1126 /*
1127 * Always use EDD if the disk supports it, otherwise fall back
1128 * to CHS mode (returning an error if the cylinder number is
1129 * too large).
1130 */
1131 if (od->od_flags & BD_MODEEDD1) {
1132 static unsigned short packet[8];
1133
1134 packet[0] = 0x10;
1135 packet[1] = x;
1136 packet[2] = VTOPOFF(xp);
1137 packet[3] = VTOPSEG(xp);
1138 packet[4] = dblk & 0xffff;
1139 packet[5] = dblk >> 16;
1140 packet[6] = 0;
1141 packet[7] = 0;
1142 v86.ctl = V86_FLAGS;
1143 v86.addr = 0x13;
1144 /* Should we Write with verify ?? 0x4302 ? */
1145 v86.eax = 0x4300;
1146 v86.edx = od->od_unit;
1147 v86.ds = VTOPSEG(packet);
1148 v86.esi = VTOPOFF(packet);
1149 v86int();
1150 result = (v86.efl & 0x1);
1151 if (result == 0)
5ee58eed 1152 break;
ed987dc9 1153 } else if (cyl < 1024) {
5ee58eed
MD
1154 /* Use normal CHS addressing */
1155 v86.ctl = V86_FLAGS;
1156 v86.addr = 0x13;
1157 v86.eax = 0x300 | x;
1158 v86.ecx = ((cyl & 0xff) << 8) | ((cyl & 0x300) >> 2) | sec;
1159 v86.edx = (hd << 8) | od->od_unit;
1160 v86.es = VTOPSEG(xp);
1161 v86.ebx = VTOPOFF(xp);
1162 v86int();
1163 result = (v86.efl & 0x1);
1164 if (result == 0)
ed987dc9
MD
1165 break;
1166 } else {
1167 result = 1;
1168 break;
5ee58eed
MD
1169 }
1170 }
1171
1172 DEBUG("%d sectors from %d/%d/%d to %p (0x%x) %s", x, cyl, hd, sec - 1, p, VTOP(p), result ? "failed" : "ok");
1173 /* BUG here, cannot use v86 in printf because putchar uses it too */
1174 DEBUG("ax = 0x%04x cx = 0x%04x dx = 0x%04x status 0x%x",
1175 0x200 | x, ((cyl & 0xff) << 8) | ((cyl & 0x300) >> 2) | sec, (hd << 8) | od->od_unit, (v86.eax >> 8) & 0xff);
1176 if (result) {
1177 if (bbuf != NULL)
1178 free(bbuf);
1179 return(-1);
1180 }
1181 }
1182
1183/* hexdump(dest, (blks * BIOSDISK_SECSIZE)); */
1184 if (bbuf != NULL)
1185 free(bbuf);
1186 return(0);
1187}
984263bc
MD
1188static int
1189bd_getgeom(struct open_disk *od)
1190{
1191
1192 v86.ctl = V86_FLAGS;
1193 v86.addr = 0x13;
1194 v86.eax = 0x800;
1195 v86.edx = od->od_unit;
1196 v86int();
1197
1198 if ((v86.efl & 0x1) || /* carry set */
1199 ((v86.edx & 0xff) <= (unsigned)(od->od_unit & 0x7f))) /* unit # bad */
1200 return(1);
1201
1202 /* convert max cyl # -> # of cylinders */
1203 od->od_cyl = ((v86.ecx & 0xc0) << 2) + ((v86.ecx & 0xff00) >> 8) + 1;
1204 /* convert max head # -> # of heads */
1205 od->od_hds = ((v86.edx & 0xff00) >> 8) + 1;
1206 od->od_sec = v86.ecx & 0x3f;
1207
1208 DEBUG("unit 0x%x geometry %d/%d/%d", od->od_unit, od->od_cyl, od->od_hds, od->od_sec);
1209 return(0);
1210}
1211
1212/*
1213 * Return the BIOS geometry of a given "fixed drive" in a format
1214 * suitable for the legacy bootinfo structure. Since the kernel is
1215 * expecting raw int 0x13/0x8 values for N_BIOS_GEOM drives, we
1216 * prefer to get the information directly, rather than rely on being
1217 * able to put it together from information already maintained for
1218 * different purposes and for a probably different number of drives.
1219 *
1220 * For valid drives, the geometry is expected in the format (31..0)
1221 * "000000cc cccccccc hhhhhhhh 00ssssss"; and invalid drives are
1222 * indicated by returning the geometry of a "1.2M" PC-format floppy
1223 * disk. And, incidentally, what is returned is not the geometry as
1224 * such but the highest valid cylinder, head, and sector numbers.
1225 */
1226u_int32_t
1227bd_getbigeom(int bunit)
1228{
1229
1230 v86.ctl = V86_FLAGS;
1231 v86.addr = 0x13;
1232 v86.eax = 0x800;
1233 v86.edx = 0x80 + bunit;
1234 v86int();
1235 if (v86.efl & 0x1)
1236 return 0x4f010f;
1237 return ((v86.ecx & 0xc0) << 18) | ((v86.ecx & 0xff00) << 8) |
1238 (v86.edx & 0xff00) | (v86.ecx & 0x3f);
1239}
1240
1241/*
b13267a5 1242 * Return a suitable cdev_t value for (dev).
984263bc
MD
1243 *
1244 * In the case where it looks like (dev) is a SCSI disk, we allow the number of
1245 * IDE disks to be specified in $num_ide_disks. There should be a Better Way.
1246 */
1247int
1248bd_getdev(struct i386_devdesc *dev)
1249{
1250 struct open_disk *od;
1251 int biosdev;
1252 int major;
1253 int rootdev;
1254 char *nip, *cp;
1255 int unitofs = 0, i, unit;
1256
1257 biosdev = bd_unit2bios(dev->d_kind.biosdisk.unit);
1258 DEBUG("unit %d BIOS device %d", dev->d_kind.biosdisk.unit, biosdev);
1259 if (biosdev == -1) /* not a BIOS device */
1260 return(-1);
1261 if (bd_opendisk(&od, dev) != 0) /* oops, not a viable device */
1262 return(-1);
1263
1264 if (biosdev < 0x80) {
1265 /* floppy (or emulated floppy) or ATAPI device */
1266 if (bdinfo[dev->d_kind.biosdisk.unit].bd_type == DT_ATAPI) {
1267 /* is an ATAPI disk */
1268 major = WFDMAJOR;
1269 } else {
1270 /* is a floppy disk */
1271 major = FDMAJOR;
1272 }
1273 } else {
1274 /* harddisk */
1275 if ((od->od_flags & BD_LABELOK) && (od->od_disklabel.d_type == DTYPE_SCSI)) {
1276 /* label OK, disk labelled as SCSI */
1277 major = DAMAJOR;
1278 /* check for unit number correction hint, now deprecated */
1279 if ((nip = getenv("num_ide_disks")) != NULL) {
1280 i = strtol(nip, &cp, 0);
1281 /* check for parse error */
1282 if ((cp != nip) && (*cp == 0))
1283 unitofs = i;
1284 }
1285 } else {
1286 /* assume an IDE disk */
1287 major = WDMAJOR;
1288 }
1289 }
1290 /* default root disk unit number */
1291 unit = (biosdev & 0x7f) - unitofs;
1292
1293 /* XXX a better kludge to set the root disk unit number */
1294 if ((nip = getenv("root_disk_unit")) != NULL) {
1295 i = strtol(nip, &cp, 0);
1296 /* check for parse error */
1297 if ((cp != nip) && (*cp == 0))
1298 unit = i;
1299 }
1300
1301 rootdev = MAKEBOOTDEV(major,
1302 (dev->d_kind.biosdisk.slice + 1) >> 4, /* XXX slices may be wrong here */
1303 (dev->d_kind.biosdisk.slice + 1) & 0xf,
1304 unit,
1305 dev->d_kind.biosdisk.partition);
1306 DEBUG("dev is 0x%x\n", rootdev);
1307 return(rootdev);
1308}