Initial import from FreeBSD RELENG_4:
[dragonfly.git] / sys / boot / pc32 / libi386 / biosdisk.c
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MD
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 *
26 * $FreeBSD: src/sys/boot/i386/libi386/biosdisk.c,v 1.26.2.6 2000/12/28 13:10:47 ps Exp $
27 */
28
29/*
30 * BIOS disk device handling.
31 *
32 * Ideas and algorithms from:
33 *
34 * - NetBSD libi386/biosdisk.c
35 * - FreeBSD biosboot/disk.c
36 *
37 */
38
39#include <stand.h>
40
41#include <sys/disklabel.h>
42#include <sys/diskslice.h>
43#include <sys/reboot.h>
44
45#include <stdarg.h>
46
47#include <bootstrap.h>
48#include <btxv86.h>
49#include "libi386.h"
50
51#define BIOS_NUMDRIVES 0x475
52#define BIOSDISK_SECSIZE 512
53#define BUFSIZE (1 * BIOSDISK_SECSIZE)
54#define MAXBDDEV MAXDEV
55
56#define DT_ATAPI 0x10 /* disk type for ATAPI floppies */
57#define WDMAJOR 0 /* major numbers for devices we frontend for */
58#define WFDMAJOR 1
59#define FDMAJOR 2
60#define DAMAJOR 4
61
62#ifdef DISK_DEBUG
63# define DEBUG(fmt, args...) printf("%s: " fmt "\n" , __FUNCTION__ , ## args)
64#else
65# define DEBUG(fmt, args...)
66#endif
67
68struct open_disk {
69 int od_dkunit; /* disk unit number */
70 int od_unit; /* BIOS unit number */
71 int od_cyl; /* BIOS geometry */
72 int od_hds;
73 int od_sec;
74 int od_boff; /* block offset from beginning of BIOS disk */
75 int od_flags;
76#define BD_MODEINT13 0x0000
77#define BD_MODEEDD1 0x0001
78#define BD_MODEEDD3 0x0002
79#define BD_MODEMASK 0x0003
80#define BD_FLOPPY 0x0004
81#define BD_LABELOK 0x0008
82#define BD_PARTTABOK 0x0010
83 struct disklabel od_disklabel;
84 int od_nslices; /* slice count */
85 struct dos_partition od_slicetab[MAX_SLICES];
86};
87
88/*
89 * List of BIOS devices, translation from disk unit number to
90 * BIOS unit number.
91 */
92static struct bdinfo
93{
94 int bd_unit; /* BIOS unit number */
95 int bd_flags;
96 int bd_type; /* BIOS 'drive type' (floppy only) */
97} bdinfo [MAXBDDEV];
98static int nbdinfo = 0;
99
100static int bd_getgeom(struct open_disk *od);
101static int bd_read(struct open_disk *od, daddr_t dblk, int blks,
102 caddr_t dest);
103
104static int bd_int13probe(struct bdinfo *bd);
105
106static void bd_printslice(struct open_disk *od, struct dos_partition *dp,
107 char *prefix, int verbose);
108static void bd_printbsdslice(struct open_disk *od, daddr_t offset,
109 char *prefix, int verbose);
110
111static int bd_init(void);
112static int bd_strategy(void *devdata, int flag, daddr_t dblk,
113 size_t size, char *buf, size_t *rsize);
114static int bd_realstrategy(void *devdata, int flag, daddr_t dblk,
115 size_t size, char *buf, size_t *rsize);
116static int bd_open(struct open_file *f, ...);
117static int bd_close(struct open_file *f);
118static void bd_print(int verbose);
119
120struct devsw biosdisk = {
121 "disk",
122 DEVT_DISK,
123 bd_init,
124 bd_strategy,
125 bd_open,
126 bd_close,
127 noioctl,
128 bd_print,
129 NULL
130};
131
132static int bd_opendisk(struct open_disk **odp, struct i386_devdesc *dev);
133static void bd_closedisk(struct open_disk *od);
134static int bd_bestslice(struct open_disk *od);
135static void bd_checkextended(struct open_disk *od, int slicenum);
136
137/*
138 * Translate between BIOS device numbers and our private unit numbers.
139 */
140int
141bd_bios2unit(int biosdev)
142{
143 int i;
144
145 DEBUG("looking for bios device 0x%x", biosdev);
146 for (i = 0; i < nbdinfo; i++) {
147 DEBUG("bd unit %d is BIOS device 0x%x", i, bdinfo[i].bd_unit);
148 if (bdinfo[i].bd_unit == biosdev)
149 return(i);
150 }
151 return(-1);
152}
153
154int
155bd_unit2bios(int unit)
156{
157 if ((unit >= 0) && (unit < nbdinfo))
158 return(bdinfo[unit].bd_unit);
159 return(-1);
160}
161
162/*
163 * Quiz the BIOS for disk devices, save a little info about them.
164 */
165static int
166bd_init(void)
167{
168 int base, unit, nfd = 0;
169
170 /* sequence 0, 0x80 */
171 for (base = 0; base <= 0x80; base += 0x80) {
172 for (unit = base; (nbdinfo < MAXBDDEV); unit++) {
173 /* check the BIOS equipment list for number of fixed disks */
174 if((base == 0x80) &&
175 (nfd >= *(unsigned char *)PTOV(BIOS_NUMDRIVES)))
176 break;
177
178 bdinfo[nbdinfo].bd_unit = unit;
179 bdinfo[nbdinfo].bd_flags = (unit < 0x80) ? BD_FLOPPY : 0;
180
181 if (!bd_int13probe(&bdinfo[nbdinfo]))
182 break;
183
184 /* XXX we need "disk aliases" to make this simpler */
185 printf("BIOS drive %c: is disk%d\n",
186 (unit < 0x80) ? ('A' + unit) : ('C' + unit - 0x80), nbdinfo);
187 nbdinfo++;
188 if (base == 0x80)
189 nfd++;
190 }
191 }
192 return(0);
193}
194
195/*
196 * Try to detect a device supported by the legacy int13 BIOS
197 */
198static int
199bd_int13probe(struct bdinfo *bd)
200{
201 v86.ctl = V86_FLAGS;
202 v86.addr = 0x13;
203 v86.eax = 0x800;
204 v86.edx = bd->bd_unit;
205 v86int();
206
207 if (!(v86.efl & 0x1) && /* carry clear */
208 ((v86.edx & 0xff) > ((unsigned)bd->bd_unit & 0x7f))) { /* unit # OK */
209 bd->bd_flags |= BD_MODEINT13;
210 bd->bd_type = v86.ebx & 0xff;
211
212 /* Determine if we can use EDD with this device. */
213 v86.eax = 0x4100;
214 v86.edx = bd->bd_unit;
215 v86.ebx = 0x55aa;
216 v86int();
217 if (!(v86.efl & 0x1) && /* carry clear */
218 ((v86.ebx & 0xffff) == 0xaa55) && /* signature */
219 (v86.ecx & 0x1)) { /* packets mode ok */
220 bd->bd_flags |= BD_MODEEDD1;
221 if((v86.eax & 0xff00) > 0x300)
222 bd->bd_flags |= BD_MODEEDD3;
223 }
224 return(1);
225 }
226 return(0);
227}
228
229/*
230 * Print information about disks
231 */
232static void
233bd_print(int verbose)
234{
235 int i, j;
236 char line[80];
237 struct i386_devdesc dev;
238 struct open_disk *od;
239 struct dos_partition *dptr;
240
241 for (i = 0; i < nbdinfo; i++) {
242 sprintf(line, " disk%d: BIOS drive %c:\n", i,
243 (bdinfo[i].bd_unit < 0x80) ? ('A' + bdinfo[i].bd_unit) : ('C' + bdinfo[i].bd_unit - 0x80));
244 pager_output(line);
245
246 /* try to open the whole disk */
247 dev.d_kind.biosdisk.unit = i;
248 dev.d_kind.biosdisk.slice = -1;
249 dev.d_kind.biosdisk.partition = -1;
250
251 if (!bd_opendisk(&od, &dev)) {
252
253 /* Do we have a partition table? */
254 if (od->od_flags & BD_PARTTABOK) {
255 dptr = &od->od_slicetab[0];
256
257 /* Check for a "dedicated" disk */
258 if ((dptr[3].dp_typ == DOSPTYP_386BSD) &&
259 (dptr[3].dp_start == 0) &&
260 (dptr[3].dp_size == 50000)) {
261 sprintf(line, " disk%d", i);
262 bd_printbsdslice(od, 0, line, verbose);
263 } else {
264 for (j = 0; j < od->od_nslices; j++) {
265 sprintf(line, " disk%ds%d", i, j + 1);
266 bd_printslice(od, &dptr[j], line, verbose);
267 }
268 }
269 }
270 bd_closedisk(od);
271 }
272 }
273}
274
275/*
276 * Print information about slices on a disk. For the size calculations we
277 * assume a 512 byte sector.
278 */
279static void
280bd_printslice(struct open_disk *od, struct dos_partition *dp, char *prefix,
281 int verbose)
282{
283 char line[80];
284
285 switch (dp->dp_typ) {
286 case DOSPTYP_386BSD:
287 bd_printbsdslice(od, (daddr_t)dp->dp_start, prefix, verbose);
288 return;
289 case DOSPTYP_LINSWP:
290 if (verbose)
291 sprintf(line, "%s: Linux swap %.6dMB (%d - %d)\n",
292 prefix, dp->dp_size / 2048,
293 dp->dp_start, dp->dp_start + dp->dp_size);
294 else
295 sprintf(line, "%s: Linux swap\n", prefix);
296 break;
297 case DOSPTYP_LINUX:
298 /*
299 * XXX
300 * read the superblock to confirm this is an ext2fs partition?
301 */
302 if (verbose)
303 sprintf(line, "%s: ext2fs %.6dMB (%d - %d)\n", prefix,
304 dp->dp_size / 2048, dp->dp_start,
305 dp->dp_start + dp->dp_size);
306 else
307 sprintf(line, "%s: ext2fs\n", prefix);
308 break;
309 case 0x00: /* unused partition */
310 case DOSPTYP_EXT:
311 return;
312 case 0x01:
313 if (verbose)
314 sprintf(line, "%s: FAT-12 %.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: FAT-12\n", prefix);
319 break;
320 case 0x04:
321 case 0x06:
322 case 0x0e:
323 if (verbose)
324 sprintf(line, "%s: FAT-16 %.6dMB (%d - %d)\n", prefix,
325 dp->dp_size / 2048, dp->dp_start,
326 dp->dp_start + dp->dp_size);
327 else
328 sprintf(line, "%s: FAT-16\n", prefix);
329 break;
330 case 0x0b:
331 case 0x0c:
332 if (verbose)
333 sprintf(line, "%s: FAT-32 %.6dMB (%d - %d)\n", prefix,
334 dp->dp_size / 2048, dp->dp_start,
335 dp->dp_start + dp->dp_size);
336 else
337 sprintf(line, "%s: FAT-32\n", prefix);
338 break;
339 default:
340 if (verbose)
341 sprintf(line, "%s: Unknown fs: 0x%x %.6dMB (%d - %d)\n",
342 prefix, dp->dp_typ, dp->dp_size / 2048,
343 dp->dp_start, dp->dp_start + dp->dp_size);
344 else
345 sprintf(line, "%s: Unknown fs: 0x%x\n", prefix,
346 dp->dp_typ);
347 }
348 pager_output(line);
349}
350
351/*
352 * Print out each valid partition in the disklabel of a FreeBSD slice.
353 * For size calculations, we assume a 512 byte sector size.
354 */
355static void
356bd_printbsdslice(struct open_disk *od, daddr_t offset, char *prefix,
357 int verbose)
358{
359 char line[80];
360 char buf[BIOSDISK_SECSIZE];
361 struct disklabel *lp;
362 int i;
363
364 /* read disklabel */
365 if (bd_read(od, offset + LABELSECTOR, 1, buf))
366 return;
367 lp =(struct disklabel *)(&buf[0]);
368 if (lp->d_magic != DISKMAGIC) {
369 sprintf(line, "%s: FFS bad disklabel\n", prefix);
370 pager_output(line);
371 return;
372 }
373
374 /* Print partitions */
375 for (i = 0; i < lp->d_npartitions; i++) {
376 /*
377 * For each partition, make sure we know what type of fs it is. If
378 * not, then skip it. However, since floppies often have bogus
379 * fstypes, print the 'a' partition on a floppy even if it is marked
380 * unused.
381 */
382 if ((lp->d_partitions[i].p_fstype == FS_BSDFFS) ||
383 (lp->d_partitions[i].p_fstype == FS_SWAP) ||
384 (lp->d_partitions[i].p_fstype == FS_VINUM) ||
385 ((lp->d_partitions[i].p_fstype == FS_UNUSED) &&
386 (od->od_flags & BD_FLOPPY) && (i == 0))) {
387
388 /* Only print out statistics in verbose mode */
389 if (verbose)
390 sprintf(line, " %s%c: %s %.6dMB (%d - %d)\n", prefix, 'a' + i,
391 (lp->d_partitions[i].p_fstype == FS_SWAP) ? "swap" :
392 (lp->d_partitions[i].p_fstype == FS_VINUM) ? "vinum" :
393 "FFS",
394 lp->d_partitions[i].p_size / 2048,
395 lp->d_partitions[i].p_offset,
396 lp->d_partitions[i].p_offset + lp->d_partitions[i].p_size);
397 else
398 sprintf(line, " %s%c: %s\n", prefix, 'a' + i,
399 (lp->d_partitions[i].p_fstype == FS_SWAP) ? "swap" :
400 (lp->d_partitions[i].p_fstype == FS_VINUM) ? "vinum" :
401 "FFS");
402 pager_output(line);
403 }
404 }
405}
406
407
408/*
409 * Attempt to open the disk described by (dev) for use by (f).
410 *
411 * Note that the philosophy here is "give them exactly what
412 * they ask for". This is necessary because being too "smart"
413 * about what the user might want leads to complications.
414 * (eg. given no slice or partition value, with a disk that is
415 * sliced - are they after the first BSD slice, or the DOS
416 * slice before it?)
417 */
418static int
419bd_open(struct open_file *f, ...)
420{
421 va_list ap;
422 struct i386_devdesc *dev;
423 struct open_disk *od;
424 int error;
425
426 va_start(ap, f);
427 dev = va_arg(ap, struct i386_devdesc *);
428 va_end(ap);
429 if ((error = bd_opendisk(&od, dev)))
430 return(error);
431
432 /*
433 * Save our context
434 */
435 ((struct i386_devdesc *)(f->f_devdata))->d_kind.biosdisk.data = od;
436 DEBUG("open_disk %p, partition at 0x%x", od, od->od_boff);
437 return(0);
438}
439
440static int
441bd_opendisk(struct open_disk **odp, struct i386_devdesc *dev)
442{
443 struct dos_partition *dptr;
444 struct disklabel *lp;
445 struct open_disk *od;
446 int sector, slice, i;
447 int error;
448 char buf[BUFSIZE];
449
450 if (dev->d_kind.biosdisk.unit >= nbdinfo) {
451 DEBUG("attempt to open nonexistent disk");
452 return(ENXIO);
453 }
454
455 od = (struct open_disk *)malloc(sizeof(struct open_disk));
456 if (!od) {
457 DEBUG("no memory");
458 return (ENOMEM);
459 }
460
461 /* Look up BIOS unit number, intialise open_disk structure */
462 od->od_dkunit = dev->d_kind.biosdisk.unit;
463 od->od_unit = bdinfo[od->od_dkunit].bd_unit;
464 od->od_flags = bdinfo[od->od_dkunit].bd_flags;
465 od->od_boff = 0;
466 od->od_nslices = 0;
467 error = 0;
468 DEBUG("open '%s', unit 0x%x slice %d partition %c",
469 i386_fmtdev(dev), dev->d_kind.biosdisk.unit,
470 dev->d_kind.biosdisk.slice, dev->d_kind.biosdisk.partition + 'a');
471
472 /* Get geometry for this open (removable device may have changed) */
473 if (bd_getgeom(od)) {
474 DEBUG("can't get geometry");
475 error = ENXIO;
476 goto out;
477 }
478
479 /*
480 * Following calculations attempt to determine the correct value
481 * for d->od_boff by looking for the slice and partition specified,
482 * or searching for reasonable defaults.
483 */
484
485 /*
486 * Find the slice in the DOS slice table.
487 */
488 if (bd_read(od, 0, 1, buf)) {
489 DEBUG("error reading MBR");
490 error = EIO;
491 goto out;
492 }
493
494 /*
495 * Check the slice table magic.
496 */
497 if (((u_char)buf[0x1fe] != 0x55) || ((u_char)buf[0x1ff] != 0xaa)) {
498 /* If a slice number was explicitly supplied, this is an error */
499 if (dev->d_kind.biosdisk.slice > 0) {
500 DEBUG("no slice table/MBR (no magic)");
501 error = ENOENT;
502 goto out;
503 }
504 sector = 0;
505 goto unsliced; /* may be a floppy */
506 }
507
508 /*
509 * copy the partition table, then pick up any extended partitions.
510 */
511 bcopy(buf + DOSPARTOFF, &od->od_slicetab,
512 sizeof(struct dos_partition) * NDOSPART);
513 od->od_nslices = 4; /* extended slices start here */
514 for (i = 0; i < NDOSPART; i++)
515 bd_checkextended(od, i);
516 od->od_flags |= BD_PARTTABOK;
517 dptr = &od->od_slicetab[0];
518
519 /* Is this a request for the whole disk? */
520 if (dev->d_kind.biosdisk.slice == -1) {
521 sector = 0;
522 goto unsliced;
523 }
524
525 /*
526 * if a slice number was supplied but not found, this is an error.
527 */
528 if (dev->d_kind.biosdisk.slice > 0) {
529 slice = dev->d_kind.biosdisk.slice - 1;
530 if (slice >= od->od_nslices) {
531 DEBUG("slice %d not found", slice);
532 error = ENOENT;
533 goto out;
534 }
535 }
536
537 /*
538 * Check for the historically bogus MBR found on true dedicated disks
539 */
540 if ((dptr[3].dp_typ == DOSPTYP_386BSD) &&
541 (dptr[3].dp_start == 0) &&
542 (dptr[3].dp_size == 50000)) {
543 sector = 0;
544 goto unsliced;
545 }
546
547 /* Try to auto-detect the best slice; this should always give a slice number */
548 if (dev->d_kind.biosdisk.slice == 0) {
549 slice = bd_bestslice(od);
550 if (slice == -1) {
551 error = ENOENT;
552 goto out;
553 }
554 dev->d_kind.biosdisk.slice = slice;
555 }
556
557 dptr = &od->od_slicetab[0];
558 /*
559 * Accept the supplied slice number unequivocally (we may be looking
560 * at a DOS partition).
561 */
562 dptr += (dev->d_kind.biosdisk.slice - 1); /* we number 1-4, offsets are 0-3 */
563 sector = dptr->dp_start;
564 DEBUG("slice entry %d at %d, %d sectors", dev->d_kind.biosdisk.slice - 1, sector, dptr->dp_size);
565
566 /*
567 * If we are looking at a BSD slice, and the partition is < 0, assume the 'a' partition
568 */
569 if ((dptr->dp_typ == DOSPTYP_386BSD) && (dev->d_kind.biosdisk.partition < 0))
570 dev->d_kind.biosdisk.partition = 0;
571
572 unsliced:
573 /*
574 * Now we have the slice offset, look for the partition in the disklabel if we have
575 * a partition to start with.
576 *
577 * XXX we might want to check the label checksum.
578 */
579 if (dev->d_kind.biosdisk.partition < 0) {
580 od->od_boff = sector; /* no partition, must be after the slice */
581 DEBUG("opening raw slice");
582 } else {
583
584 if (bd_read(od, sector + LABELSECTOR, 1, buf)) {
585 DEBUG("error reading disklabel");
586 error = EIO;
587 goto out;
588 }
589 DEBUG("copy %d bytes of label from %p to %p", sizeof(struct disklabel), buf + LABELOFFSET, &od->od_disklabel);
590 bcopy(buf + LABELOFFSET, &od->od_disklabel, sizeof(struct disklabel));
591 lp = &od->od_disklabel;
592 od->od_flags |= BD_LABELOK;
593
594 if (lp->d_magic != DISKMAGIC) {
595 DEBUG("no disklabel");
596 error = ENOENT;
597 goto out;
598 }
599 if (dev->d_kind.biosdisk.partition >= lp->d_npartitions) {
600 DEBUG("partition '%c' exceeds partitions in table (a-'%c')",
601 'a' + dev->d_kind.biosdisk.partition, 'a' + lp->d_npartitions);
602 error = EPART;
603 goto out;
604
605 }
606
607#ifdef DISK_DEBUG
608 /* Complain if the partition is unused unless this is a floppy. */
609 if ((lp->d_partitions[dev->d_kind.biosdisk.partition].p_fstype == FS_UNUSED) &&
610 !(od->od_flags & BD_FLOPPY))
611 DEBUG("warning, partition marked as unused");
612#endif
613
614 od->od_boff = lp->d_partitions[dev->d_kind.biosdisk.partition].p_offset;
615 }
616
617 out:
618 if (error) {
619 free(od);
620 } else {
621 *odp = od; /* return the open disk */
622 }
623 return(error);
624}
625
626static void
627bd_checkextended(struct open_disk *od, int slicenum)
628{
629 char buf[BIOSDISK_SECSIZE];
630 struct dos_partition *dp;
631 u_int base;
632 int i, start, end;
633
634 dp = &od->od_slicetab[slicenum];
635 start = od->od_nslices;
636
637 if (dp->dp_size == 0)
638 goto done;
639 if (dp->dp_typ != DOSPTYP_EXT)
640 goto done;
641 if (bd_read(od, (daddr_t)dp->dp_start, 1, buf))
642 goto done;
643 if (((u_char)buf[0x1fe] != 0x55) || ((u_char)buf[0x1ff] != 0xaa)) {
644 DEBUG("no magic in extended table");
645 goto done;
646 }
647 base = dp->dp_start;
648 dp = (struct dos_partition *)(&buf[DOSPARTOFF]);
649 for (i = 0; i < NDOSPART; i++, dp++) {
650 if (dp->dp_size == 0)
651 continue;
652 if (od->od_nslices == MAX_SLICES)
653 goto done;
654 dp->dp_start += base;
655 bcopy(dp, &od->od_slicetab[od->od_nslices], sizeof(*dp));
656 od->od_nslices++;
657 }
658 end = od->od_nslices;
659
660 /*
661 * now, recursively check the slices we just added
662 */
663 for (i = start; i < end; i++)
664 bd_checkextended(od, i);
665done:
666 return;
667}
668
669/*
670 * Search for a slice with the following preferences:
671 *
672 * 1: Active FreeBSD slice
673 * 2: Non-active FreeBSD slice
674 * 3: Active Linux slice
675 * 4: non-active Linux slice
676 * 5: Active FAT/FAT32 slice
677 * 6: non-active FAT/FAT32 slice
678 */
679#define PREF_RAWDISK 0
680#define PREF_FBSD_ACT 1
681#define PREF_FBSD 2
682#define PREF_LINUX_ACT 3
683#define PREF_LINUX 4
684#define PREF_DOS_ACT 5
685#define PREF_DOS 6
686#define PREF_NONE 7
687
688/*
689 * slicelimit is in the range 0 .. NDOSPART
690 */
691static int
692bd_bestslice(struct open_disk *od)
693{
694 struct dos_partition *dp;
695 int pref, preflevel;
696 int i, prefslice;
697
698 prefslice = 0;
699 preflevel = PREF_NONE;
700
701 dp = &od->od_slicetab[0];
702 for (i = 0; i < od->od_nslices; i++, dp++) {
703
704 switch (dp->dp_typ) {
705 case DOSPTYP_386BSD: /* FreeBSD */
706 pref = dp->dp_flag & 0x80 ? PREF_FBSD_ACT : PREF_FBSD;
707 break;
708
709 case DOSPTYP_LINUX:
710 pref = dp->dp_flag & 0x80 ? PREF_LINUX_ACT : PREF_LINUX;
711 break;
712
713 case 0x01: /* DOS/Windows */
714 case 0x04:
715 case 0x06:
716 case 0x0b:
717 case 0x0c:
718 case 0x0e:
719 pref = dp->dp_flag & 0x80 ? PREF_DOS_ACT : PREF_DOS;
720 break;
721
722 default:
723 pref = PREF_NONE;
724 }
725 if (pref < preflevel) {
726 preflevel = pref;
727 prefslice = i + 1;
728 }
729 }
730 return (prefslice);
731}
732
733static int
734bd_close(struct open_file *f)
735{
736 struct open_disk *od = (struct open_disk *)(((struct i386_devdesc *)(f->f_devdata))->d_kind.biosdisk.data);
737
738 bd_closedisk(od);
739 return(0);
740}
741
742static void
743bd_closedisk(struct open_disk *od)
744{
745 DEBUG("open_disk %p", od);
746#if 0
747 /* XXX is this required? (especially if disk already open...) */
748 if (od->od_flags & BD_FLOPPY)
749 delay(3000000);
750#endif
751 free(od);
752}
753
754static int
755bd_strategy(void *devdata, int rw, daddr_t dblk, size_t size, char *buf, size_t *rsize)
756{
757 struct bcache_devdata bcd;
758 struct open_disk *od = (struct open_disk *)(((struct i386_devdesc *)devdata)->d_kind.biosdisk.data);
759
760 bcd.dv_strategy = bd_realstrategy;
761 bcd.dv_devdata = devdata;
762 return(bcache_strategy(&bcd, od->od_unit, rw, dblk+od->od_boff, size, buf, rsize));
763}
764
765static int
766bd_realstrategy(void *devdata, int rw, daddr_t dblk, size_t size, char *buf, size_t *rsize)
767{
768 struct open_disk *od = (struct open_disk *)(((struct i386_devdesc *)devdata)->d_kind.biosdisk.data);
769 int blks;
770#ifdef BD_SUPPORT_FRAGS
771 char fragbuf[BIOSDISK_SECSIZE];
772 size_t fragsize;
773
774 fragsize = size % BIOSDISK_SECSIZE;
775#else
776 if (size % BIOSDISK_SECSIZE)
777 panic("bd_strategy: %d bytes I/O not multiple of block size", size);
778#endif
779
780 DEBUG("open_disk %p", od);
781
782 if (rw != F_READ)
783 return(EROFS);
784
785
786 blks = size / BIOSDISK_SECSIZE;
787 DEBUG("read %d from %d to %p", blks, dblk, buf);
788
789 if (rsize)
790 *rsize = 0;
791 if (blks && bd_read(od, dblk, blks, buf)) {
792 DEBUG("read error");
793 return (EIO);
794 }
795#ifdef BD_SUPPORT_FRAGS
796 DEBUG("bd_strategy: frag read %d from %d+%d to %p",
797 fragsize, dblk, blks, buf + (blks * BIOSDISK_SECSIZE));
798 if (fragsize && bd_read(od, dblk + blks, 1, fragsize)) {
799 DEBUG("frag read error");
800 return(EIO);
801 }
802 bcopy(fragbuf, buf + (blks * BIOSDISK_SECSIZE), fragsize);
803#endif
804 if (rsize)
805 *rsize = size;
806 return (0);
807}
808
809/* Max number of sectors to bounce-buffer if the request crosses a 64k boundary */
810#define FLOPPY_BOUNCEBUF 18
811
812static int
813bd_read(struct open_disk *od, daddr_t dblk, int blks, caddr_t dest)
814{
815 u_int x, bpc, cyl, hd, sec, result, resid, retry, maxfer;
816 caddr_t p, xp, bbuf, breg;
817
818 /* Just in case some idiot actually tries to read -1 blocks... */
819 if (blks < 0)
820 return (-1);
821
822 bpc = (od->od_sec * od->od_hds); /* blocks per cylinder */
823 resid = blks;
824 p = dest;
825
826 /* Decide whether we have to bounce */
827 if ((od->od_unit < 0x80) &&
828 ((VTOP(dest) >> 16) != (VTOP(dest + blks * BIOSDISK_SECSIZE) >> 16))) {
829
830 /*
831 * There is a 64k physical boundary somewhere in the destination buffer, so we have
832 * to arrange a suitable bounce buffer. Allocate a buffer twice as large as we
833 * need to. Use the bottom half unless there is a break there, in which case we
834 * use the top half.
835 */
836 x = min(FLOPPY_BOUNCEBUF, (unsigned)blks);
837 bbuf = malloc(x * 2 * BIOSDISK_SECSIZE);
838 if (((u_int32_t)VTOP(bbuf) & 0xffff0000) == ((u_int32_t)VTOP(dest + x * BIOSDISK_SECSIZE) & 0xffff0000)) {
839 breg = bbuf;
840 } else {
841 breg = bbuf + x * BIOSDISK_SECSIZE;
842 }
843 maxfer = x; /* limit transfers to bounce region size */
844 } else {
845 breg = bbuf = NULL;
846 maxfer = 0;
847 }
848
849 while (resid > 0) {
850 x = dblk;
851 cyl = x / bpc; /* block # / blocks per cylinder */
852 x %= bpc; /* block offset into cylinder */
853 hd = x / od->od_sec; /* offset / blocks per track */
854 sec = x % od->od_sec; /* offset into track */
855
856 /* play it safe and don't cross track boundaries (XXX this is probably unnecessary) */
857 x = min(od->od_sec - sec, resid);
858 if (maxfer > 0)
859 x = min(x, maxfer); /* fit bounce buffer */
860
861 /* where do we transfer to? */
862 xp = bbuf == NULL ? p : breg;
863
864 /* correct sector number for 1-based BIOS numbering */
865 sec++;
866
867 /* Loop retrying the operation a couple of times. The BIOS may also retry. */
868 for (retry = 0; retry < 3; retry++) {
869 /* if retrying, reset the drive */
870 if (retry > 0) {
871 v86.ctl = V86_FLAGS;
872 v86.addr = 0x13;
873 v86.eax = 0;
874 v86.edx = od->od_unit;
875 v86int();
876 }
877
878 if(cyl > 1023) {
879 /* use EDD if the disk supports it, otherwise, return error */
880 if(od->od_flags & BD_MODEEDD1) {
881 static unsigned short packet[8];
882
883 packet[0] = 0x10;
884 packet[1] = x;
885 packet[2] = VTOPOFF(xp);
886 packet[3] = VTOPSEG(xp);
887 packet[4] = dblk & 0xffff;
888 packet[5] = dblk >> 16;
889 packet[6] = 0;
890 packet[7] = 0;
891 v86.ctl = V86_FLAGS;
892 v86.addr = 0x13;
893 v86.eax = 0x4200;
894 v86.edx = od->od_unit;
895 v86.ds = VTOPSEG(packet);
896 v86.esi = VTOPOFF(packet);
897 v86int();
898 result = (v86.efl & 0x1);
899 if(result == 0)
900 break;
901 } else {
902 result = 1;
903 break;
904 }
905 } else {
906 /* Use normal CHS addressing */
907 v86.ctl = V86_FLAGS;
908 v86.addr = 0x13;
909 v86.eax = 0x200 | x;
910 v86.ecx = ((cyl & 0xff) << 8) | ((cyl & 0x300) >> 2) | sec;
911 v86.edx = (hd << 8) | od->od_unit;
912 v86.es = VTOPSEG(xp);
913 v86.ebx = VTOPOFF(xp);
914 v86int();
915 result = (v86.efl & 0x1);
916 if (result == 0)
917 break;
918 }
919 }
920
921 DEBUG("%d sectors from %d/%d/%d to %p (0x%x) %s", x, cyl, hd, sec - 1, p, VTOP(p), result ? "failed" : "ok");
922 /* BUG here, cannot use v86 in printf because putchar uses it too */
923 DEBUG("ax = 0x%04x cx = 0x%04x dx = 0x%04x status 0x%x",
924 0x200 | x, ((cyl & 0xff) << 8) | ((cyl & 0x300) >> 2) | sec, (hd << 8) | od->od_unit, (v86.eax >> 8) & 0xff);
925 if (result) {
926 if (bbuf != NULL)
927 free(bbuf);
928 return(-1);
929 }
930 if (bbuf != NULL)
931 bcopy(breg, p, x * BIOSDISK_SECSIZE);
932 p += (x * BIOSDISK_SECSIZE);
933 dblk += x;
934 resid -= x;
935 }
936
937/* hexdump(dest, (blks * BIOSDISK_SECSIZE)); */
938 if (bbuf != NULL)
939 free(bbuf);
940 return(0);
941}
942
943static int
944bd_getgeom(struct open_disk *od)
945{
946
947 v86.ctl = V86_FLAGS;
948 v86.addr = 0x13;
949 v86.eax = 0x800;
950 v86.edx = od->od_unit;
951 v86int();
952
953 if ((v86.efl & 0x1) || /* carry set */
954 ((v86.edx & 0xff) <= (unsigned)(od->od_unit & 0x7f))) /* unit # bad */
955 return(1);
956
957 /* convert max cyl # -> # of cylinders */
958 od->od_cyl = ((v86.ecx & 0xc0) << 2) + ((v86.ecx & 0xff00) >> 8) + 1;
959 /* convert max head # -> # of heads */
960 od->od_hds = ((v86.edx & 0xff00) >> 8) + 1;
961 od->od_sec = v86.ecx & 0x3f;
962
963 DEBUG("unit 0x%x geometry %d/%d/%d", od->od_unit, od->od_cyl, od->od_hds, od->od_sec);
964 return(0);
965}
966
967/*
968 * Return the BIOS geometry of a given "fixed drive" in a format
969 * suitable for the legacy bootinfo structure. Since the kernel is
970 * expecting raw int 0x13/0x8 values for N_BIOS_GEOM drives, we
971 * prefer to get the information directly, rather than rely on being
972 * able to put it together from information already maintained for
973 * different purposes and for a probably different number of drives.
974 *
975 * For valid drives, the geometry is expected in the format (31..0)
976 * "000000cc cccccccc hhhhhhhh 00ssssss"; and invalid drives are
977 * indicated by returning the geometry of a "1.2M" PC-format floppy
978 * disk. And, incidentally, what is returned is not the geometry as
979 * such but the highest valid cylinder, head, and sector numbers.
980 */
981u_int32_t
982bd_getbigeom(int bunit)
983{
984
985 v86.ctl = V86_FLAGS;
986 v86.addr = 0x13;
987 v86.eax = 0x800;
988 v86.edx = 0x80 + bunit;
989 v86int();
990 if (v86.efl & 0x1)
991 return 0x4f010f;
992 return ((v86.ecx & 0xc0) << 18) | ((v86.ecx & 0xff00) << 8) |
993 (v86.edx & 0xff00) | (v86.ecx & 0x3f);
994}
995
996/*
997 * Return a suitable dev_t value for (dev).
998 *
999 * In the case where it looks like (dev) is a SCSI disk, we allow the number of
1000 * IDE disks to be specified in $num_ide_disks. There should be a Better Way.
1001 */
1002int
1003bd_getdev(struct i386_devdesc *dev)
1004{
1005 struct open_disk *od;
1006 int biosdev;
1007 int major;
1008 int rootdev;
1009 char *nip, *cp;
1010 int unitofs = 0, i, unit;
1011
1012 biosdev = bd_unit2bios(dev->d_kind.biosdisk.unit);
1013 DEBUG("unit %d BIOS device %d", dev->d_kind.biosdisk.unit, biosdev);
1014 if (biosdev == -1) /* not a BIOS device */
1015 return(-1);
1016 if (bd_opendisk(&od, dev) != 0) /* oops, not a viable device */
1017 return(-1);
1018
1019 if (biosdev < 0x80) {
1020 /* floppy (or emulated floppy) or ATAPI device */
1021 if (bdinfo[dev->d_kind.biosdisk.unit].bd_type == DT_ATAPI) {
1022 /* is an ATAPI disk */
1023 major = WFDMAJOR;
1024 } else {
1025 /* is a floppy disk */
1026 major = FDMAJOR;
1027 }
1028 } else {
1029 /* harddisk */
1030 if ((od->od_flags & BD_LABELOK) && (od->od_disklabel.d_type == DTYPE_SCSI)) {
1031 /* label OK, disk labelled as SCSI */
1032 major = DAMAJOR;
1033 /* check for unit number correction hint, now deprecated */
1034 if ((nip = getenv("num_ide_disks")) != NULL) {
1035 i = strtol(nip, &cp, 0);
1036 /* check for parse error */
1037 if ((cp != nip) && (*cp == 0))
1038 unitofs = i;
1039 }
1040 } else {
1041 /* assume an IDE disk */
1042 major = WDMAJOR;
1043 }
1044 }
1045 /* default root disk unit number */
1046 unit = (biosdev & 0x7f) - unitofs;
1047
1048 /* XXX a better kludge to set the root disk unit number */
1049 if ((nip = getenv("root_disk_unit")) != NULL) {
1050 i = strtol(nip, &cp, 0);
1051 /* check for parse error */
1052 if ((cp != nip) && (*cp == 0))
1053 unit = i;
1054 }
1055
1056 rootdev = MAKEBOOTDEV(major,
1057 (dev->d_kind.biosdisk.slice + 1) >> 4, /* XXX slices may be wrong here */
1058 (dev->d_kind.biosdisk.slice + 1) & 0xf,
1059 unit,
1060 dev->d_kind.biosdisk.partition);
1061 DEBUG("dev is 0x%x\n", rootdev);
1062 return(rootdev);
1063}