Catch attempts to queue to unregistered ISRs
[dragonfly.git] / sys / boot / pc32 / 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 *
26 * $FreeBSD: src/sys/boot/i386/libi386/biosdisk.c,v 1.26.2.6 2000/12/28 13:10:47 ps Exp $
e2565a42 27 * $DragonFly: src/sys/boot/pc32/libi386/biosdisk.c,v 1.4 2003/11/09 02:22:33 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>
43#include <sys/diskslice.h>
fabb8ceb 44#include <sys/bootmaj.h>
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45#include <sys/reboot.h>
46
47#include <stdarg.h>
48
49#include <bootstrap.h>
50#include <btxv86.h>
51#include "libi386.h"
52
53#define BIOS_NUMDRIVES 0x475
54#define BIOSDISK_SECSIZE 512
55#define BUFSIZE (1 * BIOSDISK_SECSIZE)
56#define MAXBDDEV MAXDEV
57
fabb8ceb 58#define DT_ATAPI 0x10 /* disk type for ATAPI floppies */
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59
60#ifdef DISK_DEBUG
61# define DEBUG(fmt, args...) printf("%s: " fmt "\n" , __FUNCTION__ , ## args)
62#else
63# define DEBUG(fmt, args...)
64#endif
65
66struct open_disk {
67 int od_dkunit; /* disk unit number */
68 int od_unit; /* BIOS unit number */
69 int od_cyl; /* BIOS geometry */
70 int od_hds;
71 int od_sec;
72 int od_boff; /* block offset from beginning of BIOS disk */
73 int od_flags;
74#define BD_MODEINT13 0x0000
75#define BD_MODEEDD1 0x0001
76#define BD_MODEEDD3 0x0002
77#define BD_MODEMASK 0x0003
78#define BD_FLOPPY 0x0004
79#define BD_LABELOK 0x0008
80#define BD_PARTTABOK 0x0010
81 struct disklabel od_disklabel;
82 int od_nslices; /* slice count */
83 struct dos_partition od_slicetab[MAX_SLICES];
84};
85
86/*
87 * List of BIOS devices, translation from disk unit number to
88 * BIOS unit number.
89 */
90static struct bdinfo
91{
92 int bd_unit; /* BIOS unit number */
93 int bd_flags;
94 int bd_type; /* BIOS 'drive type' (floppy only) */
95} bdinfo [MAXBDDEV];
96static int nbdinfo = 0;
97
98static int bd_getgeom(struct open_disk *od);
99static int bd_read(struct open_disk *od, daddr_t dblk, int blks,
100 caddr_t dest);
101
102static int bd_int13probe(struct bdinfo *bd);
103
104static void bd_printslice(struct open_disk *od, struct dos_partition *dp,
105 char *prefix, int verbose);
106static void bd_printbsdslice(struct open_disk *od, daddr_t offset,
107 char *prefix, int verbose);
108
109static int bd_init(void);
110static int bd_strategy(void *devdata, int flag, daddr_t dblk,
111 size_t size, char *buf, size_t *rsize);
112static int bd_realstrategy(void *devdata, int flag, daddr_t dblk,
113 size_t size, char *buf, size_t *rsize);
114static int bd_open(struct open_file *f, ...);
115static int bd_close(struct open_file *f);
116static void bd_print(int verbose);
117
118struct devsw biosdisk = {
119 "disk",
120 DEVT_DISK,
121 bd_init,
122 bd_strategy,
123 bd_open,
124 bd_close,
125 noioctl,
126 bd_print,
127 NULL
128};
129
130static int bd_opendisk(struct open_disk **odp, struct i386_devdesc *dev);
131static void bd_closedisk(struct open_disk *od);
132static int bd_bestslice(struct open_disk *od);
133static void bd_checkextended(struct open_disk *od, int slicenum);
134
135/*
136 * Translate between BIOS device numbers and our private unit numbers.
137 */
138int
139bd_bios2unit(int biosdev)
140{
141 int i;
142
143 DEBUG("looking for bios device 0x%x", biosdev);
144 for (i = 0; i < nbdinfo; i++) {
145 DEBUG("bd unit %d is BIOS device 0x%x", i, bdinfo[i].bd_unit);
146 if (bdinfo[i].bd_unit == biosdev)
147 return(i);
148 }
149 return(-1);
150}
151
152int
153bd_unit2bios(int unit)
154{
155 if ((unit >= 0) && (unit < nbdinfo))
156 return(bdinfo[unit].bd_unit);
157 return(-1);
158}
159
160/*
161 * Quiz the BIOS for disk devices, save a little info about them.
162 */
163static int
164bd_init(void)
165{
166 int base, unit, nfd = 0;
167
168 /* sequence 0, 0x80 */
169 for (base = 0; base <= 0x80; base += 0x80) {
170 for (unit = base; (nbdinfo < MAXBDDEV); unit++) {
171 /* check the BIOS equipment list for number of fixed disks */
172 if((base == 0x80) &&
173 (nfd >= *(unsigned char *)PTOV(BIOS_NUMDRIVES)))
174 break;
175
176 bdinfo[nbdinfo].bd_unit = unit;
177 bdinfo[nbdinfo].bd_flags = (unit < 0x80) ? BD_FLOPPY : 0;
178
179 if (!bd_int13probe(&bdinfo[nbdinfo]))
180 break;
181
182 /* XXX we need "disk aliases" to make this simpler */
183 printf("BIOS drive %c: is disk%d\n",
184 (unit < 0x80) ? ('A' + unit) : ('C' + unit - 0x80), nbdinfo);
185 nbdinfo++;
186 if (base == 0x80)
187 nfd++;
188 }
189 }
190 return(0);
191}
192
193/*
194 * Try to detect a device supported by the legacy int13 BIOS
195 */
196static int
197bd_int13probe(struct bdinfo *bd)
198{
199 v86.ctl = V86_FLAGS;
200 v86.addr = 0x13;
201 v86.eax = 0x800;
202 v86.edx = bd->bd_unit;
203 v86int();
204
205 if (!(v86.efl & 0x1) && /* carry clear */
206 ((v86.edx & 0xff) > ((unsigned)bd->bd_unit & 0x7f))) { /* unit # OK */
207 bd->bd_flags |= BD_MODEINT13;
208 bd->bd_type = v86.ebx & 0xff;
209
210 /* Determine if we can use EDD with this device. */
211 v86.eax = 0x4100;
212 v86.edx = bd->bd_unit;
213 v86.ebx = 0x55aa;
214 v86int();
215 if (!(v86.efl & 0x1) && /* carry clear */
216 ((v86.ebx & 0xffff) == 0xaa55) && /* signature */
217 (v86.ecx & 0x1)) { /* packets mode ok */
218 bd->bd_flags |= BD_MODEEDD1;
219 if((v86.eax & 0xff00) > 0x300)
220 bd->bd_flags |= BD_MODEEDD3;
221 }
222 return(1);
223 }
224 return(0);
225}
226
227/*
228 * Print information about disks
229 */
230static void
231bd_print(int verbose)
232{
233 int i, j;
234 char line[80];
235 struct i386_devdesc dev;
236 struct open_disk *od;
237 struct dos_partition *dptr;
238
239 for (i = 0; i < nbdinfo; i++) {
240 sprintf(line, " disk%d: BIOS drive %c:\n", i,
241 (bdinfo[i].bd_unit < 0x80) ? ('A' + bdinfo[i].bd_unit) : ('C' + bdinfo[i].bd_unit - 0x80));
242 pager_output(line);
243
244 /* try to open the whole disk */
245 dev.d_kind.biosdisk.unit = i;
246 dev.d_kind.biosdisk.slice = -1;
247 dev.d_kind.biosdisk.partition = -1;
248
249 if (!bd_opendisk(&od, &dev)) {
250
251 /* Do we have a partition table? */
252 if (od->od_flags & BD_PARTTABOK) {
253 dptr = &od->od_slicetab[0];
254
255 /* Check for a "dedicated" disk */
256 if ((dptr[3].dp_typ == DOSPTYP_386BSD) &&
257 (dptr[3].dp_start == 0) &&
258 (dptr[3].dp_size == 50000)) {
259 sprintf(line, " disk%d", i);
260 bd_printbsdslice(od, 0, line, verbose);
261 } else {
262 for (j = 0; j < od->od_nslices; j++) {
263 sprintf(line, " disk%ds%d", i, j + 1);
264 bd_printslice(od, &dptr[j], line, verbose);
265 }
266 }
267 }
268 bd_closedisk(od);
269 }
270 }
271}
272
273/*
274 * Print information about slices on a disk. For the size calculations we
275 * assume a 512 byte sector.
276 */
277static void
278bd_printslice(struct open_disk *od, struct dos_partition *dp, char *prefix,
279 int verbose)
280{
281 char line[80];
282
283 switch (dp->dp_typ) {
284 case DOSPTYP_386BSD:
285 bd_printbsdslice(od, (daddr_t)dp->dp_start, prefix, verbose);
286 return;
287 case DOSPTYP_LINSWP:
288 if (verbose)
289 sprintf(line, "%s: Linux swap %.6dMB (%d - %d)\n",
290 prefix, dp->dp_size / 2048,
291 dp->dp_start, dp->dp_start + dp->dp_size);
292 else
293 sprintf(line, "%s: Linux swap\n", prefix);
294 break;
295 case DOSPTYP_LINUX:
296 /*
297 * XXX
298 * read the superblock to confirm this is an ext2fs partition?
299 */
300 if (verbose)
301 sprintf(line, "%s: ext2fs %.6dMB (%d - %d)\n", prefix,
302 dp->dp_size / 2048, dp->dp_start,
303 dp->dp_start + dp->dp_size);
304 else
305 sprintf(line, "%s: ext2fs\n", prefix);
306 break;
307 case 0x00: /* unused partition */
308 case DOSPTYP_EXT:
309 return;
310 case 0x01:
311 if (verbose)
312 sprintf(line, "%s: FAT-12 %.6dMB (%d - %d)\n", prefix,
313 dp->dp_size / 2048, dp->dp_start,
314 dp->dp_start + dp->dp_size);
315 else
316 sprintf(line, "%s: FAT-12\n", prefix);
317 break;
318 case 0x04:
319 case 0x06:
320 case 0x0e:
321 if (verbose)
322 sprintf(line, "%s: FAT-16 %.6dMB (%d - %d)\n", prefix,
323 dp->dp_size / 2048, dp->dp_start,
324 dp->dp_start + dp->dp_size);
325 else
326 sprintf(line, "%s: FAT-16\n", prefix);
327 break;
328 case 0x0b:
329 case 0x0c:
330 if (verbose)
331 sprintf(line, "%s: FAT-32 %.6dMB (%d - %d)\n", prefix,
332 dp->dp_size / 2048, dp->dp_start,
333 dp->dp_start + dp->dp_size);
334 else
335 sprintf(line, "%s: FAT-32\n", prefix);
336 break;
337 default:
338 if (verbose)
339 sprintf(line, "%s: Unknown fs: 0x%x %.6dMB (%d - %d)\n",
340 prefix, dp->dp_typ, dp->dp_size / 2048,
341 dp->dp_start, dp->dp_start + dp->dp_size);
342 else
343 sprintf(line, "%s: Unknown fs: 0x%x\n", prefix,
344 dp->dp_typ);
345 }
346 pager_output(line);
347}
348
349/*
350 * Print out each valid partition in the disklabel of a FreeBSD slice.
351 * For size calculations, we assume a 512 byte sector size.
352 */
353static void
354bd_printbsdslice(struct open_disk *od, daddr_t offset, char *prefix,
355 int verbose)
356{
357 char line[80];
358 char buf[BIOSDISK_SECSIZE];
359 struct disklabel *lp;
360 int i;
361
362 /* read disklabel */
363 if (bd_read(od, offset + LABELSECTOR, 1, buf))
364 return;
365 lp =(struct disklabel *)(&buf[0]);
366 if (lp->d_magic != DISKMAGIC) {
367 sprintf(line, "%s: FFS bad disklabel\n", prefix);
368 pager_output(line);
369 return;
370 }
371
372 /* Print partitions */
373 for (i = 0; i < lp->d_npartitions; i++) {
374 /*
375 * For each partition, make sure we know what type of fs it is. If
376 * not, then skip it. However, since floppies often have bogus
377 * fstypes, print the 'a' partition on a floppy even if it is marked
378 * unused.
379 */
380 if ((lp->d_partitions[i].p_fstype == FS_BSDFFS) ||
381 (lp->d_partitions[i].p_fstype == FS_SWAP) ||
382 (lp->d_partitions[i].p_fstype == FS_VINUM) ||
383 ((lp->d_partitions[i].p_fstype == FS_UNUSED) &&
384 (od->od_flags & BD_FLOPPY) && (i == 0))) {
385
386 /* Only print out statistics in verbose mode */
387 if (verbose)
388 sprintf(line, " %s%c: %s %.6dMB (%d - %d)\n", prefix, 'a' + i,
389 (lp->d_partitions[i].p_fstype == FS_SWAP) ? "swap" :
390 (lp->d_partitions[i].p_fstype == FS_VINUM) ? "vinum" :
391 "FFS",
392 lp->d_partitions[i].p_size / 2048,
393 lp->d_partitions[i].p_offset,
394 lp->d_partitions[i].p_offset + lp->d_partitions[i].p_size);
395 else
396 sprintf(line, " %s%c: %s\n", prefix, 'a' + i,
397 (lp->d_partitions[i].p_fstype == FS_SWAP) ? "swap" :
398 (lp->d_partitions[i].p_fstype == FS_VINUM) ? "vinum" :
399 "FFS");
400 pager_output(line);
401 }
402 }
403}
404
405
406/*
407 * Attempt to open the disk described by (dev) for use by (f).
408 *
409 * Note that the philosophy here is "give them exactly what
410 * they ask for". This is necessary because being too "smart"
411 * about what the user might want leads to complications.
412 * (eg. given no slice or partition value, with a disk that is
413 * sliced - are they after the first BSD slice, or the DOS
414 * slice before it?)
415 */
416static int
417bd_open(struct open_file *f, ...)
418{
e2565a42 419 __va_list ap;
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420 struct i386_devdesc *dev;
421 struct open_disk *od;
422 int error;
423
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424 __va_start(ap, f);
425 dev = __va_arg(ap, struct i386_devdesc *);
426 __va_end(ap);
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427 if ((error = bd_opendisk(&od, dev)))
428 return(error);
429
430 /*
431 * Save our context
432 */
433 ((struct i386_devdesc *)(f->f_devdata))->d_kind.biosdisk.data = od;
434 DEBUG("open_disk %p, partition at 0x%x", od, od->od_boff);
435 return(0);
436}
437
438static int
439bd_opendisk(struct open_disk **odp, struct i386_devdesc *dev)
440{
441 struct dos_partition *dptr;
442 struct disklabel *lp;
443 struct open_disk *od;
444 int sector, slice, i;
445 int error;
446 char buf[BUFSIZE];
447
448 if (dev->d_kind.biosdisk.unit >= nbdinfo) {
449 DEBUG("attempt to open nonexistent disk");
450 return(ENXIO);
451 }
452
453 od = (struct open_disk *)malloc(sizeof(struct open_disk));
454 if (!od) {
455 DEBUG("no memory");
456 return (ENOMEM);
457 }
458
459 /* Look up BIOS unit number, intialise open_disk structure */
460 od->od_dkunit = dev->d_kind.biosdisk.unit;
461 od->od_unit = bdinfo[od->od_dkunit].bd_unit;
462 od->od_flags = bdinfo[od->od_dkunit].bd_flags;
463 od->od_boff = 0;
464 od->od_nslices = 0;
465 error = 0;
466 DEBUG("open '%s', unit 0x%x slice %d partition %c",
467 i386_fmtdev(dev), dev->d_kind.biosdisk.unit,
468 dev->d_kind.biosdisk.slice, dev->d_kind.biosdisk.partition + 'a');
469
470 /* Get geometry for this open (removable device may have changed) */
471 if (bd_getgeom(od)) {
472 DEBUG("can't get geometry");
473 error = ENXIO;
474 goto out;
475 }
476
477 /*
478 * Following calculations attempt to determine the correct value
479 * for d->od_boff by looking for the slice and partition specified,
480 * or searching for reasonable defaults.
481 */
482
483 /*
484 * Find the slice in the DOS slice table.
485 */
486 if (bd_read(od, 0, 1, buf)) {
487 DEBUG("error reading MBR");
488 error = EIO;
489 goto out;
490 }
491
492 /*
493 * Check the slice table magic.
494 */
495 if (((u_char)buf[0x1fe] != 0x55) || ((u_char)buf[0x1ff] != 0xaa)) {
496 /* If a slice number was explicitly supplied, this is an error */
497 if (dev->d_kind.biosdisk.slice > 0) {
498 DEBUG("no slice table/MBR (no magic)");
499 error = ENOENT;
500 goto out;
501 }
502 sector = 0;
503 goto unsliced; /* may be a floppy */
504 }
505
506 /*
507 * copy the partition table, then pick up any extended partitions.
508 */
509 bcopy(buf + DOSPARTOFF, &od->od_slicetab,
510 sizeof(struct dos_partition) * NDOSPART);
511 od->od_nslices = 4; /* extended slices start here */
512 for (i = 0; i < NDOSPART; i++)
513 bd_checkextended(od, i);
514 od->od_flags |= BD_PARTTABOK;
515 dptr = &od->od_slicetab[0];
516
517 /* Is this a request for the whole disk? */
518 if (dev->d_kind.biosdisk.slice == -1) {
519 sector = 0;
520 goto unsliced;
521 }
522
523 /*
524 * if a slice number was supplied but not found, this is an error.
525 */
526 if (dev->d_kind.biosdisk.slice > 0) {
527 slice = dev->d_kind.biosdisk.slice - 1;
528 if (slice >= od->od_nslices) {
529 DEBUG("slice %d not found", slice);
530 error = ENOENT;
531 goto out;
532 }
533 }
534
535 /*
536 * Check for the historically bogus MBR found on true dedicated disks
537 */
538 if ((dptr[3].dp_typ == DOSPTYP_386BSD) &&
539 (dptr[3].dp_start == 0) &&
540 (dptr[3].dp_size == 50000)) {
541 sector = 0;
542 goto unsliced;
543 }
544
545 /* Try to auto-detect the best slice; this should always give a slice number */
546 if (dev->d_kind.biosdisk.slice == 0) {
547 slice = bd_bestslice(od);
548 if (slice == -1) {
549 error = ENOENT;
550 goto out;
551 }
552 dev->d_kind.biosdisk.slice = slice;
553 }
554
555 dptr = &od->od_slicetab[0];
556 /*
557 * Accept the supplied slice number unequivocally (we may be looking
558 * at a DOS partition).
559 */
560 dptr += (dev->d_kind.biosdisk.slice - 1); /* we number 1-4, offsets are 0-3 */
561 sector = dptr->dp_start;
562 DEBUG("slice entry %d at %d, %d sectors", dev->d_kind.biosdisk.slice - 1, sector, dptr->dp_size);
563
564 /*
565 * If we are looking at a BSD slice, and the partition is < 0, assume the 'a' partition
566 */
567 if ((dptr->dp_typ == DOSPTYP_386BSD) && (dev->d_kind.biosdisk.partition < 0))
568 dev->d_kind.biosdisk.partition = 0;
569
570 unsliced:
571 /*
572 * Now we have the slice offset, look for the partition in the disklabel if we have
573 * a partition to start with.
574 *
575 * XXX we might want to check the label checksum.
576 */
577 if (dev->d_kind.biosdisk.partition < 0) {
578 od->od_boff = sector; /* no partition, must be after the slice */
579 DEBUG("opening raw slice");
580 } else {
581
582 if (bd_read(od, sector + LABELSECTOR, 1, buf)) {
583 DEBUG("error reading disklabel");
584 error = EIO;
585 goto out;
586 }
587 DEBUG("copy %d bytes of label from %p to %p", sizeof(struct disklabel), buf + LABELOFFSET, &od->od_disklabel);
588 bcopy(buf + LABELOFFSET, &od->od_disklabel, sizeof(struct disklabel));
589 lp = &od->od_disklabel;
590 od->od_flags |= BD_LABELOK;
591
592 if (lp->d_magic != DISKMAGIC) {
593 DEBUG("no disklabel");
594 error = ENOENT;
595 goto out;
596 }
597 if (dev->d_kind.biosdisk.partition >= lp->d_npartitions) {
598 DEBUG("partition '%c' exceeds partitions in table (a-'%c')",
599 'a' + dev->d_kind.biosdisk.partition, 'a' + lp->d_npartitions);
600 error = EPART;
601 goto out;
602
603 }
604
605#ifdef DISK_DEBUG
606 /* Complain if the partition is unused unless this is a floppy. */
607 if ((lp->d_partitions[dev->d_kind.biosdisk.partition].p_fstype == FS_UNUSED) &&
608 !(od->od_flags & BD_FLOPPY))
609 DEBUG("warning, partition marked as unused");
610#endif
611
612 od->od_boff = lp->d_partitions[dev->d_kind.biosdisk.partition].p_offset;
613 }
614
615 out:
616 if (error) {
617 free(od);
618 } else {
619 *odp = od; /* return the open disk */
620 }
621 return(error);
622}
623
624static void
625bd_checkextended(struct open_disk *od, int slicenum)
626{
627 char buf[BIOSDISK_SECSIZE];
628 struct dos_partition *dp;
629 u_int base;
630 int i, start, end;
631
632 dp = &od->od_slicetab[slicenum];
633 start = od->od_nslices;
634
635 if (dp->dp_size == 0)
636 goto done;
637 if (dp->dp_typ != DOSPTYP_EXT)
638 goto done;
639 if (bd_read(od, (daddr_t)dp->dp_start, 1, buf))
640 goto done;
641 if (((u_char)buf[0x1fe] != 0x55) || ((u_char)buf[0x1ff] != 0xaa)) {
642 DEBUG("no magic in extended table");
643 goto done;
644 }
645 base = dp->dp_start;
646 dp = (struct dos_partition *)(&buf[DOSPARTOFF]);
647 for (i = 0; i < NDOSPART; i++, dp++) {
648 if (dp->dp_size == 0)
649 continue;
650 if (od->od_nslices == MAX_SLICES)
651 goto done;
652 dp->dp_start += base;
653 bcopy(dp, &od->od_slicetab[od->od_nslices], sizeof(*dp));
654 od->od_nslices++;
655 }
656 end = od->od_nslices;
657
658 /*
659 * now, recursively check the slices we just added
660 */
661 for (i = start; i < end; i++)
662 bd_checkextended(od, i);
663done:
664 return;
665}
666
667/*
668 * Search for a slice with the following preferences:
669 *
670 * 1: Active FreeBSD slice
671 * 2: Non-active FreeBSD slice
672 * 3: Active Linux slice
673 * 4: non-active Linux slice
674 * 5: Active FAT/FAT32 slice
675 * 6: non-active FAT/FAT32 slice
676 */
677#define PREF_RAWDISK 0
678#define PREF_FBSD_ACT 1
679#define PREF_FBSD 2
680#define PREF_LINUX_ACT 3
681#define PREF_LINUX 4
682#define PREF_DOS_ACT 5
683#define PREF_DOS 6
684#define PREF_NONE 7
685
686/*
687 * slicelimit is in the range 0 .. NDOSPART
688 */
689static int
690bd_bestslice(struct open_disk *od)
691{
692 struct dos_partition *dp;
693 int pref, preflevel;
694 int i, prefslice;
695
696 prefslice = 0;
697 preflevel = PREF_NONE;
698
699 dp = &od->od_slicetab[0];
700 for (i = 0; i < od->od_nslices; i++, dp++) {
701
702 switch (dp->dp_typ) {
703 case DOSPTYP_386BSD: /* FreeBSD */
704 pref = dp->dp_flag & 0x80 ? PREF_FBSD_ACT : PREF_FBSD;
705 break;
706
707 case DOSPTYP_LINUX:
708 pref = dp->dp_flag & 0x80 ? PREF_LINUX_ACT : PREF_LINUX;
709 break;
710
711 case 0x01: /* DOS/Windows */
712 case 0x04:
713 case 0x06:
714 case 0x0b:
715 case 0x0c:
716 case 0x0e:
717 pref = dp->dp_flag & 0x80 ? PREF_DOS_ACT : PREF_DOS;
718 break;
719
720 default:
721 pref = PREF_NONE;
722 }
723 if (pref < preflevel) {
724 preflevel = pref;
725 prefslice = i + 1;
726 }
727 }
728 return (prefslice);
729}
730
731static int
732bd_close(struct open_file *f)
733{
734 struct open_disk *od = (struct open_disk *)(((struct i386_devdesc *)(f->f_devdata))->d_kind.biosdisk.data);
735
736 bd_closedisk(od);
737 return(0);
738}
739
740static void
741bd_closedisk(struct open_disk *od)
742{
743 DEBUG("open_disk %p", od);
744#if 0
745 /* XXX is this required? (especially if disk already open...) */
746 if (od->od_flags & BD_FLOPPY)
747 delay(3000000);
748#endif
749 free(od);
750}
751
752static int
753bd_strategy(void *devdata, int rw, daddr_t dblk, size_t size, char *buf, size_t *rsize)
754{
755 struct bcache_devdata bcd;
756 struct open_disk *od = (struct open_disk *)(((struct i386_devdesc *)devdata)->d_kind.biosdisk.data);
757
758 bcd.dv_strategy = bd_realstrategy;
759 bcd.dv_devdata = devdata;
760 return(bcache_strategy(&bcd, od->od_unit, rw, dblk+od->od_boff, size, buf, rsize));
761}
762
763static int
764bd_realstrategy(void *devdata, int rw, daddr_t dblk, size_t size, char *buf, size_t *rsize)
765{
766 struct open_disk *od = (struct open_disk *)(((struct i386_devdesc *)devdata)->d_kind.biosdisk.data);
767 int blks;
768#ifdef BD_SUPPORT_FRAGS
769 char fragbuf[BIOSDISK_SECSIZE];
770 size_t fragsize;
771
772 fragsize = size % BIOSDISK_SECSIZE;
773#else
774 if (size % BIOSDISK_SECSIZE)
775 panic("bd_strategy: %d bytes I/O not multiple of block size", size);
776#endif
777
778 DEBUG("open_disk %p", od);
779
780 if (rw != F_READ)
781 return(EROFS);
782
783
784 blks = size / BIOSDISK_SECSIZE;
785 DEBUG("read %d from %d to %p", blks, dblk, buf);
786
787 if (rsize)
788 *rsize = 0;
789 if (blks && bd_read(od, dblk, blks, buf)) {
790 DEBUG("read error");
791 return (EIO);
792 }
793#ifdef BD_SUPPORT_FRAGS
794 DEBUG("bd_strategy: frag read %d from %d+%d to %p",
795 fragsize, dblk, blks, buf + (blks * BIOSDISK_SECSIZE));
796 if (fragsize && bd_read(od, dblk + blks, 1, fragsize)) {
797 DEBUG("frag read error");
798 return(EIO);
799 }
800 bcopy(fragbuf, buf + (blks * BIOSDISK_SECSIZE), fragsize);
801#endif
802 if (rsize)
803 *rsize = size;
804 return (0);
805}
806
807/* Max number of sectors to bounce-buffer if the request crosses a 64k boundary */
808#define FLOPPY_BOUNCEBUF 18
809
810static int
811bd_read(struct open_disk *od, daddr_t dblk, int blks, caddr_t dest)
812{
813 u_int x, bpc, cyl, hd, sec, result, resid, retry, maxfer;
814 caddr_t p, xp, bbuf, breg;
815
816 /* Just in case some idiot actually tries to read -1 blocks... */
817 if (blks < 0)
818 return (-1);
819
820 bpc = (od->od_sec * od->od_hds); /* blocks per cylinder */
821 resid = blks;
822 p = dest;
823
824 /* Decide whether we have to bounce */
825 if ((od->od_unit < 0x80) &&
826 ((VTOP(dest) >> 16) != (VTOP(dest + blks * BIOSDISK_SECSIZE) >> 16))) {
827
828 /*
829 * There is a 64k physical boundary somewhere in the destination buffer, so we have
830 * to arrange a suitable bounce buffer. Allocate a buffer twice as large as we
831 * need to. Use the bottom half unless there is a break there, in which case we
832 * use the top half.
833 */
834 x = min(FLOPPY_BOUNCEBUF, (unsigned)blks);
835 bbuf = malloc(x * 2 * BIOSDISK_SECSIZE);
836 if (((u_int32_t)VTOP(bbuf) & 0xffff0000) == ((u_int32_t)VTOP(dest + x * BIOSDISK_SECSIZE) & 0xffff0000)) {
837 breg = bbuf;
838 } else {
839 breg = bbuf + x * BIOSDISK_SECSIZE;
840 }
841 maxfer = x; /* limit transfers to bounce region size */
842 } else {
843 breg = bbuf = NULL;
844 maxfer = 0;
845 }
846
847 while (resid > 0) {
848 x = dblk;
849 cyl = x / bpc; /* block # / blocks per cylinder */
850 x %= bpc; /* block offset into cylinder */
851 hd = x / od->od_sec; /* offset / blocks per track */
852 sec = x % od->od_sec; /* offset into track */
853
854 /* play it safe and don't cross track boundaries (XXX this is probably unnecessary) */
855 x = min(od->od_sec - sec, resid);
856 if (maxfer > 0)
857 x = min(x, maxfer); /* fit bounce buffer */
858
859 /* where do we transfer to? */
860 xp = bbuf == NULL ? p : breg;
861
862 /* correct sector number for 1-based BIOS numbering */
863 sec++;
864
865 /* Loop retrying the operation a couple of times. The BIOS may also retry. */
866 for (retry = 0; retry < 3; retry++) {
867 /* if retrying, reset the drive */
868 if (retry > 0) {
869 v86.ctl = V86_FLAGS;
870 v86.addr = 0x13;
871 v86.eax = 0;
872 v86.edx = od->od_unit;
873 v86int();
874 }
875
876 if(cyl > 1023) {
877 /* use EDD if the disk supports it, otherwise, return error */
878 if(od->od_flags & BD_MODEEDD1) {
879 static unsigned short packet[8];
880
881 packet[0] = 0x10;
882 packet[1] = x;
883 packet[2] = VTOPOFF(xp);
884 packet[3] = VTOPSEG(xp);
885 packet[4] = dblk & 0xffff;
886 packet[5] = dblk >> 16;
887 packet[6] = 0;
888 packet[7] = 0;
889 v86.ctl = V86_FLAGS;
890 v86.addr = 0x13;
891 v86.eax = 0x4200;
892 v86.edx = od->od_unit;
893 v86.ds = VTOPSEG(packet);
894 v86.esi = VTOPOFF(packet);
895 v86int();
896 result = (v86.efl & 0x1);
897 if(result == 0)
898 break;
899 } else {
900 result = 1;
901 break;
902 }
903 } else {
904 /* Use normal CHS addressing */
905 v86.ctl = V86_FLAGS;
906 v86.addr = 0x13;
907 v86.eax = 0x200 | x;
908 v86.ecx = ((cyl & 0xff) << 8) | ((cyl & 0x300) >> 2) | sec;
909 v86.edx = (hd << 8) | od->od_unit;
910 v86.es = VTOPSEG(xp);
911 v86.ebx = VTOPOFF(xp);
912 v86int();
913 result = (v86.efl & 0x1);
914 if (result == 0)
915 break;
916 }
917 }
918
919 DEBUG("%d sectors from %d/%d/%d to %p (0x%x) %s", x, cyl, hd, sec - 1, p, VTOP(p), result ? "failed" : "ok");
920 /* BUG here, cannot use v86 in printf because putchar uses it too */
921 DEBUG("ax = 0x%04x cx = 0x%04x dx = 0x%04x status 0x%x",
922 0x200 | x, ((cyl & 0xff) << 8) | ((cyl & 0x300) >> 2) | sec, (hd << 8) | od->od_unit, (v86.eax >> 8) & 0xff);
923 if (result) {
924 if (bbuf != NULL)
925 free(bbuf);
926 return(-1);
927 }
928 if (bbuf != NULL)
929 bcopy(breg, p, x * BIOSDISK_SECSIZE);
930 p += (x * BIOSDISK_SECSIZE);
931 dblk += x;
932 resid -= x;
933 }
934
935/* hexdump(dest, (blks * BIOSDISK_SECSIZE)); */
936 if (bbuf != NULL)
937 free(bbuf);
938 return(0);
939}
940
941static int
942bd_getgeom(struct open_disk *od)
943{
944
945 v86.ctl = V86_FLAGS;
946 v86.addr = 0x13;
947 v86.eax = 0x800;
948 v86.edx = od->od_unit;
949 v86int();
950
951 if ((v86.efl & 0x1) || /* carry set */
952 ((v86.edx & 0xff) <= (unsigned)(od->od_unit & 0x7f))) /* unit # bad */
953 return(1);
954
955 /* convert max cyl # -> # of cylinders */
956 od->od_cyl = ((v86.ecx & 0xc0) << 2) + ((v86.ecx & 0xff00) >> 8) + 1;
957 /* convert max head # -> # of heads */
958 od->od_hds = ((v86.edx & 0xff00) >> 8) + 1;
959 od->od_sec = v86.ecx & 0x3f;
960
961 DEBUG("unit 0x%x geometry %d/%d/%d", od->od_unit, od->od_cyl, od->od_hds, od->od_sec);
962 return(0);
963}
964
965/*
966 * Return the BIOS geometry of a given "fixed drive" in a format
967 * suitable for the legacy bootinfo structure. Since the kernel is
968 * expecting raw int 0x13/0x8 values for N_BIOS_GEOM drives, we
969 * prefer to get the information directly, rather than rely on being
970 * able to put it together from information already maintained for
971 * different purposes and for a probably different number of drives.
972 *
973 * For valid drives, the geometry is expected in the format (31..0)
974 * "000000cc cccccccc hhhhhhhh 00ssssss"; and invalid drives are
975 * indicated by returning the geometry of a "1.2M" PC-format floppy
976 * disk. And, incidentally, what is returned is not the geometry as
977 * such but the highest valid cylinder, head, and sector numbers.
978 */
979u_int32_t
980bd_getbigeom(int bunit)
981{
982
983 v86.ctl = V86_FLAGS;
984 v86.addr = 0x13;
985 v86.eax = 0x800;
986 v86.edx = 0x80 + bunit;
987 v86int();
988 if (v86.efl & 0x1)
989 return 0x4f010f;
990 return ((v86.ecx & 0xc0) << 18) | ((v86.ecx & 0xff00) << 8) |
991 (v86.edx & 0xff00) | (v86.ecx & 0x3f);
992}
993
994/*
995 * Return a suitable dev_t value for (dev).
996 *
997 * In the case where it looks like (dev) is a SCSI disk, we allow the number of
998 * IDE disks to be specified in $num_ide_disks. There should be a Better Way.
999 */
1000int
1001bd_getdev(struct i386_devdesc *dev)
1002{
1003 struct open_disk *od;
1004 int biosdev;
1005 int major;
1006 int rootdev;
1007 char *nip, *cp;
1008 int unitofs = 0, i, unit;
1009
1010 biosdev = bd_unit2bios(dev->d_kind.biosdisk.unit);
1011 DEBUG("unit %d BIOS device %d", dev->d_kind.biosdisk.unit, biosdev);
1012 if (biosdev == -1) /* not a BIOS device */
1013 return(-1);
1014 if (bd_opendisk(&od, dev) != 0) /* oops, not a viable device */
1015 return(-1);
1016
1017 if (biosdev < 0x80) {
1018 /* floppy (or emulated floppy) or ATAPI device */
1019 if (bdinfo[dev->d_kind.biosdisk.unit].bd_type == DT_ATAPI) {
1020 /* is an ATAPI disk */
1021 major = WFDMAJOR;
1022 } else {
1023 /* is a floppy disk */
1024 major = FDMAJOR;
1025 }
1026 } else {
1027 /* harddisk */
1028 if ((od->od_flags & BD_LABELOK) && (od->od_disklabel.d_type == DTYPE_SCSI)) {
1029 /* label OK, disk labelled as SCSI */
1030 major = DAMAJOR;
1031 /* check for unit number correction hint, now deprecated */
1032 if ((nip = getenv("num_ide_disks")) != NULL) {
1033 i = strtol(nip, &cp, 0);
1034 /* check for parse error */
1035 if ((cp != nip) && (*cp == 0))
1036 unitofs = i;
1037 }
1038 } else {
1039 /* assume an IDE disk */
1040 major = WDMAJOR;
1041 }
1042 }
1043 /* default root disk unit number */
1044 unit = (biosdev & 0x7f) - unitofs;
1045
1046 /* XXX a better kludge to set the root disk unit number */
1047 if ((nip = getenv("root_disk_unit")) != NULL) {
1048 i = strtol(nip, &cp, 0);
1049 /* check for parse error */
1050 if ((cp != nip) && (*cp == 0))
1051 unit = i;
1052 }
1053
1054 rootdev = MAKEBOOTDEV(major,
1055 (dev->d_kind.biosdisk.slice + 1) >> 4, /* XXX slices may be wrong here */
1056 (dev->d_kind.biosdisk.slice + 1) & 0xf,
1057 unit,
1058 dev->d_kind.biosdisk.partition);
1059 DEBUG("dev is 0x%x\n", rootdev);
1060 return(rootdev);
1061}