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 1.45 2004/09/21 06:46:44 wes 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/disklabel32.h>
42 #include <sys/disklabel64.h>
43 #include <sys/diskmbr.h>
44 #include <sys/dtype.h>
45 #include <machine/bootinfo.h>
46 #include <machine/psl.h>
47
48 #include <stdarg.h>
49
50 #include <bootstrap.h>
51 #include <btxv86.h>
52 #include "libi386.h"
53
54 #define BIOS_NUMDRIVES 0x475
55 #define BIOSDISK_SECSIZE 512
56 #define BUFSIZE (4 * BIOSDISK_SECSIZE)
57 #define MAXBDDEV MAXDEV
58
59 #define DT_ATAPI 0x10 /* disk type for ATAPI floppies */
60 #define WDMAJOR 0 /* major numbers for devices we frontend for */
61 #define WFDMAJOR 1
62 #define FDMAJOR 2
63 #define DAMAJOR 4
64
65 #ifdef DISK_DEBUG
66 # define DEBUG(fmt, args...) printf("%s: " fmt "\n" , __func__ , ## args)
67 #else
68 # define DEBUG(fmt, args...)
69 #endif
70
71 struct open_disk {
72 int od_dkunit; /* disk unit number */
73 int od_unit; /* BIOS unit number */
74 int od_cyl; /* BIOS geometry */
75 int od_hds;
76 int od_sec;
77 int od_boff; /* block offset from beginning of BIOS disk */
78 int od_flags;
79 #define BD_MODEINT13 0x0000
80 #define BD_MODEEDD1 0x0001
81 #define BD_MODEEDD3 0x0002
82 #define BD_MODEMASK 0x0003
83 #define BD_FLOPPY 0x0004
84 #define BD_LABELOK 0x0008
85 #define BD_PARTTABOK 0x0010
86 union {
87 struct disklabel32 od_disklabel;
88 struct disklabel64 od_disklabel64;
89 };
90 int od_nslices; /* slice count */
91 struct dos_partition od_slicetab[NEXTDOSPART];
92 };
93
94 /*
95 * List of BIOS devices, translation from disk unit number to
96 * BIOS unit number.
97 */
98 static struct bdinfo
99 {
100 int bd_unit; /* BIOS unit number */
101 int bd_flags;
102 int bd_type; /* BIOS 'drive type' (floppy only) */
103 } bdinfo [MAXBDDEV];
104 static int nbdinfo = 0;
105
106 static int bd_getgeom(struct open_disk *od);
107 static int bd_read(struct open_disk *od, daddr_t dblk, int blks,
108 caddr_t dest);
109 static int bd_write(struct open_disk *od, daddr_t dblk, int blks,
110 caddr_t dest);
111
112 static int bd_int13probe(struct bdinfo *bd);
113
114 static void bd_printslice(struct open_disk *od, struct dos_partition *dp,
115 char *prefix, int verbose);
116 static void bd_printbsdslice(struct open_disk *od, daddr_t offset,
117 char *prefix, int verbose);
118
119 static int bd_init(void);
120 static int bd_strategy(void *devdata, int flag, daddr_t dblk,
121 size_t size, char *buf, size_t *rsize);
122 static int bd_realstrategy(void *devdata, int flag, daddr_t dblk,
123 size_t size, char *buf, size_t *rsize);
124 static int bd_open(struct open_file *f, ...);
125 static int bd_close(struct open_file *f);
126 static void bd_print(int verbose);
127
128 struct devsw biosdisk = {
129 "disk",
130 DEVT_DISK,
131 bd_init,
132 bd_strategy,
133 bd_open,
134 bd_close,
135 noioctl,
136 bd_print,
137 NULL
138 };
139
140 static int bd_opendisk(struct open_disk **odp, struct i386_devdesc *dev);
141 static void bd_closedisk(struct open_disk *od);
142 static int bd_bestslice(struct open_disk *od);
143 static void bd_chainextended(struct open_disk *od, u_int32_t base,
144 u_int32_t offset);
145
146 /* also used by CD code */
147 char __aligned(16) bounce_base[BOUNCEBUF_SIZE];
148
149
150 /*
151 * Translate between BIOS device numbers and our private unit numbers.
152 */
153 int
bd_bios2unit(int biosdev)154 bd_bios2unit(int biosdev)
155 {
156 int i;
157
158 DEBUG("looking for bios device 0x%x", biosdev);
159 for (i = 0; i < nbdinfo; i++) {
160 DEBUG("bd unit %d is BIOS device 0x%x", i, bdinfo[i].bd_unit);
161 if (bdinfo[i].bd_unit == biosdev)
162 return(i);
163 }
164 return(-1);
165 }
166
167 int
bd_unit2bios(int unit)168 bd_unit2bios(int unit)
169 {
170 if ((unit >= 0) && (unit < nbdinfo))
171 return(bdinfo[unit].bd_unit);
172 return(-1);
173 }
174
175 /*
176 * Quiz the BIOS for disk devices, save a little info about them.
177 */
178 static int
bd_init(void)179 bd_init(void)
180 {
181 int base, unit, nfd = 0;
182
183 /* sequence 0, 0x80 */
184 for (base = 0; base <= 0x80; base += 0x80) {
185 for (unit = base; (nbdinfo < MAXBDDEV); unit++) {
186 /* check the BIOS equipment list for number of fixed disks */
187 if((base == 0x80) &&
188 (nfd >= *(unsigned char *)PTOV(BIOS_NUMDRIVES)))
189 break;
190
191 bdinfo[nbdinfo].bd_unit = unit;
192 bdinfo[nbdinfo].bd_flags = (unit < 0x80) ? BD_FLOPPY : 0;
193
194 if (!bd_int13probe(&bdinfo[nbdinfo]))
195 break;
196
197 /* XXX we need "disk aliases" to make this simpler */
198 printf("BIOS drive %c: is disk%d\n",
199 (unit < 0x80) ? ('A' + unit) : ('C' + unit - 0x80), nbdinfo);
200 nbdinfo++;
201 if (base == 0x80)
202 nfd++;
203 }
204 }
205 return(0);
206 }
207
208 /*
209 * Try to detect a device supported by the legacy int13 BIOS
210 */
211 static int
bd_int13probe(struct bdinfo * bd)212 bd_int13probe(struct bdinfo *bd)
213 {
214 v86.ctl = V86_FLAGS;
215 v86.addr = 0x13;
216 v86.eax = 0x800;
217 v86.edx = bd->bd_unit;
218 v86int();
219
220 if (!(v86.efl & PSL_C) && /* carry clear */
221 ((v86.edx & 0xff) > ((unsigned)bd->bd_unit & 0x7f))) { /* unit # OK */
222
223 /*
224 * Ignore devices with an absurd sector size.
225 */
226 if ((v86.ecx & 0x3f) == 0) {
227 DEBUG("Invalid geometry for unit %d", bd->bd_unit);
228 return(0);
229 }
230 bd->bd_flags |= BD_MODEINT13;
231 bd->bd_type = v86.ebx & 0xff;
232
233 /* Determine if we can use EDD with this device. */
234 v86.ctl = V86_FLAGS;
235 v86.addr = 0x13;
236 v86.eax = 0x4100;
237 v86.edx = bd->bd_unit;
238 v86.ebx = 0x55aa;
239 v86int();
240 if (!(v86.efl & PSL_C) && /* carry clear */
241 ((v86.ebx & 0xffff) == 0xaa55) && /* signature */
242 (v86.ecx & 0x1)) { /* packets mode ok */
243 bd->bd_flags |= BD_MODEEDD1;
244 if((v86.eax & 0xff00) > 0x300)
245 bd->bd_flags |= BD_MODEEDD3;
246 }
247 return(1);
248 }
249 return(0);
250 }
251
252 /*
253 * Print information about disks
254 */
255 static void
bd_print(int verbose)256 bd_print(int verbose)
257 {
258 int i, j;
259 char line[80];
260 struct i386_devdesc dev;
261 struct open_disk *od;
262 struct dos_partition *dptr;
263
264 for (i = 0; i < nbdinfo; i++) {
265 sprintf(line, " disk%d: BIOS drive %c:\n", i,
266 (bdinfo[i].bd_unit < 0x80) ? ('A' + bdinfo[i].bd_unit) : ('C' + bdinfo[i].bd_unit - 0x80));
267 pager_output(line);
268
269 /* try to open the whole disk */
270 dev.d_kind.biosdisk.unit = i;
271 dev.d_kind.biosdisk.slice = -1;
272 dev.d_kind.biosdisk.partition = -1;
273
274 if (!bd_opendisk(&od, &dev)) {
275
276 /* Do we have a partition table? */
277 if (od->od_flags & BD_PARTTABOK) {
278 dptr = &od->od_slicetab[0];
279
280 /* Check for a "dedicated" disk */
281 if ((dptr[3].dp_typ == DOSPTYP_386BSD ||
282 dptr[3].dp_typ == DOSPTYP_NETBSD ||
283 dptr[3].dp_typ == DOSPTYP_DFLYBSD) &&
284 (dptr[3].dp_start == 0) &&
285 (dptr[3].dp_size == 50000)) {
286 sprintf(line, " disk%d", i);
287 bd_printbsdslice(od, 0, line, verbose);
288 } else {
289 for (j = 0; j < od->od_nslices; j++) {
290 sprintf(line, " disk%ds%d", i, j + 1);
291 bd_printslice(od, &dptr[j], line, verbose);
292 }
293 }
294 }
295 bd_closedisk(od);
296 }
297 }
298 }
299
300 /*
301 * Print information about slices on a disk. For the size calculations we
302 * assume a 512 byte sector.
303 */
304 static void
bd_printslice(struct open_disk * od,struct dos_partition * dp,char * prefix,int verbose)305 bd_printslice(struct open_disk *od, struct dos_partition *dp, char *prefix,
306 int verbose)
307 {
308 char line[80];
309
310 switch (dp->dp_typ) {
311 case DOSPTYP_DFLYBSD:
312 case DOSPTYP_386BSD:
313 case DOSPTYP_NETBSD:
314 /* XXX: possibly add types 0 and 1, as in subr_disk, for gpt magic */
315 bd_printbsdslice(od, (daddr_t)dp->dp_start, prefix, verbose);
316 return;
317 case DOSPTYP_LINSWP:
318 if (verbose)
319 sprintf(line, "%s: Linux swap %.6dMB (%d - %d)\n",
320 prefix, dp->dp_size / 2048,
321 dp->dp_start, dp->dp_start + dp->dp_size);
322 else
323 sprintf(line, "%s: Linux swap\n", prefix);
324 break;
325 case DOSPTYP_LINUX:
326 /*
327 * XXX
328 * read the superblock to confirm this is an ext2fs partition?
329 */
330 if (verbose)
331 sprintf(line, "%s: ext2fs %.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: ext2fs\n", prefix);
336 break;
337 case 0x00: /* unused partition */
338 case DOSPTYP_EXT:
339 return;
340 case 0x01:
341 if (verbose)
342 sprintf(line, "%s: FAT-12 %.6dMB (%d - %d)\n", prefix,
343 dp->dp_size / 2048, dp->dp_start,
344 dp->dp_start + dp->dp_size);
345 else
346 sprintf(line, "%s: FAT-12\n", prefix);
347 break;
348 case 0x04:
349 case 0x06:
350 case 0x0e:
351 if (verbose)
352 sprintf(line, "%s: FAT-16 %.6dMB (%d - %d)\n", prefix,
353 dp->dp_size / 2048, dp->dp_start,
354 dp->dp_start + dp->dp_size);
355 else
356 sprintf(line, "%s: FAT-16\n", prefix);
357 break;
358 case 0x0b:
359 case 0x0c:
360 if (verbose)
361 sprintf(line, "%s: FAT-32 %.6dMB (%d - %d)\n", prefix,
362 dp->dp_size / 2048, dp->dp_start,
363 dp->dp_start + dp->dp_size);
364 else
365 sprintf(line, "%s: FAT-32\n", prefix);
366 break;
367 default:
368 if (verbose)
369 sprintf(line, "%s: Unknown fs: 0x%x %.6dMB (%d - %d)\n",
370 prefix, dp->dp_typ, dp->dp_size / 2048,
371 dp->dp_start, dp->dp_start + dp->dp_size);
372 else
373 sprintf(line, "%s: Unknown fs: 0x%x\n", prefix,
374 dp->dp_typ);
375 }
376 pager_output(line);
377 }
378
379 static void
print_partition(u_int8_t fstype,unsigned long long offset,unsigned long long size,int i,int od_flags,char * prefix,int verbose,int type)380 print_partition(u_int8_t fstype, unsigned long long offset,
381 unsigned long long size, int i, int od_flags,
382 char *prefix, int verbose, int type)
383 {
384 char line[80];
385
386 /*
387 * For each partition, make sure we know what type of fs it is. If
388 * not, then skip it. However, since floppies often have bogus
389 * fstypes, print the 'a' partition on a floppy even if it is marked
390 * unused.
391 */
392 if ((fstype == FS_SWAP) ||
393 (fstype == FS_VINUM) ||
394 (fstype == FS_HAMMER) ||
395 (fstype == FS_HAMMER2) ||
396 (fstype == FS_BSDFFS) ||
397 (fstype == FS_ZFS) ||
398 (fstype == FS_JFS2) ||
399 ((fstype == FS_UNUSED) &&
400 (od_flags & BD_FLOPPY) && (i == 0))) {
401
402 /* Only print out statistics in verbose mode */
403 if (verbose) {
404 sprintf(line, "%c %s%c: %s %.6lluMB (%llu - %llu)\n",
405 /* prefix disks that can be used to load modules with '*' */
406 ((fstype == FS_BSDFFS) || (fstype == FS_UNUSED) ||
407 (fstype == FS_VINUM)) ? '*' : ' ',
408 prefix, 'a' + i,
409 (fstype == FS_SWAP) ? "swap" :
410 (fstype == FS_VINUM) ? "vinum" :
411 (fstype == FS_HAMMER) ? "HAMMER" :
412 (fstype == FS_HAMMER2) ? "HAMMER2" :
413 (fstype == FS_JFS2) ? "JFS2" :
414 (fstype == FS_ZFS) ? "ZFS" :
415 (fstype == FS_BSDFFS) ? "FFS" :
416 "(unknown)",
417 (type==32)?(size / 2048):(size/1024/1024),
418 offset,
419 offset + size);
420 } else {
421 sprintf(line, "%c %s%c: %s\n",
422 /* prefix disks that can be used to load modules with '*' */
423 ((fstype == FS_BSDFFS) || (fstype == FS_UNUSED) ||
424 (fstype == FS_VINUM)) ? '*' : ' ',
425 prefix, 'a' + i,
426 (fstype == FS_SWAP) ? "swap" :
427 (fstype == FS_VINUM) ? "vinum" :
428 (fstype == FS_HAMMER) ? "HAMMER" :
429 (fstype == FS_HAMMER2) ? "HAMMER2" :
430 (fstype == FS_JFS2) ? "JFS2" :
431 (fstype == FS_ZFS) ? "ZFS" :
432 (fstype == FS_BSDFFS) ? "FFS" :
433 "(unknown)");
434 }
435
436 pager_output(line);
437 }
438 }
439
440 /*
441 * Print out each valid partition in the disklabel of a FreeBSD slice.
442 * For size calculations, we assume a 512 byte sector size.
443 */
444 static void
bd_printbsdslice(struct open_disk * od,daddr_t offset,char * prefix,int verbose)445 bd_printbsdslice(struct open_disk *od, daddr_t offset, char *prefix,
446 int verbose)
447 {
448 char line[80];
449 char buf[BIOSDISK_SECSIZE*2];
450 struct disklabel32 *lp = NULL;
451 struct disklabel64 *lp64 = NULL;
452 int i;
453
454 /* read disklabel */
455 if (bd_read(od, offset + LABELSECTOR32, 1, buf))
456 return;
457 lp =(struct disklabel32 *)(&buf[0]);
458 if (lp->d_magic != DISKMAGIC32) {
459 if (bd_read(od, offset, 2, buf))
460 return;
461
462 lp64 =(struct disklabel64 *)(&buf[0]);
463 if (lp64->d_magic != DISKMAGIC64) {
464 sprintf(line, "%s: bad disklabel\n", prefix);
465 pager_output(line);
466 return;
467 }
468 lp = NULL; /* PARANOID */
469 }
470 if (lp64) {
471 /* We got ourselves a disklabel64 here */
472 for (i = 0; i < lp64->d_npartitions; i++) {
473 if (lp64->d_partitions[i].p_bsize == 0)
474 continue;
475
476 print_partition(lp64->d_partitions[i].p_fstype,
477 lp64->d_partitions[i].p_boffset,
478 lp64->d_partitions[i].p_bsize,
479 i, od->od_flags, prefix, verbose, 64);
480 }
481 } else if (lp) {
482 /* Print partitions */
483 for (i = 0; i < lp->d_npartitions; i++) {
484 print_partition(lp->d_partitions[i].p_fstype,
485 lp->d_partitions[i].p_offset,
486 lp->d_partitions[i].p_size,
487 i, od->od_flags, prefix, verbose, 32);
488 }
489 }
490 }
491
492
493 /*
494 * Attempt to open the disk described by (dev) for use by (f).
495 *
496 * Note that the philosophy here is "give them exactly what
497 * they ask for". This is necessary because being too "smart"
498 * about what the user might want leads to complications.
499 * (eg. given no slice or partition value, with a disk that is
500 * sliced - are they after the first BSD slice, or the DOS
501 * slice before it?)
502 */
503 static int
bd_open(struct open_file * f,...)504 bd_open(struct open_file *f, ...)
505 {
506 va_list ap;
507 struct i386_devdesc *dev;
508 struct open_disk *od;
509 int error;
510
511 va_start(ap, f);
512 dev = va_arg(ap, struct i386_devdesc *);
513 va_end(ap);
514 if ((error = bd_opendisk(&od, dev)))
515 return(error);
516
517 /*
518 * Save our context
519 */
520 ((struct i386_devdesc *)(f->f_devdata))->d_kind.biosdisk.data = od;
521 DEBUG("open_disk %p, partition at 0x%x", od, od->od_boff);
522 return(0);
523 }
524
525 static int
bd_opendisk(struct open_disk ** odp,struct i386_devdesc * dev)526 bd_opendisk(struct open_disk **odp, struct i386_devdesc *dev)
527 {
528 struct dos_partition *dptr;
529 struct disklabel32 *lp;
530 struct disklabel64 *lp64;
531 struct open_disk *od;
532 int sector, slice, i;
533 int error;
534 static char buf[BUFSIZE];
535
536 if (dev->d_kind.biosdisk.unit >= nbdinfo) {
537 DEBUG("attempt to open nonexistent disk");
538 return(ENXIO);
539 }
540
541 od = (struct open_disk *)malloc(sizeof(struct open_disk));
542 if (!od) {
543 DEBUG("no memory");
544 return (ENOMEM);
545 }
546
547 /* Look up BIOS unit number, intialise open_disk structure */
548 od->od_dkunit = dev->d_kind.biosdisk.unit;
549 od->od_unit = bdinfo[od->od_dkunit].bd_unit;
550 od->od_flags = bdinfo[od->od_dkunit].bd_flags;
551 od->od_boff = 0;
552 od->od_nslices = 0;
553 error = 0;
554 DEBUG("open '%s', unit 0x%x slice %d partition %c",
555 i386_fmtdev(dev), dev->d_kind.biosdisk.unit,
556 dev->d_kind.biosdisk.slice, dev->d_kind.biosdisk.partition + 'a');
557
558 /* Get geometry for this open (removable device may have changed) */
559 if (bd_getgeom(od)) {
560 DEBUG("can't get geometry");
561 error = ENXIO;
562 goto out;
563 }
564
565 /*
566 * Following calculations attempt to determine the correct value
567 * for d->od_boff by looking for the slice and partition specified,
568 * or searching for reasonable defaults.
569 */
570
571 /*
572 * Find the slice in the DOS slice table.
573 */
574 if (bd_read(od, 0, 1, buf)) {
575 DEBUG("error reading MBR");
576 error = EIO;
577 goto out;
578 }
579
580 /*
581 * Check the slice table magic.
582 */
583 if (((u_char)buf[0x1fe] != 0x55) || ((u_char)buf[0x1ff] != 0xaa)) {
584 /* If a slice number was explicitly supplied, this is an error */
585 if (dev->d_kind.biosdisk.slice > 0) {
586 DEBUG("no slice table/MBR (no magic)");
587 error = ENOENT;
588 goto out;
589 }
590 sector = 0;
591 goto unsliced; /* may be a floppy */
592 }
593
594 /*
595 * copy the partition table, then pick up any extended partitions. The
596 * base partition table always has four entries, even if some of them
597 * represented extended partitions. However, any additional sub-extended
598 * partitions will be silently recursed and not included in the slice
599 * table.
600 */
601 bcopy(buf + DOSPARTOFF, &od->od_slicetab,
602 sizeof(struct dos_partition) * NDOSPART);
603 od->od_nslices = NDOSPART;
604
605 dptr = &od->od_slicetab[0];
606 for (i = 0; i < NDOSPART; i++, dptr++) {
607 if ((dptr->dp_typ == DOSPTYP_EXT) || (dptr->dp_typ == DOSPTYP_EXTLBA))
608 bd_chainextended(od, dptr->dp_start, 0); /* 1st offset is zero */
609 }
610 od->od_flags |= BD_PARTTABOK;
611 dptr = &od->od_slicetab[0];
612
613 /*
614 * Overflow entries are not loaded into memory but we still keep
615 * track of the count. Fix it up now.
616 */
617 if (od->od_nslices > NEXTDOSPART)
618 od->od_nslices = NEXTDOSPART;
619
620 /*
621 * Is this a request for the whole disk?
622 */
623 if (dev->d_kind.biosdisk.slice == -1) {
624 sector = 0;
625 goto unsliced;
626 }
627
628 /*
629 * if a slice number was supplied but not found, this is an error.
630 */
631 if (dev->d_kind.biosdisk.slice > 0) {
632 slice = dev->d_kind.biosdisk.slice - 1;
633 if (slice >= od->od_nslices) {
634 DEBUG("slice %d not found", slice);
635 error = ENOENT;
636 goto out;
637 }
638 }
639
640 /*
641 * Check for the historically bogus MBR found on true dedicated disks
642 */
643 if ((dptr[3].dp_typ == DOSPTYP_386BSD ||
644 dptr[3].dp_typ == DOSPTYP_DFLYBSD) &&
645 (dptr[3].dp_start == 0) &&
646 (dptr[3].dp_size == 50000)) {
647 sector = 0;
648 goto unsliced;
649 }
650
651 /* Try to auto-detect the best slice; this should always give a slice number */
652 if (dev->d_kind.biosdisk.slice == 0) {
653 slice = bd_bestslice(od);
654 if (slice == -1) {
655 error = ENOENT;
656 goto out;
657 }
658 dev->d_kind.biosdisk.slice = slice;
659 }
660
661 dptr = &od->od_slicetab[0];
662 /*
663 * Accept the supplied slice number unequivocally (we may be looking
664 * at a DOS partition).
665 */
666 dptr += (dev->d_kind.biosdisk.slice - 1); /* we number 1-4, offsets are 0-3 */
667 sector = dptr->dp_start;
668 DEBUG("slice entry %d at %d, %d sectors", dev->d_kind.biosdisk.slice - 1, sector, dptr->dp_size);
669
670 /*
671 * If we are looking at a BSD slice, and the partition is < 0,
672 * assume the 'a' partition
673 */
674 if ((dptr->dp_typ == DOSPTYP_386BSD ||
675 dptr->dp_typ == DOSPTYP_DFLYBSD) &&
676 dev->d_kind.biosdisk.partition < 0) {
677 dev->d_kind.biosdisk.partition = 0;
678 }
679
680 unsliced:
681 /*
682 * Now we have the slice offset, look for the partition in the disklabel if we have
683 * a partition to start with.
684 *
685 * XXX we might want to check the label checksum.
686 */
687 if (dev->d_kind.biosdisk.partition < 0) {
688 od->od_boff = sector; /* no partition, must be after the slice */
689 DEBUG("opening raw slice");
690 } else {
691
692 if (bd_read(od, sector + LABELSECTOR32, 1, buf)) {
693 DEBUG("error reading disklabel");
694 error = EIO;
695 goto out;
696 }
697 DEBUG("copy %d bytes of label from %p to %p", sizeof(struct disklabel32), buf + LABELOFFSET32, &od->od_disklabel);
698 bcopy(buf + LABELOFFSET32, &od->od_disklabel, sizeof(struct disklabel32));
699 lp = &od->od_disklabel;
700
701 if (lp->d_magic == DISKMAGIC32) {
702 od->od_flags |= BD_LABELOK;
703
704 if (dev->d_kind.biosdisk.partition >= lp->d_npartitions) {
705 DEBUG("partition '%c' exceeds partitions in table (a-'%c')",
706 'a' + dev->d_kind.biosdisk.partition, 'a' + lp->d_npartitions);
707 error = EPART;
708 goto out;
709
710 }
711
712 #ifdef DISK_DEBUG
713 /* Complain if the partition is unused unless this is a floppy. */
714 if ((lp->d_partitions[dev->d_kind.biosdisk.partition].p_fstype == FS_UNUSED) &&
715 !(od->od_flags & BD_FLOPPY))
716 DEBUG("warning, partition marked as unused");
717 #endif
718
719 od->od_boff =
720 lp->d_partitions[dev->d_kind.biosdisk.partition].p_offset -
721 lp->d_partitions[RAW_PART].p_offset +
722 sector;
723
724 goto out;
725 }
726
727 /* else maybe DISKLABEL64? */
728
729 if (bd_read(od, sector, (sizeof(od->od_disklabel64) + 511) / 512, buf)) {
730 DEBUG("error reading disklabel");
731 error = EIO;
732 goto out;
733 }
734 DEBUG("copy %d bytes of label from %p to %p", sizeof(od->od_disklabel64), buf, &od->od_disklabel64);
735 bcopy(buf, &od->od_disklabel64, sizeof(od->od_disklabel64));
736 lp64 = &od->od_disklabel64;
737
738 if (lp64->d_magic == DISKMAGIC64) {
739 od->od_flags |= BD_LABELOK;
740
741 if (dev->d_kind.biosdisk.partition >= lp64->d_npartitions ||
742 lp64->d_partitions[dev->d_kind.biosdisk.partition].p_bsize == 0) {
743 DEBUG("partition '%c' exceeds partitions in table (a-'%c')",
744 'a' + dev->d_kind.biosdisk.partition, 'a' + lp64->d_npartitions);
745 error = EPART;
746 goto out;
747
748 }
749
750 od->od_boff =
751 lp64->d_partitions[dev->d_kind.biosdisk.partition].p_boffset / 512 +
752 sector;
753
754 DEBUG("disklabel64 slice at %d", od->od_boff);
755
756 } else {
757 DEBUG("no disklabel");
758 error = ENOENT;
759 }
760 }
761
762 out:
763 if (error) {
764 free(od);
765 } else {
766 *odp = od; /* return the open disk */
767 }
768 return(error);
769 }
770
771
772 static void
bd_chainextended(struct open_disk * od,u_int32_t base,u_int32_t offset)773 bd_chainextended(struct open_disk *od, u_int32_t base, u_int32_t offset)
774 {
775 char buf[BIOSDISK_SECSIZE];
776 struct dos_partition *dp1, *dp2;
777 int i;
778
779 if (bd_read(od, (daddr_t)(base + offset), 1, buf)) {
780 printf("\nerror reading extended partition table");
781 return;
782 }
783
784 /*
785 * dp1 points to the first record in the on-disk XPT,
786 * dp2 points to the next entry in the in-memory parition table.
787 *
788 * NOTE: dp2 may be out of bounds if od_nslices >= NEXTDOSPART.
789 *
790 * NOTE: unlike the extended partitions in our primary dos partition
791 * table, we do not record recursed extended partitions themselves
792 * in our in-memory partition table.
793 *
794 * NOTE: recording within our in-memory table must be breadth first
795 * ot match what the kernel does. Thus, two passes are required.
796 *
797 * NOTE: partitioning programs which support extended partitions seem
798 * to always use the first entry for the user partition and the
799 * second entry to chain, and also appear to disallow more then one
800 * extended partition at each level. Nevertheless we make our code
801 * somewhat more generic (and the same as the kernel's own slice
802 * scan).
803 */
804 dp1 = (struct dos_partition *)(&buf[DOSPARTOFF]);
805 dp2 = &od->od_slicetab[od->od_nslices];
806
807 for (i = 0; i < NDOSPART; ++i, ++dp1) {
808 if (dp1->dp_scyl == 0 && dp1->dp_shd == 0 &&
809 dp1->dp_ssect == 0 && dp1->dp_start == 0 &&
810 dp1->dp_size == 0) {
811 continue;
812 }
813 if ((dp1->dp_typ == DOSPTYP_EXT) ||
814 (dp1->dp_typ == DOSPTYP_EXTLBA)) {
815 /*
816 * breadth first traversal, must skip in the
817 * first pass
818 */
819 continue;
820 }
821
822 /*
823 * Only load up the in-memory data if we haven't overflowed
824 * our in-memory array.
825 */
826 if (od->od_nslices < NEXTDOSPART) {
827 dp2->dp_typ = dp1->dp_typ;
828 dp2->dp_start = base + offset + dp1->dp_start;
829 dp2->dp_size = dp1->dp_size;
830 }
831 ++od->od_nslices;
832 ++dp2;
833 }
834
835 /*
836 * Pass 2 - handle extended partitions. Note that the extended
837 * slice itself is not stored in the slice array when we recurse,
838 * but any 'original' top-level extended slices are. This is to
839 * match what the kernel does.
840 */
841 dp1 -= NDOSPART;
842 for (i = 0; i < NDOSPART; ++i, ++dp1) {
843 if (dp1->dp_scyl == 0 && dp1->dp_shd == 0 &&
844 dp1->dp_ssect == 0 && dp1->dp_start == 0 &&
845 dp1->dp_size == 0) {
846 continue;
847 }
848 if ((dp1->dp_typ == DOSPTYP_EXT) ||
849 (dp1->dp_typ == DOSPTYP_EXTLBA))
850 bd_chainextended(od, base, dp1->dp_start);
851 }
852 }
853
854 /*
855 * Search for a slice with the following preferences:
856 *
857 * 1: Active FreeBSD slice
858 * 2: Non-active FreeBSD slice
859 * 3: Active Linux slice
860 * 4: non-active Linux slice
861 * 5: Active FAT/FAT32 slice
862 * 6: non-active FAT/FAT32 slice
863 */
864 #define PREF_RAWDISK 0
865 #define PREF_FBSD_ACT 1
866 #define PREF_FBSD 2
867 #define PREF_LINUX_ACT 3
868 #define PREF_LINUX 4
869 #define PREF_DOS_ACT 5
870 #define PREF_DOS 6
871 #define PREF_NONE 7
872
873 /*
874 * slicelimit is in the range 0 .. NDOSPART
875 */
876 static int
bd_bestslice(struct open_disk * od)877 bd_bestslice(struct open_disk *od)
878 {
879 struct dos_partition *dp;
880 int pref, preflevel;
881 int i, prefslice;
882
883 prefslice = 0;
884 preflevel = PREF_NONE;
885
886 dp = &od->od_slicetab[0];
887 for (i = 0; i < od->od_nslices; i++, dp++) {
888 switch (dp->dp_typ) {
889 case DOSPTYP_DFLYBSD: /* DragonFlyBSD */
890 case DOSPTYP_386BSD: /* FreeBSD and old DFlyBSD */
891 pref = dp->dp_flag & 0x80 ? PREF_FBSD_ACT : PREF_FBSD;
892 break;
893
894 case DOSPTYP_LINUX:
895 pref = dp->dp_flag & 0x80 ? PREF_LINUX_ACT : PREF_LINUX;
896 break;
897
898 case 0x01: /* DOS/Windows */
899 case 0x04:
900 case 0x06:
901 case 0x0b:
902 case 0x0c:
903 case 0x0e:
904 pref = dp->dp_flag & 0x80 ? PREF_DOS_ACT : PREF_DOS;
905 break;
906
907 default:
908 pref = PREF_NONE;
909 }
910 if (pref < preflevel) {
911 preflevel = pref;
912 prefslice = i + 1;
913 }
914 }
915 return (prefslice);
916 }
917
918 static int
bd_close(struct open_file * f)919 bd_close(struct open_file *f)
920 {
921 struct open_disk *od = (struct open_disk *)(((struct i386_devdesc *)(f->f_devdata))->d_kind.biosdisk.data);
922
923 bd_closedisk(od);
924 return(0);
925 }
926
927 static void
bd_closedisk(struct open_disk * od)928 bd_closedisk(struct open_disk *od)
929 {
930 DEBUG("open_disk %p", od);
931 #if 0
932 /* XXX is this required? (especially if disk already open...) */
933 if (od->od_flags & BD_FLOPPY)
934 delay(3000000);
935 #endif
936 free(od);
937 }
938
939 static int
bd_strategy(void * devdata,int rw,daddr_t dblk,size_t size,char * buf,size_t * rsize)940 bd_strategy(void *devdata, int rw, daddr_t dblk, size_t size, char *buf, size_t *rsize)
941 {
942 struct bcache_devdata bcd;
943 struct open_disk *od = (struct open_disk *)(((struct i386_devdesc *)devdata)->d_kind.biosdisk.data);
944
945 bcd.dv_strategy = bd_realstrategy;
946 bcd.dv_devdata = devdata;
947 return(bcache_strategy(&bcd, od->od_unit, rw, dblk+od->od_boff, size, buf, rsize));
948 }
949
950 static int
bd_realstrategy(void * devdata,int rw,daddr_t dblk,size_t size,char * buf,size_t * rsize)951 bd_realstrategy(void *devdata, int rw, daddr_t dblk, size_t size, char *buf, size_t *rsize)
952 {
953 struct open_disk *od = (struct open_disk *)(((struct i386_devdesc *)devdata)->d_kind.biosdisk.data);
954 int blks;
955 #ifdef BD_SUPPORT_FRAGS
956 char fragbuf[BIOSDISK_SECSIZE];
957 size_t fragsize;
958
959 fragsize = size % BIOSDISK_SECSIZE;
960 #else
961 if (size % BIOSDISK_SECSIZE)
962 panic("bd_strategy: %d bytes I/O not multiple of block size", size);
963 #endif
964
965 DEBUG("open_disk %p", od);
966
967 switch(rw){
968 case F_READ:
969 blks = size / BIOSDISK_SECSIZE;
970 DEBUG("read %d from %d to %p", blks, dblk, buf);
971
972 if (rsize)
973 *rsize = 0;
974 if (blks && bd_read(od, dblk, blks, buf)) {
975 DEBUG("read error");
976 return (EIO);
977 }
978 #ifdef BD_SUPPORT_FRAGS
979 DEBUG("bd_strategy: frag read %d from %d+%d to %p",
980 fragsize, dblk, blks, buf + (blks * BIOSDISK_SECSIZE));
981 if (fragsize && bd_read(od, dblk + blks, 1, fragsize)) {
982 DEBUG("frag read error");
983 return(EIO);
984 }
985 bcopy(fragbuf, buf + (blks * BIOSDISK_SECSIZE), fragsize);
986 #endif
987 if (rsize)
988 *rsize = size;
989 return (0);
990 case F_WRITE :
991 blks = size / BIOSDISK_SECSIZE;
992 DEBUG("write %d from %d to %p", blks, dblk, buf);
993
994 if (rsize)
995 *rsize = 0;
996 if (blks && bd_write(od, dblk, blks, buf)) {
997 DEBUG("write error");
998 return (EIO);
999 }
1000 #ifdef BD_SUPPORT_FRAGS
1001 if(fragsize) {
1002 DEBUG("Attempted to write a frag");
1003 return (EIO);
1004 }
1005 #endif
1006 if (rsize)
1007 *rsize = size;
1008 return (0);
1009 default:
1010 break; /* DO NOTHING */
1011 }
1012 return EROFS;
1013 }
1014
1015 static int
bd_read(struct open_disk * od,daddr_t dblk,int blks,caddr_t dest)1016 bd_read(struct open_disk *od, daddr_t dblk, int blks, caddr_t dest)
1017 {
1018 u_int x, bpc, cyl, hd, sec, result, resid, retry, maxfer;
1019 caddr_t p, xp, bbuf, breg;
1020
1021 /* Just in case some idiot actually tries to read -1 blocks... */
1022 if (blks < 0)
1023 return (-1);
1024
1025 bpc = (od->od_sec * od->od_hds); /* blocks per cylinder */
1026 resid = blks;
1027 p = dest;
1028
1029 /*
1030 * Always bounce. Our buffer is probably not segment-addressable.
1031 */
1032 if (1) {
1033 /*
1034 * There is a 64k physical boundary somewhere in the destination
1035 * buffer, so we have to arrange a suitable bounce buffer. Allocate
1036 * a buffer twice as large as we need to. Use the bottom half unless
1037 * there is a break there, in which case we use the top half.
1038 */
1039 bbuf = bounce_base;
1040 x = min(BOUNCEBUF_SECTS / 2, (unsigned)blks);
1041
1042 if (((u_int32_t)VTOP(bbuf) & 0xffff8000) ==
1043 ((u_int32_t)VTOP(bbuf + x * BIOSDISK_SECSIZE - 1) & 0xffff8000)) {
1044 breg = bbuf;
1045 } else {
1046 breg = bbuf + x * BIOSDISK_SECSIZE;
1047 }
1048 maxfer = x; /* limit transfers to bounce region size */
1049 } else {
1050 breg = bbuf = NULL;
1051 maxfer = 0;
1052 }
1053
1054 while (resid > 0) {
1055 x = dblk;
1056 cyl = x / bpc; /* block # / blocks per cylinder */
1057 x %= bpc; /* block offset into cylinder */
1058 hd = x / od->od_sec; /* offset / blocks per track */
1059 sec = x % od->od_sec; /* offset into track */
1060
1061 /* play it safe and don't cross track boundaries (XXX this is probably unnecessary) */
1062 x = szmin(od->od_sec - sec, resid);
1063 if (maxfer > 0)
1064 x = min(x, maxfer); /* fit bounce buffer */
1065
1066 /* where do we transfer to? */
1067 xp = (bbuf == NULL ? p : breg);
1068
1069 /* correct sector number for 1-based BIOS numbering */
1070 sec++;
1071
1072 /*
1073 * Loop retrying the operation a couple of times. The BIOS may also
1074 * retry.
1075 */
1076 for (retry = 0; retry < 3; retry++) {
1077 /*
1078 * If retrying, reset the drive.
1079 */
1080 if (retry > 0) {
1081 v86.ctl = V86_FLAGS;
1082 v86.addr = 0x13;
1083 v86.eax = 0;
1084 v86.edx = od->od_unit;
1085 v86int();
1086 }
1087
1088 /*
1089 * Always use EDD if the disk supports it, otherwise fall back
1090 * to CHS mode (returning an error if the cylinder number is
1091 * too large).
1092 */
1093 if (od->od_flags & BD_MODEEDD1) {
1094 static unsigned short packet[8];
1095
1096 packet[0] = 0x10;
1097 packet[1] = x;
1098 packet[2] = VTOPOFF(xp);
1099 packet[3] = VTOPSEG(xp);
1100 packet[4] = dblk & 0xffff;
1101 packet[5] = dblk >> 16;
1102 packet[6] = 0;
1103 packet[7] = 0;
1104 v86.ctl = V86_FLAGS;
1105 v86.addr = 0x13;
1106 v86.eax = 0x4200;
1107 v86.edx = od->od_unit;
1108 v86.ds = VTOPSEG(packet);
1109 v86.esi = VTOPOFF(packet);
1110 v86int();
1111 result = (v86.efl & PSL_C);
1112 if (result == 0)
1113 break;
1114 } else if (cyl < 1024) {
1115 /* Use normal CHS addressing */
1116 v86.ctl = V86_FLAGS;
1117 v86.addr = 0x13;
1118 v86.eax = 0x200 | x;
1119 v86.ecx = ((cyl & 0xff) << 8) | ((cyl & 0x300) >> 2) | sec;
1120 v86.edx = (hd << 8) | od->od_unit;
1121 v86.es = VTOPSEG(xp);
1122 v86.ebx = VTOPOFF(xp);
1123 v86int();
1124 result = (v86.efl & PSL_C);
1125 if (result == 0)
1126 break;
1127 } else {
1128 result = 1;
1129 break;
1130 }
1131 }
1132
1133 DEBUG("%u sectors from %u/%u/%d to %p (0x%x) %s",
1134 x, cyl, hd, sec - 1, p, VTOP(p), result ? "failed" : "ok");
1135 /* BUG here, cannot use v86 in printf because putchar uses it too */
1136 DEBUG("ax = 0x%04x cx = 0x%04x dx = 0x%04x status 0x%x",
1137 0x200 | x,
1138 ((cyl & 0xff) << 8) | ((cyl & 0x300) >> 2) | sec,
1139 (hd << 8) | od->od_unit,
1140 (v86.eax >> 8) & 0xff);
1141 if (result)
1142 return(-1);
1143 if (bbuf != NULL)
1144 bcopy(breg, p, x * BIOSDISK_SECSIZE);
1145 p += (x * BIOSDISK_SECSIZE);
1146 dblk += x;
1147 resid -= x;
1148 }
1149
1150 /* hexdump(dest, (blks * BIOSDISK_SECSIZE)); */
1151 return(0);
1152 }
1153
1154
1155 static int
bd_write(struct open_disk * od,daddr_t dblk,int blks,caddr_t dest)1156 bd_write(struct open_disk *od, daddr_t dblk, int blks, caddr_t dest)
1157 {
1158 u_int x, bpc, cyl, hd, sec, result, resid, retry, maxfer;
1159 caddr_t p, xp, bbuf, breg;
1160
1161 /* Just in case some idiot actually tries to read -1 blocks... */
1162 if (blks < 0)
1163 return (-1);
1164
1165 bpc = (od->od_sec * od->od_hds); /* blocks per cylinder */
1166 resid = blks;
1167 p = dest;
1168
1169 /*
1170 * Always bounce. Our buffer is probably not segment-addressable.
1171 */
1172 if (1) {
1173 /*
1174 * There is a 64k physical boundary somewhere in the destination
1175 * buffer, so we have to arrange a suitable bounce buffer. Allocate
1176 * a buffer twice as large as we need to. Use the bottom half
1177 * unless there is a break there, in which case we use the top half.
1178 */
1179 bbuf = bounce_base;
1180 x = min(BOUNCEBUF_SECTS / 2, (unsigned)blks);
1181
1182 if (((u_int32_t)VTOP(bbuf) & 0xffff8000) ==
1183 ((u_int32_t)VTOP(bbuf + x * BIOSDISK_SECSIZE - 1) & 0xffff8000)) {
1184 breg = bbuf;
1185 } else {
1186 breg = bbuf + x * BIOSDISK_SECSIZE;
1187 }
1188 maxfer = x; /* limit transfers to bounce region size */
1189 } else {
1190 breg = bbuf = NULL;
1191 maxfer = 0;
1192 }
1193
1194 while (resid > 0) {
1195 x = dblk;
1196 cyl = x / bpc; /* block # / blocks per cylinder */
1197 x %= bpc; /* block offset into cylinder */
1198 hd = x / od->od_sec; /* offset / blocks per track */
1199 sec = x % od->od_sec; /* offset into track */
1200
1201 /* play it safe and don't cross track boundaries (XXX this is probably unnecessary) */
1202 x = szmin(od->od_sec - sec, resid);
1203 if (maxfer > 0)
1204 x = szmin(x, maxfer); /* fit bounce buffer */
1205
1206 /* where do we transfer to? */
1207 xp = (bbuf == NULL ? p : breg);
1208
1209 /* correct sector number for 1-based BIOS numbering */
1210 sec++;
1211
1212
1213 /* Put your Data In, Put your Data out,
1214 Put your Data In, and shake it all about
1215 */
1216 if (bbuf != NULL)
1217 bcopy(p, breg, x * BIOSDISK_SECSIZE);
1218 p += (x * BIOSDISK_SECSIZE);
1219 dblk += x;
1220 resid -= x;
1221
1222 /*
1223 * Loop retrying the operation a couple of times. The BIOS may also
1224 * retry.
1225 */
1226 for (retry = 0; retry < 3; retry++) {
1227 /*
1228 * If retrying, reset the drive.
1229 */
1230 if (retry > 0) {
1231 v86.ctl = V86_FLAGS;
1232 v86.addr = 0x13;
1233 v86.eax = 0;
1234 v86.edx = od->od_unit;
1235 v86int();
1236 }
1237
1238 /*
1239 * Always use EDD if the disk supports it, otherwise fall back
1240 * to CHS mode (returning an error if the cylinder number is
1241 * too large).
1242 */
1243 if (od->od_flags & BD_MODEEDD1) {
1244 static unsigned short packet[8];
1245
1246 packet[0] = 0x10;
1247 packet[1] = x;
1248 packet[2] = VTOPOFF(xp);
1249 packet[3] = VTOPSEG(xp);
1250 packet[4] = dblk & 0xffff;
1251 packet[5] = dblk >> 16;
1252 packet[6] = 0;
1253 packet[7] = 0;
1254 v86.ctl = V86_FLAGS;
1255 v86.addr = 0x13;
1256 /* Should we Write with verify ?? 0x4302 ? */
1257 v86.eax = 0x4300;
1258 v86.edx = od->od_unit;
1259 v86.ds = VTOPSEG(packet);
1260 v86.esi = VTOPOFF(packet);
1261 v86int();
1262 result = (v86.efl & PSL_C);
1263 if (result == 0)
1264 break;
1265 } else if (cyl < 1024) {
1266 /* Use normal CHS addressing */
1267 v86.ctl = V86_FLAGS;
1268 v86.addr = 0x13;
1269 v86.eax = 0x300 | x;
1270 v86.ecx = ((cyl & 0xff) << 8) | ((cyl & 0x300) >> 2) | sec;
1271 v86.edx = (hd << 8) | od->od_unit;
1272 v86.es = VTOPSEG(xp);
1273 v86.ebx = VTOPOFF(xp);
1274 v86int();
1275 result = (v86.efl & PSL_C);
1276 if (result == 0)
1277 break;
1278 } else {
1279 result = 1;
1280 break;
1281 }
1282 }
1283
1284 DEBUG("%u sectors from %u/%u/%d to %p (0x%x) %s", x, cyl, hd, sec - 1, p, VTOP(p), result ? "failed" : "ok");
1285 /* BUG here, cannot use v86 in printf because putchar uses it too */
1286 DEBUG("ax = 0x%04x cx = 0x%04x dx = 0x%04x status 0x%x",
1287 0x200 | x, ((cyl & 0xff) << 8) | ((cyl & 0x300) >> 2) | sec, (hd << 8) | od->od_unit, (v86.eax >> 8) & 0xff);
1288 if (result)
1289 return(-1);
1290 }
1291
1292 /* hexdump(dest, (blks * BIOSDISK_SECSIZE)); */
1293 return(0);
1294 }
1295 static int
bd_getgeom(struct open_disk * od)1296 bd_getgeom(struct open_disk *od)
1297 {
1298
1299 v86.ctl = V86_FLAGS;
1300 v86.addr = 0x13;
1301 v86.eax = 0x800;
1302 v86.edx = od->od_unit;
1303 v86int();
1304
1305 if ((v86.efl & PSL_C) || /* carry set */
1306 ((v86.edx & 0xff) <= (unsigned)(od->od_unit & 0x7f))) /* unit # bad */
1307 return(1);
1308
1309 /* convert max cyl # -> # of cylinders */
1310 od->od_cyl = ((v86.ecx & 0xc0) << 2) + ((v86.ecx & 0xff00) >> 8) + 1;
1311 /* convert max head # -> # of heads */
1312 od->od_hds = ((v86.edx & 0xff00) >> 8) + 1;
1313 od->od_sec = v86.ecx & 0x3f;
1314
1315 DEBUG("unit 0x%x geometry %d/%d/%d", od->od_unit, od->od_cyl, od->od_hds, od->od_sec);
1316 return(0);
1317 }
1318
1319 /*
1320 * Return the BIOS geometry of a given "fixed drive" in a format
1321 * suitable for the legacy bootinfo structure. Since the kernel is
1322 * expecting raw int 0x13/0x8 values for N_BIOS_GEOM drives, we
1323 * prefer to get the information directly, rather than rely on being
1324 * able to put it together from information already maintained for
1325 * different purposes and for a probably different number of drives.
1326 *
1327 * For valid drives, the geometry is expected in the format (31..0)
1328 * "000000cc cccccccc hhhhhhhh 00ssssss"; and invalid drives are
1329 * indicated by returning the geometry of a "1.2M" PC-format floppy
1330 * disk. And, incidentally, what is returned is not the geometry as
1331 * such but the highest valid cylinder, head, and sector numbers.
1332 */
1333 u_int32_t
bd_getbigeom(int bunit)1334 bd_getbigeom(int bunit)
1335 {
1336
1337 v86.ctl = V86_FLAGS;
1338 v86.addr = 0x13;
1339 v86.eax = 0x800;
1340 v86.edx = 0x80 + bunit;
1341 v86int();
1342 if (v86.efl & PSL_C)
1343 return 0x4f010f;
1344 return ((v86.ecx & 0xc0) << 18) | ((v86.ecx & 0xff00) << 8) |
1345 (v86.edx & 0xff00) | (v86.ecx & 0x3f);
1346 }
1347
1348 /*
1349 * Return a suitable cdev_t value for (dev).
1350 *
1351 * In the case where it looks like (dev) is a SCSI disk, we allow the number of
1352 * IDE disks to be specified in $num_ide_disks. There should be a Better Way.
1353 */
1354 int
bd_getdev(struct i386_devdesc * dev)1355 bd_getdev(struct i386_devdesc *dev)
1356 {
1357 struct open_disk *od;
1358 int biosdev;
1359 int major;
1360 int rootdev;
1361 char *nip, *cp;
1362 int unitofs = 0, i, unit;
1363
1364 biosdev = bd_unit2bios(dev->d_kind.biosdisk.unit);
1365 DEBUG("unit %d BIOS device %d", dev->d_kind.biosdisk.unit, biosdev);
1366 if (biosdev == -1) /* not a BIOS device */
1367 return(-1);
1368 if (bd_opendisk(&od, dev) != 0) /* oops, not a viable device */
1369 return(-1);
1370
1371 if (biosdev < 0x80) {
1372 /* floppy (or emulated floppy) or ATAPI device */
1373 if (bdinfo[dev->d_kind.biosdisk.unit].bd_type == DT_ATAPI) {
1374 /* is an ATAPI disk */
1375 major = WFDMAJOR;
1376 } else {
1377 /* is a floppy disk */
1378 major = FDMAJOR;
1379 }
1380 } else {
1381 /* harddisk */
1382 if ((od->od_flags & BD_LABELOK) && (od->od_disklabel.d_type == DTYPE_SCSI)) {
1383 /* label OK, disk labelled as SCSI */
1384 major = DAMAJOR;
1385 /* check for unit number correction hint, now deprecated */
1386 if ((nip = getenv("num_ide_disks")) != NULL) {
1387 i = strtol(nip, &cp, 0);
1388 /* check for parse error */
1389 if ((cp != nip) && (*cp == 0))
1390 unitofs = i;
1391 }
1392 } else {
1393 /* assume an IDE disk */
1394 major = WDMAJOR;
1395 }
1396 }
1397 /* default root disk unit number */
1398 unit = (biosdev & 0x7f) - unitofs;
1399
1400 /* XXX a better kludge to set the root disk unit number */
1401 if ((nip = getenv("root_disk_unit")) != NULL) {
1402 i = strtol(nip, &cp, 0);
1403 /* check for parse error */
1404 if ((cp != nip) && (*cp == 0))
1405 unit = i;
1406 }
1407
1408 rootdev = MAKEBOOTDEV(major, dev->d_kind.biosdisk.slice + 1, unit,
1409 dev->d_kind.biosdisk.partition);
1410 DEBUG("dev is 0x%x\n", rootdev);
1411 return(rootdev);
1412 }
1413