2 * Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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
26 * $FreeBSD: src/sys/boot/i386/libi386/biosdisk.c,v 1.26.2.6 2000/12/28 13:10:47 ps Exp $
27 * $DragonFly: src/sys/boot/pc32/libi386/biosdisk.c,v 1.3 2003/07/21 05:50:22 dillon Exp $
31 * BIOS disk device handling.
33 * Ideas and algorithms from:
35 * - NetBSD libi386/biosdisk.c
36 * - FreeBSD biosboot/disk.c
42 #include <sys/disklabel.h>
43 #include <sys/diskslice.h>
44 #include <sys/bootmaj.h>
45 #include <sys/reboot.h>
49 #include <bootstrap.h>
53 #define BIOS_NUMDRIVES 0x475
54 #define BIOSDISK_SECSIZE 512
55 #define BUFSIZE (1 * BIOSDISK_SECSIZE)
56 #define MAXBDDEV MAXDEV
58 #define DT_ATAPI 0x10 /* disk type for ATAPI floppies */
61 # define DEBUG(fmt, args...) printf("%s: " fmt "\n" , __FUNCTION__ , ## args)
63 # define DEBUG(fmt, args...)
67 int od_dkunit; /* disk unit number */
68 int od_unit; /* BIOS unit number */
69 int od_cyl; /* BIOS geometry */
72 int od_boff; /* block offset from beginning of BIOS disk */
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];
87 * List of BIOS devices, translation from disk unit number to
92 int bd_unit; /* BIOS unit number */
94 int bd_type; /* BIOS 'drive type' (floppy only) */
96 static int nbdinfo = 0;
98 static int bd_getgeom(struct open_disk *od);
99 static int bd_read(struct open_disk *od, daddr_t dblk, int blks,
102 static int bd_int13probe(struct bdinfo *bd);
104 static void bd_printslice(struct open_disk *od, struct dos_partition *dp,
105 char *prefix, int verbose);
106 static void bd_printbsdslice(struct open_disk *od, daddr_t offset,
107 char *prefix, int verbose);
109 static int bd_init(void);
110 static int bd_strategy(void *devdata, int flag, daddr_t dblk,
111 size_t size, char *buf, size_t *rsize);
112 static int bd_realstrategy(void *devdata, int flag, daddr_t dblk,
113 size_t size, char *buf, size_t *rsize);
114 static int bd_open(struct open_file *f, ...);
115 static int bd_close(struct open_file *f);
116 static void bd_print(int verbose);
118 struct devsw biosdisk = {
130 static int bd_opendisk(struct open_disk **odp, struct i386_devdesc *dev);
131 static void bd_closedisk(struct open_disk *od);
132 static int bd_bestslice(struct open_disk *od);
133 static void bd_checkextended(struct open_disk *od, int slicenum);
136 * Translate between BIOS device numbers and our private unit numbers.
139 bd_bios2unit(int biosdev)
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)
153 bd_unit2bios(int unit)
155 if ((unit >= 0) && (unit < nbdinfo))
156 return(bdinfo[unit].bd_unit);
161 * Quiz the BIOS for disk devices, save a little info about them.
166 int base, unit, nfd = 0;
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 */
173 (nfd >= *(unsigned char *)PTOV(BIOS_NUMDRIVES)))
176 bdinfo[nbdinfo].bd_unit = unit;
177 bdinfo[nbdinfo].bd_flags = (unit < 0x80) ? BD_FLOPPY : 0;
179 if (!bd_int13probe(&bdinfo[nbdinfo]))
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);
194 * Try to detect a device supported by the legacy int13 BIOS
197 bd_int13probe(struct bdinfo *bd)
202 v86.edx = bd->bd_unit;
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;
210 /* Determine if we can use EDD with this device. */
212 v86.edx = bd->bd_unit;
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;
228 * Print information about disks
231 bd_print(int verbose)
235 struct i386_devdesc dev;
236 struct open_disk *od;
237 struct dos_partition *dptr;
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));
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;
249 if (!bd_opendisk(&od, &dev)) {
251 /* Do we have a partition table? */
252 if (od->od_flags & BD_PARTTABOK) {
253 dptr = &od->od_slicetab[0];
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);
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);
274 * Print information about slices on a disk. For the size calculations we
275 * assume a 512 byte sector.
278 bd_printslice(struct open_disk *od, struct dos_partition *dp, char *prefix,
283 switch (dp->dp_typ) {
285 bd_printbsdslice(od, (daddr_t)dp->dp_start, prefix, 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);
293 sprintf(line, "%s: Linux swap\n", prefix);
298 * read the superblock to confirm this is an ext2fs partition?
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);
305 sprintf(line, "%s: ext2fs\n", prefix);
307 case 0x00: /* unused partition */
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);
316 sprintf(line, "%s: FAT-12\n", prefix);
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);
326 sprintf(line, "%s: FAT-16\n", prefix);
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);
335 sprintf(line, "%s: FAT-32\n", prefix);
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);
343 sprintf(line, "%s: Unknown fs: 0x%x\n", prefix,
350 * Print out each valid partition in the disklabel of a FreeBSD slice.
351 * For size calculations, we assume a 512 byte sector size.
354 bd_printbsdslice(struct open_disk *od, daddr_t offset, char *prefix,
358 char buf[BIOSDISK_SECSIZE];
359 struct disklabel *lp;
363 if (bd_read(od, offset + LABELSECTOR, 1, buf))
365 lp =(struct disklabel *)(&buf[0]);
366 if (lp->d_magic != DISKMAGIC) {
367 sprintf(line, "%s: FFS bad disklabel\n", prefix);
372 /* Print partitions */
373 for (i = 0; i < lp->d_npartitions; i++) {
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
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))) {
386 /* Only print out statistics in verbose mode */
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" :
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);
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" :
407 * Attempt to open the disk described by (dev) for use by (f).
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
417 bd_open(struct open_file *f, ...)
420 struct i386_devdesc *dev;
421 struct open_disk *od;
425 dev = va_arg(ap, struct i386_devdesc *);
427 if ((error = bd_opendisk(&od, dev)))
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);
439 bd_opendisk(struct open_disk **odp, struct i386_devdesc *dev)
441 struct dos_partition *dptr;
442 struct disklabel *lp;
443 struct open_disk *od;
444 int sector, slice, i;
448 if (dev->d_kind.biosdisk.unit >= nbdinfo) {
449 DEBUG("attempt to open nonexistent disk");
453 od = (struct open_disk *)malloc(sizeof(struct open_disk));
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;
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');
470 /* Get geometry for this open (removable device may have changed) */
471 if (bd_getgeom(od)) {
472 DEBUG("can't get geometry");
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.
484 * Find the slice in the DOS slice table.
486 if (bd_read(od, 0, 1, buf)) {
487 DEBUG("error reading MBR");
493 * Check the slice table magic.
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)");
503 goto unsliced; /* may be a floppy */
507 * copy the partition table, then pick up any extended partitions.
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];
517 /* Is this a request for the whole disk? */
518 if (dev->d_kind.biosdisk.slice == -1) {
524 * if a slice number was supplied but not found, this is an error.
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);
536 * Check for the historically bogus MBR found on true dedicated disks
538 if ((dptr[3].dp_typ == DOSPTYP_386BSD) &&
539 (dptr[3].dp_start == 0) &&
540 (dptr[3].dp_size == 50000)) {
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);
552 dev->d_kind.biosdisk.slice = slice;
555 dptr = &od->od_slicetab[0];
557 * Accept the supplied slice number unequivocally (we may be looking
558 * at a DOS partition).
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);
565 * If we are looking at a BSD slice, and the partition is < 0, assume the 'a' partition
567 if ((dptr->dp_typ == DOSPTYP_386BSD) && (dev->d_kind.biosdisk.partition < 0))
568 dev->d_kind.biosdisk.partition = 0;
572 * Now we have the slice offset, look for the partition in the disklabel if we have
573 * a partition to start with.
575 * XXX we might want to check the label checksum.
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");
582 if (bd_read(od, sector + LABELSECTOR, 1, buf)) {
583 DEBUG("error reading disklabel");
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;
592 if (lp->d_magic != DISKMAGIC) {
593 DEBUG("no disklabel");
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);
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");
612 od->od_boff = lp->d_partitions[dev->d_kind.biosdisk.partition].p_offset;
619 *odp = od; /* return the open disk */
625 bd_checkextended(struct open_disk *od, int slicenum)
627 char buf[BIOSDISK_SECSIZE];
628 struct dos_partition *dp;
632 dp = &od->od_slicetab[slicenum];
633 start = od->od_nslices;
635 if (dp->dp_size == 0)
637 if (dp->dp_typ != DOSPTYP_EXT)
639 if (bd_read(od, (daddr_t)dp->dp_start, 1, buf))
641 if (((u_char)buf[0x1fe] != 0x55) || ((u_char)buf[0x1ff] != 0xaa)) {
642 DEBUG("no magic in extended table");
646 dp = (struct dos_partition *)(&buf[DOSPARTOFF]);
647 for (i = 0; i < NDOSPART; i++, dp++) {
648 if (dp->dp_size == 0)
650 if (od->od_nslices == MAX_SLICES)
652 dp->dp_start += base;
653 bcopy(dp, &od->od_slicetab[od->od_nslices], sizeof(*dp));
656 end = od->od_nslices;
659 * now, recursively check the slices we just added
661 for (i = start; i < end; i++)
662 bd_checkextended(od, i);
668 * Search for a slice with the following preferences:
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
677 #define PREF_RAWDISK 0
678 #define PREF_FBSD_ACT 1
680 #define PREF_LINUX_ACT 3
682 #define PREF_DOS_ACT 5
687 * slicelimit is in the range 0 .. NDOSPART
690 bd_bestslice(struct open_disk *od)
692 struct dos_partition *dp;
697 preflevel = PREF_NONE;
699 dp = &od->od_slicetab[0];
700 for (i = 0; i < od->od_nslices; i++, dp++) {
702 switch (dp->dp_typ) {
703 case DOSPTYP_386BSD: /* FreeBSD */
704 pref = dp->dp_flag & 0x80 ? PREF_FBSD_ACT : PREF_FBSD;
708 pref = dp->dp_flag & 0x80 ? PREF_LINUX_ACT : PREF_LINUX;
711 case 0x01: /* DOS/Windows */
717 pref = dp->dp_flag & 0x80 ? PREF_DOS_ACT : PREF_DOS;
723 if (pref < preflevel) {
732 bd_close(struct open_file *f)
734 struct open_disk *od = (struct open_disk *)(((struct i386_devdesc *)(f->f_devdata))->d_kind.biosdisk.data);
741 bd_closedisk(struct open_disk *od)
743 DEBUG("open_disk %p", od);
745 /* XXX is this required? (especially if disk already open...) */
746 if (od->od_flags & BD_FLOPPY)
753 bd_strategy(void *devdata, int rw, daddr_t dblk, size_t size, char *buf, size_t *rsize)
755 struct bcache_devdata bcd;
756 struct open_disk *od = (struct open_disk *)(((struct i386_devdesc *)devdata)->d_kind.biosdisk.data);
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));
764 bd_realstrategy(void *devdata, int rw, daddr_t dblk, size_t size, char *buf, size_t *rsize)
766 struct open_disk *od = (struct open_disk *)(((struct i386_devdesc *)devdata)->d_kind.biosdisk.data);
768 #ifdef BD_SUPPORT_FRAGS
769 char fragbuf[BIOSDISK_SECSIZE];
772 fragsize = size % BIOSDISK_SECSIZE;
774 if (size % BIOSDISK_SECSIZE)
775 panic("bd_strategy: %d bytes I/O not multiple of block size", size);
778 DEBUG("open_disk %p", od);
784 blks = size / BIOSDISK_SECSIZE;
785 DEBUG("read %d from %d to %p", blks, dblk, buf);
789 if (blks && bd_read(od, dblk, blks, buf)) {
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");
800 bcopy(fragbuf, buf + (blks * BIOSDISK_SECSIZE), fragsize);
807 /* Max number of sectors to bounce-buffer if the request crosses a 64k boundary */
808 #define FLOPPY_BOUNCEBUF 18
811 bd_read(struct open_disk *od, daddr_t dblk, int blks, caddr_t dest)
813 u_int x, bpc, cyl, hd, sec, result, resid, retry, maxfer;
814 caddr_t p, xp, bbuf, breg;
816 /* Just in case some idiot actually tries to read -1 blocks... */
820 bpc = (od->od_sec * od->od_hds); /* blocks per cylinder */
824 /* Decide whether we have to bounce */
825 if ((od->od_unit < 0x80) &&
826 ((VTOP(dest) >> 16) != (VTOP(dest + blks * BIOSDISK_SECSIZE) >> 16))) {
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
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)) {
839 breg = bbuf + x * BIOSDISK_SECSIZE;
841 maxfer = x; /* limit transfers to bounce region size */
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 */
854 /* play it safe and don't cross track boundaries (XXX this is probably unnecessary) */
855 x = min(od->od_sec - sec, resid);
857 x = min(x, maxfer); /* fit bounce buffer */
859 /* where do we transfer to? */
860 xp = bbuf == NULL ? p : breg;
862 /* correct sector number for 1-based BIOS numbering */
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 */
872 v86.edx = od->od_unit;
877 /* use EDD if the disk supports it, otherwise, return error */
878 if(od->od_flags & BD_MODEEDD1) {
879 static unsigned short packet[8];
883 packet[2] = VTOPOFF(xp);
884 packet[3] = VTOPSEG(xp);
885 packet[4] = dblk & 0xffff;
886 packet[5] = dblk >> 16;
892 v86.edx = od->od_unit;
893 v86.ds = VTOPSEG(packet);
894 v86.esi = VTOPOFF(packet);
896 result = (v86.efl & 0x1);
904 /* Use normal CHS addressing */
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);
913 result = (v86.efl & 0x1);
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);
929 bcopy(breg, p, x * BIOSDISK_SECSIZE);
930 p += (x * BIOSDISK_SECSIZE);
935 /* hexdump(dest, (blks * BIOSDISK_SECSIZE)); */
942 bd_getgeom(struct open_disk *od)
948 v86.edx = od->od_unit;
951 if ((v86.efl & 0x1) || /* carry set */
952 ((v86.edx & 0xff) <= (unsigned)(od->od_unit & 0x7f))) /* unit # bad */
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;
961 DEBUG("unit 0x%x geometry %d/%d/%d", od->od_unit, od->od_cyl, od->od_hds, od->od_sec);
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.
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.
980 bd_getbigeom(int bunit)
986 v86.edx = 0x80 + bunit;
990 return ((v86.ecx & 0xc0) << 18) | ((v86.ecx & 0xff00) << 8) |
991 (v86.edx & 0xff00) | (v86.ecx & 0x3f);
995 * Return a suitable dev_t value for (dev).
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.
1001 bd_getdev(struct i386_devdesc *dev)
1003 struct open_disk *od;
1008 int unitofs = 0, i, unit;
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 */
1014 if (bd_opendisk(&od, dev) != 0) /* oops, not a viable device */
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 */
1023 /* is a floppy disk */
1028 if ((od->od_flags & BD_LABELOK) && (od->od_disklabel.d_type == DTYPE_SCSI)) {
1029 /* label OK, disk labelled as SCSI */
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))
1039 /* assume an IDE disk */
1043 /* default root disk unit number */
1044 unit = (biosdev & 0x7f) - unitofs;
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))
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,
1058 dev->d_kind.biosdisk.partition);
1059 DEBUG("dev is 0x%x\n", rootdev);