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 1.40 2003/08/25 23:28:31 obrien Exp $
27 * $DragonFly: src/sys/boot/pc32/libi386/biosdisk.c,v 1.5 2003/11/10 06:08:36 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/diskmbr.h>
44 #include <machine/bootinfo.h>
48 #include <bootstrap.h>
52 #define BIOS_NUMDRIVES 0x475
53 #define BIOSDISK_SECSIZE 512
54 #define BUFSIZE (1 * BIOSDISK_SECSIZE)
55 #define MAXBDDEV MAXDEV
57 #define DT_ATAPI 0x10 /* disk type for ATAPI floppies */
58 #define WDMAJOR 0 /* major numbers for devices we frontend for */
64 # define DEBUG(fmt, args...) printf("%s: " fmt "\n" , __func__ , ## args)
66 # define DEBUG(fmt, args...)
70 int od_dkunit; /* disk unit number */
71 int od_unit; /* BIOS unit number */
72 int od_cyl; /* BIOS geometry */
75 int od_boff; /* block offset from beginning of BIOS disk */
77 #define BD_MODEINT13 0x0000
78 #define BD_MODEEDD1 0x0001
79 #define BD_MODEEDD3 0x0002
80 #define BD_MODEMASK 0x0003
81 #define BD_FLOPPY 0x0004
82 #define BD_LABELOK 0x0008
83 #define BD_PARTTABOK 0x0010
84 struct disklabel od_disklabel;
85 int od_nslices; /* slice count */
86 struct dos_partition od_slicetab[NEXTDOSPART];
90 * List of BIOS devices, translation from disk unit number to
95 int bd_unit; /* BIOS unit number */
97 int bd_type; /* BIOS 'drive type' (floppy only) */
99 static int nbdinfo = 0;
101 static int bd_getgeom(struct open_disk *od);
102 static int bd_read(struct open_disk *od, daddr_t dblk, int blks,
104 static int bd_write(struct open_disk *od, daddr_t dblk, int blks,
107 static int bd_int13probe(struct bdinfo *bd);
109 static void bd_printslice(struct open_disk *od, struct dos_partition *dp,
110 char *prefix, int verbose);
111 static void bd_printbsdslice(struct open_disk *od, daddr_t offset,
112 char *prefix, int verbose);
114 static int bd_init(void);
115 static int bd_strategy(void *devdata, int flag, daddr_t dblk,
116 size_t size, char *buf, size_t *rsize);
117 static int bd_realstrategy(void *devdata, int flag, daddr_t dblk,
118 size_t size, char *buf, size_t *rsize);
119 static int bd_open(struct open_file *f, ...);
120 static int bd_close(struct open_file *f);
121 static void bd_print(int verbose);
123 struct devsw biosdisk = {
135 static int bd_opendisk(struct open_disk **odp, struct i386_devdesc *dev);
136 static void bd_closedisk(struct open_disk *od);
137 static int bd_bestslice(struct open_disk *od);
138 static void bd_checkextended(struct open_disk *od, int slicenum);
141 * Translate between BIOS device numbers and our private unit numbers.
144 bd_bios2unit(int biosdev)
148 DEBUG("looking for bios device 0x%x", biosdev);
149 for (i = 0; i < nbdinfo; i++) {
150 DEBUG("bd unit %d is BIOS device 0x%x", i, bdinfo[i].bd_unit);
151 if (bdinfo[i].bd_unit == biosdev)
158 bd_unit2bios(int unit)
160 if ((unit >= 0) && (unit < nbdinfo))
161 return(bdinfo[unit].bd_unit);
166 * Quiz the BIOS for disk devices, save a little info about them.
171 int base, unit, nfd = 0;
173 /* sequence 0, 0x80 */
174 for (base = 0; base <= 0x80; base += 0x80) {
175 for (unit = base; (nbdinfo < MAXBDDEV); unit++) {
176 /* check the BIOS equipment list for number of fixed disks */
178 (nfd >= *(unsigned char *)PTOV(BIOS_NUMDRIVES)))
181 bdinfo[nbdinfo].bd_unit = unit;
182 bdinfo[nbdinfo].bd_flags = (unit < 0x80) ? BD_FLOPPY : 0;
184 if (!bd_int13probe(&bdinfo[nbdinfo]))
187 /* XXX we need "disk aliases" to make this simpler */
188 printf("BIOS drive %c: is disk%d\n",
189 (unit < 0x80) ? ('A' + unit) : ('C' + unit - 0x80), nbdinfo);
199 * Try to detect a device supported by the legacy int13 BIOS
202 bd_int13probe(struct bdinfo *bd)
207 v86.edx = bd->bd_unit;
210 if (!(v86.efl & 0x1) && /* carry clear */
211 ((v86.edx & 0xff) > ((unsigned)bd->bd_unit & 0x7f))) { /* unit # OK */
212 bd->bd_flags |= BD_MODEINT13;
213 bd->bd_type = v86.ebx & 0xff;
215 /* Determine if we can use EDD with this device. */
217 v86.edx = bd->bd_unit;
220 if (!(v86.efl & 0x1) && /* carry clear */
221 ((v86.ebx & 0xffff) == 0xaa55) && /* signature */
222 (v86.ecx & 0x1)) { /* packets mode ok */
223 bd->bd_flags |= BD_MODEEDD1;
224 if((v86.eax & 0xff00) > 0x300)
225 bd->bd_flags |= BD_MODEEDD3;
233 * Print information about disks
236 bd_print(int verbose)
240 struct i386_devdesc dev;
241 struct open_disk *od;
242 struct dos_partition *dptr;
244 for (i = 0; i < nbdinfo; i++) {
245 sprintf(line, " disk%d: BIOS drive %c:\n", i,
246 (bdinfo[i].bd_unit < 0x80) ? ('A' + bdinfo[i].bd_unit) : ('C' + bdinfo[i].bd_unit - 0x80));
249 /* try to open the whole disk */
250 dev.d_kind.biosdisk.unit = i;
251 dev.d_kind.biosdisk.slice = -1;
252 dev.d_kind.biosdisk.partition = -1;
254 if (!bd_opendisk(&od, &dev)) {
256 /* Do we have a partition table? */
257 if (od->od_flags & BD_PARTTABOK) {
258 dptr = &od->od_slicetab[0];
260 /* Check for a "dedicated" disk */
261 if ((dptr[3].dp_typ == DOSPTYP_386BSD) &&
262 (dptr[3].dp_start == 0) &&
263 (dptr[3].dp_size == 50000)) {
264 sprintf(line, " disk%d", i);
265 bd_printbsdslice(od, 0, line, verbose);
267 for (j = 0; j < od->od_nslices; j++) {
268 sprintf(line, " disk%ds%d", i, j + 1);
269 bd_printslice(od, &dptr[j], line, verbose);
279 * Print information about slices on a disk. For the size calculations we
280 * assume a 512 byte sector.
283 bd_printslice(struct open_disk *od, struct dos_partition *dp, char *prefix,
288 switch (dp->dp_typ) {
290 bd_printbsdslice(od, (daddr_t)dp->dp_start, prefix, verbose);
294 sprintf(line, "%s: Linux swap %.6dMB (%d - %d)\n",
295 prefix, dp->dp_size / 2048,
296 dp->dp_start, dp->dp_start + dp->dp_size);
298 sprintf(line, "%s: Linux swap\n", prefix);
303 * read the superblock to confirm this is an ext2fs partition?
306 sprintf(line, "%s: ext2fs %.6dMB (%d - %d)\n", prefix,
307 dp->dp_size / 2048, dp->dp_start,
308 dp->dp_start + dp->dp_size);
310 sprintf(line, "%s: ext2fs\n", prefix);
312 case 0x00: /* unused partition */
317 sprintf(line, "%s: FAT-12 %.6dMB (%d - %d)\n", prefix,
318 dp->dp_size / 2048, dp->dp_start,
319 dp->dp_start + dp->dp_size);
321 sprintf(line, "%s: FAT-12\n", prefix);
327 sprintf(line, "%s: FAT-16 %.6dMB (%d - %d)\n", prefix,
328 dp->dp_size / 2048, dp->dp_start,
329 dp->dp_start + dp->dp_size);
331 sprintf(line, "%s: FAT-16\n", prefix);
336 sprintf(line, "%s: FAT-32 %.6dMB (%d - %d)\n", prefix,
337 dp->dp_size / 2048, dp->dp_start,
338 dp->dp_start + dp->dp_size);
340 sprintf(line, "%s: FAT-32\n", prefix);
344 sprintf(line, "%s: Unknown fs: 0x%x %.6dMB (%d - %d)\n",
345 prefix, dp->dp_typ, dp->dp_size / 2048,
346 dp->dp_start, dp->dp_start + dp->dp_size);
348 sprintf(line, "%s: Unknown fs: 0x%x\n", prefix,
355 * Print out each valid partition in the disklabel of a FreeBSD slice.
356 * For size calculations, we assume a 512 byte sector size.
359 bd_printbsdslice(struct open_disk *od, daddr_t offset, char *prefix,
363 char buf[BIOSDISK_SECSIZE];
364 struct disklabel *lp;
368 if (bd_read(od, offset + LABELSECTOR, 1, buf))
370 lp =(struct disklabel *)(&buf[0]);
371 if (lp->d_magic != DISKMAGIC) {
372 sprintf(line, "%s: FFS bad disklabel\n", prefix);
377 /* Print partitions */
378 for (i = 0; i < lp->d_npartitions; i++) {
380 * For each partition, make sure we know what type of fs it is. If
381 * not, then skip it. However, since floppies often have bogus
382 * fstypes, print the 'a' partition on a floppy even if it is marked
385 if ((lp->d_partitions[i].p_fstype == FS_BSDFFS) ||
386 (lp->d_partitions[i].p_fstype == FS_SWAP) ||
387 (lp->d_partitions[i].p_fstype == FS_VINUM) ||
388 ((lp->d_partitions[i].p_fstype == FS_UNUSED) &&
389 (od->od_flags & BD_FLOPPY) && (i == 0))) {
391 /* Only print out statistics in verbose mode */
393 sprintf(line, " %s%c: %s %.6dMB (%d - %d)\n", prefix, 'a' + i,
394 (lp->d_partitions[i].p_fstype == FS_SWAP) ? "swap" :
395 (lp->d_partitions[i].p_fstype == FS_VINUM) ? "vinum" :
397 lp->d_partitions[i].p_size / 2048,
398 lp->d_partitions[i].p_offset,
399 lp->d_partitions[i].p_offset + lp->d_partitions[i].p_size);
401 sprintf(line, " %s%c: %s\n", prefix, 'a' + i,
402 (lp->d_partitions[i].p_fstype == FS_SWAP) ? "swap" :
403 (lp->d_partitions[i].p_fstype == FS_VINUM) ? "vinum" :
412 * Attempt to open the disk described by (dev) for use by (f).
414 * Note that the philosophy here is "give them exactly what
415 * they ask for". This is necessary because being too "smart"
416 * about what the user might want leads to complications.
417 * (eg. given no slice or partition value, with a disk that is
418 * sliced - are they after the first BSD slice, or the DOS
422 bd_open(struct open_file *f, ...)
425 struct i386_devdesc *dev;
426 struct open_disk *od;
430 dev = va_arg(ap, struct i386_devdesc *);
432 if ((error = bd_opendisk(&od, dev)))
438 ((struct i386_devdesc *)(f->f_devdata))->d_kind.biosdisk.data = od;
439 DEBUG("open_disk %p, partition at 0x%x", od, od->od_boff);
444 bd_opendisk(struct open_disk **odp, struct i386_devdesc *dev)
446 struct dos_partition *dptr;
447 struct disklabel *lp;
448 struct open_disk *od;
449 int sector, slice, i;
453 if (dev->d_kind.biosdisk.unit >= nbdinfo) {
454 DEBUG("attempt to open nonexistent disk");
458 od = (struct open_disk *)malloc(sizeof(struct open_disk));
464 /* Look up BIOS unit number, intialise open_disk structure */
465 od->od_dkunit = dev->d_kind.biosdisk.unit;
466 od->od_unit = bdinfo[od->od_dkunit].bd_unit;
467 od->od_flags = bdinfo[od->od_dkunit].bd_flags;
471 DEBUG("open '%s', unit 0x%x slice %d partition %c",
472 i386_fmtdev(dev), dev->d_kind.biosdisk.unit,
473 dev->d_kind.biosdisk.slice, dev->d_kind.biosdisk.partition + 'a');
475 /* Get geometry for this open (removable device may have changed) */
476 if (bd_getgeom(od)) {
477 DEBUG("can't get geometry");
483 * Following calculations attempt to determine the correct value
484 * for d->od_boff by looking for the slice and partition specified,
485 * or searching for reasonable defaults.
489 * Find the slice in the DOS slice table.
491 if (bd_read(od, 0, 1, buf)) {
492 DEBUG("error reading MBR");
498 * Check the slice table magic.
500 if (((u_char)buf[0x1fe] != 0x55) || ((u_char)buf[0x1ff] != 0xaa)) {
501 /* If a slice number was explicitly supplied, this is an error */
502 if (dev->d_kind.biosdisk.slice > 0) {
503 DEBUG("no slice table/MBR (no magic)");
508 goto unsliced; /* may be a floppy */
512 * copy the partition table, then pick up any extended partitions.
514 bcopy(buf + DOSPARTOFF, &od->od_slicetab,
515 sizeof(struct dos_partition) * NDOSPART);
516 od->od_nslices = 4; /* extended slices start here */
517 for (i = 0; i < NDOSPART; i++)
518 bd_checkextended(od, i);
519 od->od_flags |= BD_PARTTABOK;
520 dptr = &od->od_slicetab[0];
522 /* Is this a request for the whole disk? */
523 if (dev->d_kind.biosdisk.slice == -1) {
529 * if a slice number was supplied but not found, this is an error.
531 if (dev->d_kind.biosdisk.slice > 0) {
532 slice = dev->d_kind.biosdisk.slice - 1;
533 if (slice >= od->od_nslices) {
534 DEBUG("slice %d not found", slice);
541 * Check for the historically bogus MBR found on true dedicated disks
543 if ((dptr[3].dp_typ == DOSPTYP_386BSD) &&
544 (dptr[3].dp_start == 0) &&
545 (dptr[3].dp_size == 50000)) {
550 /* Try to auto-detect the best slice; this should always give a slice number */
551 if (dev->d_kind.biosdisk.slice == 0) {
552 slice = bd_bestslice(od);
557 dev->d_kind.biosdisk.slice = slice;
560 dptr = &od->od_slicetab[0];
562 * Accept the supplied slice number unequivocally (we may be looking
563 * at a DOS partition).
565 dptr += (dev->d_kind.biosdisk.slice - 1); /* we number 1-4, offsets are 0-3 */
566 sector = dptr->dp_start;
567 DEBUG("slice entry %d at %d, %d sectors", dev->d_kind.biosdisk.slice - 1, sector, dptr->dp_size);
570 * If we are looking at a BSD slice, and the partition is < 0, assume the 'a' partition
572 if ((dptr->dp_typ == DOSPTYP_386BSD) && (dev->d_kind.biosdisk.partition < 0))
573 dev->d_kind.biosdisk.partition = 0;
577 * Now we have the slice offset, look for the partition in the disklabel if we have
578 * a partition to start with.
580 * XXX we might want to check the label checksum.
582 if (dev->d_kind.biosdisk.partition < 0) {
583 od->od_boff = sector; /* no partition, must be after the slice */
584 DEBUG("opening raw slice");
587 if (bd_read(od, sector + LABELSECTOR, 1, buf)) {
588 DEBUG("error reading disklabel");
592 DEBUG("copy %d bytes of label from %p to %p", sizeof(struct disklabel), buf + LABELOFFSET, &od->od_disklabel);
593 bcopy(buf + LABELOFFSET, &od->od_disklabel, sizeof(struct disklabel));
594 lp = &od->od_disklabel;
595 od->od_flags |= BD_LABELOK;
597 if (lp->d_magic != DISKMAGIC) {
598 DEBUG("no disklabel");
602 if (dev->d_kind.biosdisk.partition >= lp->d_npartitions) {
603 DEBUG("partition '%c' exceeds partitions in table (a-'%c')",
604 'a' + dev->d_kind.biosdisk.partition, 'a' + lp->d_npartitions);
611 /* Complain if the partition is unused unless this is a floppy. */
612 if ((lp->d_partitions[dev->d_kind.biosdisk.partition].p_fstype == FS_UNUSED) &&
613 !(od->od_flags & BD_FLOPPY))
614 DEBUG("warning, partition marked as unused");
618 lp->d_partitions[dev->d_kind.biosdisk.partition].p_offset -
619 lp->d_partitions[RAW_PART].p_offset +
627 *odp = od; /* return the open disk */
633 bd_checkextended(struct open_disk *od, int slicenum)
635 char buf[BIOSDISK_SECSIZE];
636 struct dos_partition *dp;
640 dp = &od->od_slicetab[slicenum];
641 start = od->od_nslices;
643 if (dp->dp_size == 0)
645 if (dp->dp_typ != DOSPTYP_EXT)
647 if (bd_read(od, (daddr_t)dp->dp_start, 1, buf))
649 if (((u_char)buf[0x1fe] != 0x55) || ((u_char)buf[0x1ff] != 0xaa)) {
650 DEBUG("no magic in extended table");
654 dp = (struct dos_partition *)(&buf[DOSPARTOFF]);
655 for (i = 0; i < NDOSPART; i++, dp++) {
656 if (dp->dp_size == 0)
658 if (od->od_nslices == NEXTDOSPART)
660 dp->dp_start += base;
661 bcopy(dp, &od->od_slicetab[od->od_nslices], sizeof(*dp));
664 end = od->od_nslices;
667 * now, recursively check the slices we just added
669 for (i = start; i < end; i++)
670 bd_checkextended(od, i);
676 * Search for a slice with the following preferences:
678 * 1: Active FreeBSD slice
679 * 2: Non-active FreeBSD slice
680 * 3: Active Linux slice
681 * 4: non-active Linux slice
682 * 5: Active FAT/FAT32 slice
683 * 6: non-active FAT/FAT32 slice
685 #define PREF_RAWDISK 0
686 #define PREF_FBSD_ACT 1
688 #define PREF_LINUX_ACT 3
690 #define PREF_DOS_ACT 5
695 * slicelimit is in the range 0 .. NDOSPART
698 bd_bestslice(struct open_disk *od)
700 struct dos_partition *dp;
705 preflevel = PREF_NONE;
707 dp = &od->od_slicetab[0];
708 for (i = 0; i < od->od_nslices; i++, dp++) {
710 switch (dp->dp_typ) {
711 case DOSPTYP_386BSD: /* FreeBSD */
712 pref = dp->dp_flag & 0x80 ? PREF_FBSD_ACT : PREF_FBSD;
716 pref = dp->dp_flag & 0x80 ? PREF_LINUX_ACT : PREF_LINUX;
719 case 0x01: /* DOS/Windows */
725 pref = dp->dp_flag & 0x80 ? PREF_DOS_ACT : PREF_DOS;
731 if (pref < preflevel) {
740 bd_close(struct open_file *f)
742 struct open_disk *od = (struct open_disk *)(((struct i386_devdesc *)(f->f_devdata))->d_kind.biosdisk.data);
749 bd_closedisk(struct open_disk *od)
751 DEBUG("open_disk %p", od);
753 /* XXX is this required? (especially if disk already open...) */
754 if (od->od_flags & BD_FLOPPY)
761 bd_strategy(void *devdata, int rw, daddr_t dblk, size_t size, char *buf, size_t *rsize)
763 struct bcache_devdata bcd;
764 struct open_disk *od = (struct open_disk *)(((struct i386_devdesc *)devdata)->d_kind.biosdisk.data);
766 bcd.dv_strategy = bd_realstrategy;
767 bcd.dv_devdata = devdata;
768 return(bcache_strategy(&bcd, od->od_unit, rw, dblk+od->od_boff, size, buf, rsize));
772 bd_realstrategy(void *devdata, int rw, daddr_t dblk, size_t size, char *buf, size_t *rsize)
774 struct open_disk *od = (struct open_disk *)(((struct i386_devdesc *)devdata)->d_kind.biosdisk.data);
776 #ifdef BD_SUPPORT_FRAGS
777 char fragbuf[BIOSDISK_SECSIZE];
780 fragsize = size % BIOSDISK_SECSIZE;
782 if (size % BIOSDISK_SECSIZE)
783 panic("bd_strategy: %d bytes I/O not multiple of block size", size);
786 DEBUG("open_disk %p", od);
791 blks = size / BIOSDISK_SECSIZE;
792 DEBUG("read %d from %d to %p", blks, dblk, buf);
796 if (blks && bd_read(od, dblk, blks, buf)) {
800 #ifdef BD_SUPPORT_FRAGS
801 DEBUG("bd_strategy: frag read %d from %d+%d to %p",
802 fragsize, dblk, blks, buf + (blks * BIOSDISK_SECSIZE));
803 if (fragsize && bd_read(od, dblk + blks, 1, fragsize)) {
804 DEBUG("frag read error");
807 bcopy(fragbuf, buf + (blks * BIOSDISK_SECSIZE), fragsize);
815 blks = size / BIOSDISK_SECSIZE;
816 DEBUG("write %d from %d to %p", blks, dblk, buf);
820 if (blks && bd_write(od, dblk, blks, buf)) {
821 DEBUG("write error");
824 #ifdef BD_SUPPORT_FRAGS
826 DEBUG("Attempted to write a frag");
841 /* Max number of sectors to bounce-buffer if the request crosses a 64k boundary */
842 #define FLOPPY_BOUNCEBUF 18
845 bd_read(struct open_disk *od, daddr_t dblk, int blks, caddr_t dest)
847 u_int x, bpc, cyl, hd, sec, result, resid, retry, maxfer;
848 caddr_t p, xp, bbuf, breg;
850 /* Just in case some idiot actually tries to read -1 blocks... */
854 bpc = (od->od_sec * od->od_hds); /* blocks per cylinder */
858 /* Decide whether we have to bounce */
859 if ((od->od_unit < 0x80) &&
860 ((VTOP(dest) >> 16) != (VTOP(dest + blks * BIOSDISK_SECSIZE) >> 16))) {
863 * There is a 64k physical boundary somewhere in the destination buffer, so we have
864 * to arrange a suitable bounce buffer. Allocate a buffer twice as large as we
865 * need to. Use the bottom half unless there is a break there, in which case we
868 x = min(FLOPPY_BOUNCEBUF, (unsigned)blks);
869 bbuf = malloc(x * 2 * BIOSDISK_SECSIZE);
870 if (((u_int32_t)VTOP(bbuf) & 0xffff0000) == ((u_int32_t)VTOP(dest + x * BIOSDISK_SECSIZE) & 0xffff0000)) {
873 breg = bbuf + x * BIOSDISK_SECSIZE;
875 maxfer = x; /* limit transfers to bounce region size */
883 cyl = x / bpc; /* block # / blocks per cylinder */
884 x %= bpc; /* block offset into cylinder */
885 hd = x / od->od_sec; /* offset / blocks per track */
886 sec = x % od->od_sec; /* offset into track */
888 /* play it safe and don't cross track boundaries (XXX this is probably unnecessary) */
889 x = min(od->od_sec - sec, resid);
891 x = min(x, maxfer); /* fit bounce buffer */
893 /* where do we transfer to? */
894 xp = bbuf == NULL ? p : breg;
896 /* correct sector number for 1-based BIOS numbering */
899 /* Loop retrying the operation a couple of times. The BIOS may also retry. */
900 for (retry = 0; retry < 3; retry++) {
901 /* if retrying, reset the drive */
906 v86.edx = od->od_unit;
911 /* use EDD if the disk supports it, otherwise, return error */
912 if(od->od_flags & BD_MODEEDD1) {
913 static unsigned short packet[8];
917 packet[2] = VTOPOFF(xp);
918 packet[3] = VTOPSEG(xp);
919 packet[4] = dblk & 0xffff;
920 packet[5] = dblk >> 16;
926 v86.edx = od->od_unit;
927 v86.ds = VTOPSEG(packet);
928 v86.esi = VTOPOFF(packet);
930 result = (v86.efl & 0x1);
938 /* Use normal CHS addressing */
942 v86.ecx = ((cyl & 0xff) << 8) | ((cyl & 0x300) >> 2) | sec;
943 v86.edx = (hd << 8) | od->od_unit;
944 v86.es = VTOPSEG(xp);
945 v86.ebx = VTOPOFF(xp);
947 result = (v86.efl & 0x1);
953 DEBUG("%d sectors from %d/%d/%d to %p (0x%x) %s", x, cyl, hd, sec - 1, p, VTOP(p), result ? "failed" : "ok");
954 /* BUG here, cannot use v86 in printf because putchar uses it too */
955 DEBUG("ax = 0x%04x cx = 0x%04x dx = 0x%04x status 0x%x",
956 0x200 | x, ((cyl & 0xff) << 8) | ((cyl & 0x300) >> 2) | sec, (hd << 8) | od->od_unit, (v86.eax >> 8) & 0xff);
963 bcopy(breg, p, x * BIOSDISK_SECSIZE);
964 p += (x * BIOSDISK_SECSIZE);
969 /* hexdump(dest, (blks * BIOSDISK_SECSIZE)); */
977 bd_write(struct open_disk *od, daddr_t dblk, int blks, caddr_t dest)
979 u_int x, bpc, cyl, hd, sec, result, resid, retry, maxfer;
980 caddr_t p, xp, bbuf, breg;
982 /* Just in case some idiot actually tries to read -1 blocks... */
986 bpc = (od->od_sec * od->od_hds); /* blocks per cylinder */
990 /* Decide whether we have to bounce */
991 if ((od->od_unit < 0x80) &&
992 ((VTOP(dest) >> 16) != (VTOP(dest + blks * BIOSDISK_SECSIZE) >> 16))) {
995 * There is a 64k physical boundary somewhere in the destination buffer, so we have
996 * to arrange a suitable bounce buffer. Allocate a buffer twice as large as we
997 * need to. Use the bottom half unless there is a break there, in which case we
1001 x = min(FLOPPY_BOUNCEBUF, (unsigned)blks);
1002 bbuf = malloc(x * 2 * BIOSDISK_SECSIZE);
1003 if (((u_int32_t)VTOP(bbuf) & 0xffff0000) == ((u_int32_t)VTOP(dest + x * BIOSDISK_SECSIZE) & 0xffff0000)) {
1006 breg = bbuf + x * BIOSDISK_SECSIZE;
1008 maxfer = x; /* limit transfers to bounce region size */
1016 cyl = x / bpc; /* block # / blocks per cylinder */
1017 x %= bpc; /* block offset into cylinder */
1018 hd = x / od->od_sec; /* offset / blocks per track */
1019 sec = x % od->od_sec; /* offset into track */
1021 /* play it safe and don't cross track boundaries (XXX this is probably unnecessary) */
1022 x = min(od->od_sec - sec, resid);
1024 x = min(x, maxfer); /* fit bounce buffer */
1026 /* where do we transfer to? */
1027 xp = bbuf == NULL ? p : breg;
1029 /* correct sector number for 1-based BIOS numbering */
1033 /* Put your Data In, Put your Data out,
1034 Put your Data In, and shake it all about
1037 bcopy(p, breg, x * BIOSDISK_SECSIZE);
1038 p += (x * BIOSDISK_SECSIZE);
1042 /* Loop retrying the operation a couple of times. The BIOS may also retry. */
1043 for (retry = 0; retry < 3; retry++) {
1044 /* if retrying, reset the drive */
1046 v86.ctl = V86_FLAGS;
1049 v86.edx = od->od_unit;
1054 /* use EDD if the disk supports it, otherwise, return error */
1055 if(od->od_flags & BD_MODEEDD1) {
1056 static unsigned short packet[8];
1060 packet[2] = VTOPOFF(xp);
1061 packet[3] = VTOPSEG(xp);
1062 packet[4] = dblk & 0xffff;
1063 packet[5] = dblk >> 16;
1066 v86.ctl = V86_FLAGS;
1068 /* Should we Write with verify ?? 0x4302 ? */
1070 v86.edx = od->od_unit;
1071 v86.ds = VTOPSEG(packet);
1072 v86.esi = VTOPOFF(packet);
1074 result = (v86.efl & 0x1);
1082 /* Use normal CHS addressing */
1083 v86.ctl = V86_FLAGS;
1085 v86.eax = 0x300 | x;
1086 v86.ecx = ((cyl & 0xff) << 8) | ((cyl & 0x300) >> 2) | sec;
1087 v86.edx = (hd << 8) | od->od_unit;
1088 v86.es = VTOPSEG(xp);
1089 v86.ebx = VTOPOFF(xp);
1091 result = (v86.efl & 0x1);
1097 DEBUG("%d sectors from %d/%d/%d to %p (0x%x) %s", x, cyl, hd, sec - 1, p, VTOP(p), result ? "failed" : "ok");
1098 /* BUG here, cannot use v86 in printf because putchar uses it too */
1099 DEBUG("ax = 0x%04x cx = 0x%04x dx = 0x%04x status 0x%x",
1100 0x200 | x, ((cyl & 0xff) << 8) | ((cyl & 0x300) >> 2) | sec, (hd << 8) | od->od_unit, (v86.eax >> 8) & 0xff);
1108 /* hexdump(dest, (blks * BIOSDISK_SECSIZE)); */
1114 bd_getgeom(struct open_disk *od)
1117 v86.ctl = V86_FLAGS;
1120 v86.edx = od->od_unit;
1123 if ((v86.efl & 0x1) || /* carry set */
1124 ((v86.edx & 0xff) <= (unsigned)(od->od_unit & 0x7f))) /* unit # bad */
1127 /* convert max cyl # -> # of cylinders */
1128 od->od_cyl = ((v86.ecx & 0xc0) << 2) + ((v86.ecx & 0xff00) >> 8) + 1;
1129 /* convert max head # -> # of heads */
1130 od->od_hds = ((v86.edx & 0xff00) >> 8) + 1;
1131 od->od_sec = v86.ecx & 0x3f;
1133 DEBUG("unit 0x%x geometry %d/%d/%d", od->od_unit, od->od_cyl, od->od_hds, od->od_sec);
1138 * Return the BIOS geometry of a given "fixed drive" in a format
1139 * suitable for the legacy bootinfo structure. Since the kernel is
1140 * expecting raw int 0x13/0x8 values for N_BIOS_GEOM drives, we
1141 * prefer to get the information directly, rather than rely on being
1142 * able to put it together from information already maintained for
1143 * different purposes and for a probably different number of drives.
1145 * For valid drives, the geometry is expected in the format (31..0)
1146 * "000000cc cccccccc hhhhhhhh 00ssssss"; and invalid drives are
1147 * indicated by returning the geometry of a "1.2M" PC-format floppy
1148 * disk. And, incidentally, what is returned is not the geometry as
1149 * such but the highest valid cylinder, head, and sector numbers.
1152 bd_getbigeom(int bunit)
1155 v86.ctl = V86_FLAGS;
1158 v86.edx = 0x80 + bunit;
1162 return ((v86.ecx & 0xc0) << 18) | ((v86.ecx & 0xff00) << 8) |
1163 (v86.edx & 0xff00) | (v86.ecx & 0x3f);
1167 * Return a suitable dev_t value for (dev).
1169 * In the case where it looks like (dev) is a SCSI disk, we allow the number of
1170 * IDE disks to be specified in $num_ide_disks. There should be a Better Way.
1173 bd_getdev(struct i386_devdesc *dev)
1175 struct open_disk *od;
1180 int unitofs = 0, i, unit;
1182 biosdev = bd_unit2bios(dev->d_kind.biosdisk.unit);
1183 DEBUG("unit %d BIOS device %d", dev->d_kind.biosdisk.unit, biosdev);
1184 if (biosdev == -1) /* not a BIOS device */
1186 if (bd_opendisk(&od, dev) != 0) /* oops, not a viable device */
1189 if (biosdev < 0x80) {
1190 /* floppy (or emulated floppy) or ATAPI device */
1191 if (bdinfo[dev->d_kind.biosdisk.unit].bd_type == DT_ATAPI) {
1192 /* is an ATAPI disk */
1195 /* is a floppy disk */
1200 if ((od->od_flags & BD_LABELOK) && (od->od_disklabel.d_type == DTYPE_SCSI)) {
1201 /* label OK, disk labelled as SCSI */
1203 /* check for unit number correction hint, now deprecated */
1204 if ((nip = getenv("num_ide_disks")) != NULL) {
1205 i = strtol(nip, &cp, 0);
1206 /* check for parse error */
1207 if ((cp != nip) && (*cp == 0))
1211 /* assume an IDE disk */
1215 /* default root disk unit number */
1216 unit = (biosdev & 0x7f) - unitofs;
1218 /* XXX a better kludge to set the root disk unit number */
1219 if ((nip = getenv("root_disk_unit")) != NULL) {
1220 i = strtol(nip, &cp, 0);
1221 /* check for parse error */
1222 if ((cp != nip) && (*cp == 0))
1226 rootdev = MAKEBOOTDEV(major,
1227 (dev->d_kind.biosdisk.slice + 1) >> 4, /* XXX slices may be wrong here */
1228 (dev->d_kind.biosdisk.slice + 1) & 0xf,
1230 dev->d_kind.biosdisk.partition);
1231 DEBUG("dev is 0x%x\n", rootdev);