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 1.2 2003/06/17 04:28:18 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/reboot.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" , __FUNCTION__ , ## 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[MAX_SLICES];
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,
105 static int bd_int13probe(struct bdinfo *bd);
107 static void bd_printslice(struct open_disk *od, struct dos_partition *dp,
108 char *prefix, int verbose);
109 static void bd_printbsdslice(struct open_disk *od, daddr_t offset,
110 char *prefix, int verbose);
112 static int bd_init(void);
113 static int bd_strategy(void *devdata, int flag, daddr_t dblk,
114 size_t size, char *buf, size_t *rsize);
115 static int bd_realstrategy(void *devdata, int flag, daddr_t dblk,
116 size_t size, char *buf, size_t *rsize);
117 static int bd_open(struct open_file *f, ...);
118 static int bd_close(struct open_file *f);
119 static void bd_print(int verbose);
121 struct devsw biosdisk = {
133 static int bd_opendisk(struct open_disk **odp, struct i386_devdesc *dev);
134 static void bd_closedisk(struct open_disk *od);
135 static int bd_bestslice(struct open_disk *od);
136 static void bd_checkextended(struct open_disk *od, int slicenum);
139 * Translate between BIOS device numbers and our private unit numbers.
142 bd_bios2unit(int biosdev)
146 DEBUG("looking for bios device 0x%x", biosdev);
147 for (i = 0; i < nbdinfo; i++) {
148 DEBUG("bd unit %d is BIOS device 0x%x", i, bdinfo[i].bd_unit);
149 if (bdinfo[i].bd_unit == biosdev)
156 bd_unit2bios(int unit)
158 if ((unit >= 0) && (unit < nbdinfo))
159 return(bdinfo[unit].bd_unit);
164 * Quiz the BIOS for disk devices, save a little info about them.
169 int base, unit, nfd = 0;
171 /* sequence 0, 0x80 */
172 for (base = 0; base <= 0x80; base += 0x80) {
173 for (unit = base; (nbdinfo < MAXBDDEV); unit++) {
174 /* check the BIOS equipment list for number of fixed disks */
176 (nfd >= *(unsigned char *)PTOV(BIOS_NUMDRIVES)))
179 bdinfo[nbdinfo].bd_unit = unit;
180 bdinfo[nbdinfo].bd_flags = (unit < 0x80) ? BD_FLOPPY : 0;
182 if (!bd_int13probe(&bdinfo[nbdinfo]))
185 /* XXX we need "disk aliases" to make this simpler */
186 printf("BIOS drive %c: is disk%d\n",
187 (unit < 0x80) ? ('A' + unit) : ('C' + unit - 0x80), nbdinfo);
197 * Try to detect a device supported by the legacy int13 BIOS
200 bd_int13probe(struct bdinfo *bd)
205 v86.edx = bd->bd_unit;
208 if (!(v86.efl & 0x1) && /* carry clear */
209 ((v86.edx & 0xff) > ((unsigned)bd->bd_unit & 0x7f))) { /* unit # OK */
210 bd->bd_flags |= BD_MODEINT13;
211 bd->bd_type = v86.ebx & 0xff;
213 /* Determine if we can use EDD with this device. */
215 v86.edx = bd->bd_unit;
218 if (!(v86.efl & 0x1) && /* carry clear */
219 ((v86.ebx & 0xffff) == 0xaa55) && /* signature */
220 (v86.ecx & 0x1)) { /* packets mode ok */
221 bd->bd_flags |= BD_MODEEDD1;
222 if((v86.eax & 0xff00) > 0x300)
223 bd->bd_flags |= BD_MODEEDD3;
231 * Print information about disks
234 bd_print(int verbose)
238 struct i386_devdesc dev;
239 struct open_disk *od;
240 struct dos_partition *dptr;
242 for (i = 0; i < nbdinfo; i++) {
243 sprintf(line, " disk%d: BIOS drive %c:\n", i,
244 (bdinfo[i].bd_unit < 0x80) ? ('A' + bdinfo[i].bd_unit) : ('C' + bdinfo[i].bd_unit - 0x80));
247 /* try to open the whole disk */
248 dev.d_kind.biosdisk.unit = i;
249 dev.d_kind.biosdisk.slice = -1;
250 dev.d_kind.biosdisk.partition = -1;
252 if (!bd_opendisk(&od, &dev)) {
254 /* Do we have a partition table? */
255 if (od->od_flags & BD_PARTTABOK) {
256 dptr = &od->od_slicetab[0];
258 /* Check for a "dedicated" disk */
259 if ((dptr[3].dp_typ == DOSPTYP_386BSD) &&
260 (dptr[3].dp_start == 0) &&
261 (dptr[3].dp_size == 50000)) {
262 sprintf(line, " disk%d", i);
263 bd_printbsdslice(od, 0, line, verbose);
265 for (j = 0; j < od->od_nslices; j++) {
266 sprintf(line, " disk%ds%d", i, j + 1);
267 bd_printslice(od, &dptr[j], line, verbose);
277 * Print information about slices on a disk. For the size calculations we
278 * assume a 512 byte sector.
281 bd_printslice(struct open_disk *od, struct dos_partition *dp, char *prefix,
286 switch (dp->dp_typ) {
288 bd_printbsdslice(od, (daddr_t)dp->dp_start, prefix, verbose);
292 sprintf(line, "%s: Linux swap %.6dMB (%d - %d)\n",
293 prefix, dp->dp_size / 2048,
294 dp->dp_start, dp->dp_start + dp->dp_size);
296 sprintf(line, "%s: Linux swap\n", prefix);
301 * read the superblock to confirm this is an ext2fs partition?
304 sprintf(line, "%s: ext2fs %.6dMB (%d - %d)\n", prefix,
305 dp->dp_size / 2048, dp->dp_start,
306 dp->dp_start + dp->dp_size);
308 sprintf(line, "%s: ext2fs\n", prefix);
310 case 0x00: /* unused partition */
315 sprintf(line, "%s: FAT-12 %.6dMB (%d - %d)\n", prefix,
316 dp->dp_size / 2048, dp->dp_start,
317 dp->dp_start + dp->dp_size);
319 sprintf(line, "%s: FAT-12\n", prefix);
325 sprintf(line, "%s: FAT-16 %.6dMB (%d - %d)\n", prefix,
326 dp->dp_size / 2048, dp->dp_start,
327 dp->dp_start + dp->dp_size);
329 sprintf(line, "%s: FAT-16\n", prefix);
334 sprintf(line, "%s: FAT-32 %.6dMB (%d - %d)\n", prefix,
335 dp->dp_size / 2048, dp->dp_start,
336 dp->dp_start + dp->dp_size);
338 sprintf(line, "%s: FAT-32\n", prefix);
342 sprintf(line, "%s: Unknown fs: 0x%x %.6dMB (%d - %d)\n",
343 prefix, dp->dp_typ, dp->dp_size / 2048,
344 dp->dp_start, dp->dp_start + dp->dp_size);
346 sprintf(line, "%s: Unknown fs: 0x%x\n", prefix,
353 * Print out each valid partition in the disklabel of a FreeBSD slice.
354 * For size calculations, we assume a 512 byte sector size.
357 bd_printbsdslice(struct open_disk *od, daddr_t offset, char *prefix,
361 char buf[BIOSDISK_SECSIZE];
362 struct disklabel *lp;
366 if (bd_read(od, offset + LABELSECTOR, 1, buf))
368 lp =(struct disklabel *)(&buf[0]);
369 if (lp->d_magic != DISKMAGIC) {
370 sprintf(line, "%s: FFS bad disklabel\n", prefix);
375 /* Print partitions */
376 for (i = 0; i < lp->d_npartitions; i++) {
378 * For each partition, make sure we know what type of fs it is. If
379 * not, then skip it. However, since floppies often have bogus
380 * fstypes, print the 'a' partition on a floppy even if it is marked
383 if ((lp->d_partitions[i].p_fstype == FS_BSDFFS) ||
384 (lp->d_partitions[i].p_fstype == FS_SWAP) ||
385 (lp->d_partitions[i].p_fstype == FS_VINUM) ||
386 ((lp->d_partitions[i].p_fstype == FS_UNUSED) &&
387 (od->od_flags & BD_FLOPPY) && (i == 0))) {
389 /* Only print out statistics in verbose mode */
391 sprintf(line, " %s%c: %s %.6dMB (%d - %d)\n", prefix, 'a' + i,
392 (lp->d_partitions[i].p_fstype == FS_SWAP) ? "swap" :
393 (lp->d_partitions[i].p_fstype == FS_VINUM) ? "vinum" :
395 lp->d_partitions[i].p_size / 2048,
396 lp->d_partitions[i].p_offset,
397 lp->d_partitions[i].p_offset + lp->d_partitions[i].p_size);
399 sprintf(line, " %s%c: %s\n", prefix, 'a' + i,
400 (lp->d_partitions[i].p_fstype == FS_SWAP) ? "swap" :
401 (lp->d_partitions[i].p_fstype == FS_VINUM) ? "vinum" :
410 * Attempt to open the disk described by (dev) for use by (f).
412 * Note that the philosophy here is "give them exactly what
413 * they ask for". This is necessary because being too "smart"
414 * about what the user might want leads to complications.
415 * (eg. given no slice or partition value, with a disk that is
416 * sliced - are they after the first BSD slice, or the DOS
420 bd_open(struct open_file *f, ...)
423 struct i386_devdesc *dev;
424 struct open_disk *od;
428 dev = va_arg(ap, struct i386_devdesc *);
430 if ((error = bd_opendisk(&od, dev)))
436 ((struct i386_devdesc *)(f->f_devdata))->d_kind.biosdisk.data = od;
437 DEBUG("open_disk %p, partition at 0x%x", od, od->od_boff);
442 bd_opendisk(struct open_disk **odp, struct i386_devdesc *dev)
444 struct dos_partition *dptr;
445 struct disklabel *lp;
446 struct open_disk *od;
447 int sector, slice, i;
451 if (dev->d_kind.biosdisk.unit >= nbdinfo) {
452 DEBUG("attempt to open nonexistent disk");
456 od = (struct open_disk *)malloc(sizeof(struct open_disk));
462 /* Look up BIOS unit number, intialise open_disk structure */
463 od->od_dkunit = dev->d_kind.biosdisk.unit;
464 od->od_unit = bdinfo[od->od_dkunit].bd_unit;
465 od->od_flags = bdinfo[od->od_dkunit].bd_flags;
469 DEBUG("open '%s', unit 0x%x slice %d partition %c",
470 i386_fmtdev(dev), dev->d_kind.biosdisk.unit,
471 dev->d_kind.biosdisk.slice, dev->d_kind.biosdisk.partition + 'a');
473 /* Get geometry for this open (removable device may have changed) */
474 if (bd_getgeom(od)) {
475 DEBUG("can't get geometry");
481 * Following calculations attempt to determine the correct value
482 * for d->od_boff by looking for the slice and partition specified,
483 * or searching for reasonable defaults.
487 * Find the slice in the DOS slice table.
489 if (bd_read(od, 0, 1, buf)) {
490 DEBUG("error reading MBR");
496 * Check the slice table magic.
498 if (((u_char)buf[0x1fe] != 0x55) || ((u_char)buf[0x1ff] != 0xaa)) {
499 /* If a slice number was explicitly supplied, this is an error */
500 if (dev->d_kind.biosdisk.slice > 0) {
501 DEBUG("no slice table/MBR (no magic)");
506 goto unsliced; /* may be a floppy */
510 * copy the partition table, then pick up any extended partitions.
512 bcopy(buf + DOSPARTOFF, &od->od_slicetab,
513 sizeof(struct dos_partition) * NDOSPART);
514 od->od_nslices = 4; /* extended slices start here */
515 for (i = 0; i < NDOSPART; i++)
516 bd_checkextended(od, i);
517 od->od_flags |= BD_PARTTABOK;
518 dptr = &od->od_slicetab[0];
520 /* Is this a request for the whole disk? */
521 if (dev->d_kind.biosdisk.slice == -1) {
527 * if a slice number was supplied but not found, this is an error.
529 if (dev->d_kind.biosdisk.slice > 0) {
530 slice = dev->d_kind.biosdisk.slice - 1;
531 if (slice >= od->od_nslices) {
532 DEBUG("slice %d not found", slice);
539 * Check for the historically bogus MBR found on true dedicated disks
541 if ((dptr[3].dp_typ == DOSPTYP_386BSD) &&
542 (dptr[3].dp_start == 0) &&
543 (dptr[3].dp_size == 50000)) {
548 /* Try to auto-detect the best slice; this should always give a slice number */
549 if (dev->d_kind.biosdisk.slice == 0) {
550 slice = bd_bestslice(od);
555 dev->d_kind.biosdisk.slice = slice;
558 dptr = &od->od_slicetab[0];
560 * Accept the supplied slice number unequivocally (we may be looking
561 * at a DOS partition).
563 dptr += (dev->d_kind.biosdisk.slice - 1); /* we number 1-4, offsets are 0-3 */
564 sector = dptr->dp_start;
565 DEBUG("slice entry %d at %d, %d sectors", dev->d_kind.biosdisk.slice - 1, sector, dptr->dp_size);
568 * If we are looking at a BSD slice, and the partition is < 0, assume the 'a' partition
570 if ((dptr->dp_typ == DOSPTYP_386BSD) && (dev->d_kind.biosdisk.partition < 0))
571 dev->d_kind.biosdisk.partition = 0;
575 * Now we have the slice offset, look for the partition in the disklabel if we have
576 * a partition to start with.
578 * XXX we might want to check the label checksum.
580 if (dev->d_kind.biosdisk.partition < 0) {
581 od->od_boff = sector; /* no partition, must be after the slice */
582 DEBUG("opening raw slice");
585 if (bd_read(od, sector + LABELSECTOR, 1, buf)) {
586 DEBUG("error reading disklabel");
590 DEBUG("copy %d bytes of label from %p to %p", sizeof(struct disklabel), buf + LABELOFFSET, &od->od_disklabel);
591 bcopy(buf + LABELOFFSET, &od->od_disklabel, sizeof(struct disklabel));
592 lp = &od->od_disklabel;
593 od->od_flags |= BD_LABELOK;
595 if (lp->d_magic != DISKMAGIC) {
596 DEBUG("no disklabel");
600 if (dev->d_kind.biosdisk.partition >= lp->d_npartitions) {
601 DEBUG("partition '%c' exceeds partitions in table (a-'%c')",
602 'a' + dev->d_kind.biosdisk.partition, 'a' + lp->d_npartitions);
609 /* Complain if the partition is unused unless this is a floppy. */
610 if ((lp->d_partitions[dev->d_kind.biosdisk.partition].p_fstype == FS_UNUSED) &&
611 !(od->od_flags & BD_FLOPPY))
612 DEBUG("warning, partition marked as unused");
615 od->od_boff = lp->d_partitions[dev->d_kind.biosdisk.partition].p_offset;
622 *odp = od; /* return the open disk */
628 bd_checkextended(struct open_disk *od, int slicenum)
630 char buf[BIOSDISK_SECSIZE];
631 struct dos_partition *dp;
635 dp = &od->od_slicetab[slicenum];
636 start = od->od_nslices;
638 if (dp->dp_size == 0)
640 if (dp->dp_typ != DOSPTYP_EXT)
642 if (bd_read(od, (daddr_t)dp->dp_start, 1, buf))
644 if (((u_char)buf[0x1fe] != 0x55) || ((u_char)buf[0x1ff] != 0xaa)) {
645 DEBUG("no magic in extended table");
649 dp = (struct dos_partition *)(&buf[DOSPARTOFF]);
650 for (i = 0; i < NDOSPART; i++, dp++) {
651 if (dp->dp_size == 0)
653 if (od->od_nslices == MAX_SLICES)
655 dp->dp_start += base;
656 bcopy(dp, &od->od_slicetab[od->od_nslices], sizeof(*dp));
659 end = od->od_nslices;
662 * now, recursively check the slices we just added
664 for (i = start; i < end; i++)
665 bd_checkextended(od, i);
671 * Search for a slice with the following preferences:
673 * 1: Active FreeBSD slice
674 * 2: Non-active FreeBSD slice
675 * 3: Active Linux slice
676 * 4: non-active Linux slice
677 * 5: Active FAT/FAT32 slice
678 * 6: non-active FAT/FAT32 slice
680 #define PREF_RAWDISK 0
681 #define PREF_FBSD_ACT 1
683 #define PREF_LINUX_ACT 3
685 #define PREF_DOS_ACT 5
690 * slicelimit is in the range 0 .. NDOSPART
693 bd_bestslice(struct open_disk *od)
695 struct dos_partition *dp;
700 preflevel = PREF_NONE;
702 dp = &od->od_slicetab[0];
703 for (i = 0; i < od->od_nslices; i++, dp++) {
705 switch (dp->dp_typ) {
706 case DOSPTYP_386BSD: /* FreeBSD */
707 pref = dp->dp_flag & 0x80 ? PREF_FBSD_ACT : PREF_FBSD;
711 pref = dp->dp_flag & 0x80 ? PREF_LINUX_ACT : PREF_LINUX;
714 case 0x01: /* DOS/Windows */
720 pref = dp->dp_flag & 0x80 ? PREF_DOS_ACT : PREF_DOS;
726 if (pref < preflevel) {
735 bd_close(struct open_file *f)
737 struct open_disk *od = (struct open_disk *)(((struct i386_devdesc *)(f->f_devdata))->d_kind.biosdisk.data);
744 bd_closedisk(struct open_disk *od)
746 DEBUG("open_disk %p", od);
748 /* XXX is this required? (especially if disk already open...) */
749 if (od->od_flags & BD_FLOPPY)
756 bd_strategy(void *devdata, int rw, daddr_t dblk, size_t size, char *buf, size_t *rsize)
758 struct bcache_devdata bcd;
759 struct open_disk *od = (struct open_disk *)(((struct i386_devdesc *)devdata)->d_kind.biosdisk.data);
761 bcd.dv_strategy = bd_realstrategy;
762 bcd.dv_devdata = devdata;
763 return(bcache_strategy(&bcd, od->od_unit, rw, dblk+od->od_boff, size, buf, rsize));
767 bd_realstrategy(void *devdata, int rw, daddr_t dblk, size_t size, char *buf, size_t *rsize)
769 struct open_disk *od = (struct open_disk *)(((struct i386_devdesc *)devdata)->d_kind.biosdisk.data);
771 #ifdef BD_SUPPORT_FRAGS
772 char fragbuf[BIOSDISK_SECSIZE];
775 fragsize = size % BIOSDISK_SECSIZE;
777 if (size % BIOSDISK_SECSIZE)
778 panic("bd_strategy: %d bytes I/O not multiple of block size", size);
781 DEBUG("open_disk %p", od);
787 blks = size / BIOSDISK_SECSIZE;
788 DEBUG("read %d from %d to %p", blks, dblk, buf);
792 if (blks && bd_read(od, dblk, blks, buf)) {
796 #ifdef BD_SUPPORT_FRAGS
797 DEBUG("bd_strategy: frag read %d from %d+%d to %p",
798 fragsize, dblk, blks, buf + (blks * BIOSDISK_SECSIZE));
799 if (fragsize && bd_read(od, dblk + blks, 1, fragsize)) {
800 DEBUG("frag read error");
803 bcopy(fragbuf, buf + (blks * BIOSDISK_SECSIZE), fragsize);
810 /* Max number of sectors to bounce-buffer if the request crosses a 64k boundary */
811 #define FLOPPY_BOUNCEBUF 18
814 bd_read(struct open_disk *od, daddr_t dblk, int blks, caddr_t dest)
816 u_int x, bpc, cyl, hd, sec, result, resid, retry, maxfer;
817 caddr_t p, xp, bbuf, breg;
819 /* Just in case some idiot actually tries to read -1 blocks... */
823 bpc = (od->od_sec * od->od_hds); /* blocks per cylinder */
827 /* Decide whether we have to bounce */
828 if ((od->od_unit < 0x80) &&
829 ((VTOP(dest) >> 16) != (VTOP(dest + blks * BIOSDISK_SECSIZE) >> 16))) {
832 * There is a 64k physical boundary somewhere in the destination buffer, so we have
833 * to arrange a suitable bounce buffer. Allocate a buffer twice as large as we
834 * need to. Use the bottom half unless there is a break there, in which case we
837 x = min(FLOPPY_BOUNCEBUF, (unsigned)blks);
838 bbuf = malloc(x * 2 * BIOSDISK_SECSIZE);
839 if (((u_int32_t)VTOP(bbuf) & 0xffff0000) == ((u_int32_t)VTOP(dest + x * BIOSDISK_SECSIZE) & 0xffff0000)) {
842 breg = bbuf + x * BIOSDISK_SECSIZE;
844 maxfer = x; /* limit transfers to bounce region size */
852 cyl = x / bpc; /* block # / blocks per cylinder */
853 x %= bpc; /* block offset into cylinder */
854 hd = x / od->od_sec; /* offset / blocks per track */
855 sec = x % od->od_sec; /* offset into track */
857 /* play it safe and don't cross track boundaries (XXX this is probably unnecessary) */
858 x = min(od->od_sec - sec, resid);
860 x = min(x, maxfer); /* fit bounce buffer */
862 /* where do we transfer to? */
863 xp = bbuf == NULL ? p : breg;
865 /* correct sector number for 1-based BIOS numbering */
868 /* Loop retrying the operation a couple of times. The BIOS may also retry. */
869 for (retry = 0; retry < 3; retry++) {
870 /* if retrying, reset the drive */
875 v86.edx = od->od_unit;
880 /* use EDD if the disk supports it, otherwise, return error */
881 if(od->od_flags & BD_MODEEDD1) {
882 static unsigned short packet[8];
886 packet[2] = VTOPOFF(xp);
887 packet[3] = VTOPSEG(xp);
888 packet[4] = dblk & 0xffff;
889 packet[5] = dblk >> 16;
895 v86.edx = od->od_unit;
896 v86.ds = VTOPSEG(packet);
897 v86.esi = VTOPOFF(packet);
899 result = (v86.efl & 0x1);
907 /* Use normal CHS addressing */
911 v86.ecx = ((cyl & 0xff) << 8) | ((cyl & 0x300) >> 2) | sec;
912 v86.edx = (hd << 8) | od->od_unit;
913 v86.es = VTOPSEG(xp);
914 v86.ebx = VTOPOFF(xp);
916 result = (v86.efl & 0x1);
922 DEBUG("%d sectors from %d/%d/%d to %p (0x%x) %s", x, cyl, hd, sec - 1, p, VTOP(p), result ? "failed" : "ok");
923 /* BUG here, cannot use v86 in printf because putchar uses it too */
924 DEBUG("ax = 0x%04x cx = 0x%04x dx = 0x%04x status 0x%x",
925 0x200 | x, ((cyl & 0xff) << 8) | ((cyl & 0x300) >> 2) | sec, (hd << 8) | od->od_unit, (v86.eax >> 8) & 0xff);
932 bcopy(breg, p, x * BIOSDISK_SECSIZE);
933 p += (x * BIOSDISK_SECSIZE);
938 /* hexdump(dest, (blks * BIOSDISK_SECSIZE)); */
945 bd_getgeom(struct open_disk *od)
951 v86.edx = od->od_unit;
954 if ((v86.efl & 0x1) || /* carry set */
955 ((v86.edx & 0xff) <= (unsigned)(od->od_unit & 0x7f))) /* unit # bad */
958 /* convert max cyl # -> # of cylinders */
959 od->od_cyl = ((v86.ecx & 0xc0) << 2) + ((v86.ecx & 0xff00) >> 8) + 1;
960 /* convert max head # -> # of heads */
961 od->od_hds = ((v86.edx & 0xff00) >> 8) + 1;
962 od->od_sec = v86.ecx & 0x3f;
964 DEBUG("unit 0x%x geometry %d/%d/%d", od->od_unit, od->od_cyl, od->od_hds, od->od_sec);
969 * Return the BIOS geometry of a given "fixed drive" in a format
970 * suitable for the legacy bootinfo structure. Since the kernel is
971 * expecting raw int 0x13/0x8 values for N_BIOS_GEOM drives, we
972 * prefer to get the information directly, rather than rely on being
973 * able to put it together from information already maintained for
974 * different purposes and for a probably different number of drives.
976 * For valid drives, the geometry is expected in the format (31..0)
977 * "000000cc cccccccc hhhhhhhh 00ssssss"; and invalid drives are
978 * indicated by returning the geometry of a "1.2M" PC-format floppy
979 * disk. And, incidentally, what is returned is not the geometry as
980 * such but the highest valid cylinder, head, and sector numbers.
983 bd_getbigeom(int bunit)
989 v86.edx = 0x80 + bunit;
993 return ((v86.ecx & 0xc0) << 18) | ((v86.ecx & 0xff00) << 8) |
994 (v86.edx & 0xff00) | (v86.ecx & 0x3f);
998 * Return a suitable dev_t value for (dev).
1000 * In the case where it looks like (dev) is a SCSI disk, we allow the number of
1001 * IDE disks to be specified in $num_ide_disks. There should be a Better Way.
1004 bd_getdev(struct i386_devdesc *dev)
1006 struct open_disk *od;
1011 int unitofs = 0, i, unit;
1013 biosdev = bd_unit2bios(dev->d_kind.biosdisk.unit);
1014 DEBUG("unit %d BIOS device %d", dev->d_kind.biosdisk.unit, biosdev);
1015 if (biosdev == -1) /* not a BIOS device */
1017 if (bd_opendisk(&od, dev) != 0) /* oops, not a viable device */
1020 if (biosdev < 0x80) {
1021 /* floppy (or emulated floppy) or ATAPI device */
1022 if (bdinfo[dev->d_kind.biosdisk.unit].bd_type == DT_ATAPI) {
1023 /* is an ATAPI disk */
1026 /* is a floppy disk */
1031 if ((od->od_flags & BD_LABELOK) && (od->od_disklabel.d_type == DTYPE_SCSI)) {
1032 /* label OK, disk labelled as SCSI */
1034 /* check for unit number correction hint, now deprecated */
1035 if ((nip = getenv("num_ide_disks")) != NULL) {
1036 i = strtol(nip, &cp, 0);
1037 /* check for parse error */
1038 if ((cp != nip) && (*cp == 0))
1042 /* assume an IDE disk */
1046 /* default root disk unit number */
1047 unit = (biosdev & 0x7f) - unitofs;
1049 /* XXX a better kludge to set the root disk unit number */
1050 if ((nip = getenv("root_disk_unit")) != NULL) {
1051 i = strtol(nip, &cp, 0);
1052 /* check for parse error */
1053 if ((cp != nip) && (*cp == 0))
1057 rootdev = MAKEBOOTDEV(major,
1058 (dev->d_kind.biosdisk.slice + 1) >> 4, /* XXX slices may be wrong here */
1059 (dev->d_kind.biosdisk.slice + 1) & 0xf,
1061 dev->d_kind.biosdisk.partition);
1062 DEBUG("dev is 0x%x\n", rootdev);