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 $
30 * BIOS disk device handling.
32 * Ideas and algorithms from:
34 * - NetBSD libi386/biosdisk.c
35 * - FreeBSD biosboot/disk.c
41 #include <sys/disklabel.h>
42 #include <sys/diskslice.h>
43 #include <sys/reboot.h>
47 #include <bootstrap.h>
51 #define BIOS_NUMDRIVES 0x475
52 #define BIOSDISK_SECSIZE 512
53 #define BUFSIZE (1 * BIOSDISK_SECSIZE)
54 #define MAXBDDEV MAXDEV
56 #define DT_ATAPI 0x10 /* disk type for ATAPI floppies */
57 #define WDMAJOR 0 /* major numbers for devices we frontend for */
63 # define DEBUG(fmt, args...) printf("%s: " fmt "\n" , __FUNCTION__ , ## args)
65 # define DEBUG(fmt, args...)
69 int od_dkunit; /* disk unit number */
70 int od_unit; /* BIOS unit number */
71 int od_cyl; /* BIOS geometry */
74 int od_boff; /* block offset from beginning of BIOS disk */
76 #define BD_MODEINT13 0x0000
77 #define BD_MODEEDD1 0x0001
78 #define BD_MODEEDD3 0x0002
79 #define BD_MODEMASK 0x0003
80 #define BD_FLOPPY 0x0004
81 #define BD_LABELOK 0x0008
82 #define BD_PARTTABOK 0x0010
83 struct disklabel od_disklabel;
84 int od_nslices; /* slice count */
85 struct dos_partition od_slicetab[MAX_SLICES];
89 * List of BIOS devices, translation from disk unit number to
94 int bd_unit; /* BIOS unit number */
96 int bd_type; /* BIOS 'drive type' (floppy only) */
98 static int nbdinfo = 0;
100 static int bd_getgeom(struct open_disk *od);
101 static int bd_read(struct open_disk *od, daddr_t dblk, int blks,
104 static int bd_int13probe(struct bdinfo *bd);
106 static void bd_printslice(struct open_disk *od, struct dos_partition *dp,
107 char *prefix, int verbose);
108 static void bd_printbsdslice(struct open_disk *od, daddr_t offset,
109 char *prefix, int verbose);
111 static int bd_init(void);
112 static int bd_strategy(void *devdata, int flag, daddr_t dblk,
113 size_t size, char *buf, size_t *rsize);
114 static int bd_realstrategy(void *devdata, int flag, daddr_t dblk,
115 size_t size, char *buf, size_t *rsize);
116 static int bd_open(struct open_file *f, ...);
117 static int bd_close(struct open_file *f);
118 static void bd_print(int verbose);
120 struct devsw biosdisk = {
132 static int bd_opendisk(struct open_disk **odp, struct i386_devdesc *dev);
133 static void bd_closedisk(struct open_disk *od);
134 static int bd_bestslice(struct open_disk *od);
135 static void bd_checkextended(struct open_disk *od, int slicenum);
138 * Translate between BIOS device numbers and our private unit numbers.
141 bd_bios2unit(int biosdev)
145 DEBUG("looking for bios device 0x%x", biosdev);
146 for (i = 0; i < nbdinfo; i++) {
147 DEBUG("bd unit %d is BIOS device 0x%x", i, bdinfo[i].bd_unit);
148 if (bdinfo[i].bd_unit == biosdev)
155 bd_unit2bios(int unit)
157 if ((unit >= 0) && (unit < nbdinfo))
158 return(bdinfo[unit].bd_unit);
163 * Quiz the BIOS for disk devices, save a little info about them.
168 int base, unit, nfd = 0;
170 /* sequence 0, 0x80 */
171 for (base = 0; base <= 0x80; base += 0x80) {
172 for (unit = base; (nbdinfo < MAXBDDEV); unit++) {
173 /* check the BIOS equipment list for number of fixed disks */
175 (nfd >= *(unsigned char *)PTOV(BIOS_NUMDRIVES)))
178 bdinfo[nbdinfo].bd_unit = unit;
179 bdinfo[nbdinfo].bd_flags = (unit < 0x80) ? BD_FLOPPY : 0;
181 if (!bd_int13probe(&bdinfo[nbdinfo]))
184 /* XXX we need "disk aliases" to make this simpler */
185 printf("BIOS drive %c: is disk%d\n",
186 (unit < 0x80) ? ('A' + unit) : ('C' + unit - 0x80), nbdinfo);
196 * Try to detect a device supported by the legacy int13 BIOS
199 bd_int13probe(struct bdinfo *bd)
204 v86.edx = bd->bd_unit;
207 if (!(v86.efl & 0x1) && /* carry clear */
208 ((v86.edx & 0xff) > ((unsigned)bd->bd_unit & 0x7f))) { /* unit # OK */
209 bd->bd_flags |= BD_MODEINT13;
210 bd->bd_type = v86.ebx & 0xff;
212 /* Determine if we can use EDD with this device. */
214 v86.edx = bd->bd_unit;
217 if (!(v86.efl & 0x1) && /* carry clear */
218 ((v86.ebx & 0xffff) == 0xaa55) && /* signature */
219 (v86.ecx & 0x1)) { /* packets mode ok */
220 bd->bd_flags |= BD_MODEEDD1;
221 if((v86.eax & 0xff00) > 0x300)
222 bd->bd_flags |= BD_MODEEDD3;
230 * Print information about disks
233 bd_print(int verbose)
237 struct i386_devdesc dev;
238 struct open_disk *od;
239 struct dos_partition *dptr;
241 for (i = 0; i < nbdinfo; i++) {
242 sprintf(line, " disk%d: BIOS drive %c:\n", i,
243 (bdinfo[i].bd_unit < 0x80) ? ('A' + bdinfo[i].bd_unit) : ('C' + bdinfo[i].bd_unit - 0x80));
246 /* try to open the whole disk */
247 dev.d_kind.biosdisk.unit = i;
248 dev.d_kind.biosdisk.slice = -1;
249 dev.d_kind.biosdisk.partition = -1;
251 if (!bd_opendisk(&od, &dev)) {
253 /* Do we have a partition table? */
254 if (od->od_flags & BD_PARTTABOK) {
255 dptr = &od->od_slicetab[0];
257 /* Check for a "dedicated" disk */
258 if ((dptr[3].dp_typ == DOSPTYP_386BSD) &&
259 (dptr[3].dp_start == 0) &&
260 (dptr[3].dp_size == 50000)) {
261 sprintf(line, " disk%d", i);
262 bd_printbsdslice(od, 0, line, verbose);
264 for (j = 0; j < od->od_nslices; j++) {
265 sprintf(line, " disk%ds%d", i, j + 1);
266 bd_printslice(od, &dptr[j], line, verbose);
276 * Print information about slices on a disk. For the size calculations we
277 * assume a 512 byte sector.
280 bd_printslice(struct open_disk *od, struct dos_partition *dp, char *prefix,
285 switch (dp->dp_typ) {
287 bd_printbsdslice(od, (daddr_t)dp->dp_start, prefix, verbose);
291 sprintf(line, "%s: Linux swap %.6dMB (%d - %d)\n",
292 prefix, dp->dp_size / 2048,
293 dp->dp_start, dp->dp_start + dp->dp_size);
295 sprintf(line, "%s: Linux swap\n", prefix);
300 * read the superblock to confirm this is an ext2fs partition?
303 sprintf(line, "%s: ext2fs %.6dMB (%d - %d)\n", prefix,
304 dp->dp_size / 2048, dp->dp_start,
305 dp->dp_start + dp->dp_size);
307 sprintf(line, "%s: ext2fs\n", prefix);
309 case 0x00: /* unused partition */
314 sprintf(line, "%s: FAT-12 %.6dMB (%d - %d)\n", prefix,
315 dp->dp_size / 2048, dp->dp_start,
316 dp->dp_start + dp->dp_size);
318 sprintf(line, "%s: FAT-12\n", prefix);
324 sprintf(line, "%s: FAT-16 %.6dMB (%d - %d)\n", prefix,
325 dp->dp_size / 2048, dp->dp_start,
326 dp->dp_start + dp->dp_size);
328 sprintf(line, "%s: FAT-16\n", prefix);
333 sprintf(line, "%s: FAT-32 %.6dMB (%d - %d)\n", prefix,
334 dp->dp_size / 2048, dp->dp_start,
335 dp->dp_start + dp->dp_size);
337 sprintf(line, "%s: FAT-32\n", prefix);
341 sprintf(line, "%s: Unknown fs: 0x%x %.6dMB (%d - %d)\n",
342 prefix, dp->dp_typ, dp->dp_size / 2048,
343 dp->dp_start, dp->dp_start + dp->dp_size);
345 sprintf(line, "%s: Unknown fs: 0x%x\n", prefix,
352 * Print out each valid partition in the disklabel of a FreeBSD slice.
353 * For size calculations, we assume a 512 byte sector size.
356 bd_printbsdslice(struct open_disk *od, daddr_t offset, char *prefix,
360 char buf[BIOSDISK_SECSIZE];
361 struct disklabel *lp;
365 if (bd_read(od, offset + LABELSECTOR, 1, buf))
367 lp =(struct disklabel *)(&buf[0]);
368 if (lp->d_magic != DISKMAGIC) {
369 sprintf(line, "%s: FFS bad disklabel\n", prefix);
374 /* Print partitions */
375 for (i = 0; i < lp->d_npartitions; i++) {
377 * For each partition, make sure we know what type of fs it is. If
378 * not, then skip it. However, since floppies often have bogus
379 * fstypes, print the 'a' partition on a floppy even if it is marked
382 if ((lp->d_partitions[i].p_fstype == FS_BSDFFS) ||
383 (lp->d_partitions[i].p_fstype == FS_SWAP) ||
384 (lp->d_partitions[i].p_fstype == FS_VINUM) ||
385 ((lp->d_partitions[i].p_fstype == FS_UNUSED) &&
386 (od->od_flags & BD_FLOPPY) && (i == 0))) {
388 /* Only print out statistics in verbose mode */
390 sprintf(line, " %s%c: %s %.6dMB (%d - %d)\n", prefix, 'a' + i,
391 (lp->d_partitions[i].p_fstype == FS_SWAP) ? "swap" :
392 (lp->d_partitions[i].p_fstype == FS_VINUM) ? "vinum" :
394 lp->d_partitions[i].p_size / 2048,
395 lp->d_partitions[i].p_offset,
396 lp->d_partitions[i].p_offset + lp->d_partitions[i].p_size);
398 sprintf(line, " %s%c: %s\n", prefix, 'a' + i,
399 (lp->d_partitions[i].p_fstype == FS_SWAP) ? "swap" :
400 (lp->d_partitions[i].p_fstype == FS_VINUM) ? "vinum" :
409 * Attempt to open the disk described by (dev) for use by (f).
411 * Note that the philosophy here is "give them exactly what
412 * they ask for". This is necessary because being too "smart"
413 * about what the user might want leads to complications.
414 * (eg. given no slice or partition value, with a disk that is
415 * sliced - are they after the first BSD slice, or the DOS
419 bd_open(struct open_file *f, ...)
422 struct i386_devdesc *dev;
423 struct open_disk *od;
427 dev = va_arg(ap, struct i386_devdesc *);
429 if ((error = bd_opendisk(&od, dev)))
435 ((struct i386_devdesc *)(f->f_devdata))->d_kind.biosdisk.data = od;
436 DEBUG("open_disk %p, partition at 0x%x", od, od->od_boff);
441 bd_opendisk(struct open_disk **odp, struct i386_devdesc *dev)
443 struct dos_partition *dptr;
444 struct disklabel *lp;
445 struct open_disk *od;
446 int sector, slice, i;
450 if (dev->d_kind.biosdisk.unit >= nbdinfo) {
451 DEBUG("attempt to open nonexistent disk");
455 od = (struct open_disk *)malloc(sizeof(struct open_disk));
461 /* Look up BIOS unit number, intialise open_disk structure */
462 od->od_dkunit = dev->d_kind.biosdisk.unit;
463 od->od_unit = bdinfo[od->od_dkunit].bd_unit;
464 od->od_flags = bdinfo[od->od_dkunit].bd_flags;
468 DEBUG("open '%s', unit 0x%x slice %d partition %c",
469 i386_fmtdev(dev), dev->d_kind.biosdisk.unit,
470 dev->d_kind.biosdisk.slice, dev->d_kind.biosdisk.partition + 'a');
472 /* Get geometry for this open (removable device may have changed) */
473 if (bd_getgeom(od)) {
474 DEBUG("can't get geometry");
480 * Following calculations attempt to determine the correct value
481 * for d->od_boff by looking for the slice and partition specified,
482 * or searching for reasonable defaults.
486 * Find the slice in the DOS slice table.
488 if (bd_read(od, 0, 1, buf)) {
489 DEBUG("error reading MBR");
495 * Check the slice table magic.
497 if (((u_char)buf[0x1fe] != 0x55) || ((u_char)buf[0x1ff] != 0xaa)) {
498 /* If a slice number was explicitly supplied, this is an error */
499 if (dev->d_kind.biosdisk.slice > 0) {
500 DEBUG("no slice table/MBR (no magic)");
505 goto unsliced; /* may be a floppy */
509 * copy the partition table, then pick up any extended partitions.
511 bcopy(buf + DOSPARTOFF, &od->od_slicetab,
512 sizeof(struct dos_partition) * NDOSPART);
513 od->od_nslices = 4; /* extended slices start here */
514 for (i = 0; i < NDOSPART; i++)
515 bd_checkextended(od, i);
516 od->od_flags |= BD_PARTTABOK;
517 dptr = &od->od_slicetab[0];
519 /* Is this a request for the whole disk? */
520 if (dev->d_kind.biosdisk.slice == -1) {
526 * if a slice number was supplied but not found, this is an error.
528 if (dev->d_kind.biosdisk.slice > 0) {
529 slice = dev->d_kind.biosdisk.slice - 1;
530 if (slice >= od->od_nslices) {
531 DEBUG("slice %d not found", slice);
538 * Check for the historically bogus MBR found on true dedicated disks
540 if ((dptr[3].dp_typ == DOSPTYP_386BSD) &&
541 (dptr[3].dp_start == 0) &&
542 (dptr[3].dp_size == 50000)) {
547 /* Try to auto-detect the best slice; this should always give a slice number */
548 if (dev->d_kind.biosdisk.slice == 0) {
549 slice = bd_bestslice(od);
554 dev->d_kind.biosdisk.slice = slice;
557 dptr = &od->od_slicetab[0];
559 * Accept the supplied slice number unequivocally (we may be looking
560 * at a DOS partition).
562 dptr += (dev->d_kind.biosdisk.slice - 1); /* we number 1-4, offsets are 0-3 */
563 sector = dptr->dp_start;
564 DEBUG("slice entry %d at %d, %d sectors", dev->d_kind.biosdisk.slice - 1, sector, dptr->dp_size);
567 * If we are looking at a BSD slice, and the partition is < 0, assume the 'a' partition
569 if ((dptr->dp_typ == DOSPTYP_386BSD) && (dev->d_kind.biosdisk.partition < 0))
570 dev->d_kind.biosdisk.partition = 0;
574 * Now we have the slice offset, look for the partition in the disklabel if we have
575 * a partition to start with.
577 * XXX we might want to check the label checksum.
579 if (dev->d_kind.biosdisk.partition < 0) {
580 od->od_boff = sector; /* no partition, must be after the slice */
581 DEBUG("opening raw slice");
584 if (bd_read(od, sector + LABELSECTOR, 1, buf)) {
585 DEBUG("error reading disklabel");
589 DEBUG("copy %d bytes of label from %p to %p", sizeof(struct disklabel), buf + LABELOFFSET, &od->od_disklabel);
590 bcopy(buf + LABELOFFSET, &od->od_disklabel, sizeof(struct disklabel));
591 lp = &od->od_disklabel;
592 od->od_flags |= BD_LABELOK;
594 if (lp->d_magic != DISKMAGIC) {
595 DEBUG("no disklabel");
599 if (dev->d_kind.biosdisk.partition >= lp->d_npartitions) {
600 DEBUG("partition '%c' exceeds partitions in table (a-'%c')",
601 'a' + dev->d_kind.biosdisk.partition, 'a' + lp->d_npartitions);
608 /* Complain if the partition is unused unless this is a floppy. */
609 if ((lp->d_partitions[dev->d_kind.biosdisk.partition].p_fstype == FS_UNUSED) &&
610 !(od->od_flags & BD_FLOPPY))
611 DEBUG("warning, partition marked as unused");
614 od->od_boff = lp->d_partitions[dev->d_kind.biosdisk.partition].p_offset;
621 *odp = od; /* return the open disk */
627 bd_checkextended(struct open_disk *od, int slicenum)
629 char buf[BIOSDISK_SECSIZE];
630 struct dos_partition *dp;
634 dp = &od->od_slicetab[slicenum];
635 start = od->od_nslices;
637 if (dp->dp_size == 0)
639 if (dp->dp_typ != DOSPTYP_EXT)
641 if (bd_read(od, (daddr_t)dp->dp_start, 1, buf))
643 if (((u_char)buf[0x1fe] != 0x55) || ((u_char)buf[0x1ff] != 0xaa)) {
644 DEBUG("no magic in extended table");
648 dp = (struct dos_partition *)(&buf[DOSPARTOFF]);
649 for (i = 0; i < NDOSPART; i++, dp++) {
650 if (dp->dp_size == 0)
652 if (od->od_nslices == MAX_SLICES)
654 dp->dp_start += base;
655 bcopy(dp, &od->od_slicetab[od->od_nslices], sizeof(*dp));
658 end = od->od_nslices;
661 * now, recursively check the slices we just added
663 for (i = start; i < end; i++)
664 bd_checkextended(od, i);
670 * Search for a slice with the following preferences:
672 * 1: Active FreeBSD slice
673 * 2: Non-active FreeBSD slice
674 * 3: Active Linux slice
675 * 4: non-active Linux slice
676 * 5: Active FAT/FAT32 slice
677 * 6: non-active FAT/FAT32 slice
679 #define PREF_RAWDISK 0
680 #define PREF_FBSD_ACT 1
682 #define PREF_LINUX_ACT 3
684 #define PREF_DOS_ACT 5
689 * slicelimit is in the range 0 .. NDOSPART
692 bd_bestslice(struct open_disk *od)
694 struct dos_partition *dp;
699 preflevel = PREF_NONE;
701 dp = &od->od_slicetab[0];
702 for (i = 0; i < od->od_nslices; i++, dp++) {
704 switch (dp->dp_typ) {
705 case DOSPTYP_386BSD: /* FreeBSD */
706 pref = dp->dp_flag & 0x80 ? PREF_FBSD_ACT : PREF_FBSD;
710 pref = dp->dp_flag & 0x80 ? PREF_LINUX_ACT : PREF_LINUX;
713 case 0x01: /* DOS/Windows */
719 pref = dp->dp_flag & 0x80 ? PREF_DOS_ACT : PREF_DOS;
725 if (pref < preflevel) {
734 bd_close(struct open_file *f)
736 struct open_disk *od = (struct open_disk *)(((struct i386_devdesc *)(f->f_devdata))->d_kind.biosdisk.data);
743 bd_closedisk(struct open_disk *od)
745 DEBUG("open_disk %p", od);
747 /* XXX is this required? (especially if disk already open...) */
748 if (od->od_flags & BD_FLOPPY)
755 bd_strategy(void *devdata, int rw, daddr_t dblk, size_t size, char *buf, size_t *rsize)
757 struct bcache_devdata bcd;
758 struct open_disk *od = (struct open_disk *)(((struct i386_devdesc *)devdata)->d_kind.biosdisk.data);
760 bcd.dv_strategy = bd_realstrategy;
761 bcd.dv_devdata = devdata;
762 return(bcache_strategy(&bcd, od->od_unit, rw, dblk+od->od_boff, size, buf, rsize));
766 bd_realstrategy(void *devdata, int rw, daddr_t dblk, size_t size, char *buf, size_t *rsize)
768 struct open_disk *od = (struct open_disk *)(((struct i386_devdesc *)devdata)->d_kind.biosdisk.data);
770 #ifdef BD_SUPPORT_FRAGS
771 char fragbuf[BIOSDISK_SECSIZE];
774 fragsize = size % BIOSDISK_SECSIZE;
776 if (size % BIOSDISK_SECSIZE)
777 panic("bd_strategy: %d bytes I/O not multiple of block size", size);
780 DEBUG("open_disk %p", od);
786 blks = size / BIOSDISK_SECSIZE;
787 DEBUG("read %d from %d to %p", blks, dblk, buf);
791 if (blks && bd_read(od, dblk, blks, buf)) {
795 #ifdef BD_SUPPORT_FRAGS
796 DEBUG("bd_strategy: frag read %d from %d+%d to %p",
797 fragsize, dblk, blks, buf + (blks * BIOSDISK_SECSIZE));
798 if (fragsize && bd_read(od, dblk + blks, 1, fragsize)) {
799 DEBUG("frag read error");
802 bcopy(fragbuf, buf + (blks * BIOSDISK_SECSIZE), fragsize);
809 /* Max number of sectors to bounce-buffer if the request crosses a 64k boundary */
810 #define FLOPPY_BOUNCEBUF 18
813 bd_read(struct open_disk *od, daddr_t dblk, int blks, caddr_t dest)
815 u_int x, bpc, cyl, hd, sec, result, resid, retry, maxfer;
816 caddr_t p, xp, bbuf, breg;
818 /* Just in case some idiot actually tries to read -1 blocks... */
822 bpc = (od->od_sec * od->od_hds); /* blocks per cylinder */
826 /* Decide whether we have to bounce */
827 if ((od->od_unit < 0x80) &&
828 ((VTOP(dest) >> 16) != (VTOP(dest + blks * BIOSDISK_SECSIZE) >> 16))) {
831 * There is a 64k physical boundary somewhere in the destination buffer, so we have
832 * to arrange a suitable bounce buffer. Allocate a buffer twice as large as we
833 * need to. Use the bottom half unless there is a break there, in which case we
836 x = min(FLOPPY_BOUNCEBUF, (unsigned)blks);
837 bbuf = malloc(x * 2 * BIOSDISK_SECSIZE);
838 if (((u_int32_t)VTOP(bbuf) & 0xffff0000) == ((u_int32_t)VTOP(dest + x * BIOSDISK_SECSIZE) & 0xffff0000)) {
841 breg = bbuf + x * BIOSDISK_SECSIZE;
843 maxfer = x; /* limit transfers to bounce region size */
851 cyl = x / bpc; /* block # / blocks per cylinder */
852 x %= bpc; /* block offset into cylinder */
853 hd = x / od->od_sec; /* offset / blocks per track */
854 sec = x % od->od_sec; /* offset into track */
856 /* play it safe and don't cross track boundaries (XXX this is probably unnecessary) */
857 x = min(od->od_sec - sec, resid);
859 x = min(x, maxfer); /* fit bounce buffer */
861 /* where do we transfer to? */
862 xp = bbuf == NULL ? p : breg;
864 /* correct sector number for 1-based BIOS numbering */
867 /* Loop retrying the operation a couple of times. The BIOS may also retry. */
868 for (retry = 0; retry < 3; retry++) {
869 /* if retrying, reset the drive */
874 v86.edx = od->od_unit;
879 /* use EDD if the disk supports it, otherwise, return error */
880 if(od->od_flags & BD_MODEEDD1) {
881 static unsigned short packet[8];
885 packet[2] = VTOPOFF(xp);
886 packet[3] = VTOPSEG(xp);
887 packet[4] = dblk & 0xffff;
888 packet[5] = dblk >> 16;
894 v86.edx = od->od_unit;
895 v86.ds = VTOPSEG(packet);
896 v86.esi = VTOPOFF(packet);
898 result = (v86.efl & 0x1);
906 /* Use normal CHS addressing */
910 v86.ecx = ((cyl & 0xff) << 8) | ((cyl & 0x300) >> 2) | sec;
911 v86.edx = (hd << 8) | od->od_unit;
912 v86.es = VTOPSEG(xp);
913 v86.ebx = VTOPOFF(xp);
915 result = (v86.efl & 0x1);
921 DEBUG("%d sectors from %d/%d/%d to %p (0x%x) %s", x, cyl, hd, sec - 1, p, VTOP(p), result ? "failed" : "ok");
922 /* BUG here, cannot use v86 in printf because putchar uses it too */
923 DEBUG("ax = 0x%04x cx = 0x%04x dx = 0x%04x status 0x%x",
924 0x200 | x, ((cyl & 0xff) << 8) | ((cyl & 0x300) >> 2) | sec, (hd << 8) | od->od_unit, (v86.eax >> 8) & 0xff);
931 bcopy(breg, p, x * BIOSDISK_SECSIZE);
932 p += (x * BIOSDISK_SECSIZE);
937 /* hexdump(dest, (blks * BIOSDISK_SECSIZE)); */
944 bd_getgeom(struct open_disk *od)
950 v86.edx = od->od_unit;
953 if ((v86.efl & 0x1) || /* carry set */
954 ((v86.edx & 0xff) <= (unsigned)(od->od_unit & 0x7f))) /* unit # bad */
957 /* convert max cyl # -> # of cylinders */
958 od->od_cyl = ((v86.ecx & 0xc0) << 2) + ((v86.ecx & 0xff00) >> 8) + 1;
959 /* convert max head # -> # of heads */
960 od->od_hds = ((v86.edx & 0xff00) >> 8) + 1;
961 od->od_sec = v86.ecx & 0x3f;
963 DEBUG("unit 0x%x geometry %d/%d/%d", od->od_unit, od->od_cyl, od->od_hds, od->od_sec);
968 * Return the BIOS geometry of a given "fixed drive" in a format
969 * suitable for the legacy bootinfo structure. Since the kernel is
970 * expecting raw int 0x13/0x8 values for N_BIOS_GEOM drives, we
971 * prefer to get the information directly, rather than rely on being
972 * able to put it together from information already maintained for
973 * different purposes and for a probably different number of drives.
975 * For valid drives, the geometry is expected in the format (31..0)
976 * "000000cc cccccccc hhhhhhhh 00ssssss"; and invalid drives are
977 * indicated by returning the geometry of a "1.2M" PC-format floppy
978 * disk. And, incidentally, what is returned is not the geometry as
979 * such but the highest valid cylinder, head, and sector numbers.
982 bd_getbigeom(int bunit)
988 v86.edx = 0x80 + bunit;
992 return ((v86.ecx & 0xc0) << 18) | ((v86.ecx & 0xff00) << 8) |
993 (v86.edx & 0xff00) | (v86.ecx & 0x3f);
997 * Return a suitable dev_t value for (dev).
999 * In the case where it looks like (dev) is a SCSI disk, we allow the number of
1000 * IDE disks to be specified in $num_ide_disks. There should be a Better Way.
1003 bd_getdev(struct i386_devdesc *dev)
1005 struct open_disk *od;
1010 int unitofs = 0, i, unit;
1012 biosdev = bd_unit2bios(dev->d_kind.biosdisk.unit);
1013 DEBUG("unit %d BIOS device %d", dev->d_kind.biosdisk.unit, biosdev);
1014 if (biosdev == -1) /* not a BIOS device */
1016 if (bd_opendisk(&od, dev) != 0) /* oops, not a viable device */
1019 if (biosdev < 0x80) {
1020 /* floppy (or emulated floppy) or ATAPI device */
1021 if (bdinfo[dev->d_kind.biosdisk.unit].bd_type == DT_ATAPI) {
1022 /* is an ATAPI disk */
1025 /* is a floppy disk */
1030 if ((od->od_flags & BD_LABELOK) && (od->od_disklabel.d_type == DTYPE_SCSI)) {
1031 /* label OK, disk labelled as SCSI */
1033 /* check for unit number correction hint, now deprecated */
1034 if ((nip = getenv("num_ide_disks")) != NULL) {
1035 i = strtol(nip, &cp, 0);
1036 /* check for parse error */
1037 if ((cp != nip) && (*cp == 0))
1041 /* assume an IDE disk */
1045 /* default root disk unit number */
1046 unit = (biosdev & 0x7f) - unitofs;
1048 /* XXX a better kludge to set the root disk unit number */
1049 if ((nip = getenv("root_disk_unit")) != NULL) {
1050 i = strtol(nip, &cp, 0);
1051 /* check for parse error */
1052 if ((cp != nip) && (*cp == 0))
1056 rootdev = MAKEBOOTDEV(major,
1057 (dev->d_kind.biosdisk.slice + 1) >> 4, /* XXX slices may be wrong here */
1058 (dev->d_kind.biosdisk.slice + 1) & 0xf,
1060 dev->d_kind.biosdisk.partition);
1061 DEBUG("dev is 0x%x\n", rootdev);