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 1.45 2004/09/21 06:46:44 wes Exp $
27 * $DragonFly: src/sys/boot/pc32/libi386/biosdisk.c,v 1.12 2007/06/18 05:13:42 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/disklabel32.h>
43 #include <sys/diskmbr.h>
44 #include <sys/dtype.h>
45 #include <machine/bootinfo.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 */
59 #define WDMAJOR 0 /* major numbers for devices we frontend for */
65 # define DEBUG(fmt, args...) printf("%s: " fmt "\n" , __func__ , ## args)
67 # define DEBUG(fmt, args...)
71 int od_dkunit; /* disk unit number */
72 int od_unit; /* BIOS unit number */
73 int od_cyl; /* BIOS geometry */
76 int od_boff; /* block offset from beginning of BIOS disk */
78 #define BD_MODEINT13 0x0000
79 #define BD_MODEEDD1 0x0001
80 #define BD_MODEEDD3 0x0002
81 #define BD_MODEMASK 0x0003
82 #define BD_FLOPPY 0x0004
83 #define BD_LABELOK 0x0008
84 #define BD_PARTTABOK 0x0010
85 struct disklabel32 od_disklabel;
86 int od_nslices; /* slice count */
87 struct dos_partition od_slicetab[NEXTDOSPART];
91 * List of BIOS devices, translation from disk unit number to
96 int bd_unit; /* BIOS unit number */
98 int bd_type; /* BIOS 'drive type' (floppy only) */
100 static int nbdinfo = 0;
102 static int bd_getgeom(struct open_disk *od);
103 static int bd_read(struct open_disk *od, daddr_t dblk, int blks,
105 static int bd_write(struct open_disk *od, daddr_t dblk, int blks,
108 static int bd_int13probe(struct bdinfo *bd);
110 static void bd_printslice(struct open_disk *od, struct dos_partition *dp,
111 char *prefix, int verbose);
112 static void bd_printbsdslice(struct open_disk *od, daddr_t offset,
113 char *prefix, int verbose);
115 static int bd_init(void);
116 static int bd_strategy(void *devdata, int flag, daddr_t dblk,
117 size_t size, char *buf, size_t *rsize);
118 static int bd_realstrategy(void *devdata, int flag, daddr_t dblk,
119 size_t size, char *buf, size_t *rsize);
120 static int bd_open(struct open_file *f, ...);
121 static int bd_close(struct open_file *f);
122 static void bd_print(int verbose);
124 struct devsw biosdisk = {
136 static int bd_opendisk(struct open_disk **odp, struct i386_devdesc *dev);
137 static void bd_closedisk(struct open_disk *od);
138 static int bd_bestslice(struct open_disk *od);
139 static void bd_chainextended(struct open_disk *od, u_int32_t base, u_int32_t offset);
142 * Translate between BIOS device numbers and our private unit numbers.
145 bd_bios2unit(int biosdev)
149 DEBUG("looking for bios device 0x%x", biosdev);
150 for (i = 0; i < nbdinfo; i++) {
151 DEBUG("bd unit %d is BIOS device 0x%x", i, bdinfo[i].bd_unit);
152 if (bdinfo[i].bd_unit == biosdev)
159 bd_unit2bios(int unit)
161 if ((unit >= 0) && (unit < nbdinfo))
162 return(bdinfo[unit].bd_unit);
167 * Quiz the BIOS for disk devices, save a little info about them.
172 int base, unit, nfd = 0;
174 /* sequence 0, 0x80 */
175 for (base = 0; base <= 0x80; base += 0x80) {
176 for (unit = base; (nbdinfo < MAXBDDEV); unit++) {
177 /* check the BIOS equipment list for number of fixed disks */
179 (nfd >= *(unsigned char *)PTOV(BIOS_NUMDRIVES)))
182 bdinfo[nbdinfo].bd_unit = unit;
183 bdinfo[nbdinfo].bd_flags = (unit < 0x80) ? BD_FLOPPY : 0;
185 if (!bd_int13probe(&bdinfo[nbdinfo]))
188 /* XXX we need "disk aliases" to make this simpler */
189 printf("BIOS drive %c: is disk%d\n",
190 (unit < 0x80) ? ('A' + unit) : ('C' + unit - 0x80), nbdinfo);
200 * Try to detect a device supported by the legacy int13 BIOS
203 bd_int13probe(struct bdinfo *bd)
208 v86.edx = bd->bd_unit;
211 if (!(v86.efl & 0x1) && /* carry clear */
212 ((v86.edx & 0xff) > ((unsigned)bd->bd_unit & 0x7f))) { /* unit # OK */
215 * Ignore devices with an absurd sector size.
217 if ((v86.ecx & 0x3f) == 0) {
218 DEBUG("Invalid geometry for unit %d", bd->bd_unit);
221 bd->bd_flags |= BD_MODEINT13;
222 bd->bd_type = v86.ebx & 0xff;
224 /* Determine if we can use EDD with this device. */
226 v86.edx = bd->bd_unit;
229 if (!(v86.efl & 0x1) && /* carry clear */
230 ((v86.ebx & 0xffff) == 0xaa55) && /* signature */
231 (v86.ecx & 0x1)) { /* packets mode ok */
232 bd->bd_flags |= BD_MODEEDD1;
233 if((v86.eax & 0xff00) > 0x300)
234 bd->bd_flags |= BD_MODEEDD3;
242 * Print information about disks
245 bd_print(int verbose)
249 struct i386_devdesc dev;
250 struct open_disk *od;
251 struct dos_partition *dptr;
253 for (i = 0; i < nbdinfo; i++) {
254 sprintf(line, " disk%d: BIOS drive %c:\n", i,
255 (bdinfo[i].bd_unit < 0x80) ? ('A' + bdinfo[i].bd_unit) : ('C' + bdinfo[i].bd_unit - 0x80));
258 /* try to open the whole disk */
259 dev.d_kind.biosdisk.unit = i;
260 dev.d_kind.biosdisk.slice = -1;
261 dev.d_kind.biosdisk.partition = -1;
263 if (!bd_opendisk(&od, &dev)) {
265 /* Do we have a partition table? */
266 if (od->od_flags & BD_PARTTABOK) {
267 dptr = &od->od_slicetab[0];
269 /* Check for a "dedicated" disk */
270 if ((dptr[3].dp_typ == DOSPTYP_386BSD) &&
271 (dptr[3].dp_start == 0) &&
272 (dptr[3].dp_size == 50000)) {
273 sprintf(line, " disk%d", i);
274 bd_printbsdslice(od, 0, line, verbose);
276 for (j = 0; j < od->od_nslices; j++) {
277 sprintf(line, " disk%ds%d", i, j + 1);
278 bd_printslice(od, &dptr[j], line, verbose);
288 * Print information about slices on a disk. For the size calculations we
289 * assume a 512 byte sector.
292 bd_printslice(struct open_disk *od, struct dos_partition *dp, char *prefix,
297 switch (dp->dp_typ) {
299 bd_printbsdslice(od, (daddr_t)dp->dp_start, prefix, verbose);
303 sprintf(line, "%s: Linux swap %.6dMB (%d - %d)\n",
304 prefix, dp->dp_size / 2048,
305 dp->dp_start, dp->dp_start + dp->dp_size);
307 sprintf(line, "%s: Linux swap\n", prefix);
312 * read the superblock to confirm this is an ext2fs partition?
315 sprintf(line, "%s: ext2fs %.6dMB (%d - %d)\n", prefix,
316 dp->dp_size / 2048, dp->dp_start,
317 dp->dp_start + dp->dp_size);
319 sprintf(line, "%s: ext2fs\n", prefix);
321 case 0x00: /* unused partition */
326 sprintf(line, "%s: FAT-12 %.6dMB (%d - %d)\n", prefix,
327 dp->dp_size / 2048, dp->dp_start,
328 dp->dp_start + dp->dp_size);
330 sprintf(line, "%s: FAT-12\n", prefix);
336 sprintf(line, "%s: FAT-16 %.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-16\n", prefix);
345 sprintf(line, "%s: FAT-32 %.6dMB (%d - %d)\n", prefix,
346 dp->dp_size / 2048, dp->dp_start,
347 dp->dp_start + dp->dp_size);
349 sprintf(line, "%s: FAT-32\n", prefix);
353 sprintf(line, "%s: Unknown fs: 0x%x %.6dMB (%d - %d)\n",
354 prefix, dp->dp_typ, dp->dp_size / 2048,
355 dp->dp_start, dp->dp_start + dp->dp_size);
357 sprintf(line, "%s: Unknown fs: 0x%x\n", prefix,
364 * Print out each valid partition in the disklabel of a FreeBSD slice.
365 * For size calculations, we assume a 512 byte sector size.
368 bd_printbsdslice(struct open_disk *od, daddr_t offset, char *prefix,
372 char buf[BIOSDISK_SECSIZE];
373 struct disklabel32 *lp;
377 if (bd_read(od, offset + LABELSECTOR32, 1, buf))
379 lp =(struct disklabel32 *)(&buf[0]);
380 if (lp->d_magic != DISKMAGIC32) {
381 sprintf(line, "%s: FFS bad disklabel\n", prefix);
386 /* Print partitions */
387 for (i = 0; i < lp->d_npartitions; i++) {
389 * For each partition, make sure we know what type of fs it is. If
390 * not, then skip it. However, since floppies often have bogus
391 * fstypes, print the 'a' partition on a floppy even if it is marked
394 if ((lp->d_partitions[i].p_fstype == FS_BSDFFS) ||
395 (lp->d_partitions[i].p_fstype == FS_SWAP) ||
396 (lp->d_partitions[i].p_fstype == FS_VINUM) ||
397 ((lp->d_partitions[i].p_fstype == FS_UNUSED) &&
398 (od->od_flags & BD_FLOPPY) && (i == 0))) {
400 /* Only print out statistics in verbose mode */
402 sprintf(line, " %s%c: %s %.6dMB (%d - %d)\n", prefix, 'a' + i,
403 (lp->d_partitions[i].p_fstype == FS_SWAP) ? "swap" :
404 (lp->d_partitions[i].p_fstype == FS_VINUM) ? "vinum" :
406 lp->d_partitions[i].p_size / 2048,
407 lp->d_partitions[i].p_offset,
408 lp->d_partitions[i].p_offset + lp->d_partitions[i].p_size);
410 sprintf(line, " %s%c: %s\n", prefix, 'a' + i,
411 (lp->d_partitions[i].p_fstype == FS_SWAP) ? "swap" :
412 (lp->d_partitions[i].p_fstype == FS_VINUM) ? "vinum" :
421 * Attempt to open the disk described by (dev) for use by (f).
423 * Note that the philosophy here is "give them exactly what
424 * they ask for". This is necessary because being too "smart"
425 * about what the user might want leads to complications.
426 * (eg. given no slice or partition value, with a disk that is
427 * sliced - are they after the first BSD slice, or the DOS
431 bd_open(struct open_file *f, ...)
434 struct i386_devdesc *dev;
435 struct open_disk *od;
439 dev = va_arg(ap, struct i386_devdesc *);
441 if ((error = bd_opendisk(&od, dev)))
447 ((struct i386_devdesc *)(f->f_devdata))->d_kind.biosdisk.data = od;
448 DEBUG("open_disk %p, partition at 0x%x", od, od->od_boff);
453 bd_opendisk(struct open_disk **odp, struct i386_devdesc *dev)
455 struct dos_partition *dptr;
456 struct disklabel32 *lp;
457 struct open_disk *od;
458 int sector, slice, i;
462 if (dev->d_kind.biosdisk.unit >= nbdinfo) {
463 DEBUG("attempt to open nonexistent disk");
467 od = (struct open_disk *)malloc(sizeof(struct open_disk));
473 /* Look up BIOS unit number, intialise open_disk structure */
474 od->od_dkunit = dev->d_kind.biosdisk.unit;
475 od->od_unit = bdinfo[od->od_dkunit].bd_unit;
476 od->od_flags = bdinfo[od->od_dkunit].bd_flags;
480 DEBUG("open '%s', unit 0x%x slice %d partition %c",
481 i386_fmtdev(dev), dev->d_kind.biosdisk.unit,
482 dev->d_kind.biosdisk.slice, dev->d_kind.biosdisk.partition + 'a');
484 /* Get geometry for this open (removable device may have changed) */
485 if (bd_getgeom(od)) {
486 DEBUG("can't get geometry");
492 * Following calculations attempt to determine the correct value
493 * for d->od_boff by looking for the slice and partition specified,
494 * or searching for reasonable defaults.
498 * Find the slice in the DOS slice table.
500 if (bd_read(od, 0, 1, buf)) {
501 DEBUG("error reading MBR");
507 * Check the slice table magic.
509 if (((u_char)buf[0x1fe] != 0x55) || ((u_char)buf[0x1ff] != 0xaa)) {
510 /* If a slice number was explicitly supplied, this is an error */
511 if (dev->d_kind.biosdisk.slice > 0) {
512 DEBUG("no slice table/MBR (no magic)");
517 goto unsliced; /* may be a floppy */
521 * copy the partition table, then pick up any extended partitions. The
522 * base partition table always has four entries, even if some of them
523 * represented extended partitions. However, any additional sub-extended
524 * partitions will be silently recursed and not included in the slice
527 bcopy(buf + DOSPARTOFF, &od->od_slicetab,
528 sizeof(struct dos_partition) * NDOSPART);
529 od->od_nslices = NDOSPART;
531 dptr = &od->od_slicetab[0];
532 for (i = 0; i < NDOSPART; i++, dptr++) {
533 if ((dptr->dp_typ == DOSPTYP_EXT) || (dptr->dp_typ == DOSPTYP_EXTLBA))
534 bd_chainextended(od, dptr->dp_start, 0); /* 1st offset is zero */
536 od->od_flags |= BD_PARTTABOK;
537 dptr = &od->od_slicetab[0];
540 * Overflow entries are not loaded into memory but we still keep
541 * track of the count. Fix it up now.
543 if (od->od_nslices > NEXTDOSPART)
544 od->od_nslices = NEXTDOSPART;
547 * Is this a request for the whole disk?
549 if (dev->d_kind.biosdisk.slice == -1) {
555 * if a slice number was supplied but not found, this is an error.
557 if (dev->d_kind.biosdisk.slice > 0) {
558 slice = dev->d_kind.biosdisk.slice - 1;
559 if (slice >= od->od_nslices) {
560 DEBUG("slice %d not found", slice);
567 * Check for the historically bogus MBR found on true dedicated disks
569 if ((dptr[3].dp_typ == DOSPTYP_386BSD) &&
570 (dptr[3].dp_start == 0) &&
571 (dptr[3].dp_size == 50000)) {
576 /* Try to auto-detect the best slice; this should always give a slice number */
577 if (dev->d_kind.biosdisk.slice == 0) {
578 slice = bd_bestslice(od);
583 dev->d_kind.biosdisk.slice = slice;
586 dptr = &od->od_slicetab[0];
588 * Accept the supplied slice number unequivocally (we may be looking
589 * at a DOS partition).
591 dptr += (dev->d_kind.biosdisk.slice - 1); /* we number 1-4, offsets are 0-3 */
592 sector = dptr->dp_start;
593 DEBUG("slice entry %d at %d, %d sectors", dev->d_kind.biosdisk.slice - 1, sector, dptr->dp_size);
596 * If we are looking at a BSD slice, and the partition is < 0, assume the 'a' partition
598 if ((dptr->dp_typ == DOSPTYP_386BSD) && (dev->d_kind.biosdisk.partition < 0))
599 dev->d_kind.biosdisk.partition = 0;
603 * Now we have the slice offset, look for the partition in the disklabel if we have
604 * a partition to start with.
606 * XXX we might want to check the label checksum.
608 if (dev->d_kind.biosdisk.partition < 0) {
609 od->od_boff = sector; /* no partition, must be after the slice */
610 DEBUG("opening raw slice");
613 if (bd_read(od, sector + LABELSECTOR32, 1, buf)) {
614 DEBUG("error reading disklabel");
618 DEBUG("copy %d bytes of label from %p to %p", sizeof(struct disklabel32), buf + LABELOFFSET32, &od->od_disklabel);
619 bcopy(buf + LABELOFFSET32, &od->od_disklabel, sizeof(struct disklabel32));
620 lp = &od->od_disklabel;
621 od->od_flags |= BD_LABELOK;
623 if (lp->d_magic != DISKMAGIC32) {
624 DEBUG("no disklabel");
628 if (dev->d_kind.biosdisk.partition >= lp->d_npartitions) {
629 DEBUG("partition '%c' exceeds partitions in table (a-'%c')",
630 'a' + dev->d_kind.biosdisk.partition, 'a' + lp->d_npartitions);
637 /* Complain if the partition is unused unless this is a floppy. */
638 if ((lp->d_partitions[dev->d_kind.biosdisk.partition].p_fstype == FS_UNUSED) &&
639 !(od->od_flags & BD_FLOPPY))
640 DEBUG("warning, partition marked as unused");
644 lp->d_partitions[dev->d_kind.biosdisk.partition].p_offset -
645 lp->d_partitions[RAW_PART].p_offset +
653 *odp = od; /* return the open disk */
660 bd_chainextended(struct open_disk *od, u_int32_t base, u_int32_t offset)
662 char buf[BIOSDISK_SECSIZE];
663 struct dos_partition *dp1, *dp2;
666 if (bd_read(od, (daddr_t)(base + offset), 1, buf)) {
667 printf("\nerror reading extended partition table");
672 * dp1 points to the first record in the on-disk XPT,
673 * dp2 points to the next entry in the in-memory parition table.
675 * NOTE: dp2 may be out of bounds if od_nslices >= NEXTDOSPART.
677 * NOTE: unlike the extended partitions in our primary dos partition
678 * table, we do not record recursed extended partitions themselves
679 * in our in-memory partition table.
681 * NOTE: recording within our in-memory table must be breadth first
682 * ot match what the kernel does. Thus, two passes are required.
684 * NOTE: partitioning programs which support extended partitions seem
685 * to always use the first entry for the user partition and the
686 * second entry to chain, and also appear to disallow more then one
687 * extended partition at each level. Nevertheless we make our code
688 * somewhat more generic (and the same as the kernel's own slice
691 dp1 = (struct dos_partition *)(&buf[DOSPARTOFF]);
692 dp2 = &od->od_slicetab[od->od_nslices];
694 for (i = 0; i < NDOSPART; ++i, ++dp1) {
695 if (dp1->dp_scyl == 0 && dp1->dp_shd == 0 &&
696 dp1->dp_ssect == 0 && dp1->dp_start == 0 &&
700 if ((dp1->dp_typ == DOSPTYP_EXT) ||
701 (dp1->dp_typ == DOSPTYP_EXTLBA)) {
703 * breadth first traversal, must skip in the
710 * Only load up the in-memory data if we haven't overflowed
711 * our in-memory array.
713 if (od->od_nslices < NEXTDOSPART) {
714 dp2->dp_typ = dp1->dp_typ;
715 dp2->dp_start = base + offset + dp1->dp_start;
716 dp2->dp_size = dp1->dp_size;
723 * Pass 2 - handle extended partitions. Note that the extended
724 * slice itself is not stored in the slice array when we recurse,
725 * but any 'original' top-level extended slices are. This is to
726 * match what the kernel does.
729 for (i = 0; i < NDOSPART; ++i, ++dp1) {
730 if (dp1->dp_scyl == 0 && dp1->dp_shd == 0 &&
731 dp1->dp_ssect == 0 && dp1->dp_start == 0 &&
735 if ((dp1->dp_typ == DOSPTYP_EXT) ||
736 (dp1->dp_typ == DOSPTYP_EXTLBA)) {
737 bd_chainextended(od, base, dp1->dp_start);
744 * Search for a slice with the following preferences:
746 * 1: Active FreeBSD slice
747 * 2: Non-active FreeBSD slice
748 * 3: Active Linux slice
749 * 4: non-active Linux slice
750 * 5: Active FAT/FAT32 slice
751 * 6: non-active FAT/FAT32 slice
753 #define PREF_RAWDISK 0
754 #define PREF_FBSD_ACT 1
756 #define PREF_LINUX_ACT 3
758 #define PREF_DOS_ACT 5
763 * slicelimit is in the range 0 .. NDOSPART
766 bd_bestslice(struct open_disk *od)
768 struct dos_partition *dp;
773 preflevel = PREF_NONE;
775 dp = &od->od_slicetab[0];
776 for (i = 0; i < od->od_nslices; i++, dp++) {
777 switch (dp->dp_typ) {
778 case DOSPTYP_386BSD: /* FreeBSD */
779 pref = dp->dp_flag & 0x80 ? PREF_FBSD_ACT : PREF_FBSD;
783 pref = dp->dp_flag & 0x80 ? PREF_LINUX_ACT : PREF_LINUX;
786 case 0x01: /* DOS/Windows */
792 pref = dp->dp_flag & 0x80 ? PREF_DOS_ACT : PREF_DOS;
798 if (pref < preflevel) {
807 bd_close(struct open_file *f)
809 struct open_disk *od = (struct open_disk *)(((struct i386_devdesc *)(f->f_devdata))->d_kind.biosdisk.data);
816 bd_closedisk(struct open_disk *od)
818 DEBUG("open_disk %p", od);
820 /* XXX is this required? (especially if disk already open...) */
821 if (od->od_flags & BD_FLOPPY)
828 bd_strategy(void *devdata, int rw, daddr_t dblk, size_t size, char *buf, size_t *rsize)
830 struct bcache_devdata bcd;
831 struct open_disk *od = (struct open_disk *)(((struct i386_devdesc *)devdata)->d_kind.biosdisk.data);
833 bcd.dv_strategy = bd_realstrategy;
834 bcd.dv_devdata = devdata;
835 return(bcache_strategy(&bcd, od->od_unit, rw, dblk+od->od_boff, size, buf, rsize));
839 bd_realstrategy(void *devdata, int rw, daddr_t dblk, size_t size, char *buf, size_t *rsize)
841 struct open_disk *od = (struct open_disk *)(((struct i386_devdesc *)devdata)->d_kind.biosdisk.data);
843 #ifdef BD_SUPPORT_FRAGS
844 char fragbuf[BIOSDISK_SECSIZE];
847 fragsize = size % BIOSDISK_SECSIZE;
849 if (size % BIOSDISK_SECSIZE)
850 panic("bd_strategy: %d bytes I/O not multiple of block size", size);
853 DEBUG("open_disk %p", od);
857 blks = size / BIOSDISK_SECSIZE;
858 DEBUG("read %d from %d to %p", blks, dblk, buf);
862 if (blks && bd_read(od, dblk, blks, buf)) {
866 #ifdef BD_SUPPORT_FRAGS
867 DEBUG("bd_strategy: frag read %d from %d+%d to %p",
868 fragsize, dblk, blks, buf + (blks * BIOSDISK_SECSIZE));
869 if (fragsize && bd_read(od, dblk + blks, 1, fragsize)) {
870 DEBUG("frag read error");
873 bcopy(fragbuf, buf + (blks * BIOSDISK_SECSIZE), fragsize);
879 blks = size / BIOSDISK_SECSIZE;
880 DEBUG("write %d from %d to %p", blks, dblk, buf);
884 if (blks && bd_write(od, dblk, blks, buf)) {
885 DEBUG("write error");
888 #ifdef BD_SUPPORT_FRAGS
890 DEBUG("Attempted to write a frag");
898 break; /* DO NOTHING */
903 /* Max number of sectors to bounce-buffer if the request crosses a 64k boundary */
904 #define FLOPPY_BOUNCEBUF 18
907 bd_read(struct open_disk *od, daddr_t dblk, int blks, caddr_t dest)
909 u_int x, bpc, cyl, hd, sec, result, resid, retry, maxfer;
910 caddr_t p, xp, bbuf, breg;
912 /* Just in case some idiot actually tries to read -1 blocks... */
916 bpc = (od->od_sec * od->od_hds); /* blocks per cylinder */
920 /* Decide whether we have to bounce */
921 if ((od->od_unit < 0x80) &&
922 ((VTOP(dest) >> 16) != (VTOP(dest + blks * BIOSDISK_SECSIZE) >> 16))) {
925 * There is a 64k physical boundary somewhere in the destination buffer, so we have
926 * to arrange a suitable bounce buffer. Allocate a buffer twice as large as we
927 * need to. Use the bottom half unless there is a break there, in which case we
930 x = min(FLOPPY_BOUNCEBUF, (unsigned)blks);
931 bbuf = malloc(x * 2 * BIOSDISK_SECSIZE);
932 if (((u_int32_t)VTOP(bbuf) & 0xffff0000) == ((u_int32_t)VTOP(bbuf + x * BIOSDISK_SECSIZE) & 0xffff0000)) {
935 breg = bbuf + x * BIOSDISK_SECSIZE;
937 maxfer = x; /* limit transfers to bounce region size */
945 cyl = x / bpc; /* block # / blocks per cylinder */
946 x %= bpc; /* block offset into cylinder */
947 hd = x / od->od_sec; /* offset / blocks per track */
948 sec = x % od->od_sec; /* offset into track */
950 /* play it safe and don't cross track boundaries (XXX this is probably unnecessary) */
951 x = min(od->od_sec - sec, resid);
953 x = min(x, maxfer); /* fit bounce buffer */
955 /* where do we transfer to? */
956 xp = bbuf == NULL ? p : breg;
958 /* correct sector number for 1-based BIOS numbering */
962 * Loop retrying the operation a couple of times. The BIOS may also
965 for (retry = 0; retry < 3; retry++) {
967 * If retrying, reset the drive.
973 v86.edx = od->od_unit;
978 * Always use EDD if the disk supports it, otherwise fall back
979 * to CHS mode (returning an error if the cylinder number is
982 if (od->od_flags & BD_MODEEDD1) {
983 static unsigned short packet[8];
987 packet[2] = VTOPOFF(xp);
988 packet[3] = VTOPSEG(xp);
989 packet[4] = dblk & 0xffff;
990 packet[5] = dblk >> 16;
996 v86.edx = od->od_unit;
997 v86.ds = VTOPSEG(packet);
998 v86.esi = VTOPOFF(packet);
1000 result = (v86.efl & 0x1);
1003 } else if (cyl < 1024) {
1004 /* Use normal CHS addressing */
1005 v86.ctl = V86_FLAGS;
1007 v86.eax = 0x200 | x;
1008 v86.ecx = ((cyl & 0xff) << 8) | ((cyl & 0x300) >> 2) | sec;
1009 v86.edx = (hd << 8) | od->od_unit;
1010 v86.es = VTOPSEG(xp);
1011 v86.ebx = VTOPOFF(xp);
1013 result = (v86.efl & 0x1);
1022 DEBUG("%d sectors from %d/%d/%d to %p (0x%x) %s", x, cyl, hd, sec - 1, p, VTOP(p), result ? "failed" : "ok");
1023 /* BUG here, cannot use v86 in printf because putchar uses it too */
1024 DEBUG("ax = 0x%04x cx = 0x%04x dx = 0x%04x status 0x%x",
1025 0x200 | x, ((cyl & 0xff) << 8) | ((cyl & 0x300) >> 2) | sec, (hd << 8) | od->od_unit, (v86.eax >> 8) & 0xff);
1032 bcopy(breg, p, x * BIOSDISK_SECSIZE);
1033 p += (x * BIOSDISK_SECSIZE);
1038 /* hexdump(dest, (blks * BIOSDISK_SECSIZE)); */
1046 bd_write(struct open_disk *od, daddr_t dblk, int blks, caddr_t dest)
1048 u_int x, bpc, cyl, hd, sec, result, resid, retry, maxfer;
1049 caddr_t p, xp, bbuf, breg;
1051 /* Just in case some idiot actually tries to read -1 blocks... */
1055 bpc = (od->od_sec * od->od_hds); /* blocks per cylinder */
1059 /* Decide whether we have to bounce */
1060 if ((od->od_unit < 0x80) &&
1061 ((VTOP(dest) >> 16) != (VTOP(dest + blks * BIOSDISK_SECSIZE) >> 16))) {
1064 * There is a 64k physical boundary somewhere in the destination buffer, so we have
1065 * to arrange a suitable bounce buffer. Allocate a buffer twice as large as we
1066 * need to. Use the bottom half unless there is a break there, in which case we
1070 x = min(FLOPPY_BOUNCEBUF, (unsigned)blks);
1071 bbuf = malloc(x * 2 * BIOSDISK_SECSIZE);
1072 if (((u_int32_t)VTOP(bbuf) & 0xffff0000) == ((u_int32_t)VTOP(bbuf + x * BIOSDISK_SECSIZE) & 0xffff0000)) {
1075 breg = bbuf + x * BIOSDISK_SECSIZE;
1077 maxfer = x; /* limit transfers to bounce region size */
1085 cyl = x / bpc; /* block # / blocks per cylinder */
1086 x %= bpc; /* block offset into cylinder */
1087 hd = x / od->od_sec; /* offset / blocks per track */
1088 sec = x % od->od_sec; /* offset into track */
1090 /* play it safe and don't cross track boundaries (XXX this is probably unnecessary) */
1091 x = min(od->od_sec - sec, resid);
1093 x = min(x, maxfer); /* fit bounce buffer */
1095 /* where do we transfer to? */
1096 xp = bbuf == NULL ? p : breg;
1098 /* correct sector number for 1-based BIOS numbering */
1102 /* Put your Data In, Put your Data out,
1103 Put your Data In, and shake it all about
1106 bcopy(p, breg, x * BIOSDISK_SECSIZE);
1107 p += (x * BIOSDISK_SECSIZE);
1112 * Loop retrying the operation a couple of times. The BIOS may also
1115 for (retry = 0; retry < 3; retry++) {
1117 * If retrying, reset the drive.
1120 v86.ctl = V86_FLAGS;
1123 v86.edx = od->od_unit;
1128 * Always use EDD if the disk supports it, otherwise fall back
1129 * to CHS mode (returning an error if the cylinder number is
1132 if (od->od_flags & BD_MODEEDD1) {
1133 static unsigned short packet[8];
1137 packet[2] = VTOPOFF(xp);
1138 packet[3] = VTOPSEG(xp);
1139 packet[4] = dblk & 0xffff;
1140 packet[5] = dblk >> 16;
1143 v86.ctl = V86_FLAGS;
1145 /* Should we Write with verify ?? 0x4302 ? */
1147 v86.edx = od->od_unit;
1148 v86.ds = VTOPSEG(packet);
1149 v86.esi = VTOPOFF(packet);
1151 result = (v86.efl & 0x1);
1154 } else if (cyl < 1024) {
1155 /* Use normal CHS addressing */
1156 v86.ctl = V86_FLAGS;
1158 v86.eax = 0x300 | x;
1159 v86.ecx = ((cyl & 0xff) << 8) | ((cyl & 0x300) >> 2) | sec;
1160 v86.edx = (hd << 8) | od->od_unit;
1161 v86.es = VTOPSEG(xp);
1162 v86.ebx = VTOPOFF(xp);
1164 result = (v86.efl & 0x1);
1173 DEBUG("%d sectors from %d/%d/%d to %p (0x%x) %s", x, cyl, hd, sec - 1, p, VTOP(p), result ? "failed" : "ok");
1174 /* BUG here, cannot use v86 in printf because putchar uses it too */
1175 DEBUG("ax = 0x%04x cx = 0x%04x dx = 0x%04x status 0x%x",
1176 0x200 | x, ((cyl & 0xff) << 8) | ((cyl & 0x300) >> 2) | sec, (hd << 8) | od->od_unit, (v86.eax >> 8) & 0xff);
1184 /* hexdump(dest, (blks * BIOSDISK_SECSIZE)); */
1190 bd_getgeom(struct open_disk *od)
1193 v86.ctl = V86_FLAGS;
1196 v86.edx = od->od_unit;
1199 if ((v86.efl & 0x1) || /* carry set */
1200 ((v86.edx & 0xff) <= (unsigned)(od->od_unit & 0x7f))) /* unit # bad */
1203 /* convert max cyl # -> # of cylinders */
1204 od->od_cyl = ((v86.ecx & 0xc0) << 2) + ((v86.ecx & 0xff00) >> 8) + 1;
1205 /* convert max head # -> # of heads */
1206 od->od_hds = ((v86.edx & 0xff00) >> 8) + 1;
1207 od->od_sec = v86.ecx & 0x3f;
1209 DEBUG("unit 0x%x geometry %d/%d/%d", od->od_unit, od->od_cyl, od->od_hds, od->od_sec);
1214 * Return the BIOS geometry of a given "fixed drive" in a format
1215 * suitable for the legacy bootinfo structure. Since the kernel is
1216 * expecting raw int 0x13/0x8 values for N_BIOS_GEOM drives, we
1217 * prefer to get the information directly, rather than rely on being
1218 * able to put it together from information already maintained for
1219 * different purposes and for a probably different number of drives.
1221 * For valid drives, the geometry is expected in the format (31..0)
1222 * "000000cc cccccccc hhhhhhhh 00ssssss"; and invalid drives are
1223 * indicated by returning the geometry of a "1.2M" PC-format floppy
1224 * disk. And, incidentally, what is returned is not the geometry as
1225 * such but the highest valid cylinder, head, and sector numbers.
1228 bd_getbigeom(int bunit)
1231 v86.ctl = V86_FLAGS;
1234 v86.edx = 0x80 + bunit;
1238 return ((v86.ecx & 0xc0) << 18) | ((v86.ecx & 0xff00) << 8) |
1239 (v86.edx & 0xff00) | (v86.ecx & 0x3f);
1243 * Return a suitable cdev_t value for (dev).
1245 * In the case where it looks like (dev) is a SCSI disk, we allow the number of
1246 * IDE disks to be specified in $num_ide_disks. There should be a Better Way.
1249 bd_getdev(struct i386_devdesc *dev)
1251 struct open_disk *od;
1256 int unitofs = 0, i, unit;
1258 biosdev = bd_unit2bios(dev->d_kind.biosdisk.unit);
1259 DEBUG("unit %d BIOS device %d", dev->d_kind.biosdisk.unit, biosdev);
1260 if (biosdev == -1) /* not a BIOS device */
1262 if (bd_opendisk(&od, dev) != 0) /* oops, not a viable device */
1265 if (biosdev < 0x80) {
1266 /* floppy (or emulated floppy) or ATAPI device */
1267 if (bdinfo[dev->d_kind.biosdisk.unit].bd_type == DT_ATAPI) {
1268 /* is an ATAPI disk */
1271 /* is a floppy disk */
1276 if ((od->od_flags & BD_LABELOK) && (od->od_disklabel.d_type == DTYPE_SCSI)) {
1277 /* label OK, disk labelled as SCSI */
1279 /* check for unit number correction hint, now deprecated */
1280 if ((nip = getenv("num_ide_disks")) != NULL) {
1281 i = strtol(nip, &cp, 0);
1282 /* check for parse error */
1283 if ((cp != nip) && (*cp == 0))
1287 /* assume an IDE disk */
1291 /* default root disk unit number */
1292 unit = (biosdev & 0x7f) - unitofs;
1294 /* XXX a better kludge to set the root disk unit number */
1295 if ((nip = getenv("root_disk_unit")) != NULL) {
1296 i = strtol(nip, &cp, 0);
1297 /* check for parse error */
1298 if ((cp != nip) && (*cp == 0))
1302 rootdev = MAKEBOOTDEV(major,
1303 (dev->d_kind.biosdisk.slice + 1) >> 4, /* XXX slices may be wrong here */
1304 (dev->d_kind.biosdisk.slice + 1) & 0xf,
1306 dev->d_kind.biosdisk.partition);
1307 DEBUG("dev is 0x%x\n", rootdev);