2 * Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
3 * Copyright (c) 2012 Andrey V. Elsukov <ae@FreeBSD.org>
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
32 * BIOS disk device handling.
34 * Ideas and algorithms from:
36 * - NetBSD libi386/biosdisk.c
37 * - FreeBSD biosboot/disk.c
42 #include <sys/limits.h>
44 #include <machine/bootinfo.h>
48 #include <bootstrap.h>
54 #define BIOS_NUMDRIVES 0x475
55 #define BIOSDISK_SECSIZE 512
56 #define BUFSIZE (1 * BIOSDISK_SECSIZE)
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 * List of BIOS devices, translation from disk unit number to
76 int bd_unit; /* BIOS unit number */
77 int bd_cyl; /* BIOS geometry */
81 #define BD_MODEINT13 0x0000
82 #define BD_MODEEDD1 0x0001
83 #define BD_MODEEDD3 0x0002
84 #define BD_MODEMASK 0x0003
85 #define BD_FLOPPY 0x0004
86 int bd_type; /* BIOS 'drive type' (floppy only) */
87 uint16_t bd_sectorsize; /* Sector size */
88 uint64_t bd_sectors; /* Disk size */
89 int bd_open; /* reference counter */
90 void *bd_bcache; /* buffer cache data */
92 static int nbdinfo = 0;
94 #define BD(dev) (bdinfo[(dev)->dd.d_unit])
98 static void bd_io_workaround(struct disk_devdesc *dev);
100 static int bd_io(struct disk_devdesc *, daddr_t, int, caddr_t, int);
101 static int bd_int13probe(struct bdinfo *bd);
103 static int bd_init(void);
104 static int bd_strategy(void *devdata, int flag, daddr_t dblk, size_t size,
105 char *buf, size_t *rsize);
106 static int bd_realstrategy(void *devdata, int flag, daddr_t dblk, size_t size,
107 char *buf, size_t *rsize);
108 static int bd_open(struct open_file *f, ...);
109 static int bd_close(struct open_file *f);
110 static int bd_ioctl(struct open_file *f, u_long cmd, void *data);
111 static int bd_print(int verbose);
113 struct devsw biosdisk = {
126 * Translate between BIOS device numbers and our private unit numbers.
129 bd_bios2unit(int biosdev)
133 DEBUG("looking for bios device 0x%x", biosdev);
134 for (i = 0; i < nbdinfo; i++) {
135 DEBUG("bd unit %d is BIOS device 0x%x", i, bdinfo[i].bd_unit);
136 if (bdinfo[i].bd_unit == biosdev)
143 bd_unit2bios(int unit)
146 if ((unit >= 0) && (unit < nbdinfo))
147 return (bdinfo[unit].bd_unit);
152 * Quiz the BIOS for disk devices, save a little info about them.
157 int base, unit, nfd = 0;
159 /* sequence 0, 0x80 */
160 for (base = 0; base <= 0x80; base += 0x80) {
161 for (unit = base; (nbdinfo < MAXBDDEV); unit++) {
164 * Check the BIOS equipment list for number
168 (nfd >= *(unsigned char *)PTOV(BIOS_NUMDRIVES)))
171 bdinfo[nbdinfo].bd_open = 0;
172 bdinfo[nbdinfo].bd_bcache = NULL;
173 bdinfo[nbdinfo].bd_unit = unit;
174 bdinfo[nbdinfo].bd_flags = unit < 0x80 ? BD_FLOPPY: 0;
175 if (!bd_int13probe(&bdinfo[nbdinfo]))
178 /* XXX we need "disk aliases" to make this simpler */
179 printf("BIOS drive %c: is disk%d\n", (unit < 0x80) ?
180 ('A' + unit): ('C' + unit - 0x80), nbdinfo);
186 bcache_add_dev(nbdinfo);
191 * Try to detect a device supported by the legacy int13 BIOS
194 bd_int13probe(struct bdinfo *bd)
196 struct edd_params params;
197 int ret = 1; /* assume success */
202 v86.edx = bd->bd_unit;
205 /* Don't error out if we get bad sector number, try EDD as well */
206 if (V86_CY(v86.efl) || /* carry set */
207 (v86.edx & 0xff) <= (unsigned)(bd->bd_unit & 0x7f)) /* unit # bad */
208 return (0); /* skip device */
210 if ((v86.ecx & 0x3f) == 0) /* absurd sector number */
211 ret = 0; /* set error */
213 /* Convert max cyl # -> # of cylinders */
214 bd->bd_cyl = ((v86.ecx & 0xc0) << 2) + ((v86.ecx & 0xff00) >> 8) + 1;
215 /* Convert max head # -> # of heads */
216 bd->bd_hds = ((v86.edx & 0xff00) >> 8) + 1;
217 bd->bd_sec = v86.ecx & 0x3f;
218 bd->bd_type = v86.ebx & 0xff;
219 bd->bd_flags |= BD_MODEINT13;
221 /* Calculate sectors count from the geometry */
222 bd->bd_sectors = bd->bd_cyl * bd->bd_hds * bd->bd_sec;
223 bd->bd_sectorsize = BIOSDISK_SECSIZE;
224 DEBUG("unit 0x%x geometry %d/%d/%d", bd->bd_unit, bd->bd_cyl,
225 bd->bd_hds, bd->bd_sec);
227 /* Determine if we can use EDD with this device. */
231 v86.edx = bd->bd_unit;
234 if (V86_CY(v86.efl) || /* carry set */
235 (v86.ebx & 0xffff) != 0xaa55 || /* signature */
236 (v86.ecx & EDD_INTERFACE_FIXED_DISK) == 0)
237 return (ret); /* return code from int13 AH=08 */
240 bd->bd_flags |= BD_MODEEDD1;
241 if ((v86.eax & 0xff00) >= 0x3000)
242 bd->bd_flags |= BD_MODEEDD3;
243 /* Get disk params */
244 params.len = sizeof(struct edd_params);
248 v86.edx = bd->bd_unit;
249 v86.ds = VTOPSEG(¶ms);
250 v86.esi = VTOPOFF(¶ms);
252 if (!V86_CY(v86.efl)) {
256 * Sector size must be a multiple of 512 bytes.
257 * An alternate test would be to check power of 2,
258 * powerof2(params.sector_size).
259 * 4K is largest read buffer we can use at this time.
261 if (params.sector_size >= 512 &&
262 params.sector_size <= 4096 &&
263 (params.sector_size % BIOSDISK_SECSIZE) == 0)
264 bd->bd_sectorsize = params.sector_size;
266 total = bd->bd_sectorsize * params.sectors;
267 if (params.sectors != 0) {
268 /* Only update if we did not overflow. */
269 if (total > params.sectors)
270 bd->bd_sectors = params.sectors;
273 total = (uint64_t)params.cylinders *
274 params.heads * params.sectors_per_track;
275 if (total > 0 && bd->bd_sectors > total)
276 bd->bd_sectors = total;
280 DEBUG("unit 0x%x flags %x, sectors %llu, sectorsize %u",
281 bd->bd_unit, bd->bd_flags, bd->bd_sectors, bd->bd_sectorsize);
286 * Print information about disks
289 bd_print(int verbose)
291 static char line[80];
292 struct disk_devdesc dev;
298 printf("%s devices:", biosdisk.dv_name);
299 if ((ret = pager_output("\n")) != 0)
302 for (i = 0; i < nbdinfo; i++) {
303 snprintf(line, sizeof(line),
304 " disk%d: BIOS drive %c (%ju X %u):\n", i,
305 (bdinfo[i].bd_unit < 0x80) ? ('A' + bdinfo[i].bd_unit):
306 ('C' + bdinfo[i].bd_unit - 0x80),
307 (uintmax_t)bdinfo[i].bd_sectors,
308 bdinfo[i].bd_sectorsize);
309 if ((ret = pager_output(line)) != 0)
312 dev.dd.d_dev = &biosdisk;
315 dev.d_partition = -1;
317 bdinfo[i].bd_sectorsize * bdinfo[i].bd_sectors,
318 bdinfo[i].bd_sectorsize) == 0) {
319 snprintf(line, sizeof(line), " disk%d", i);
320 ret = disk_print(&dev, line, verbose);
330 * Attempt to open the disk described by (dev) for use by (f).
332 * Note that the philosophy here is "give them exactly what
333 * they ask for". This is necessary because being too "smart"
334 * about what the user might want leads to complications.
335 * (eg. given no slice or partition value, with a disk that is
336 * sliced - are they after the first BSD slice, or the DOS
340 bd_open(struct open_file *f, ...)
342 struct disk_devdesc *dev;
343 struct disk_devdesc disk;
349 dev = va_arg(ap, struct disk_devdesc *);
352 if (dev->dd.d_unit < 0 || dev->dd.d_unit >= nbdinfo)
355 if (BD(dev).bd_bcache == NULL)
356 BD(dev).bd_bcache = bcache_allocate();
359 * Read disk size from partition.
360 * This is needed to work around buggy BIOS systems returning
361 * wrong (truncated) disk media size.
362 * During bd_probe() we tested if the mulitplication of bd_sectors
363 * would overflow so it should be safe to perform here.
365 disk.dd.d_dev = dev->dd.d_dev;
366 disk.dd.d_unit = dev->dd.d_unit;
368 disk.d_partition = -1;
371 if (disk_open(&disk, BD(dev).bd_sectors * BD(dev).bd_sectorsize,
372 BD(dev).bd_sectorsize) == 0) {
374 if (disk_ioctl(&disk, DIOCGMEDIASIZE, &size) == 0) {
375 size /= BD(dev).bd_sectorsize;
376 if (size > BD(dev).bd_sectors)
377 BD(dev).bd_sectors = size;
382 rc = disk_open(dev, BD(dev).bd_sectors * BD(dev).bd_sectorsize,
383 BD(dev).bd_sectorsize);
386 if (BD(dev).bd_open == 0) {
387 bcache_free(BD(dev).bd_bcache);
388 BD(dev).bd_bcache = NULL;
395 bd_close(struct open_file *f)
397 struct disk_devdesc *dev;
399 dev = (struct disk_devdesc *)f->f_devdata;
401 if (BD(dev).bd_open == 0) {
402 bcache_free(BD(dev).bd_bcache);
403 BD(dev).bd_bcache = NULL;
405 return (disk_close(dev));
409 bd_ioctl(struct open_file *f, u_long cmd, void *data)
411 struct disk_devdesc *dev;
414 dev = (struct disk_devdesc *)f->f_devdata;
416 rc = disk_ioctl(dev, cmd, data);
421 case DIOCGSECTORSIZE:
422 *(uint32_t *)data = BD(dev).bd_sectorsize;
425 *(uint64_t *)data = BD(dev).bd_sectors * BD(dev).bd_sectorsize;
434 bd_strategy(void *devdata, int rw, daddr_t dblk, size_t size,
435 char *buf, size_t *rsize)
437 struct bcache_devdata bcd;
438 struct disk_devdesc *dev;
440 dev = (struct disk_devdesc *)devdata;
441 bcd.dv_strategy = bd_realstrategy;
442 bcd.dv_devdata = devdata;
443 bcd.dv_cache = BD(dev).bd_bcache;
444 return (bcache_strategy(&bcd, rw, dblk + dev->d_offset, size,
449 bd_realstrategy(void *devdata, int rw, daddr_t dblk, size_t size,
450 char *buf, size_t *rsize)
452 struct disk_devdesc *dev = (struct disk_devdesc *)devdata;
453 uint64_t disk_blocks, offset;
454 size_t blks, blkoff, bsize, rest;
459 * First make sure the IO size is a multiple of 512 bytes. While we do
460 * process partial reads below, the strategy mechanism is built
461 * assuming IO is a multiple of 512B blocks. If the request is not
462 * a multiple of 512B blocks, it has to be some sort of bug.
464 if (size == 0 || (size % BIOSDISK_SECSIZE) != 0) {
465 printf("bd_strategy: %d bytes I/O not multiple of %d\n",
466 size, BIOSDISK_SECSIZE);
470 DEBUG("open_disk %p", dev);
472 offset = dblk * BIOSDISK_SECSIZE;
473 dblk = offset / BD(dev).bd_sectorsize;
474 blkoff = offset % BD(dev).bd_sectorsize;
477 * Check the value of the size argument. We do have quite small
478 * heap (64MB), but we do not know good upper limit, so we check against
479 * INT_MAX here. This will also protect us against possible overflows
480 * while translating block count to bytes.
482 if (size > INT_MAX) {
483 DEBUG("too large I/O: %zu bytes", size);
487 blks = size / BD(dev).bd_sectorsize;
488 if (blks == 0 || (size % BD(dev).bd_sectorsize) != 0)
491 if (dblk > dblk + blks)
498 * Get disk blocks, this value is either for whole disk or for
501 if (disk_ioctl(dev, DIOCGMEDIASIZE, &disk_blocks) == 0) {
502 /* DIOCGMEDIASIZE returns bytes. */
503 disk_blocks /= BD(dev).bd_sectorsize;
505 /* We should not get here. Just try to survive. */
506 disk_blocks = BD(dev).bd_sectors - dev->d_offset;
509 /* Validate source block address. */
510 if (dblk < dev->d_offset || dblk >= dev->d_offset + disk_blocks)
514 * Truncate if we are crossing disk or partition end.
516 if (dblk + blks >= dev->d_offset + disk_blocks) {
517 blks = dev->d_offset + disk_blocks - dblk;
518 size = blks * BD(dev).bd_sectorsize;
519 DEBUG("short I/O %d", blks);
522 if (V86_IO_BUFFER_SIZE / BD(dev).bd_sectorsize == 0)
523 panic("BUG: Real mode buffer is too small\n");
525 bbuf = PTOV(V86_IO_BUFFER);
529 int x = min(blks, V86_IO_BUFFER_SIZE / BD(dev).bd_sectorsize);
531 switch (rw & F_MASK) {
533 DEBUG("read %d from %lld to %p", x, dblk, buf);
534 bsize = BD(dev).bd_sectorsize * x - blkoff;
538 if ((rc = bd_io(dev, dblk, x, bbuf, BD_RD)) != 0)
541 bcopy(bbuf + blkoff, buf, bsize);
544 DEBUG("write %d from %lld to %p", x, dblk, buf);
547 * We got offset to sector, read 1 sector to
551 bsize = BD(dev).bd_sectorsize - blkoff;
552 bsize = min(bsize, rest);
553 rc = bd_io(dev, dblk, x, bbuf, BD_RD);
554 } else if (rest < BD(dev).bd_sectorsize) {
556 * The remaining block is not full
557 * sector. Read 1 sector to bbuf.
561 rc = bd_io(dev, dblk, x, bbuf, BD_RD);
563 /* We can write full sector(s). */
564 bsize = BD(dev).bd_sectorsize * x;
567 * Put your Data In, Put your Data out,
568 * Put your Data In, and shake it all about
570 bcopy(buf, bbuf + blkoff, bsize);
571 if ((rc = bd_io(dev, dblk, x, bbuf, BD_WR)) != 0)
593 bd_edd_io(struct disk_devdesc *dev, daddr_t dblk, int blks, caddr_t dest,
596 static struct edd_packet packet;
598 packet.len = sizeof(struct edd_packet);
600 packet.off = VTOPOFF(dest);
601 packet.seg = VTOPSEG(dest);
605 /* Should we Write with verify ?? 0x4302 ? */
606 if (dowrite == BD_WR)
610 v86.edx = BD(dev).bd_unit;
611 v86.ds = VTOPSEG(&packet);
612 v86.esi = VTOPOFF(&packet);
615 return (v86.eax >> 8);
620 bd_chs_io(struct disk_devdesc *dev, daddr_t dblk, int blks, caddr_t dest,
623 uint32_t x, bpc, cyl, hd, sec;
625 bpc = BD(dev).bd_sec * BD(dev).bd_hds; /* blocks per cylinder */
627 cyl = x / bpc; /* block # / blocks per cylinder */
628 x %= bpc; /* block offset into cylinder */
629 hd = x / BD(dev).bd_sec; /* offset / blocks per track */
630 sec = x % BD(dev).bd_sec; /* offset into track */
632 /* correct sector number for 1-based BIOS numbering */
636 /* CHS doesn't support cylinders > 1023. */
642 if (dowrite == BD_WR)
643 v86.eax = 0x300 | blks;
645 v86.eax = 0x200 | blks;
646 v86.ecx = ((cyl & 0xff) << 8) | ((cyl & 0x300) >> 2) | sec;
647 v86.edx = (hd << 8) | BD(dev).bd_unit;
648 v86.es = VTOPSEG(dest);
649 v86.ebx = VTOPOFF(dest);
652 return (v86.eax >> 8);
657 bd_io_workaround(struct disk_devdesc *dev)
659 uint8_t buf[8 * 1024];
661 bd_edd_io(dev, 0xffffffff, 1, (caddr_t)buf, BD_RD);
665 bd_io(struct disk_devdesc *dev, daddr_t dblk, int blks, caddr_t dest,
670 /* Just in case some idiot actually tries to read/write -1 blocks... */
675 * Workaround for a problem with some HP ProLiant BIOS failing to work
676 * out the boot disk after installation. hrs and kuriyama discovered
677 * this problem with an HP ProLiant DL320e Gen 8 with a 3TB HDD, and
678 * discovered that an int13h call seems to cause a buffer overrun in
679 * the bios. The problem is alleviated by doing an extra read before
680 * the buggy read. It is not immediately known whether other models
681 * are similarly affected.
682 * Loop retrying the operation a couple of times. The BIOS
685 if (dowrite == BD_RD && dblk >= 0x100000000)
686 bd_io_workaround(dev);
687 for (retry = 0; retry < 3; retry++) {
688 /* if retrying, reset the drive */
693 v86.edx = BD(dev).bd_unit;
697 if (BD(dev).bd_flags & BD_MODEEDD1)
698 result = bd_edd_io(dev, dblk, blks, dest, dowrite);
700 result = bd_chs_io(dev, dblk, blks, dest, dowrite);
707 * 0x20 - Controller failure. This is common error when the
708 * media is not present.
710 if (result != 0 && result != 0x20) {
711 if (dowrite == BD_WR) {
712 printf("%s%d: Write %d sector(s) from %p (0x%x) "
713 "to %lld: 0x%x\n", dev->dd.d_dev->dv_name,
714 dev->dd.d_unit, blks, dest, VTOP(dest), dblk,
717 printf("%s%d: Read %d sector(s) from %lld to %p "
718 "(0x%x): 0x%x\n", dev->dd.d_dev->dv_name,
719 dev->dd.d_unit, blks, dblk, dest, VTOP(dest),
728 * Return the BIOS geometry of a given "fixed drive" in a format
729 * suitable for the legacy bootinfo structure. Since the kernel is
730 * expecting raw int 0x13/0x8 values for N_BIOS_GEOM drives, we
731 * prefer to get the information directly, rather than rely on being
732 * able to put it together from information already maintained for
733 * different purposes and for a probably different number of drives.
735 * For valid drives, the geometry is expected in the format (31..0)
736 * "000000cc cccccccc hhhhhhhh 00ssssss"; and invalid drives are
737 * indicated by returning the geometry of a "1.2M" PC-format floppy
738 * disk. And, incidentally, what is returned is not the geometry as
739 * such but the highest valid cylinder, head, and sector numbers.
742 bd_getbigeom(int bunit)
748 v86.edx = 0x80 + bunit;
752 return (((v86.ecx & 0xc0) << 18) | ((v86.ecx & 0xff00) << 8) |
753 (v86.edx & 0xff00) | (v86.ecx & 0x3f));
757 * Return a suitable dev_t value for (dev).
759 * In the case where it looks like (dev) is a SCSI disk, we allow the number of
760 * IDE disks to be specified in $num_ide_disks. There should be a Better Way.
763 bd_getdev(struct i386_devdesc *d)
765 struct disk_devdesc *dev;
772 dev = (struct disk_devdesc *)d;
773 biosdev = bd_unit2bios(dev->dd.d_unit);
774 DEBUG("unit %d BIOS device %d", dev->dd.d_unit, biosdev);
775 if (biosdev == -1) /* not a BIOS device */
777 if (disk_open(dev, BD(dev).bd_sectors * BD(dev).bd_sectorsize,
778 BD(dev).bd_sectorsize) != 0) /* oops, not a viable device */
783 if (biosdev < 0x80) {
784 /* floppy (or emulated floppy) or ATAPI device */
785 if (bdinfo[dev->dd.d_unit].bd_type == DT_ATAPI) {
786 /* is an ATAPI disk */
789 /* is a floppy disk */
793 /* assume an IDE disk */
796 /* default root disk unit number */
797 unit = biosdev & 0x7f;
799 /* XXX a better kludge to set the root disk unit number */
800 if ((nip = getenv("root_disk_unit")) != NULL) {
801 i = strtol(nip, &cp, 0);
802 /* check for parse error */
803 if ((cp != nip) && (*cp == 0))
807 rootdev = MAKEBOOTDEV(major, dev->d_slice + 1, unit, dev->d_partition);
808 DEBUG("dev is 0x%x\n", rootdev);