1/*-
2 * Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
3 * Copyright (c) 2012 Andrey V. Elsukov <ae@FreeBSD.org>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
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.
14 *
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
25 * SUCH DAMAGE.
26 */
27
28#include <sys/cdefs.h>
29__FBSDID("$FreeBSD$");
30
31/*
32 * BIOS disk device handling.
33 *
34 * Ideas and algorithms from:
35 *
36 * - NetBSD libi386/biosdisk.c
37 * - FreeBSD biosboot/disk.c
38 *
39 */
40
41#include <sys/disk.h>
42#include <sys/limits.h>
43#include <sys/queue.h>
44#include <stand.h>
45#include <machine/bootinfo.h>
46#include <stdarg.h>
47#include <stdbool.h>
48
49#include <bootstrap.h>
50#include <btxv86.h>
51#include <edd.h>
52#include "disk.h"
53#include "libi386.h"
54
55#define	BIOS_NUMDRIVES		0x475
56#define	BIOSDISK_SECSIZE	512
57#define	BUFSIZE			(1 * BIOSDISK_SECSIZE)
58
59#define	DT_ATAPI	0x10	/* disk type for ATAPI floppies */
60#define	WDMAJOR		0	/* major numbers for devices we frontend for */
61#define	WFDMAJOR	1
62#define	FDMAJOR		2
63#define	DAMAJOR		4
64#define	ACDMAJOR	117
65#define	CDMAJOR		15
66
67/*
68 * INT13 commands
69 */
70#define	CMD_RESET	0x0000
71#define	CMD_READ_CHS	0x0200
72#define	CMD_WRITE_CHS	0x0300
73#define	CMD_READ_PARAM	0x0800
74#define	CMD_DRIVE_TYPE	0x1500
75#define	CMD_CHECK_EDD	0x4100
76#define	CMD_READ_LBA	0x4200
77#define	CMD_WRITE_LBA	0x4300
78#define	CMD_EXT_PARAM	0x4800
79#define	CMD_CD_GET_STATUS 0x4b01
80
81#define	DISK_BIOS	0x13
82
83#ifdef DISK_DEBUG
84#define	DPRINTF(fmt, args...)	printf("%s: " fmt "\n", __func__, ## args)
85#else
86#define	DPRINTF(fmt, args...)	((void)0)
87#endif
88
89struct specification_packet {
90	uint8_t		sp_size;
91	uint8_t		sp_bootmedia;
92	uint8_t		sp_drive;
93	uint8_t		sp_controller;
94	uint32_t	sp_lba;
95	uint16_t	sp_devicespec;
96	uint16_t	sp_buffersegment;
97	uint16_t	sp_loadsegment;
98	uint16_t	sp_sectorcount;
99	uint16_t	sp_cylsec;
100	uint8_t		sp_head;
101	uint8_t		sp_dummy[16];	/* Avoid memory corruption */
102};
103
104/*
105 * List of BIOS devices, translation from disk unit number to
106 * BIOS unit number.
107 */
108typedef struct bdinfo
109{
110	STAILQ_ENTRY(bdinfo)	bd_link;	/* link in device list */
111	int		bd_unit;	/* BIOS unit number */
112	int		bd_cyl;		/* BIOS geometry */
113	int		bd_hds;
114	int		bd_sec;
115	int		bd_flags;
116#define	BD_MODEINT13	0x0000
117#define	BD_MODEEDD1	0x0001
118#define	BD_MODEEDD3	0x0002
119#define	BD_MODEEDD	(BD_MODEEDD1 | BD_MODEEDD3)
120#define	BD_MODEMASK	0x0003
121#define	BD_FLOPPY	0x0004
122#define	BD_CDROM	0x0008
123#define	BD_NO_MEDIA	0x0010
124	int		bd_type;	/* BIOS 'drive type' (floppy only) */
125	uint16_t	bd_sectorsize;	/* Sector size */
126	uint64_t	bd_sectors;	/* Disk size */
127	int		bd_open;	/* reference counter */
128	void		*bd_bcache;	/* buffer cache data */
129} bdinfo_t;
130
131#define	BD_RD		0
132#define	BD_WR		1
133
134typedef STAILQ_HEAD(bdinfo_list, bdinfo) bdinfo_list_t;
135static bdinfo_list_t fdinfo = STAILQ_HEAD_INITIALIZER(fdinfo);
136static bdinfo_list_t cdinfo = STAILQ_HEAD_INITIALIZER(cdinfo);
137static bdinfo_list_t hdinfo = STAILQ_HEAD_INITIALIZER(hdinfo);
138
139static void bd_io_workaround(bdinfo_t *);
140static int bd_io(struct disk_devdesc *, bdinfo_t *, daddr_t, int, caddr_t, int);
141static bool bd_int13probe(bdinfo_t *);
142
143static int bd_init(void);
144static int cd_init(void);
145static int fd_init(void);
146static int bd_strategy(void *devdata, int flag, daddr_t dblk, size_t size,
147    char *buf, size_t *rsize);
148static int bd_realstrategy(void *devdata, int flag, daddr_t dblk, size_t size,
149    char *buf, size_t *rsize);
150static int bd_open(struct open_file *f, ...);
151static int bd_close(struct open_file *f);
152static int bd_ioctl(struct open_file *f, u_long cmd, void *data);
153static int bd_print(int verbose);
154static int cd_print(int verbose);
155static int fd_print(int verbose);
156static void bd_reset_disk(int);
157static int bd_get_diskinfo_std(struct bdinfo *);
158
159struct devsw biosfd = {
160	.dv_name = "fd",
161	.dv_type = DEVT_FD,
162	.dv_init = fd_init,
163	.dv_strategy = bd_strategy,
164	.dv_open = bd_open,
165	.dv_close = bd_close,
166	.dv_ioctl = bd_ioctl,
167	.dv_print = fd_print,
168	.dv_cleanup = NULL
169};
170
171struct devsw bioscd = {
172	.dv_name = "cd",
173	.dv_type = DEVT_CD,
174	.dv_init = cd_init,
175	.dv_strategy = bd_strategy,
176	.dv_open = bd_open,
177	.dv_close = bd_close,
178	.dv_ioctl = bd_ioctl,
179	.dv_print = cd_print,
180	.dv_cleanup = NULL
181};
182
183struct devsw bioshd = {
184	.dv_name = "disk",
185	.dv_type = DEVT_DISK,
186	.dv_init = bd_init,
187	.dv_strategy = bd_strategy,
188	.dv_open = bd_open,
189	.dv_close = bd_close,
190	.dv_ioctl = bd_ioctl,
191	.dv_print = bd_print,
192	.dv_cleanup = NULL
193};
194
195static bdinfo_list_t *
196bd_get_bdinfo_list(struct devsw *dev)
197{
198	if (dev->dv_type == DEVT_DISK)
199		return (&hdinfo);
200	if (dev->dv_type == DEVT_CD)
201		return (&cdinfo);
202	if (dev->dv_type == DEVT_FD)
203		return (&fdinfo);
204	return (NULL);
205}
206
207/* XXX this gets called way way too often, investigate */
208static bdinfo_t *
209bd_get_bdinfo(struct devdesc *dev)
210{
211	bdinfo_list_t *bdi;
212	bdinfo_t *bd = NULL;
213	int unit;
214
215	bdi = bd_get_bdinfo_list(dev->d_dev);
216	if (bdi == NULL)
217		return (bd);
218
219	unit = 0;
220	STAILQ_FOREACH(bd, bdi, bd_link) {
221		if (unit == dev->d_unit)
222			return (bd);
223		unit++;
224	}
225	return (bd);
226}
227
228/*
229 * Translate between BIOS device numbers and our private unit numbers.
230 */
231int
232bd_bios2unit(int biosdev)
233{
234	bdinfo_list_t *bdi[] = { &fdinfo, &cdinfo, &hdinfo, NULL };
235	bdinfo_t *bd;
236	int i, unit;
237
238	DPRINTF("looking for bios device 0x%x", biosdev);
239	for (i = 0; bdi[i] != NULL; i++) {
240		unit = 0;
241		STAILQ_FOREACH(bd, bdi[i], bd_link) {
242			if (bd->bd_unit == biosdev) {
243				DPRINTF("bd unit %d is BIOS device 0x%x", unit,
244				    bd->bd_unit);
245				return (unit);
246			}
247			unit++;
248		}
249	}
250	return (-1);
251}
252
253int
254bd_unit2bios(struct i386_devdesc *dev)
255{
256	bdinfo_list_t *bdi;
257	bdinfo_t *bd;
258	int unit;
259
260	bdi = bd_get_bdinfo_list(dev->dd.d_dev);
261	if (bdi == NULL)
262		return (-1);
263
264	unit = 0;
265	STAILQ_FOREACH(bd, bdi, bd_link) {
266		if (unit == dev->dd.d_unit)
267			return (bd->bd_unit);
268		unit++;
269	}
270	return (-1);
271}
272
273/*
274 * Use INT13 AH=15 - Read Drive Type.
275 */
276static int
277fd_count(void)
278{
279	int drive;
280
281	for (drive = 0; drive < MAXBDDEV; drive++) {
282		bd_reset_disk(drive);
283
284		v86.ctl = V86_FLAGS;
285		v86.addr = DISK_BIOS;
286		v86.eax = CMD_DRIVE_TYPE;
287		v86.edx = drive;
288		v86int();
289
290		if (V86_CY(v86.efl))
291			break;
292
293		if ((v86.eax & 0x300) == 0)
294			break;
295	}
296
297	return (drive);
298}
299
300/*
301 * Quiz the BIOS for disk devices, save a little info about them.
302 */
303static int
304fd_init(void)
305{
306	int unit, numfd;
307	bdinfo_t *bd;
308
309	numfd = fd_count();
310	for (unit = 0; unit < numfd; unit++) {
311		if ((bd = calloc(1, sizeof(*bd))) == NULL)
312			break;
313
314		bd->bd_sectorsize = BIOSDISK_SECSIZE;
315		bd->bd_flags = BD_FLOPPY;
316		bd->bd_unit = unit;
317
318		/* Use std diskinfo for floppy drive */
319		if (bd_get_diskinfo_std(bd) != 0) {
320			free(bd);
321			break;
322		}
323		if (bd->bd_sectors == 0)
324			bd->bd_flags |= BD_NO_MEDIA;
325
326		printf("BIOS drive %c: is %s%d\n", ('A' + unit),
327		    biosfd.dv_name, unit);
328
329		STAILQ_INSERT_TAIL(&fdinfo, bd, bd_link);
330	}
331
332	bcache_add_dev(unit);
333	return (0);
334}
335
336static int
337bd_init(void)
338{
339	int base, unit;
340	bdinfo_t *bd;
341
342	base = 0x80;
343	for (unit = 0; unit < *(unsigned char *)PTOV(BIOS_NUMDRIVES); unit++) {
344		/*
345		 * Check the BIOS equipment list for number of fixed disks.
346		 */
347		if ((bd = calloc(1, sizeof(*bd))) == NULL)
348			break;
349		bd->bd_unit = base + unit;
350		if (!bd_int13probe(bd)) {
351			free(bd);
352			break;
353		}
354
355		printf("BIOS drive %c: is %s%d\n", ('C' + unit),
356		    bioshd.dv_name, unit);
357
358		STAILQ_INSERT_TAIL(&hdinfo, bd, bd_link);
359	}
360	bcache_add_dev(unit);
361	return (0);
362}
363
364/*
365 * We can't quiz, we have to be told what device to use, so this function
366 * doesn't do anything.  Instead, the loader calls bc_add() with the BIOS
367 * device number to add.
368 */
369static int
370cd_init(void)
371{
372
373	return (0);
374}
375
376/*
377 * Information from bootable CD-ROM.
378 */
379static int
380bd_get_diskinfo_cd(struct bdinfo *bd)
381{
382	struct specification_packet bc_sp;
383	int ret = -1;
384
385	(void) memset(&bc_sp, 0, sizeof (bc_sp));
386	/* Set sp_size as per specification. */
387	bc_sp.sp_size = sizeof (bc_sp) - sizeof (bc_sp.sp_dummy);
388
389        v86.ctl = V86_FLAGS;
390        v86.addr = DISK_BIOS;
391        v86.eax = CMD_CD_GET_STATUS;
392        v86.edx = bd->bd_unit;
393        v86.ds = VTOPSEG(&bc_sp);
394        v86.esi = VTOPOFF(&bc_sp);
395        v86int();
396
397	if ((v86.eax & 0xff00) == 0 &&
398	    bc_sp.sp_drive == bd->bd_unit) {
399		bd->bd_cyl = ((bc_sp.sp_cylsec & 0xc0) << 2) +
400		    ((bc_sp.sp_cylsec & 0xff00) >> 8) + 1;
401		bd->bd_sec = bc_sp.sp_cylsec & 0x3f;
402		bd->bd_hds = bc_sp.sp_head + 1;
403		bd->bd_sectors = (uint64_t)bd->bd_cyl * bd->bd_hds * bd->bd_sec;
404
405		if (bc_sp.sp_bootmedia & 0x0F) {
406			/* Floppy or hard-disk emulation */
407			bd->bd_sectorsize = BIOSDISK_SECSIZE;
408			return (-1);
409		} else {
410			bd->bd_sectorsize = 2048;
411			bd->bd_flags = BD_MODEEDD | BD_CDROM;
412			ret = 0;
413		}
414	}
415
416	/*
417	 * If this is the boot_drive, default to non-emulation bootable CD-ROM.
418	 */
419	if (ret != 0 && bd->bd_unit >= 0x88) {
420		bd->bd_cyl = 0;
421		bd->bd_hds = 1;
422		bd->bd_sec = 15;
423		bd->bd_sectorsize = 2048;
424		bd->bd_flags = BD_MODEEDD | BD_CDROM;
425		bd->bd_sectors = 0;
426		ret = 0;
427	}
428
429	/*
430	 * Note we can not use bd_get_diskinfo_ext() nor bd_get_diskinfo_std()
431	 * here - some systems do get hung with those.
432	 */
433	/*
434	 * Still no size? use 7.961GB. The size does not really matter
435	 * as long as it is reasonably large to make our reads to pass
436	 * the sector count check.
437	 */
438	if (bd->bd_sectors == 0)
439		bd->bd_sectors = 4173824;
440
441	return (ret);
442}
443
444int
445bc_add(int biosdev)
446{
447	bdinfo_t *bd;
448	int nbcinfo = 0;
449
450	if (!STAILQ_EMPTY(&cdinfo))
451                return (-1);
452
453	if ((bd = calloc(1, sizeof(*bd))) == NULL)
454		return (-1);
455
456	bd->bd_unit = biosdev;
457	if (bd_get_diskinfo_cd(bd) < 0) {
458		free(bd);
459		return (-1);
460	}
461
462	STAILQ_INSERT_TAIL(&cdinfo, bd, bd_link);
463        printf("BIOS CD is cd%d\n", nbcinfo);
464        nbcinfo++;
465        bcache_add_dev(nbcinfo);        /* register cd device in bcache */
466        return(0);
467}
468
469/*
470 * Return EDD version or 0 if EDD is not supported on this drive.
471 */
472static int
473bd_check_extensions(int unit)
474{
475	/* do not use ext calls for floppy devices */
476	if (unit < 0x80)
477		return (0);
478
479	/* Determine if we can use EDD with this device. */
480	v86.ctl = V86_FLAGS;
481	v86.addr = DISK_BIOS;
482	v86.eax = CMD_CHECK_EDD;
483	v86.edx = unit;
484	v86.ebx = EDD_QUERY_MAGIC;
485	v86int();
486
487	if (V86_CY(v86.efl) ||			/* carry set */
488	    (v86.ebx & 0xffff) != EDD_INSTALLED) /* signature */
489		return (0);
490
491	/* extended disk access functions (AH=42h-44h,47h,48h) supported */
492	if ((v86.ecx & EDD_INTERFACE_FIXED_DISK) == 0)
493		return (0);
494
495	return ((v86.eax >> 8) & 0xff);
496}
497
498static void
499bd_reset_disk(int unit)
500{
501	/* reset disk */
502	v86.ctl = V86_FLAGS;
503	v86.addr = DISK_BIOS;
504	v86.eax = CMD_RESET;
505	v86.edx = unit;
506	v86int();
507}
508
509/*
510 * Read CHS info. Return 0 on success, error otherwise.
511 */
512static int
513bd_get_diskinfo_std(struct bdinfo *bd)
514{
515	bzero(&v86, sizeof(v86));
516	v86.ctl = V86_FLAGS;
517	v86.addr = DISK_BIOS;
518	v86.eax = CMD_READ_PARAM;
519	v86.edx = bd->bd_unit;
520	v86int();
521
522	if (V86_CY(v86.efl) && ((v86.eax & 0xff00) != 0))
523		return ((v86.eax & 0xff00) >> 8);
524
525	/* return custom error on absurd sector number */
526	if ((v86.ecx & 0x3f) == 0)
527		return (0x60);
528
529	bd->bd_cyl = ((v86.ecx & 0xc0) << 2) + ((v86.ecx & 0xff00) >> 8) + 1;
530	/* Convert max head # -> # of heads */
531	bd->bd_hds = ((v86.edx & 0xff00) >> 8) + 1;
532	bd->bd_sec = v86.ecx & 0x3f;
533	bd->bd_type = v86.ebx;
534	bd->bd_sectors = (uint64_t)bd->bd_cyl * bd->bd_hds * bd->bd_sec;
535
536	return (0);
537}
538
539/*
540 * Read EDD info. Return 0 on success, error otherwise.
541 *
542 * Avoid stack corruption on some systems by adding extra bytes to
543 * params block.
544 */
545static int
546bd_get_diskinfo_ext(struct bdinfo *bd)
547{
548	struct disk_params {
549		struct edd_params head;
550		struct edd_device_path_v3 device_path;
551		uint8_t dummy[16];
552	} __packed dparams;
553	struct edd_params *params;
554	uint64_t total;
555
556	params = &dparams.head;
557
558	/* Get disk params */
559	bzero(&dparams, sizeof(dparams));
560	params->len = sizeof(struct edd_params_v3);
561	v86.ctl = V86_FLAGS;
562	v86.addr = DISK_BIOS;
563	v86.eax = CMD_EXT_PARAM;
564	v86.edx = bd->bd_unit;
565	v86.ds = VTOPSEG(&dparams);
566	v86.esi = VTOPOFF(&dparams);
567	v86int();
568
569	if (V86_CY(v86.efl) && ((v86.eax & 0xff00) != 0))
570		return ((v86.eax & 0xff00) >> 8);
571
572	/*
573	 * Sector size must be a multiple of 512 bytes.
574	 * An alternate test would be to check power of 2,
575	 * powerof2(params.sector_size).
576	 * 16K is largest read buffer we can use at this time.
577	 */
578	if (params->sector_size >= 512 &&
579	    params->sector_size <= 16384 &&
580	    (params->sector_size % BIOSDISK_SECSIZE) == 0)
581		bd->bd_sectorsize = params->sector_size;
582
583	bd->bd_cyl = params->cylinders;
584	bd->bd_hds = params->heads;
585	bd->bd_sec = params->sectors_per_track;
586
587	if (params->sectors != 0) {
588		total = params->sectors;
589	} else {
590		total = (uint64_t)params->cylinders *
591		    params->heads * params->sectors_per_track;
592	}
593	bd->bd_sectors = total;
594
595	return (0);
596}
597
598/*
599 * Try to detect a device supported by the legacy int13 BIOS
600 */
601static bool
602bd_int13probe(bdinfo_t *bd)
603{
604	int edd, ret;
605
606	bd->bd_flags &= ~BD_NO_MEDIA;
607
608	if ((bd->bd_flags & BD_CDROM) != 0) {
609		return (bd_get_diskinfo_cd(bd) == 0);
610	}
611
612	edd = bd_check_extensions(bd->bd_unit);
613	if (edd == 0)
614		bd->bd_flags |= BD_MODEINT13;
615	else if (edd < 0x30)
616		bd->bd_flags |= BD_MODEEDD1;
617	else
618		bd->bd_flags |= BD_MODEEDD3;
619
620	/* Default sector size */
621	if (bd->bd_sectorsize == 0)
622		bd->bd_sectorsize = BIOSDISK_SECSIZE;
623
624	/*
625	 * Test if the floppy device is present, so we can avoid receiving
626	 * bogus information from bd_get_diskinfo_std().
627	 */
628	if (bd->bd_unit < 0x80) {
629		/* reset disk */
630		bd_reset_disk(bd->bd_unit);
631
632		/* Get disk type */
633		v86.ctl = V86_FLAGS;
634		v86.addr = DISK_BIOS;
635		v86.eax = CMD_DRIVE_TYPE;
636		v86.edx = bd->bd_unit;
637		v86int();
638		if (V86_CY(v86.efl) || (v86.eax & 0x300) == 0)
639			return (false);
640	}
641
642	ret = 1;
643	if (edd != 0)
644		ret = bd_get_diskinfo_ext(bd);
645	if (ret != 0 || bd->bd_sectors == 0)
646		ret = bd_get_diskinfo_std(bd);
647
648	if (ret != 0 && bd->bd_unit < 0x80) {
649		/* Set defaults for 1.44 floppy */
650		bd->bd_cyl = 80;
651		bd->bd_hds = 2;
652		bd->bd_sec = 18;
653		bd->bd_sectors = 2880;
654		/* Since we are there, there most likely is no media */
655		bd->bd_flags |= BD_NO_MEDIA;
656		ret = 0;
657	}
658
659	if (ret != 0) {
660		if (bd->bd_sectors != 0 && edd != 0) {
661			bd->bd_sec = 63;
662			bd->bd_hds = 255;
663			bd->bd_cyl =
664			    (bd->bd_sectors + bd->bd_sec * bd->bd_hds - 1) /
665			    bd->bd_sec * bd->bd_hds;
666		} else {
667			const char *dv_name;
668
669			if ((bd->bd_flags & BD_FLOPPY) != 0)
670				dv_name = biosfd.dv_name;
671			else
672				dv_name = bioshd.dv_name;
673
674			printf("Can not get information about %s unit %#x\n",
675			    dv_name, bd->bd_unit);
676			return (false);
677		}
678	}
679
680	if (bd->bd_sec == 0)
681		bd->bd_sec = 63;
682	if (bd->bd_hds == 0)
683		bd->bd_hds = 255;
684
685	if (bd->bd_sectors == 0)
686		bd->bd_sectors = (uint64_t)bd->bd_cyl * bd->bd_hds * bd->bd_sec;
687
688	DPRINTF("unit 0x%x geometry %d/%d/%d\n", bd->bd_unit, bd->bd_cyl,
689	    bd->bd_hds, bd->bd_sec);
690
691	return (true);
692}
693
694static int
695bd_count(bdinfo_list_t *bdi)
696{
697	bdinfo_t *bd;
698	int i;
699
700	i = 0;
701	STAILQ_FOREACH(bd, bdi, bd_link)
702		i++;
703	return (i);
704}
705
706/*
707 * Print information about disks
708 */
709static int
710bd_print_common(struct devsw *dev, bdinfo_list_t *bdi, int verbose)
711{
712	char line[80];
713	struct disk_devdesc devd;
714	bdinfo_t *bd;
715	int i, ret = 0;
716	char drive;
717
718	if (STAILQ_EMPTY(bdi))
719		return (0);
720
721	printf("%s devices:", dev->dv_name);
722	if ((ret = pager_output("\n")) != 0)
723		return (ret);
724
725	i = -1;
726	STAILQ_FOREACH(bd, bdi, bd_link) {
727		i++;
728
729		switch (dev->dv_type) {
730		case DEVT_FD:
731			drive = 'A';
732			break;
733		case DEVT_CD:
734			drive = 'C' + bd_count(&hdinfo);
735			break;
736		default:
737			drive = 'C';
738			break;
739		}
740
741		snprintf(line, sizeof(line),
742		    "    %s%d:   BIOS drive %c (%s%ju X %u):\n",
743		    dev->dv_name, i, drive + i,
744		    (bd->bd_flags & BD_NO_MEDIA) == BD_NO_MEDIA ?
745		    "no media, " : "",
746		    (uintmax_t)bd->bd_sectors,
747		    bd->bd_sectorsize);
748		if ((ret = pager_output(line)) != 0)
749			break;
750
751		if ((bd->bd_flags & BD_NO_MEDIA) == BD_NO_MEDIA)
752			continue;
753
754		if (dev->dv_type != DEVT_DISK)
755			continue;
756
757		devd.dd.d_dev = dev;
758		devd.dd.d_unit = i;
759		devd.d_slice = D_SLICENONE;
760		devd.d_partition = D_PARTNONE;
761		if (disk_open(&devd,
762		    bd->bd_sectorsize * bd->bd_sectors,
763		    bd->bd_sectorsize) == 0) {
764			snprintf(line, sizeof(line), "    %s%d",
765			    dev->dv_name, i);
766			ret = disk_print(&devd, line, verbose);
767			disk_close(&devd);
768			if (ret != 0)
769				break;
770		}
771	}
772	return (ret);
773}
774
775static int
776fd_print(int verbose)
777{
778	return (bd_print_common(&biosfd, &fdinfo, verbose));
779}
780
781static int
782bd_print(int verbose)
783{
784	return (bd_print_common(&bioshd, &hdinfo, verbose));
785}
786
787static int
788cd_print(int verbose)
789{
790	return (bd_print_common(&bioscd, &cdinfo, verbose));
791}
792
793/*
794 * Read disk size from partition.
795 * This is needed to work around buggy BIOS systems returning
796 * wrong (truncated) disk media size.
797 * During bd_probe() we tested if the multiplication of bd_sectors
798 * would overflow so it should be safe to perform here.
799 */
800static uint64_t
801bd_disk_get_sectors(struct disk_devdesc *dev)
802{
803	bdinfo_t *bd;
804	struct disk_devdesc disk;
805	uint64_t size;
806
807	bd = bd_get_bdinfo(&dev->dd);
808	if (bd == NULL)
809		return (0);
810
811	disk.dd.d_dev = dev->dd.d_dev;
812	disk.dd.d_unit = dev->dd.d_unit;
813	disk.d_slice = D_SLICENONE;
814	disk.d_partition = D_PARTNONE;
815	disk.d_offset = 0;
816
817	size = bd->bd_sectors * bd->bd_sectorsize;
818	if (disk_open(&disk, size, bd->bd_sectorsize) == 0) {
819		(void) disk_ioctl(&disk, DIOCGMEDIASIZE, &size);
820		disk_close(&disk);
821	}
822	return (size / bd->bd_sectorsize);
823}
824
825/*
826 * Attempt to open the disk described by (dev) for use by (f).
827 *
828 * Note that the philosophy here is "give them exactly what
829 * they ask for".  This is necessary because being too "smart"
830 * about what the user might want leads to complications.
831 * (eg. given no slice or partition value, with a disk that is
832 *  sliced - are they after the first BSD slice, or the DOS
833 *  slice before it?)
834 */
835static int
836bd_open(struct open_file *f, ...)
837{
838	bdinfo_t *bd;
839	struct disk_devdesc *dev;
840	va_list ap;
841	int rc;
842
843	va_start(ap, f);
844	dev = va_arg(ap, struct disk_devdesc *);
845	va_end(ap);
846
847	bd = bd_get_bdinfo(&dev->dd);
848	if (bd == NULL)
849		return (EIO);
850
851	if ((bd->bd_flags & BD_NO_MEDIA) == BD_NO_MEDIA) {
852		if (!bd_int13probe(bd))
853			return (EIO);
854		if ((bd->bd_flags & BD_NO_MEDIA) == BD_NO_MEDIA)
855			return (EIO);
856	}
857	if (bd->bd_bcache == NULL)
858	    bd->bd_bcache = bcache_allocate();
859
860	if (bd->bd_open == 0)
861		bd->bd_sectors = bd_disk_get_sectors(dev);
862	bd->bd_open++;
863
864	rc = 0;
865	if (dev->dd.d_dev->dv_type == DEVT_DISK) {
866		rc = disk_open(dev, bd->bd_sectors * bd->bd_sectorsize,
867		    bd->bd_sectorsize);
868		if (rc != 0) {
869			bd->bd_open--;
870			if (bd->bd_open == 0) {
871				bcache_free(bd->bd_bcache);
872				bd->bd_bcache = NULL;
873			}
874		}
875	}
876	return (rc);
877}
878
879static int
880bd_close(struct open_file *f)
881{
882	struct disk_devdesc *dev;
883	bdinfo_t *bd;
884	int rc = 0;
885
886	dev = (struct disk_devdesc *)f->f_devdata;
887	bd = bd_get_bdinfo(&dev->dd);
888	if (bd == NULL)
889		return (EIO);
890
891	bd->bd_open--;
892	if (bd->bd_open == 0) {
893	    bcache_free(bd->bd_bcache);
894	    bd->bd_bcache = NULL;
895	}
896	if (dev->dd.d_dev->dv_type == DEVT_DISK)
897		rc = disk_close(dev);
898	return (rc);
899}
900
901static int
902bd_ioctl(struct open_file *f, u_long cmd, void *data)
903{
904	bdinfo_t *bd;
905	struct disk_devdesc *dev;
906	int rc;
907
908	dev = (struct disk_devdesc *)f->f_devdata;
909	bd = bd_get_bdinfo(&dev->dd);
910	if (bd == NULL)
911		return (EIO);
912
913	if (dev->dd.d_dev->dv_type == DEVT_DISK) {
914		rc = disk_ioctl(dev, cmd, data);
915		if (rc != ENOTTY)
916			return (rc);
917	}
918
919	switch (cmd) {
920	case DIOCGSECTORSIZE:
921		*(uint32_t *)data = bd->bd_sectorsize;
922		break;
923	case DIOCGMEDIASIZE:
924		*(uint64_t *)data = bd->bd_sectors * bd->bd_sectorsize;
925		break;
926	default:
927		return (ENOTTY);
928	}
929	return (0);
930}
931
932static int
933bd_strategy(void *devdata, int rw, daddr_t dblk, size_t size,
934    char *buf, size_t *rsize)
935{
936	bdinfo_t *bd;
937	struct bcache_devdata bcd;
938	struct disk_devdesc *dev;
939	daddr_t offset;
940
941	dev = (struct disk_devdesc *)devdata;
942	bd = bd_get_bdinfo(&dev->dd);
943	if (bd == NULL)
944		return (EINVAL);
945
946	bcd.dv_strategy = bd_realstrategy;
947	bcd.dv_devdata = devdata;
948	bcd.dv_cache = bd->bd_bcache;
949
950	offset = 0;
951	if (dev->dd.d_dev->dv_type == DEVT_DISK) {
952
953		offset = dev->d_offset * bd->bd_sectorsize;
954		offset /= BIOSDISK_SECSIZE;
955	}
956	return (bcache_strategy(&bcd, rw, dblk + offset, size,
957	    buf, rsize));
958}
959
960static int
961bd_realstrategy(void *devdata, int rw, daddr_t dblk, size_t size,
962    char *buf, size_t *rsize)
963{
964	struct disk_devdesc *dev = (struct disk_devdesc *)devdata;
965	bdinfo_t *bd;
966	uint64_t disk_blocks, offset, d_offset;
967	size_t blks, blkoff, bsize, bio_size, rest;
968	caddr_t bbuf = NULL;
969	int rc;
970
971	bd = bd_get_bdinfo(&dev->dd);
972	if (bd == NULL || (bd->bd_flags & BD_NO_MEDIA) == BD_NO_MEDIA)
973		return (EIO);
974
975	/*
976	 * First make sure the IO size is a multiple of 512 bytes. While we do
977	 * process partial reads below, the strategy mechanism is built
978	 * assuming IO is a multiple of 512B blocks. If the request is not
979	 * a multiple of 512B blocks, it has to be some sort of bug.
980	 */
981	if (size == 0 || (size % BIOSDISK_SECSIZE) != 0) {
982		printf("bd_strategy: %d bytes I/O not multiple of %d\n",
983		    size, BIOSDISK_SECSIZE);
984		return (EIO);
985	}
986
987	DPRINTF("open_disk %p", dev);
988
989	offset = dblk * BIOSDISK_SECSIZE;
990	dblk = offset / bd->bd_sectorsize;
991	blkoff = offset % bd->bd_sectorsize;
992
993	/*
994	 * Check the value of the size argument. We do have quite small
995	 * heap (64MB), but we do not know good upper limit, so we check against
996	 * INT_MAX here. This will also protect us against possible overflows
997	 * while translating block count to bytes.
998	 */
999	if (size > INT_MAX) {
1000		DPRINTF("too large I/O: %zu bytes", size);
1001		return (EIO);
1002	}
1003
1004	blks = size / bd->bd_sectorsize;
1005	if (blks == 0 || (size % bd->bd_sectorsize) != 0)
1006		blks++;
1007
1008	if (dblk > dblk + blks)
1009		return (EIO);
1010
1011	if (rsize)
1012		*rsize = 0;
1013
1014	/*
1015	 * Get disk blocks, this value is either for whole disk or for
1016	 * partition.
1017	 */
1018	d_offset = 0;
1019	disk_blocks = 0;
1020	if (dev->dd.d_dev->dv_type == DEVT_DISK) {
1021		if (disk_ioctl(dev, DIOCGMEDIASIZE, &disk_blocks) == 0) {
1022			/* DIOCGMEDIASIZE does return bytes. */
1023			disk_blocks /= bd->bd_sectorsize;
1024		}
1025		d_offset = dev->d_offset;
1026	}
1027	if (disk_blocks == 0)
1028		disk_blocks = bd->bd_sectors - d_offset;
1029
1030	/* Validate source block address. */
1031	if (dblk < d_offset || dblk >= d_offset + disk_blocks)
1032		return (EIO);
1033
1034	/*
1035	 * Truncate if we are crossing disk or partition end.
1036	 */
1037	if (dblk + blks >= d_offset + disk_blocks) {
1038		blks = d_offset + disk_blocks - dblk;
1039		size = blks * bd->bd_sectorsize;
1040		DPRINTF("short I/O %d", blks);
1041	}
1042
1043	bio_size = min(BIO_BUFFER_SIZE, size);
1044	while (bio_size > bd->bd_sectorsize) {
1045		bbuf = bio_alloc(bio_size);
1046		if (bbuf != NULL)
1047			break;
1048		bio_size -= bd->bd_sectorsize;
1049	}
1050	if (bbuf == NULL) {
1051		bio_size = V86_IO_BUFFER_SIZE;
1052		if (bio_size / bd->bd_sectorsize == 0)
1053			panic("BUG: Real mode buffer is too small");
1054
1055		/* Use alternate 4k buffer */
1056		bbuf = PTOV(V86_IO_BUFFER);
1057	}
1058	rest = size;
1059	rc = 0;
1060	while (blks > 0) {
1061		int x = min(blks, bio_size / bd->bd_sectorsize);
1062
1063		switch (rw & F_MASK) {
1064		case F_READ:
1065			DPRINTF("read %d from %lld to %p", x, dblk, buf);
1066			bsize = bd->bd_sectorsize * x - blkoff;
1067			if (rest < bsize)
1068				bsize = rest;
1069
1070			if ((rc = bd_io(dev, bd, dblk, x, bbuf, BD_RD)) != 0) {
1071				rc = EIO;
1072				goto error;
1073			}
1074
1075			bcopy(bbuf + blkoff, buf, bsize);
1076			break;
1077		case F_WRITE :
1078			DPRINTF("write %d from %lld to %p", x, dblk, buf);
1079			if (blkoff != 0) {
1080				/*
1081				 * We got offset to sector, read 1 sector to
1082				 * bbuf.
1083				 */
1084				x = 1;
1085				bsize = bd->bd_sectorsize - blkoff;
1086				bsize = min(bsize, rest);
1087				rc = bd_io(dev, bd, dblk, x, bbuf, BD_RD);
1088			} else if (rest < bd->bd_sectorsize) {
1089				/*
1090				 * The remaining block is not full
1091				 * sector. Read 1 sector to bbuf.
1092				 */
1093				x = 1;
1094				bsize = rest;
1095				rc = bd_io(dev, bd, dblk, x, bbuf, BD_RD);
1096			} else {
1097				/* We can write full sector(s). */
1098				bsize = bd->bd_sectorsize * x;
1099			}
1100			/*
1101			 * Put your Data In, Put your Data out,
1102			 * Put your Data In, and shake it all about
1103			 */
1104			bcopy(buf, bbuf + blkoff, bsize);
1105			if ((rc = bd_io(dev, bd, dblk, x, bbuf, BD_WR)) != 0) {
1106				rc = EIO;
1107				goto error;
1108			}
1109
1110			break;
1111		default:
1112			/* DO NOTHING */
1113			rc = EROFS;
1114			goto error;
1115		}
1116
1117		blkoff = 0;
1118		buf += bsize;
1119		rest -= bsize;
1120		blks -= x;
1121		dblk += x;
1122	}
1123
1124	if (rsize != NULL)
1125		*rsize = size;
1126error:
1127	if (bbuf != PTOV(V86_IO_BUFFER))
1128		bio_free(bbuf, bio_size);
1129	return (rc);
1130}
1131
1132static int
1133bd_edd_io(bdinfo_t *bd, daddr_t dblk, int blks, caddr_t dest,
1134    int dowrite)
1135{
1136	static struct edd_packet packet;
1137
1138	packet.len = sizeof(struct edd_packet);
1139	packet.count = blks;
1140	packet.off = VTOPOFF(dest);
1141	packet.seg = VTOPSEG(dest);
1142	packet.lba = dblk;
1143	v86.ctl = V86_FLAGS;
1144	v86.addr = DISK_BIOS;
1145	if (dowrite == BD_WR)
1146		v86.eax = CMD_WRITE_LBA; /* maybe Write with verify 0x4302? */
1147	else
1148		v86.eax = CMD_READ_LBA;
1149	v86.edx = bd->bd_unit;
1150	v86.ds = VTOPSEG(&packet);
1151	v86.esi = VTOPOFF(&packet);
1152	v86int();
1153	if (V86_CY(v86.efl))
1154		return (v86.eax >> 8);
1155	return (0);
1156}
1157
1158static int
1159bd_chs_io(bdinfo_t *bd, daddr_t dblk, int blks, caddr_t dest,
1160    int dowrite)
1161{
1162	uint32_t x, bpc, cyl, hd, sec;
1163
1164	bpc = bd->bd_sec * bd->bd_hds;	/* blocks per cylinder */
1165	x = dblk;
1166	cyl = x / bpc;			/* block # / blocks per cylinder */
1167	x %= bpc;				/* block offset into cylinder */
1168	hd = x / bd->bd_sec;		/* offset / blocks per track */
1169	sec = x % bd->bd_sec;		/* offset into track */
1170
1171	/* correct sector number for 1-based BIOS numbering */
1172	sec++;
1173
1174	if (cyl > 1023) {
1175		/* CHS doesn't support cylinders > 1023. */
1176		return (1);
1177	}
1178
1179	v86.ctl = V86_FLAGS;
1180	v86.addr = DISK_BIOS;
1181	if (dowrite == BD_WR)
1182		v86.eax = CMD_WRITE_CHS | blks;
1183	else
1184		v86.eax = CMD_READ_CHS | blks;
1185	v86.ecx = ((cyl & 0xff) << 8) | ((cyl & 0x300) >> 2) | sec;
1186	v86.edx = (hd << 8) | bd->bd_unit;
1187	v86.es = VTOPSEG(dest);
1188	v86.ebx = VTOPOFF(dest);
1189	v86int();
1190	if (V86_CY(v86.efl))
1191		return (v86.eax >> 8);
1192	return (0);
1193}
1194
1195static void
1196bd_io_workaround(bdinfo_t *bd)
1197{
1198	uint8_t buf[8 * 1024];
1199
1200	bd_edd_io(bd, 0xffffffff, 1, (caddr_t)buf, BD_RD);
1201}
1202
1203static int
1204bd_io(struct disk_devdesc *dev, bdinfo_t *bd, daddr_t dblk, int blks,
1205    caddr_t dest, int dowrite)
1206{
1207	int result, retry;
1208
1209	/* Just in case some idiot actually tries to read/write -1 blocks... */
1210	if (blks < 0)
1211		return (-1);
1212
1213	/*
1214	 * Workaround for a problem with some HP ProLiant BIOS failing to work
1215	 * out the boot disk after installation. hrs and kuriyama discovered
1216	 * this problem with an HP ProLiant DL320e Gen 8 with a 3TB HDD, and
1217	 * discovered that an int13h call seems to cause a buffer overrun in
1218	 * the bios. The problem is alleviated by doing an extra read before
1219	 * the buggy read. It is not immediately known whether other models
1220	 * are similarly affected.
1221	 * Loop retrying the operation a couple of times.  The BIOS
1222	 * may also retry.
1223	 */
1224	if (dowrite == BD_RD && dblk >= 0x100000000)
1225		bd_io_workaround(bd);
1226	for (retry = 0; retry < 3; retry++) {
1227		if (bd->bd_flags & BD_MODEEDD)
1228			result = bd_edd_io(bd, dblk, blks, dest, dowrite);
1229		else
1230			result = bd_chs_io(bd, dblk, blks, dest, dowrite);
1231
1232		if (result == 0) {
1233			if (bd->bd_flags & BD_NO_MEDIA)
1234				bd->bd_flags &= ~BD_NO_MEDIA;
1235			break;
1236		}
1237
1238		bd_reset_disk(bd->bd_unit);
1239
1240		/*
1241		 * Error codes:
1242		 * 20h	controller failure
1243		 * 31h	no media in drive (IBM/MS INT 13 extensions)
1244		 * 80h	no media in drive, VMWare (Fusion)
1245		 * There is no reason to repeat the IO with errors above.
1246		 */
1247		if (result == 0x20 || result == 0x31 || result == 0x80) {
1248			bd->bd_flags |= BD_NO_MEDIA;
1249			break;
1250		}
1251	}
1252
1253	if (result != 0 && (bd->bd_flags & BD_NO_MEDIA) == 0) {
1254		if (dowrite == BD_WR) {
1255			printf("%s%d: Write %d sector(s) from %p (0x%x) "
1256			    "to %lld: 0x%x\n", dev->dd.d_dev->dv_name,
1257			    dev->dd.d_unit, blks, dest, VTOP(dest), dblk,
1258			    result);
1259		} else {
1260			printf("%s%d: Read %d sector(s) from %lld to %p "
1261			    "(0x%x): 0x%x\n", dev->dd.d_dev->dv_name,
1262			    dev->dd.d_unit, blks, dblk, dest, VTOP(dest),
1263			    result);
1264		}
1265	}
1266
1267	return (result);
1268}
1269
1270/*
1271 * Return the BIOS geometry of a given "fixed drive" in a format
1272 * suitable for the legacy bootinfo structure.  Since the kernel is
1273 * expecting raw int 0x13/0x8 values for N_BIOS_GEOM drives, we
1274 * prefer to get the information directly, rather than rely on being
1275 * able to put it together from information already maintained for
1276 * different purposes and for a probably different number of drives.
1277 *
1278 * For valid drives, the geometry is expected in the format (31..0)
1279 * "000000cc cccccccc hhhhhhhh 00ssssss"; and invalid drives are
1280 * indicated by returning the geometry of a "1.2M" PC-format floppy
1281 * disk.  And, incidentally, what is returned is not the geometry as
1282 * such but the highest valid cylinder, head, and sector numbers.
1283 */
1284uint32_t
1285bd_getbigeom(int bunit)
1286{
1287
1288	v86.ctl = V86_FLAGS;
1289	v86.addr = DISK_BIOS;
1290	v86.eax = CMD_READ_PARAM;
1291	v86.edx = 0x80 + bunit;
1292	v86int();
1293	if (V86_CY(v86.efl))
1294		return (0x4f010f);
1295	return (((v86.ecx & 0xc0) << 18) | ((v86.ecx & 0xff00) << 8) |
1296	    (v86.edx & 0xff00) | (v86.ecx & 0x3f));
1297}
1298
1299/*
1300 * Return a suitable dev_t value for (dev).
1301 *
1302 * In the case where it looks like (dev) is a SCSI disk, we allow the number of
1303 * IDE disks to be specified in $num_ide_disks.  There should be a Better Way.
1304 */
1305int
1306bd_getdev(struct i386_devdesc *d)
1307{
1308	struct disk_devdesc *dev;
1309	bdinfo_t *bd;
1310	int	biosdev;
1311	int	major;
1312	int	rootdev;
1313	char	*nip, *cp;
1314	int	i, unit, slice, partition;
1315
1316	/* XXX: Assume partition 'a'. */
1317	slice = 0;
1318	partition = 0;
1319
1320	dev = (struct disk_devdesc *)d;
1321	bd = bd_get_bdinfo(&dev->dd);
1322	if (bd == NULL)
1323		return (-1);
1324
1325	biosdev = bd_unit2bios(d);
1326	DPRINTF("unit %d BIOS device %d", dev->dd.d_unit, biosdev);
1327	if (biosdev == -1)			/* not a BIOS device */
1328		return (-1);
1329
1330	if (dev->dd.d_dev->dv_type == DEVT_DISK) {
1331		if (disk_open(dev, bd->bd_sectors * bd->bd_sectorsize,
1332		    bd->bd_sectorsize) != 0)	/* oops, not a viable device */
1333			return (-1);
1334		else
1335			disk_close(dev);
1336		slice = dev->d_slice + 1;
1337		partition = dev->d_partition;
1338	}
1339
1340	if (biosdev < 0x80) {
1341		/* floppy (or emulated floppy) or ATAPI device */
1342		if (bd->bd_type == DT_ATAPI) {
1343			/* is an ATAPI disk */
1344			major = WFDMAJOR;
1345		} else {
1346			/* is a floppy disk */
1347			major = FDMAJOR;
1348		}
1349	} else {
1350		/* assume an IDE disk */
1351		major = WDMAJOR;
1352	}
1353	/* default root disk unit number */
1354	unit = biosdev & 0x7f;
1355
1356	if (dev->dd.d_dev->dv_type == DEVT_CD) {
1357		/*
1358		 * XXX: Need to examine device spec here to figure out if
1359		 * SCSI or ATAPI.  No idea on how to figure out device number.
1360		 * All we can really pass to the kernel is what bus and device
1361		 * on which bus we were booted from, which dev_t isn't well
1362		 * suited to since those number don't match to unit numbers
1363		 * very well.  We may just need to engage in a hack where
1364		 * we pass -C to the boot args if we are the boot device.
1365		 */
1366		major = ACDMAJOR;
1367		unit = 0;       /* XXX */
1368	}
1369
1370	/* XXX a better kludge to set the root disk unit number */
1371	if ((nip = getenv("root_disk_unit")) != NULL) {
1372		i = strtol(nip, &cp, 0);
1373		/* check for parse error */
1374		if ((cp != nip) && (*cp == 0))
1375			unit = i;
1376	}
1377
1378	rootdev = MAKEBOOTDEV(major, slice, unit, partition);
1379	DPRINTF("dev is 0x%x\n", rootdev);
1380	return (rootdev);
1381}
1382