xref: /openbsd/sys/arch/amd64/stand/libsa/biosdev.c (revision 70aaba56)
1 /*	$OpenBSD: biosdev.c,v 1.26 2015/10/01 16:16:23 krw Exp $	*/
2 
3 /*
4  * Copyright (c) 1996 Michael Shalayeff
5  * Copyright (c) 2003 Tobias Weingartner
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
19  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  */
30 
31 #include <sys/param.h>
32 #include <sys/reboot.h>
33 #include <sys/disklabel.h>
34 #include <isofs/cd9660/iso.h>
35 #include <lib/libsa/saerrno.h>
36 #include <machine/tss.h>
37 #include <machine/biosvar.h>
38 
39 #include "biosdev.h"
40 #include "disk.h"
41 #include "libsa.h"
42 
43 #ifdef SOFTRAID
44 #include <dev/softraidvar.h>
45 #include "softraid.h"
46 #endif
47 
48 static const char *biosdisk_err(u_int);
49 static int biosdisk_errno(u_int);
50 
51 int CHS_rw (int, int, int, int, int, int, void *);
52 static int EDD_rw (int, int, u_int32_t, u_int32_t, void *);
53 
54 static int biosd_io(int, bios_diskinfo_t *, u_int, int, void *);
55 static u_int findopenbsd(bios_diskinfo_t *, const char **);
56 
57 extern int debug;
58 int bios_bootdev;
59 int bios_cddev = -1;		/* Set by srt0 if coming from CD */
60 
61 struct EDD_CB {
62 	u_int8_t  edd_len;	/* size of packet */
63 	u_int8_t  edd_res1;	/* reserved */
64 	u_int8_t  edd_nblk;	/* # of blocks to transfer */
65 	u_int8_t  edd_res2;	/* reserved */
66 	u_int16_t edd_off;	/* address of buffer (offset) */
67 	u_int16_t edd_seg;	/* address of buffer (segment) */
68 	u_int64_t edd_daddr;	/* starting block */
69 };
70 
71 /*
72  * reset disk system
73  */
74 static int
75 biosdreset(int dev)
76 {
77 	int rv;
78 
79 	__asm volatile (DOINT(0x13) "; setc %b0" : "=a" (rv)
80 	    : "0" (0), "d" (dev) : "%ecx", "cc");
81 
82 	return ((rv & 0xff)? rv >> 8 : 0);
83 }
84 
85 /*
86  * Fill out a bios_diskinfo_t for this device.
87  * Return 0 if all ok.
88  * Return 1 if not ok.
89  */
90 int
91 bios_getdiskinfo(int dev, bios_diskinfo_t *pdi)
92 {
93 	u_int rv;
94 
95 	/* Just reset, don't check return code */
96 	rv = biosdreset(dev);
97 
98 #ifdef BIOS_DEBUG
99 	if (debug)
100 		printf("getinfo: try #8, 0x%x, %p\n", dev, pdi);
101 #endif
102 	__asm volatile (DOINT(0x13) "\n\t"
103 	    "setc %b0; movzbl %h1, %1\n\t"
104 	    "movzbl %%cl, %3; andb $0x3f, %b3\n\t"
105 	    "xchgb %%cl, %%ch; rolb $2, %%ch"
106 	    : "=a" (rv), "=d" (pdi->bios_heads),
107 	      "=c" (pdi->bios_cylinders),
108 	      "=b" (pdi->bios_sectors)
109 	    : "0" (0x0800), "1" (dev) : "cc");
110 
111 #ifdef BIOS_DEBUG
112 	if (debug) {
113 		printf("getinfo: got #8\n");
114 		printf("disk 0x%x: %d,%d,%d\n", dev, pdi->bios_cylinders,
115 		    pdi->bios_heads, pdi->bios_sectors);
116 	}
117 #endif
118 	if (rv & 0xff)
119 		return 1;
120 
121 	/* Fix up info */
122 	pdi->bios_number = dev;
123 	pdi->bios_heads++;
124 	pdi->bios_cylinders &= 0x3ff;
125 	pdi->bios_cylinders++;
126 
127 	/* NOTE:
128 	 * This currently hangs/reboots some machines
129 	 * The IBM ThinkPad 750ED for one.
130 	 *
131 	 * Funny that an IBM/MS extension would not be
132 	 * implemented by an IBM system...
133 	 *
134 	 * Future hangs (when reported) can be "fixed"
135 	 * with getSYSCONFaddr() and an exceptions list.
136 	 */
137 	if (dev & 0x80 && (dev == 0x80 || dev == 0x81 || dev == bios_bootdev)) {
138 		int bm;
139 
140 #ifdef BIOS_DEBUG
141 		if (debug)
142 			printf("getinfo: try #41, 0x%x\n", dev);
143 #endif
144 		/* EDD support check */
145 		__asm volatile(DOINT(0x13) "; setc %b0"
146 			 : "=a" (rv), "=c" (bm)
147 			 : "0" (0x4100), "b" (0x55aa), "d" (dev) : "cc");
148 		if (!(rv & 0xff) && (BIOS_regs.biosr_bx & 0xffff) == 0xaa55)
149 			pdi->bios_edd = (bm & 0xffff) | ((rv & 0xff) << 16);
150 		else
151 			pdi->bios_edd = -1;
152 
153 #ifdef BIOS_DEBUG
154 		if (debug) {
155 			printf("getinfo: got #41\n");
156 			printf("disk 0x%x: 0x%x\n", dev, bm);
157 		}
158 #endif
159 		/*
160 		 * If extended disk access functions are not supported
161 		 * there is not much point on doing EDD.
162 		 */
163 		if (!(pdi->bios_edd & EXT_BM_EDA))
164 			pdi->bios_edd = -1;
165 	} else
166 		pdi->bios_edd = -1;
167 
168 	/* Skip sanity check for CHS options in EDD mode. */
169 	if (pdi->bios_edd != -1)
170 		return 0;
171 
172 	/* Sanity check */
173 	if (!pdi->bios_cylinders || !pdi->bios_heads || !pdi->bios_sectors)
174 		return 1;
175 
176 	/* CD-ROMs sometimes return heads == 1 */
177 	if (pdi->bios_heads < 2)
178 		return 1;
179 
180 	return 0;
181 }
182 
183 /*
184  * Read/Write a block from given place using the BIOS.
185  */
186 int
187 CHS_rw(int rw, int dev, int cyl, int head, int sect, int nsect, void *buf)
188 {
189 	int rv;
190 
191 	rw = rw == F_READ ? 2 : 3;
192 	BIOS_regs.biosr_es = (u_int32_t)buf >> 4;
193 	__asm volatile ("movb %b7, %h1\n\t"
194 	    "movb %b6, %%dh\n\t"
195 	    "andl $0xf, %4\n\t"
196 	    /* cylinder; the highest 2 bits of cyl is in %cl */
197 	    "xchgb %%ch, %%cl\n\t"
198 	    "rorb  $2, %%cl\n\t"
199 	    "orb %b5, %%cl\n\t"
200 	    "inc %%cx\n\t"
201 	    DOINT(0x13) "\n\t"
202 	    "setc %b0"
203 	    : "=a" (rv)
204 	    : "0" (nsect), "d" (dev), "c" (cyl),
205 	      "b" (buf), "m" (sect), "m" (head),
206 	      "m" (rw)
207 	    : "cc", "memory");
208 
209 	return ((rv & 0xff)? rv >> 8 : 0);
210 }
211 
212 static __inline int
213 EDD_rw(int rw, int dev, u_int32_t daddr, u_int32_t nblk, void *buf)
214 {
215 	int rv;
216 	volatile static struct EDD_CB cb;
217 
218 	/* Zero out reserved stuff */
219 	cb.edd_res1 = 0;
220 	cb.edd_res2 = 0;
221 
222 	/* Fill in parameters */
223 	cb.edd_len = sizeof(cb);
224 	cb.edd_nblk = nblk;
225 	cb.edd_seg = ((u_int32_t)buf >> 4) & 0xffff;
226 	cb.edd_off = (u_int32_t)buf & 0xf;
227 	cb.edd_daddr = daddr;
228 
229 	/* if offset/segment are zero, punt */
230 	if (!cb.edd_seg && !cb.edd_off)
231 		return 1;
232 
233 	/* Call extended read/write (with disk packet) */
234 	BIOS_regs.biosr_ds = (u_int32_t)&cb >> 4;
235 	__asm volatile (DOINT(0x13) "; setc %b0" : "=a" (rv)
236 	    : "0" ((rw == F_READ)? 0x4200: 0x4300),
237 	      "d" (dev), "S" ((int) (&cb) & 0xf) : "%ecx", "cc");
238 	return ((rv & 0xff)? rv >> 8 : 0);
239 }
240 
241 /*
242  * Read given sector, handling retry/errors/etc.
243  */
244 int
245 biosd_io(int rw, bios_diskinfo_t *bd, u_int off, int nsect, void *buf)
246 {
247 	int dev = bd->bios_number;
248 	int j, error;
249 	void *bb, *bb1 = NULL;
250 	int bbsize = nsect * DEV_BSIZE;
251 
252 	if (bd->flags & BDI_EL_TORITO) {	/* It's a CD device */
253 		dev &= 0xff;			/* Mask out this flag bit */
254 
255 		/*
256 		 * sys/lib/libsa/cd9600.c converts 2,048-byte CD sectors
257 		 * to DEV_BSIZE blocks before calling the device strategy
258 		 * routine.  However, the El Torito spec says that the
259 		 * BIOS will work in 2,048-byte sectors.  So shift back.
260 		 */
261 		off /= (ISO_DEFAULT_BLOCK_SIZE / DEV_BSIZE);
262 		nsect /= (ISO_DEFAULT_BLOCK_SIZE / DEV_BSIZE);
263 	}
264 
265 	/*
266 	 * Use a bounce buffer to not cross 64k DMA boundary, and to
267 	 * not access 1 MB or above.
268 	 */
269 	if (((((u_int32_t)buf) & ~0xffff) !=
270 	    (((u_int32_t)buf + bbsize) & ~0xffff)) ||
271 	    (((u_int32_t)buf) >= 0x100000)) {
272 		/*
273 		 * XXX we believe that all the io is buffered
274 		 * by fs routines, so no big reads anyway
275 		 */
276 		bb = bb1 = alloc(bbsize);
277 		if (rw != F_READ)
278 			bcopy(buf, bb, bbsize);
279 	} else
280 		bb = buf;
281 
282 	/* Try to do operation up to 5 times */
283 	for (error = 1, j = 5; j-- && error; ) {
284 		/* CHS or LBA access? */
285 		if (bd->bios_edd != -1) {
286 			error = EDD_rw(rw, dev, off, nsect, bb);
287 		} else {
288 			int cyl, head, sect;
289 			size_t i, n;
290 			char *p = bb;
291 
292 			/* Handle track boundaries */
293 			for (error = i = 0; error == 0 && i < nsect;
294 			    i += n, off += n, p += n * DEV_BSIZE) {
295 
296 				btochs(off, cyl, head, sect, bd->bios_heads,
297 				    bd->bios_sectors);
298 
299 				if ((sect + (nsect - i)) >= bd->bios_sectors)
300 					n = bd->bios_sectors - sect;
301 				else
302 					n = nsect - i;
303 
304 				error = CHS_rw(rw, dev, cyl, head, sect, n, p);
305 
306 				/* ECC corrected */
307 				if (error == 0x11)
308 					error = 0;
309 			}
310 		}
311 		switch (error) {
312 		case 0x00:	/* No errors */
313 		case 0x11:	/* ECC corrected */
314 			error = 0;
315 			break;
316 
317 		default:	/* All other errors */
318 #ifdef BIOS_DEBUG
319 			if (debug)
320 				printf("\nBIOS error 0x%x (%s)\n",
321 				    error, biosdisk_err(error));
322 #endif
323 			biosdreset(dev);
324 			break;
325 		}
326 	}
327 
328 	if (bb != buf && rw == F_READ)
329 		bcopy(bb, buf, bbsize);
330 	free(bb1, bbsize);
331 
332 #ifdef BIOS_DEBUG
333 	if (debug) {
334 		if (error != 0)
335 			printf("=0x%x(%s)", error, biosdisk_err(error));
336 		putchar('\n');
337 	}
338 #endif
339 
340 	return error;
341 }
342 
343 int
344 biosd_diskio(int rw, struct diskinfo *dip, u_int off, int nsect, void *buf)
345 {
346 	return biosd_io(rw, &dip->bios_info, off, nsect, buf);
347 }
348 /*
349  * Try to read the bsd label on the given BIOS device.
350  */
351 static u_int
352 findopenbsd(bios_diskinfo_t *bd, const char **err)
353 {
354 	struct dos_mbr mbr;
355 	struct dos_partition *dp;
356 	u_int mbroff = DOSBBSECTOR;
357 	u_int mbr_eoff = DOSBBSECTOR;	/* Offset of MBR extended partition. */
358 	int error, i, maxebr = DOS_MAXEBR, nextebr;
359 
360 again:
361 	if (!maxebr--) {
362 		*err = "too many extended partitions";
363 		return (-1);
364 	}
365 
366 	/* Read MBR */
367 	bzero(&mbr, sizeof(mbr));
368 	error = biosd_io(F_READ, bd, mbroff, 1, &mbr);
369 	if (error) {
370 		*err = biosdisk_err(error);
371 		return (-1);
372 	}
373 
374 	/* check mbr signature */
375 	if (mbr.dmbr_sign != DOSMBR_SIGNATURE) {
376 		*err = "bad MBR signature\n";
377 		return (-1);
378 	}
379 
380 	/* Search for OpenBSD partition */
381 	nextebr = 0;
382 	for (i = 0; i < NDOSPART; i++) {
383 		dp = &mbr.dmbr_parts[i];
384 		if (!dp->dp_size)
385 			continue;
386 #ifdef BIOS_DEBUG
387 		if (debug)
388 			printf("found partition %u: "
389 			    "type %u (0x%x) offset %u (0x%x)\n",
390 			    (int)(dp - mbr.dmbr_parts),
391 			    dp->dp_typ, dp->dp_typ,
392 			    dp->dp_start, dp->dp_start);
393 #endif
394 		if (dp->dp_typ == DOSPTYP_OPENBSD) {
395 			if (dp->dp_start > (dp->dp_start + mbroff))
396 				continue;
397 			return (dp->dp_start + mbroff);
398 		}
399 
400 		/*
401 		 * Record location of next ebr if and only if this is the first
402 		 * extended partition in this boot record!
403 		 */
404 		if (!nextebr && (dp->dp_typ == DOSPTYP_EXTEND ||
405 		    dp->dp_typ == DOSPTYP_EXTENDL)) {
406 			nextebr = dp->dp_start + mbr_eoff;
407 			if (nextebr < dp->dp_start)
408 				nextebr = (u_int)-1;
409 			if (mbr_eoff == DOSBBSECTOR)
410 				mbr_eoff = dp->dp_start;
411 		}
412 	}
413 
414 	if (nextebr && nextebr != (u_int)-1) {
415 		mbroff = nextebr;
416 		goto again;
417 	}
418 
419 	return (-1);
420 }
421 
422 const char *
423 bios_getdisklabel(bios_diskinfo_t *bd, struct disklabel *label)
424 {
425 	u_int start = 0;
426 	char buf[DEV_BSIZE];
427 	const char *err = NULL;
428 	int error;
429 
430 	/* Sanity check */
431 	if (bd->bios_edd == -1 &&
432 	    (bd->bios_heads == 0 || bd->bios_sectors == 0))
433 		return "failed to read disklabel";
434 
435 	/* MBR is a harddisk thing */
436 	if (bd->bios_number & 0x80) {
437 		start = findopenbsd(bd, &err);
438 		if (start == (u_int)-1) {
439 			if (err != NULL)
440 				return (err);
441 			return "no OpenBSD partition\n";
442 		}
443 	}
444 	start = LABELSECTOR + start;
445 
446 	/* Load BSD disklabel */
447 #ifdef BIOS_DEBUG
448 	if (debug)
449 		printf("loading disklabel @ %u\n", start);
450 #endif
451 	/* read disklabel */
452 	error = biosd_io(F_READ, bd, start, 1, buf);
453 
454 	if (error)
455 		return "failed to read disklabel";
456 
457 	/* Fill in disklabel */
458 	return (getdisklabel(buf, label));
459 }
460 
461 int
462 biosopen(struct open_file *f, ...)
463 {
464 #ifdef SOFTRAID
465 	struct sr_boot_volume *bv;
466 #endif
467 	register char *cp, **file;
468 	dev_t maj, unit, part;
469 	struct diskinfo *dip;
470 	int biosdev, devlen;
471 	const char *st;
472 	va_list ap;
473 	char *dev;
474 
475 	va_start(ap, f);
476 	cp = *(file = va_arg(ap, char **));
477 	va_end(ap);
478 
479 #ifdef BIOS_DEBUG
480 	if (debug)
481 		printf("%s\n", cp);
482 #endif
483 
484 	f->f_devdata = NULL;
485 
486 	/* Search for device specification. */
487 	dev = cp;
488 	if (cp[4] == ':')
489 		devlen = 2;
490 	else if (cp[5] == ':')
491 		devlen = 3;
492 	else
493 		return ENOENT;
494 	cp += devlen;
495 
496 	/* Get unit. */
497 	if ('0' <= *cp && *cp <= '9')
498 		unit = *cp++ - '0';
499 	else {
500 		printf("Bad unit number\n");
501 		return EUNIT;
502 	}
503 
504 	/* Get partition. */
505 	if ('a' <= *cp && *cp <= 'p')
506 		part = *cp++ - 'a';
507 	else {
508 		printf("Bad partition\n");
509 		return EPART;
510 	}
511 
512 	/* Get filename. */
513 	cp++;	/* skip ':' */
514 	if (*cp != 0)
515 		*file = cp;
516 	else
517 		f->f_flags |= F_RAW;
518 
519 #ifdef SOFTRAID
520 	/* Intercept softraid disks. */
521 	if (strncmp("sr", dev, 2) == 0) {
522 
523 		/* Create a fake diskinfo for this softraid volume. */
524 		SLIST_FOREACH(bv, &sr_volumes, sbv_link)
525 			if (bv->sbv_unit == unit)
526 				break;
527 		if (bv == NULL) {
528 			printf("Unknown device: sr%d\n", unit);
529 			return EADAPT;
530 		}
531 
532 		if (bv->sbv_level == 'C' && bv->sbv_keys == NULL)
533 			if (sr_crypto_decrypt_keys(bv) != 0)
534 				return EPERM;
535 
536 		if (bv->sbv_diskinfo == NULL) {
537 			dip = alloc(sizeof(struct diskinfo));
538 			bzero(dip, sizeof(*dip));
539 			bv->sbv_diskinfo = dip;
540 			dip->sr_vol = bv;
541 			dip->bios_info.flags |= BDI_BADLABEL;
542 		}
543 
544 		dip = bv->sbv_diskinfo;
545 
546 		if (dip->bios_info.flags & BDI_BADLABEL) {
547 			/* Attempt to read disklabel. */
548 			bv->sbv_part = 'c';
549 			if (sr_getdisklabel(bv, &dip->disklabel))
550 				return ERDLAB;
551 			dip->bios_info.flags &= ~BDI_BADLABEL;
552 		}
553 
554 		bv->sbv_part = part + 'a';
555 
556 		bootdev_dip = dip;
557 		f->f_devdata = dip;
558 
559 		return 0;
560 	}
561 #endif
562 
563 	for (maj = 0; maj < nbdevs &&
564 	    strncmp(dev, bdevs[maj], devlen); maj++);
565 	if (maj >= nbdevs) {
566 		printf("Unknown device: ");
567 		for (cp = *file; *cp != ':'; cp++)
568 			putchar(*cp);
569 		putchar('\n');
570 		return EADAPT;
571 	}
572 
573 	biosdev = unit;
574 	switch (maj) {
575 	case 0:  /* wd */
576 	case 4:  /* sd */
577 	case 17: /* hd */
578 		biosdev |= 0x80;
579 		break;
580 	case 2:  /* fd */
581 		break;
582 	case 6:  /* cd */
583 		biosdev = bios_bootdev & 0xff;
584 		break;
585 	default:
586 		return ENXIO;
587 	}
588 
589 	/* Find device */
590 	bootdev_dip = dip = dklookup(biosdev);
591 
592 	/* Fix up bootdev */
593 	{ dev_t bsd_dev;
594 		bsd_dev = dip->bios_info.bsd_dev;
595 		dip->bsddev = MAKEBOOTDEV(B_TYPE(bsd_dev), B_ADAPTOR(bsd_dev),
596 		    B_CONTROLLER(bsd_dev), unit, part);
597 		dip->bootdev = MAKEBOOTDEV(B_TYPE(bsd_dev), B_ADAPTOR(bsd_dev),
598 		    B_CONTROLLER(bsd_dev), B_UNIT(bsd_dev), part);
599 	}
600 
601 #if 0
602 	dip->bios_info.bsd_dev = dip->bootdev;
603 	bootdev = dip->bootdev;
604 #endif
605 
606 #ifdef BIOS_DEBUG
607 	if (debug) {
608 		printf("BIOS geometry: heads=%u, s/t=%u; EDD=%d\n",
609 		    dip->bios_info.bios_heads, dip->bios_info.bios_sectors,
610 		    dip->bios_info.bios_edd);
611 	}
612 #endif
613 
614 	/* Try for disklabel again (might be removable media) */
615 	if (dip->bios_info.flags & BDI_BADLABEL) {
616 		st = bios_getdisklabel(&dip->bios_info, &dip->disklabel);
617 #ifdef BIOS_DEBUG
618 		if (debug && st)
619 			printf("%s\n", st);
620 #endif
621 		if (!st) {
622 			dip->bios_info.flags &= ~BDI_BADLABEL;
623 			dip->bios_info.flags |= BDI_GOODLABEL;
624 		} else
625 			return ERDLAB;
626 	}
627 
628 	f->f_devdata = dip;
629 
630 	return 0;
631 }
632 
633 const u_char bidos_errs[] =
634 /* ignored	"\x00" "successful completion\0" */
635 		"\x01" "invalid function/parameter\0"
636 		"\x02" "address mark not found\0"
637 		"\x03" "write-protected\0"
638 		"\x04" "sector not found\0"
639 		"\x05" "reset failed\0"
640 		"\x06" "disk changed\0"
641 		"\x07" "drive parameter activity failed\0"
642 		"\x08" "DMA overrun\0"
643 		"\x09" "data boundary error\0"
644 		"\x0A" "bad sector detected\0"
645 		"\x0B" "bad track detected\0"
646 		"\x0C" "invalid media\0"
647 		"\x0E" "control data address mark detected\0"
648 		"\x0F" "DMA arbitration level out of range\0"
649 		"\x10" "uncorrectable CRC or ECC error on read\0"
650 /* ignored	"\x11" "data ECC corrected\0" */
651 		"\x20" "controller failure\0"
652 		"\x31" "no media in drive\0"
653 		"\x32" "incorrect drive type in CMOS\0"
654 		"\x40" "seek failed\0"
655 		"\x80" "operation timed out\0"
656 		"\xAA" "drive not ready\0"
657 		"\xB0" "volume not locked in drive\0"
658 		"\xB1" "volume locked in drive\0"
659 		"\xB2" "volume not removable\0"
660 		"\xB3" "volume in use\0"
661 		"\xB4" "lock count exceeded\0"
662 		"\xB5" "valid eject request failed\0"
663 		"\xBB" "undefined error\0"
664 		"\xCC" "write fault\0"
665 		"\xE0" "status register error\0"
666 		"\xFF" "sense operation failed\0"
667 		"\x00" "\0";
668 
669 static const char *
670 biosdisk_err(u_int error)
671 {
672 	register const u_char *p = bidos_errs;
673 
674 	while (*p && *p != error)
675 		while (*p++);
676 
677 	return ++p;
678 }
679 
680 const struct biosdisk_errors {
681 	u_char error;
682 	u_char errno;
683 } tab[] = {
684 	{ 0x01, EINVAL },
685 	{ 0x03, EROFS },
686 	{ 0x08, EINVAL },
687 	{ 0x09, EINVAL },
688 	{ 0x0A, EBSE },
689 	{ 0x0B, EBSE },
690 	{ 0x0C, ENXIO },
691 	{ 0x0D, EINVAL },
692 	{ 0x10, EECC },
693 	{ 0x20, EHER },
694 	{ 0x31, ENXIO },
695 	{ 0x32, ENXIO },
696 	{ 0x00, EIO }
697 };
698 
699 static int
700 biosdisk_errno(u_int error)
701 {
702 	register const struct biosdisk_errors *p;
703 
704 	if (error == 0)
705 		return 0;
706 
707 	for (p = tab; p->error && p->error != error; p++);
708 
709 	return p->errno;
710 }
711 
712 int
713 biosstrategy(void *devdata, int rw, daddr32_t blk, size_t size, void *buf,
714     size_t *rsize)
715 {
716 	struct diskinfo *dip = (struct diskinfo *)devdata;
717 	bios_diskinfo_t *bd = &dip->bios_info;
718 	u_int8_t error = 0;
719 	size_t nsect;
720 
721 #ifdef SOFTRAID
722 	/* Intercept strategy for softraid volumes. */
723 	if (dip->sr_vol)
724 		return sr_strategy(dip->sr_vol, rw, blk, size, buf, rsize);
725 #endif
726 
727 	nsect = (size + DEV_BSIZE - 1) / DEV_BSIZE;
728 	blk += dip->disklabel.d_partitions[B_PARTITION(dip->bsddev)].p_offset;
729 
730 	/* Read all, sub-functions handle track boundaries */
731 	if (blk < 0)
732 		error = EINVAL;
733 	else
734 		error = biosd_io(rw, bd, blk, nsect, buf);
735 
736 #ifdef BIOS_DEBUG
737 	if (debug) {
738 		if (error != 0)
739 			printf("=0x%x(%s)", error, biosdisk_err(error));
740 		putchar('\n');
741 	}
742 #endif
743 
744 	if (rsize != NULL)
745 		*rsize = nsect * DEV_BSIZE;
746 
747 	return (biosdisk_errno(error));
748 }
749 
750 int
751 biosclose(struct open_file *f)
752 {
753 	f->f_devdata = NULL;
754 
755 	return 0;
756 }
757 
758 int
759 biosioctl(struct open_file *f, u_long cmd, void *data)
760 {
761 	return 0;
762 }
763