xref: /netbsd-src/sys/arch/i386/stand/lib/biosdisk.c (revision b5677b36047b601b9addaaa494a58ceae82c2a6c)
1 /*	$NetBSD: biosdisk.c,v 1.28 2008/01/05 15:28:43 dsl Exp $	*/
2 
3 /*
4  * Copyright (c) 1996, 1998
5  *	Matthias Drochner.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  *
27  */
28 
29 /*
30  * raw BIOS disk device for libsa.
31  * needs lowlevel parts from bios_disk.S and biosdisk_ll.c
32  * partly from netbsd:sys/arch/i386/boot/disk.c
33  * no bad144 handling!
34  *
35  * A lot of this must match sys/kern/subr_disk_mbr.c
36  */
37 
38 /*
39  * Ported to boot 386BSD by Julian Elischer (julian@tfs.com) Sept 1992
40  *
41  * Mach Operating System
42  * Copyright (c) 1992, 1991 Carnegie Mellon University
43  * All Rights Reserved.
44  *
45  * Permission to use, copy, modify and distribute this software and its
46  * documentation is hereby granted, provided that both the copyright
47  * notice and this permission notice appear in all copies of the
48  * software, derivative works or modified versions, and any portions
49  * thereof, and that both notices appear in supporting documentation.
50  *
51  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
52  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
53  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
54  *
55  * Carnegie Mellon requests users of this software to return to
56  *
57  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
58  *  School of Computer Science
59  *  Carnegie Mellon University
60  *  Pittsburgh PA 15213-3890
61  *
62  * any improvements or extensions that they make and grant Carnegie Mellon
63  * the rights to redistribute these changes.
64  */
65 
66 #include <sys/types.h>
67 #include <sys/disklabel.h>
68 #include <sys/md5.h>
69 #include <sys/param.h>
70 
71 #include <fs/cd9660/iso.h>
72 
73 #include <lib/libsa/stand.h>
74 #include <lib/libsa/saerrno.h>
75 #include <machine/stdarg.h>
76 
77 #include "libi386.h"
78 #include "biosdisk_ll.h"
79 #include "biosdisk.h"
80 #ifdef _STANDALONE
81 #include "bootinfo.h"
82 #endif
83 
84 #define BUFSIZE	2048	/* must be large enough for a CD sector */
85 
86 struct biosdisk {
87 	struct biosdisk_ll ll;
88 	int             boff;
89 	char            buf[BUFSIZE];
90 };
91 
92 #ifdef _STANDALONE
93 static struct btinfo_bootdisk bi_disk;
94 static struct btinfo_bootwedge bi_wedge;
95 #endif
96 
97 #define	RF_PROTECTED_SECTORS	64	/* XXX refer to <.../rf_optnames.h> */
98 
99 int
100 biosdisk_strategy(void *devdata, int flag, daddr_t dblk, size_t size,
101 		  void *buf, size_t *rsize)
102 {
103 	struct biosdisk *d;
104 	int blks, frag;
105 
106 	if (flag != F_READ)
107 		return EROFS;
108 
109 	d = (struct biosdisk *) devdata;
110 
111 	if (d->ll.type == BIOSDISK_TYPE_CD)
112 		dblk = dblk * DEV_BSIZE / ISO_DEFAULT_BLOCK_SIZE;
113 
114 	dblk += d->boff;
115 
116 	blks = size / d->ll.secsize;
117 	if (blks && readsects(&d->ll, dblk, blks, buf, 0)) {
118 		if (rsize)
119 			*rsize = 0;
120 		return EIO;
121 	}
122 
123 	/* needed for CD */
124 	frag = size % d->ll.secsize;
125 	if (frag) {
126 		if (readsects(&d->ll, dblk + blks, 1, d->buf, 0)) {
127 			if (rsize)
128 				*rsize = blks * d->ll.secsize;
129 			return EIO;
130 		}
131 		memcpy(buf + blks * d->ll.secsize, d->buf, frag);
132 	}
133 
134 	if (rsize)
135 		*rsize = size;
136 	return 0;
137 }
138 
139 static struct biosdisk *
140 alloc_biosdisk(int biosdev)
141 {
142 	struct biosdisk *d;
143 
144 	d = alloc(sizeof(*d));
145 	if (d == NULL)
146 		return NULL;
147 	memset(d, 0, sizeof(*d));
148 
149 	d->ll.dev = biosdev;
150 	if (set_geometry(&d->ll, NULL)) {
151 #ifdef DISK_DEBUG
152 		printf("no geometry information\n");
153 #endif
154 		dealloc(d, sizeof(*d));
155 		return NULL;
156 	}
157 	return d;
158 }
159 
160 #ifndef NO_DISKLABEL
161 static int
162 check_label(struct biosdisk *d, int sector)
163 {
164 	struct disklabel *lp;
165 
166 	/* find partition in NetBSD disklabel */
167 	if (readsects(&d->ll, sector + LABELSECTOR, 1, d->buf, 0)) {
168 #ifdef DISK_DEBUG
169 		printf("Error reading disklabel\n");
170 #endif
171 		return EIO;
172 	}
173 	lp = (struct disklabel *) (d->buf + LABELOFFSET);
174 	if (lp->d_magic != DISKMAGIC || dkcksum(lp)) {
175 #ifdef DISK_DEBUG
176 		printf("warning: no disklabel in sector %u\n", sector);
177 #endif
178 		return -1;
179 	}
180 
181 	d->boff = sector;
182 	return 0;
183 }
184 
185 static int
186 read_label(struct biosdisk *d)
187 {
188 	struct disklabel dflt_lbl;
189 	struct mbr_partition mbr[MBR_PART_COUNT];
190 	struct partition *p;
191 	int sector, i;
192 	int error;
193 	int typ;
194 	int ext_base, this_ext, next_ext;
195 #ifdef COMPAT_386BSD_MBRPART
196 	int sector_386bsd = -1;
197 #endif
198 
199 	memset(&dflt_lbl, 0, sizeof(dflt_lbl));
200 	dflt_lbl.d_npartitions = 8;
201 
202 	d->boff = 0;
203 
204 	if (d->ll.type != BIOSDISK_TYPE_HD)
205 		/* No label on floppy and CD */
206 		return -1;
207 
208 	/*
209 	 * find NetBSD Partition in DOS partition table
210 	 * XXX check magic???
211 	 */
212 	ext_base = 0;
213 	next_ext = 0;
214 	for (;;) {
215 		this_ext = ext_base + next_ext;
216 		next_ext = 0;
217 		if (readsects(&d->ll, this_ext, 1, d->buf, 0)) {
218 #ifdef DISK_DEBUG
219 			printf("error reading MBR sector %d\n", this_ext);
220 #endif
221 			return EIO;
222 		}
223 		memcpy(&mbr, ((struct mbr_sector *)d->buf)->mbr_parts,
224 		       sizeof(mbr));
225 		/* Look for NetBSD partition ID */
226 		for (i = 0; i < MBR_PART_COUNT; i++) {
227 			typ = mbr[i].mbrp_type;
228 			if (typ == 0)
229 				continue;
230 			sector = this_ext + mbr[i].mbrp_start;
231 #ifdef DISK_DEBUG
232 			printf("ptn type %d in sector %u\n", typ, sector);
233 #endif
234 			if (typ == MBR_PTYPE_NETBSD) {
235 				error = check_label(d, sector);
236 				if (error >= 0)
237 					return error;
238 			}
239 			if (MBR_IS_EXTENDED(typ)) {
240 				next_ext = mbr[i].mbrp_start;
241 				continue;
242 			}
243 #ifdef COMPAT_386BSD_MBRPART
244 			if (this_ext == 0 && typ == MBR_PTYPE_386BSD)
245 				sector_386bsd = sector;
246 #endif
247 			if (this_ext != 0) {
248 				if (dflt_lbl.d_npartitions >= MAXPARTITIONS)
249 					continue;
250 				p = &dflt_lbl.d_partitions[dflt_lbl.d_npartitions++];
251 			} else
252 				p = &dflt_lbl.d_partitions[i];
253 			p->p_offset = sector;
254 			p->p_size = mbr[i].mbrp_size;
255 			p->p_fstype = xlat_mbr_fstype(typ);
256 		}
257 		if (next_ext == 0)
258 			break;
259 		if (ext_base == 0) {
260 			ext_base = next_ext;
261 			next_ext = 0;
262 		}
263 	}
264 
265 	sector = 0;
266 #ifdef COMPAT_386BSD_MBRPART
267 	if (sector_386bsd != -1) {
268 		printf("old BSD partition ID!\n");
269 		sector = sector_386bsd;
270 	}
271 #endif
272 
273 	/*
274 	 * One of two things:
275 	 * 	1. no MBR
276 	 *	2. no NetBSD partition in MBR
277 	 *
278 	 * We simply default to "start of disk" in this case and
279 	 * press on.
280 	 */
281 	error = check_label(d, sector);
282 	if (error >= 0)
283 		return error;
284 
285 	/*
286 	 * Nothing at start of disk, return info from mbr partitions.
287 	 */
288 	/* XXX fill it to make checksum match kernel one */
289 	dflt_lbl.d_checksum = dkcksum(&dflt_lbl);
290 	memcpy(d->buf, &dflt_lbl, sizeof(dflt_lbl));
291 	return 0;
292 }
293 #endif /* NO_DISKLABEL */
294 
295 /* Determine likely partition for possible sector number of dos
296  * partition.
297  */
298 
299 int
300 biosdisk_findpartition(int biosdev, u_int sector)
301 {
302 #ifdef NO_DISKLABEL
303 	return 0;
304 #else
305 	struct biosdisk *d;
306 	int partition = 0;
307 	struct disklabel *lp;
308 #ifdef DISK_DEBUG
309 	printf("looking for partition device %x, sector %u\n", biosdev, sector);
310 #endif
311 
312 	/* Look for netbsd partition that is the dos boot one */
313 	d = alloc_biosdisk(biosdev);
314 	if (d == NULL)
315 		return 0;
316 
317 	if (read_label(d) == 0) {
318 		lp = (struct disklabel *)(d->buf + LABELOFFSET);
319 		for (partition = lp->d_npartitions; --partition;){
320 			if (lp->d_partitions[partition].p_fstype == FS_UNUSED)
321 				continue;
322 			if (lp->d_partitions[partition].p_offset == sector)
323 				break;
324 		}
325 	}
326 
327 	dealloc(d, sizeof(*d));
328 	return partition;
329 #endif /* NO_DISKLABEL */
330 }
331 
332 int
333 biosdisk_open(struct open_file *f, ...)
334 /* struct open_file *f, int biosdev, int partition */
335 {
336 	va_list ap;
337 	struct biosdisk *d;
338 	int biosdev;
339 	int partition;
340 #ifndef NO_DISKLABEL
341 	struct disklabel *lp;
342 #endif
343 	int error = 0;
344 
345 	va_start(ap, f);
346 	biosdev = va_arg(ap, int);
347 	d = alloc_biosdisk(biosdev);
348 	if (d == NULL) {
349 		error = ENXIO;
350 		goto out;
351 	}
352 
353 	partition = va_arg(ap, int);
354 #ifdef _STANDALONE
355 	bi_disk.biosdev = d->ll.dev;
356 	bi_disk.partition = partition;
357 	bi_disk.labelsector = -1;
358 
359 	bi_wedge.biosdev = d->ll.dev;
360 	bi_wedge.matchblk = -1;
361 #endif
362 
363 #ifndef NO_DISKLABEL
364 	if (partition == RAW_PART)
365 		goto nolabel;
366 	error = read_label(d);
367 	if (error == -1) {
368 		error = 0;
369 		goto nolabel;
370 	}
371 	if (error)
372 		goto out;
373 
374 	lp = (struct disklabel *) (d->buf + LABELOFFSET);
375 	if (partition >= lp->d_npartitions ||
376 	    lp->d_partitions[partition].p_fstype == FS_UNUSED) {
377 #ifdef DISK_DEBUG
378 		printf("illegal partition\n");
379 #endif
380 		error = EPART;
381 		goto out;
382 	}
383 #ifdef _STANDALONE
384 	bi_disk.labelsector = d->boff + LABELSECTOR;
385 	bi_disk.label.type = lp->d_type;
386 	memcpy(bi_disk.label.packname, lp->d_packname, 16);
387 	bi_disk.label.checksum = lp->d_checksum;
388 
389 	bi_wedge.startblk = lp->d_partitions[partition].p_offset;
390 	bi_wedge.nblks = lp->d_partitions[partition].p_size;
391 	bi_wedge.matchblk = d->boff + LABELSECTOR;
392 	bi_wedge.matchnblks = 1;
393 	{
394 		MD5_CTX ctx;
395 
396 		MD5Init(&ctx);
397 		MD5Update(&ctx, (void *) d->buf, 512);
398 		MD5Final(bi_wedge.matchhash, &ctx);
399 	}
400 #endif
401 	d->boff = lp->d_partitions[partition].p_offset;
402 	if (lp->d_partitions[partition].p_fstype == FS_RAID)
403 		d->boff += RF_PROTECTED_SECTORS;
404 nolabel:
405 #endif /* NO_DISKLABEL */
406 
407 #ifdef DISK_DEBUG
408 	printf("partition @%d\n", d->boff);
409 #endif
410 
411 #ifdef _STANDALONE
412 	BI_ADD(&bi_disk, BTINFO_BOOTDISK, sizeof(bi_disk));
413 	BI_ADD(&bi_wedge, BTINFO_BOOTWEDGE, sizeof(bi_wedge));
414 #endif
415 
416 	f->f_devdata = d;
417 out:
418         va_end(ap);
419 	if (error)
420 		dealloc(d, sizeof(struct biosdisk));
421 	return error;
422 }
423 
424 #ifndef LIBSA_NO_FS_CLOSE
425 int
426 biosdisk_close(struct open_file *f)
427 {
428 	struct biosdisk *d = f->f_devdata;
429 
430 	/* let the floppy drive go off */
431 	if (d->ll.type == BIOSDISK_TYPE_FD)
432 		delay(3000000);	/* 2s is enough on all PCs I found */
433 
434 	dealloc(d, sizeof(struct biosdisk));
435 	f->f_devdata = NULL;
436 	return 0;
437 }
438 #endif
439 
440 int
441 biosdisk_ioctl(struct open_file *f, u_long cmd, void *arg)
442 {
443 	return EIO;
444 }
445