xref: /netbsd-src/sys/arch/i386/stand/lib/biosdisk.c (revision 23c8222edbfb0f0932d88a8351d3a0cf817dfb9e)
1 /*	$NetBSD: biosdisk.c,v 1.21 2004/10/23 17:20:04 thorpej 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 
70 #include <lib/libsa/stand.h>
71 #include <lib/libsa/saerrno.h>
72 #include <machine/stdarg.h>
73 
74 #include "libi386.h"
75 #include "biosdisk_ll.h"
76 #include "biosdisk.h"
77 #ifdef _STANDALONE
78 #include "bootinfo.h"
79 #endif
80 
81 #define BUFSIZE (1 * BIOSDISK_SECSIZE)
82 
83 struct biosdisk {
84 	struct biosdisk_ll ll;
85 	int             boff;
86 	char            buf[BUFSIZE];
87 };
88 
89 #ifdef _STANDALONE
90 static struct btinfo_bootdisk bi_disk;
91 static struct btinfo_bootwedge bi_wedge;
92 #endif
93 
94 #define	RF_PROTECTED_SECTORS	64	/* XXX refer to <.../rf_optnames.h> */
95 
96 int boot_biossector;	/* disk sector partition might have started in */
97 
98 int
99 biosdiskstrategy(devdata, flag, dblk, size, buf, rsize)
100 	void           *devdata;
101 	int             flag;
102 	daddr_t         dblk;
103 	size_t          size;
104 	void           *buf;
105 	size_t         *rsize;
106 {
107 	struct biosdisk *d;
108 	int             blks, frag;
109 
110 	if (flag != F_READ)
111 		return (EROFS);
112 
113 	d = (struct biosdisk *) devdata;
114 
115 	dblk += d->boff;
116 
117 	blks = size / BIOSDISK_SECSIZE;
118 	if (blks && readsects(&d->ll, dblk, blks, buf, 0)) {
119 		if (rsize)
120 			*rsize = 0;
121 		return (EIO);
122 	}
123 	/* do we really need this? */
124 	frag = size % BIOSDISK_SECSIZE;
125 	if (frag) {
126 		if (readsects(&d->ll, dblk + blks, 1, d->buf, 0)) {
127 			if (rsize)
128 				*rsize = blks * BIOSDISK_SECSIZE;
129 			return (EIO);
130 		}
131 		memcpy(buf + blks * BIOSDISK_SECSIZE, d->buf, frag);
132 	}
133 	if (rsize)
134 		*rsize = size;
135 	return (0);
136 }
137 
138 static struct biosdisk *
139 alloc_biosdisk(int dev)
140 {
141 	struct biosdisk *d;
142 
143 	d = (struct biosdisk *)alloc(sizeof *d);
144 	if (!d)
145 		return NULL;
146 	memset(d, 0, sizeof *d);
147 
148 	d->ll.dev = dev;;
149 	if (set_geometry(&d->ll, NULL)) {
150 #ifdef DISK_DEBUG
151 		printf("no geometry information\n");
152 #endif
153 		free(d, sizeof *d);
154 		return NULL;
155 	}
156 	return d;
157 }
158 
159 #ifndef NO_DISKLABEL
160 static int
161 check_label(struct biosdisk *d, int sector)
162 {
163 	struct disklabel *lp;
164 
165 	/* find partition in NetBSD disklabel */
166 	if (readsects(&d->ll, sector + LABELSECTOR, 1, d->buf, 0)) {
167 #ifdef DISK_DEBUG
168 		printf("Error reading disklabel\n");
169 #endif
170 		return EIO;
171 	}
172 	lp = (struct disklabel *) (d->buf + LABELOFFSET);
173 	if (lp->d_magic != DISKMAGIC || dkcksum(lp)) {
174 #ifdef DISK_DEBUG
175 		printf("warning: no disklabel\n");
176 #endif
177 		return -1;
178 	}
179 
180 	d->boff = sector;
181 	return 0;
182 }
183 
184 static int
185 read_label(struct biosdisk *d)
186 {
187 	struct disklabel dflt_lbl;
188 	struct mbr_partition mbr[MBR_PART_COUNT];
189 	struct partition *p;
190 	int sector, i;
191 	int error;
192 	int typ;
193 	int ext_base, this_ext, next_ext;
194 #ifdef COMPAT_386BSD_MBRPART
195 	int sector_386bsd = -1;
196 #endif
197 
198 	memset(&dflt_lbl, 0, sizeof dflt_lbl);
199 	dflt_lbl.d_npartitions = 8;
200 
201 	d->boff = 0;
202 
203 	if (!(d->ll.dev & 0x80)) /* floppy */
204 		/* No label on floppy */
205 		return -1;
206 
207 	/*
208 	 * find NetBSD Partition in DOS partition table
209 	 * XXX check magic???
210 	 */
211 	ext_base = 0;
212 	next_ext = 0;
213 	for (;;) {
214 		this_ext = ext_base + next_ext;
215 		next_ext = 0;
216 		if (readsects(&d->ll, this_ext, 1, d->buf, 0)) {
217 #ifdef DISK_DEBUG
218 			printf("error reading MBR sector %d\n", this_ext);
219 #endif
220 			return EIO;
221 		}
222 		memcpy(&mbr, ((struct mbr_sector *)d->buf)->mbr_parts, sizeof mbr);
223 		/* Look for NetBSD partition ID */
224 		for (i = 0; i < MBR_PART_COUNT; i++) {
225 			typ = mbr[i].mbrp_type;
226 			if (typ == 0)
227 				continue;
228 			sector = this_ext + mbr[i].mbrp_start;
229 			if (typ == MBR_PTYPE_NETBSD) {
230 				error = check_label(d, sector);
231 				if (error >= 0)
232 					return error;
233 			}
234 			if (MBR_IS_EXTENDED(typ)) {
235 				next_ext = mbr[i].mbrp_start;
236 				continue;
237 			}
238 #ifdef COMPAT_386BSD_MBRPART
239 			if (this_ext == 0 && typ == MBR_PTYPE_386BSD)
240 				sector_386bsd = sector;
241 #endif
242 			if (this_ext != 0) {
243 				if (dflt_lbl.d_npartitions >= MAXPARTITIONS)
244 					continue;
245 				p = &dflt_lbl.d_partitions[dflt_lbl.d_npartitions++];
246 			} else
247 				p = &dflt_lbl.d_partitions[i];
248 			p->p_offset = sector;
249 			p->p_size = mbr[i].mbrp_size;
250 			p->p_fstype = xlat_mbr_fstype(typ);
251 		}
252 		if (next_ext == 0)
253 			break;
254 		if (ext_base == 0) {
255 			ext_base = next_ext;
256 			next_ext = 0;
257 		}
258 	}
259 
260 	sector = 0;
261 #ifdef COMPAT_386BSD_MBRPART
262 	if (sector_386bsd != -1) {
263 		printf("old BSD partition ID!\n");
264 		sector = sector_386bsd;
265 	}
266 #endif
267 
268 	/*
269 	 * One of two things:
270 	 * 	1. no MBR
271 	 *	2. no NetBSD partition in MBR
272 	 *
273 	 * We simply default to "start of disk" in this case and
274 	 * press on.
275 	 */
276 	error = check_label(d, sector);
277 	if (error >= 0)
278 		return error;
279 
280 	/*
281 	 * Nothing at start of disk, return info from mbr partitions.
282 	 */
283 	/* XXX fill it to make checksum match kernel one */
284 	dflt_lbl.d_checksum = dkcksum(&dflt_lbl);
285 	memcpy(d->buf, &dflt_lbl, sizeof dflt_lbl);
286 	return -1;
287 }
288 #endif /* NO_DISKLABEL */
289 
290 /* Determine likely partition for possible sector number of dos
291  * partition.
292  */
293 
294 u_int
295 biosdiskfindptn(int biosdev, u_int sector)
296 {
297 #ifdef NO_DISKLABEL
298 	return 0;
299 #else
300 	struct biosdisk *d;
301 	u_int partition = 0;
302 	struct disklabel *lp;
303 
304 	/* Look for netbsd partition that is the dos boot one */
305 	d = alloc_biosdisk(biosdev);
306 	if (d == NULL)
307 		return 0;
308 
309 	if (read_label(d) == 0) {
310 		lp = (struct disklabel *)(d->buf + LABELOFFSET);
311 		for (partition = lp->d_npartitions; --partition;){
312 			if (lp->d_partitions[partition].p_fstype == FS_UNUSED)
313 				continue;
314 			if (lp->d_partitions[partition].p_offset == sector)
315 				break;
316 		}
317 	}
318 
319 	free(d, sizeof *d);
320 	return partition;
321 }
322 #endif /* NO_DISKLABEL */
323 
324 int
325 biosdiskopen(struct open_file *f, ...)
326 /* file, biosdev, partition */
327 {
328 	va_list ap;
329 	struct biosdisk *d;
330 	int partition;
331 #ifndef NO_DISKLABEL
332 	struct disklabel *lp;
333 #endif
334 	int error = 0;
335 
336 	va_start(ap, f);
337 	d = alloc_biosdisk(va_arg(ap, int));
338 	if (!d) {
339 		error = ENXIO;
340 		goto out;
341 	}
342 
343 	partition = va_arg(ap, int);
344 #ifdef _STANDALONE
345 	bi_disk.biosdev = d->ll.dev;
346 	bi_disk.partition = partition;
347 	bi_disk.labelsector = -1;
348 
349 	bi_wedge.biosdev = d->ll.dev;
350 	bi_wedge.matchblk = -1;
351 #endif
352 
353 #ifndef NO_DISKLABEL
354 	if (partition == RAW_PART)
355 		goto nolabel;
356 	error = read_label(d);
357 	if (error == -1) {
358 		error = 0;
359 		goto nolabel;
360 	}
361 	if (error)
362 		goto out;
363 
364 	lp = (struct disklabel *) (d->buf + LABELOFFSET);
365 	if (partition >= lp->d_npartitions ||
366 	   lp->d_partitions[partition].p_fstype == FS_UNUSED) {
367 #ifdef DISK_DEBUG
368 		printf("illegal partition\n");
369 #endif
370 		error = EPART;
371 		goto out;
372 	}
373 #ifdef _STANDALONE
374 	bi_disk.labelsector = d->boff + LABELSECTOR;
375 	bi_disk.label.type = lp->d_type;
376 	memcpy(bi_disk.label.packname, lp->d_packname, 16);
377 	bi_disk.label.checksum = lp->d_checksum;
378 
379 	bi_wedge.startblk = lp->d_partitions[partition].p_offset;
380 	bi_wedge.nblks = lp->d_partitions[partition].p_size;
381 	bi_wedge.matchblk = d->boff + LABELSECTOR;
382 	bi_wedge.matchnblks = 1;
383 	{
384 		MD5_CTX ctx;
385 
386 		MD5Init(&ctx);
387 		MD5Update(&ctx, (void *) d->buf, 512);
388 		MD5Final(bi_wedge.matchhash, &ctx);
389 	}
390 #endif
391 	d->boff = lp->d_partitions[partition].p_offset;
392 	if (lp->d_partitions[partition].p_fstype == FS_RAID)
393 		d->boff += RF_PROTECTED_SECTORS;
394 nolabel:
395 #endif /* NO_DISKLABEL */
396 
397 #ifdef DISK_DEBUG
398 	printf("partition @%d\n", d->boff);
399 #endif
400 
401 #ifdef _STANDALONE
402 	BI_ADD(&bi_disk, BTINFO_BOOTDISK, sizeof(bi_disk));
403 	BI_ADD(&bi_wedge, BTINFO_BOOTWEDGE, sizeof(bi_wedge));
404 #endif
405 
406 	f->f_devdata = d;
407 out:
408         va_end(ap);
409 	if (error)
410 		free(d, sizeof(struct biosdisk));
411 	return (error);
412 }
413 
414 #ifndef LIBSA_NO_FS_CLOSE
415 int
416 biosdiskclose(f)
417 	struct open_file *f;
418 {
419 	struct biosdisk *d = f->f_devdata;
420 
421 	if (!(d->ll.dev & 0x80))/* let the floppy drive go off */
422 		delay(3000000);	/* 2s is enough on all PCs I found */
423 
424 	free(d, sizeof(struct biosdisk));
425 	f->f_devdata = NULL;
426 	return (0);
427 }
428 #endif
429 
430 int
431 biosdiskioctl(f, cmd, arg)
432 	struct open_file *f;
433 	u_long          cmd;
434 	void           *arg;
435 {
436 	return EIO;
437 }
438