xref: /netbsd-src/sys/arch/i386/stand/lib/biosdisk.c (revision 4b896b232495b7a9b8b94a1cf1e21873296d53b8)
1 /*	$NetBSD: biosdisk.c,v 1.20 2004/03/24 16:34:29 drochner 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 
69 #include <lib/libsa/stand.h>
70 #include <lib/libsa/saerrno.h>
71 #include <machine/stdarg.h>
72 
73 #include "libi386.h"
74 #include "biosdisk_ll.h"
75 #include "biosdisk.h"
76 #ifdef _STANDALONE
77 #include "bootinfo.h"
78 #endif
79 
80 #define BUFSIZE (1 * BIOSDISK_SECSIZE)
81 
82 struct biosdisk {
83 	struct biosdisk_ll ll;
84 	int             boff;
85 	char            buf[BUFSIZE];
86 };
87 
88 #ifdef _STANDALONE
89 static struct btinfo_bootdisk bi_disk;
90 #endif
91 
92 #define	RF_PROTECTED_SECTORS	64	/* XXX refer to <.../rf_optnames.h> */
93 
94 int boot_biossector;	/* disk sector partition might have started in */
95 
96 int
97 biosdiskstrategy(devdata, flag, dblk, size, buf, rsize)
98 	void           *devdata;
99 	int             flag;
100 	daddr_t         dblk;
101 	size_t          size;
102 	void           *buf;
103 	size_t         *rsize;
104 {
105 	struct biosdisk *d;
106 	int             blks, frag;
107 
108 	if (flag != F_READ)
109 		return (EROFS);
110 
111 	d = (struct biosdisk *) devdata;
112 
113 	dblk += d->boff;
114 
115 	blks = size / BIOSDISK_SECSIZE;
116 	if (blks && readsects(&d->ll, dblk, blks, buf, 0)) {
117 		if (rsize)
118 			*rsize = 0;
119 		return (EIO);
120 	}
121 	/* do we really need this? */
122 	frag = size % BIOSDISK_SECSIZE;
123 	if (frag) {
124 		if (readsects(&d->ll, dblk + blks, 1, d->buf, 0)) {
125 			if (rsize)
126 				*rsize = blks * BIOSDISK_SECSIZE;
127 			return (EIO);
128 		}
129 		memcpy(buf + blks * BIOSDISK_SECSIZE, d->buf, frag);
130 	}
131 	if (rsize)
132 		*rsize = size;
133 	return (0);
134 }
135 
136 static struct biosdisk *
137 alloc_biosdisk(int dev)
138 {
139 	struct biosdisk *d;
140 
141 	d = (struct biosdisk *)alloc(sizeof *d);
142 	if (!d)
143 		return NULL;
144 	memset(d, 0, sizeof *d);
145 
146 	d->ll.dev = dev;;
147 	if (set_geometry(&d->ll, NULL)) {
148 #ifdef DISK_DEBUG
149 		printf("no geometry information\n");
150 #endif
151 		free(d, sizeof *d);
152 		return NULL;
153 	}
154 	return d;
155 }
156 
157 #ifndef NO_DISKLABEL
158 static int
159 check_label(struct biosdisk *d, int sector)
160 {
161 	struct disklabel *lp;
162 
163 	/* find partition in NetBSD disklabel */
164 	if (readsects(&d->ll, sector + LABELSECTOR, 1, d->buf, 0)) {
165 #ifdef DISK_DEBUG
166 		printf("Error reading disklabel\n");
167 #endif
168 		return EIO;
169 	}
170 	lp = (struct disklabel *) (d->buf + LABELOFFSET);
171 	if (lp->d_magic != DISKMAGIC || dkcksum(lp)) {
172 #ifdef DISK_DEBUG
173 		printf("warning: no disklabel\n");
174 #endif
175 		return -1;
176 	}
177 
178 	d->boff = sector;
179 	return 0;
180 }
181 
182 static int
183 read_label(struct biosdisk *d)
184 {
185 	struct disklabel dflt_lbl;
186 	struct mbr_partition mbr[MBR_PART_COUNT];
187 	struct partition *p;
188 	int sector, i;
189 	int error;
190 	int typ;
191 	int ext_base, this_ext, next_ext;
192 #ifdef COMPAT_386BSD_MBRPART
193 	int sector_386bsd = -1;
194 #endif
195 
196 	memset(&dflt_lbl, 0, sizeof dflt_lbl);
197 	dflt_lbl.d_npartitions = 8;
198 
199 	d->boff = 0;
200 
201 	if (!(d->ll.dev & 0x80)) /* floppy */
202 		/* No label on floppy */
203 		return -1;
204 
205 	/*
206 	 * find NetBSD Partition in DOS partition table
207 	 * XXX check magic???
208 	 */
209 	ext_base = 0;
210 	next_ext = 0;
211 	for (;;) {
212 		this_ext = ext_base + next_ext;
213 		next_ext = 0;
214 		if (readsects(&d->ll, this_ext, 1, d->buf, 0)) {
215 #ifdef DISK_DEBUG
216 			printf("error reading MBR sector %d\n", this_ext);
217 #endif
218 			return EIO;
219 		}
220 		memcpy(&mbr, ((struct mbr_sector *)d->buf)->mbr_parts, sizeof mbr);
221 		/* Look for NetBSD partition ID */
222 		for (i = 0; i < MBR_PART_COUNT; i++) {
223 			typ = mbr[i].mbrp_type;
224 			if (typ == 0)
225 				continue;
226 			sector = this_ext + mbr[i].mbrp_start;
227 			if (typ == MBR_PTYPE_NETBSD) {
228 				error = check_label(d, sector);
229 				if (error >= 0)
230 					return error;
231 			}
232 			if (MBR_IS_EXTENDED(typ)) {
233 				next_ext = mbr[i].mbrp_start;
234 				continue;
235 			}
236 #ifdef COMPAT_386BSD_MBRPART
237 			if (this_ext == 0 && typ == MBR_PTYPE_386BSD)
238 				sector_386bsd = sector;
239 #endif
240 			if (this_ext != 0) {
241 				if (dflt_lbl.d_npartitions >= MAXPARTITIONS)
242 					continue;
243 				p = &dflt_lbl.d_partitions[dflt_lbl.d_npartitions++];
244 			} else
245 				p = &dflt_lbl.d_partitions[i];
246 			p->p_offset = sector;
247 			p->p_size = mbr[i].mbrp_size;
248 			p->p_fstype = xlat_mbr_fstype(typ);
249 		}
250 		if (next_ext == 0)
251 			break;
252 		if (ext_base == 0) {
253 			ext_base = next_ext;
254 			next_ext = 0;
255 		}
256 	}
257 
258 	sector = 0;
259 #ifdef COMPAT_386BSD_MBRPART
260 	if (sector_386bsd != -1) {
261 		printf("old BSD partition ID!\n");
262 		sector = sector_386bsd;
263 	}
264 #endif
265 
266 	/*
267 	 * One of two things:
268 	 * 	1. no MBR
269 	 *	2. no NetBSD partition in MBR
270 	 *
271 	 * We simply default to "start of disk" in this case and
272 	 * press on.
273 	 */
274 	error = check_label(d, sector);
275 	if (error >= 0)
276 		return error;
277 
278 	/*
279 	 * Nothing at start of disk, return info from mbr partitions.
280 	 */
281 	/* XXX fill it to make checksum match kernel one */
282 	dflt_lbl.d_checksum = dkcksum(&dflt_lbl);
283 	memcpy(d->buf, &dflt_lbl, sizeof dflt_lbl);
284 	return -1;
285 }
286 #endif /* NO_DISKLABEL */
287 
288 /* Determine likely partition for possible sector number of dos
289  * partition.
290  */
291 
292 u_int
293 biosdiskfindptn(int biosdev, u_int sector)
294 {
295 #ifdef NO_DISKLABEL
296 	return 0;
297 #else
298 	struct biosdisk *d;
299 	u_int partition = 0;
300 	struct disklabel *lp;
301 
302 	/* Look for netbsd partition that is the dos boot one */
303 	d = alloc_biosdisk(biosdev);
304 	if (d == NULL)
305 		return 0;
306 
307 	if (read_label(d) == 0) {
308 		lp = (struct disklabel *)(d->buf + LABELOFFSET);
309 		for (partition = lp->d_npartitions; --partition;){
310 			if (lp->d_partitions[partition].p_fstype == FS_UNUSED)
311 				continue;
312 			if (lp->d_partitions[partition].p_offset == sector)
313 				break;
314 		}
315 	}
316 
317 	free(d, sizeof *d);
318 	return partition;
319 }
320 #endif /* NO_DISKLABEL */
321 
322 int
323 biosdiskopen(struct open_file *f, ...)
324 /* file, biosdev, partition */
325 {
326 	va_list ap;
327 	struct biosdisk *d;
328 	int partition;
329 #ifndef NO_DISKLABEL
330 	struct disklabel *lp;
331 #endif
332 	int error = 0;
333 
334 	va_start(ap, f);
335 	d = alloc_biosdisk(va_arg(ap, int));
336 	if (!d) {
337 		error = ENXIO;
338 		goto out;
339 	}
340 
341 	partition = va_arg(ap, int);
342 #ifdef _STANDALONE
343 	bi_disk.biosdev = d->ll.dev;
344 	bi_disk.partition = partition;
345 	bi_disk.labelsector = -1;
346 #endif
347 
348 #ifndef NO_DISKLABEL
349 	if (partition == RAW_PART)
350 		goto nolabel;
351 	error = read_label(d);
352 	if (error == -1) {
353 		error = 0;
354 		goto nolabel;
355 	}
356 	if (error)
357 		goto out;
358 
359 	lp = (struct disklabel *) (d->buf + LABELOFFSET);
360 	if (partition >= lp->d_npartitions ||
361 	   lp->d_partitions[partition].p_fstype == FS_UNUSED) {
362 #ifdef DISK_DEBUG
363 		printf("illegal partition\n");
364 #endif
365 		error = EPART;
366 		goto out;
367 	}
368 #ifdef _STANDALONE
369 	bi_disk.labelsector = d->boff + LABELSECTOR;
370 	bi_disk.label.type = lp->d_type;
371 	memcpy(bi_disk.label.packname, lp->d_packname, 16);
372 	bi_disk.label.checksum = lp->d_checksum;
373 #endif
374 	d->boff = lp->d_partitions[partition].p_offset;
375 	if (lp->d_partitions[partition].p_fstype == FS_RAID)
376 		d->boff += RF_PROTECTED_SECTORS;
377 nolabel:
378 #endif /* NO_DISKLABEL */
379 
380 #ifdef DISK_DEBUG
381 	printf("partition @%d\n", d->boff);
382 #endif
383 
384 #ifdef _STANDALONE
385 	BI_ADD(&bi_disk, BTINFO_BOOTDISK, sizeof(bi_disk));
386 #endif
387 
388 	f->f_devdata = d;
389 out:
390         va_end(ap);
391 	if (error)
392 		free(d, sizeof(struct biosdisk));
393 	return (error);
394 }
395 
396 #ifndef LIBSA_NO_FS_CLOSE
397 int
398 biosdiskclose(f)
399 	struct open_file *f;
400 {
401 	struct biosdisk *d = f->f_devdata;
402 
403 	if (!(d->ll.dev & 0x80))/* let the floppy drive go off */
404 		delay(3000000);	/* 2s is enough on all PCs I found */
405 
406 	free(d, sizeof(struct biosdisk));
407 	f->f_devdata = NULL;
408 	return (0);
409 }
410 #endif
411 
412 int
413 biosdiskioctl(f, cmd, arg)
414 	struct open_file *f;
415 	u_long          cmd;
416 	void           *arg;
417 {
418 	return EIO;
419 }
420