1/*	$NetBSD: biosdisk.c,v 1.2 2011/07/06 01:19:45 mrg 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 <lib/libsa/loadfile.h>
72
73#include <machine/disklabel.h>
74
75#include "biosdisk.h"
76#include "biosdisk_ll.h"
77
78#include "bootinfo.h"
79
80#define BUFSIZE (1 * BIOSDISK_SECSIZE)
81
82struct biosdisk {
83	int	dev;
84	int	boff;
85	char	buf[BUFSIZE];
86};
87
88static struct btinfo_bootdisk bi_disk;
89
90#define	RF_PROTECTED_SECTORS	64	/* XXX refer to <.../rf_optnames.h> */
91
92static struct biosdisk *
93alloc_biosdisk(int dev)
94{
95	struct biosdisk *d;
96
97	d = (struct biosdisk *)ALLOC(sizeof(*d));
98	if (d == NULL)
99		return (NULL);
100
101	memset(d, 0, sizeof(*d));
102	d->dev = dev;
103
104	return (d);
105}
106
107static int
108check_label(struct biosdisk *d, int sector)
109{
110	struct disklabel *lp;
111
112	/* find partition in NetBSD disklabel */
113	if (readsects(d->dev, sector + LABELSECTOR, d->buf, 1)) {
114#ifdef DISK_DEBUG
115		printf("Error reading disklabel\n");
116#endif
117		return (EIO);
118	}
119
120	lp = (struct disklabel *)(d->buf + LABELOFFSET);
121	if (lp->d_magic != DISKMAGIC || dkcksum(lp)) {
122#ifdef DISK_DEBUG
123		printf("warning: no disklabel\n");
124#endif
125		return (-1);
126	}
127
128	d->boff = sector;
129	return (0);
130}
131
132static int
133read_label(struct biosdisk *d)
134{
135	struct mbr_sector *mbr_sect;
136	struct disklabel dflt_lbl;
137	struct mbr_partition mbr[MBR_PART_COUNT];
138	struct partition *p;
139	int sector, i;
140	int error;
141	int typ;
142	int ext_base, this_ext, next_ext;
143#ifdef COMPAT_386BSD_MBRPART
144	int sector_386bsd = -1;
145#endif
146
147	memset(&dflt_lbl, 0, sizeof dflt_lbl);
148	dflt_lbl.d_npartitions = 8;
149
150	d->boff = 0;
151
152	/*
153	 * find NetBSD Partition in DOS partition table
154	 * XXX check magic???
155	 */
156	ext_base = 0;
157	next_ext = 0;
158	for (;;) {
159		this_ext = ext_base + next_ext;
160		next_ext = 0;
161		mbr_sect = (struct mbr_sector *)d->buf;
162		memcpy(&mbr, mbr_sect->mbr_parts, sizeof(mbr));
163		if (readsects(d->dev, this_ext, d->buf, 1)) {
164#ifdef DISK_DEBUG
165			printf("error reading MBR sector %d\n", this_ext);
166#endif
167			return (EIO);
168		}
169		memcpy(&mbr, mbr_sect->mbr_parts, sizeof(mbr));
170		/* Look for NetBSD partition ID */
171		for (i = 0; i < MBR_PART_COUNT; i++) {
172			typ = mbr[i].mbrp_type;
173			if (typ == 0)
174				continue;
175			sector = this_ext + mbr[i].mbrp_start;
176			if (typ == MBR_PTYPE_NETBSD) {
177				error = check_label(d, sector);
178				if (error >= 0)
179					return error;
180			}
181			if (MBR_IS_EXTENDED(typ)) {
182				next_ext = mbr[i].mbrp_start;
183				continue;
184			}
185#ifdef COMPAT_386BSD_MBRPART
186			if (this_ext == 0 && typ == MBR_PTYPE_386BSD)
187				sector_386bsd = sector;
188#endif
189			if (this_ext != 0) {
190				if (dflt_lbl.d_npartitions >= MAXPARTITIONS)
191					continue;
192				p = &dflt_lbl.d_partitions[dflt_lbl.d_npartitions++];
193			} else
194				p = &dflt_lbl.d_partitions[i];
195			p->p_offset = sector;
196			p->p_size = mbr[i].mbrp_size;
197			p->p_fstype = xlat_mbr_fstype(typ);
198		}
199		if (next_ext == 0)
200			break;
201		if (ext_base == 0) {
202			ext_base = next_ext;
203			next_ext = 0;
204		}
205	}
206
207	sector = 0;
208#ifdef COMPAT_386BSD_MBRPART
209	if (sector_386bsd != -1) {
210		printf("old BSD partition ID!\n");
211		sector = sector_386bsd;
212	}
213#endif
214
215	/*
216	 * One of two things:
217	 * 	1. no MBR
218	 *	2. no NetBSD partition in MBR
219	 *
220	 * We simply default to "start of disk" in this case and
221	 * press on.
222	 */
223	error = check_label(d, sector);
224	if (error >= 0)
225		return (error);
226
227	/*
228	 * Nothing at start of disk, return info from mbr partitions.
229	 */
230	/* XXX fill it to make checksum match kernel one */
231	dflt_lbl.d_checksum = dkcksum(&dflt_lbl);
232	memcpy(d->buf, &dflt_lbl, sizeof(dflt_lbl));
233	return (-1);
234}
235
236
237/*
238 * Determine likely partition for possible sector number of dos
239 * partition.
240 */
241u_int
242biosdisk_findptn(int biosdev, u_int sector)
243{
244	struct biosdisk *d;
245	u_int partition = 0;
246	struct disklabel *lp;
247
248	/* Look for netbsd partition that is the dos boot one */
249	d = alloc_biosdisk(biosdev);
250	if (d == NULL)
251		return (0);
252
253	if (read_label(d) == 0) {
254		lp = (struct disklabel *)(d->buf + LABELOFFSET);
255		for (partition = lp->d_npartitions; --partition;){
256			if (lp->d_partitions[partition].p_fstype == FS_UNUSED)
257				continue;
258			if (lp->d_partitions[partition].p_offset == sector)
259				break;
260		}
261	}
262
263	DEALLOC(d, sizeof(*d));
264	return (partition);
265}
266
267int
268biosdisk_open(struct open_file *f, ...)
269{
270	va_list ap;
271	struct biosdisk *d;
272	struct disklabel *lp;
273	int dev;
274	int partition;
275	int error = 0;
276
277	va_start(ap, f);
278	dev = va_arg(ap, int);
279	d = alloc_biosdisk(dev);
280	if (d == NULL) {
281		error = ENXIO;
282		goto out;
283	}
284
285	partition = va_arg(ap, int);
286	bi_disk.biosdev = d->dev;
287	bi_disk.partition = partition;
288	bi_disk.labelsector = -1;
289
290	if (partition == RAW_PART)
291		goto nolabel;
292	error = read_label(d);
293	if (error == -1) {
294		error = 0;
295		goto nolabel;
296	}
297	if (error)
298		goto out;
299
300	lp = (struct disklabel *)(d->buf + LABELOFFSET);
301	if (partition >= lp->d_npartitions ||
302	   lp->d_partitions[partition].p_fstype == FS_UNUSED) {
303#ifdef DISK_DEBUG
304		printf("illegal partition\n");
305#endif
306		error = EPART;
307		goto out;
308	}
309	bi_disk.labelsector = d->boff + LABELSECTOR;
310	bi_disk.label.type = lp->d_type;
311	memcpy(bi_disk.label.packname, lp->d_packname, 16);
312	bi_disk.label.checksum = lp->d_checksum;
313
314	d->boff = lp->d_partitions[partition].p_offset;
315	if (lp->d_partitions[partition].p_fstype == FS_RAID) {
316		d->boff += RF_PROTECTED_SECTORS;
317	}
318nolabel:
319
320#ifdef DISK_DEBUG
321	printf("partition @%d\n", d->boff);
322#endif
323
324	BI_ADD(&bi_disk, BTINFO_BOOTDISK, sizeof(bi_disk));
325
326	f->f_devdata = d;
327out:
328        va_end(ap);
329	if (error)
330		DEALLOC(d, sizeof(struct biosdisk));
331	return (error);
332}
333
334int
335biosdisk_close(struct open_file *f)
336{
337	struct biosdisk *d = f->f_devdata;
338
339	DEALLOC(d, sizeof(struct biosdisk));
340	f->f_devdata = NULL;
341
342	return (0);
343}
344
345int
346biosdisk_ioctl(struct open_file *f, u_long cmd, void *arg)
347{
348
349	return (EIO);
350}
351
352int
353biosdisk_strategy(void *devdata, int flag, daddr_t dblk, size_t size, void *buf, size_t *rsize)
354{
355	struct biosdisk *d;
356	int blks;
357	int frag;
358
359	if (flag != F_READ)
360		return EROFS;
361
362	d = (struct biosdisk *)devdata;
363
364	dblk += d->boff;
365
366	blks = size / BIOSDISK_SECSIZE;
367	if (blks && readsects(d->dev, dblk, buf, blks)) {
368		if (rsize)
369			*rsize = 0;
370		return (EIO);
371	}
372
373	/* do we really need this? */
374	frag = size % BIOSDISK_SECSIZE;
375	if (frag) {
376		if (readsects(d->dev, dblk + blks, d->buf, 1)) {
377			if (rsize)
378				*rsize = blks * BIOSDISK_SECSIZE;
379			return (EIO);
380		}
381		memcpy(buf + blks * BIOSDISK_SECSIZE, d->buf, frag);
382	}
383
384	if (rsize)
385		*rsize = size;
386	return (0);
387}
388