1/*	$NetBSD: landisk.c,v 1.4 2009/04/05 11:55:39 lukem Exp $	*/
2
3/*-
4 * Copyright (c) 2003 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by David Laight.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32#if HAVE_NBTOOL_CONFIG_H
33#include "nbtool_config.h"
34#endif
35
36#include <sys/cdefs.h>
37#if !defined(__lint)
38__RCSID("$NetBSD: landisk.c,v 1.4 2009/04/05 11:55:39 lukem Exp $");
39#endif /* !__lint */
40
41#include <sys/param.h>
42
43#include <assert.h>
44#include <err.h>
45#include <md5.h>
46#include <stddef.h>
47#include <stdio.h>
48#include <stdlib.h>
49#include <string.h>
50#include <unistd.h>
51
52#include "installboot.h"
53
54static int landisk_setboot(ib_params *);
55
56struct ib_mach ib_mach_landisk =
57	{ "landisk", landisk_setboot, no_clearboot, no_editboot,
58	  IB_TIMEOUT };
59
60static int
61landisk_setboot(ib_params *params)
62{
63	struct mbr_sector mbr;
64	struct landisk_boot_params bp, *bpp;
65	uint8_t *bootstrapbuf;
66	ssize_t rv;
67	uint32_t magic;
68	size_t bootstrapsize;
69	int retval, i;
70	uint32_t bplen;
71	int bpbsize;
72
73	assert(params != NULL);
74	assert(params->fsfd != -1);
75	assert(params->filesystem != NULL);
76	assert(params->s1fd != -1);
77	assert(params->stage1 != NULL);
78
79	retval = 0;
80	bootstrapbuf = NULL;
81
82	/*
83	 * There is only 8k of space in a FFSv1 partition (and ustarfs)
84	 * so ensure we don't splat over anything important.
85	 */
86	if (params->s1stat.st_size > 8192) {
87		warnx("stage1 bootstrap `%s' is larger than 8192 bytes",
88			params->stage1);
89		goto done;
90	}
91
92	/*
93	 * Read in the existing MBR.
94	 */
95	rv = pread(params->fsfd, &mbr, sizeof(mbr), MBR_BBSECTOR);
96	if (rv == -1) {
97		warn("Reading `%s'", params->filesystem);
98		goto done;
99	} else if (rv != sizeof(mbr)) {
100		warnx("Reading `%s': short read", params->filesystem);
101		goto done;
102	}
103	if (mbr.mbr_magic != le16toh(MBR_MAGIC)) {
104		if (params->flags & IB_VERBOSE) {
105			printf(
106		    "Ignoring MBR with invalid magic in sector 0 of `%s'\n",
107			    params->filesystem);
108		}
109		memset(&mbr, 0, sizeof(mbr));
110	}
111
112	/*
113	 * Allocate a buffer, with space to round up the input file
114	 * to the next block size boundary, and with space for the boot
115	 * block.
116	 */
117	bootstrapsize = roundup(params->s1stat.st_size, 512);
118
119	bootstrapbuf = malloc(bootstrapsize);
120	if (bootstrapbuf == NULL) {
121		warn("Allocating %zu bytes",  bootstrapsize);
122		goto done;
123	}
124	memset(bootstrapbuf, 0, bootstrapsize);
125
126	/*
127	 * Read the file into the buffer.
128	 */
129	rv = pread(params->s1fd, bootstrapbuf, params->s1stat.st_size, 0);
130	if (rv == -1) {
131		warn("Reading `%s'", params->stage1);
132		goto done;
133	} else if (rv != params->s1stat.st_size) {
134		warnx("Reading `%s': short read", params->stage1);
135		goto done;
136	}
137
138	magic = *(uint32_t *)(bootstrapbuf + 512 * 2 + 4);
139	if (magic != htole32(LANDISK_BOOT_MAGIC_1)) {
140		warnx("Invalid magic in stage1 boostrap %x != %x",
141			magic, htole32(LANDISK_BOOT_MAGIC_1));
142		goto done;
143	}
144
145	/*
146	 * Determine size of BIOS Parameter Block (BPB) to copy from
147	 * original MBR to the temporary buffer by examining the first
148	 * few instruction in the new bootblock.  Supported values:
149	 *	2b a0 11	jmp ENDOF(mbr_bpbFAT32)+1, nop
150	 *      (anything else)	; don't preserve
151	 */
152	bpbsize = 0;
153#if 0
154	if (bootstrapbuf[1] == 0xa0 && bootstrapbuf[2] == 0x11 &&
155	    (bootstrapbuf[0] == 0x2b /*|| bootstrapbuf[0] == 0x1d*/)) {
156		bpbsize = bootstrapbuf[0] + 2 - MBR_BPB_OFFSET;
157	}
158#endif
159
160	/*
161	 * Ensure bootxx hasn't got any code or data (i.e, non-zero bytes) in
162	 * the partition table.
163	 */
164	for (i = 0; i < (int)sizeof(mbr.mbr_parts); i++) {
165		if (*(uint8_t *)(bootstrapbuf + MBR_PART_OFFSET + i) != 0) {
166			warnx(
167		    "Partition table has non-zero byte at offset %d in `%s'",
168			    MBR_PART_OFFSET + i, params->stage1);
169			goto done;
170		}
171	}
172
173#if 0
174	/*
175	 * Copy the BPB and the partition table from the original MBR to the
176	 * temporary buffer so that they're written back to the fs.
177	 */
178	if (bpbsize != 0) {
179		if (params->flags & IB_VERBOSE)
180			printf("Preserving %d (%#x) bytes of the BPB\n",
181			    bpbsize, bpbsize);
182		(void)memcpy(bootstrapbuf + MBR_BPB_OFFSET, &mbr.mbr_bpb,
183		    bpbsize);
184	}
185#endif
186	memcpy(bootstrapbuf + MBR_PART_OFFSET, &mbr.mbr_parts,
187	    sizeof(mbr.mbr_parts));
188
189	/*
190	 * Fill in any user-specified options into the
191	 *      struct landisk_boot_params
192	 * that's 8 bytes in from the start of the third sector.
193	 * See sys/arch/landisk/stand/bootxx/bootxx.S for more information.
194	 */
195	bpp = (void *)(bootstrapbuf + 512 * 2 + 8);
196	bplen = le32toh(bpp->bp_length);
197	if (bplen > sizeof bp)
198		/* Ignore pad space in bootxx */
199		bplen = sizeof bp;
200	/* Take (and update) local copy so we handle size mismatches */
201	memset(&bp, 0, sizeof bp);
202	memcpy(&bp, bpp, bplen);
203	if (params->flags & IB_TIMEOUT)
204		bp.bp_timeout = htole32(params->timeout);
205	/* Check we aren't trying to set anything we can't save */
206	if (bplen < sizeof bp && memcmp((char *)&bp + bplen,
207					(char *)&bp + bplen + 1,
208					sizeof bp - bplen - 1) != 0) {
209		warnx("Patch area in stage1 bootstrap is too small");
210		goto done;
211	}
212	memcpy(bpp, &bp, bplen);
213
214	if (params->flags & IB_NOWRITE) {
215		retval = 1;
216		goto done;
217	}
218
219	/*
220	 * Write MBR code to sector zero.
221	 */
222	rv = pwrite(params->fsfd, bootstrapbuf, 512, 0);
223	if (rv == -1) {
224		warn("Writing `%s'", params->filesystem);
225		goto done;
226	} else if (rv != 512) {
227		warnx("Writing `%s': short write", params->filesystem);
228		goto done;
229	}
230
231	/*
232	 * Skip disklabel in sector 1 and write bootxx to sectors 2..N.
233	 */
234	rv = pwrite(params->fsfd, bootstrapbuf + 512 * 2,
235		    bootstrapsize - 512 * 2, 512 * 2);
236	if (rv == -1) {
237		warn("Writing `%s'", params->filesystem);
238		goto done;
239	} else if ((size_t)rv != bootstrapsize - 512 * 2) {
240		warnx("Writing `%s': short write", params->filesystem);
241		goto done;
242	}
243
244	retval = 1;
245
246 done:
247	if (bootstrapbuf)
248		free(bootstrapbuf);
249	return retval;
250}
251