xref: /netbsd-src/sbin/gpt/biosboot.c (revision e89934bbf778a6d6d6894877c4da59d0c7835b0f)
1 /*	$NetBSD: biosboot.c,v 1.26 2016/06/09 19:04:43 christos Exp $ */
2 
3 /*
4  * Copyright (c) 2009 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to the NetBSD Foundation
8  * by Mike M. Volokhov. Development of this software was supported by the
9  * Google Summer of Code program.
10  * The GSoC project was mentored by Allen Briggs and Joerg Sonnenberger.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
23  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
24  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
25  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
26  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
27  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
29  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
30  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
31  * POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 #if HAVE_NBTOOL_CONFIG_H
35 #include "nbtool_config.h"
36 #endif
37 
38 #include <sys/cdefs.h>
39 #ifdef __RCSID
40 __RCSID("$NetBSD: biosboot.c,v 1.26 2016/06/09 19:04:43 christos Exp $");
41 #endif
42 
43 #include <sys/stat.h>
44 #include <sys/types.h>
45 #include <sys/ioctl.h>
46 #ifdef DIOCGWEDGEINFO
47 #include <sys/disk.h>
48 #endif
49 #include <sys/param.h>
50 #include <sys/bootblock.h>
51 
52 #include <err.h>
53 #include <fcntl.h>
54 #include <paths.h>
55 #include <stddef.h>
56 #include <stdio.h>
57 #include <stdlib.h>
58 #include <string.h>
59 #include <unistd.h>
60 
61 #include "map.h"
62 #include "gpt.h"
63 #include "gpt_private.h"
64 
65 #define DEFAULT_BOOTDIR		"/usr/mdec"
66 #define DEFAULT_BOOTCODE	"gptmbr.bin"
67 
68 static int cmd_biosboot(gpt_t, int, char *[]);
69 
70 static const char *biosboothelp[] = {
71 	"[-A] [-c bootcode] [-i index] [-L label]",
72 #if notyet
73 	"[-a alignment] [-b blocknr] [-i index] [-l label]",
74 	"[-s size] [-t type]",
75 #endif
76 };
77 
78 struct gpt_cmd c_biosboot = {
79 	"biosboot",
80 	cmd_biosboot,
81 	biosboothelp, __arraycount(biosboothelp),
82 	0,
83 };
84 
85 #define usage() gpt_usage(NULL, &c_biosboot)
86 
87 static struct mbr*
88 read_boot(gpt_t gpt, const char *bootpath)
89 {
90 	int bfd, ret = -1;
91 	struct mbr *buf;
92 	struct stat st;
93 	char *bp;
94 
95 	buf = NULL;
96 	bfd = -1;
97 
98 	if (bootpath == NULL)
99 		bp = strdup(DEFAULT_BOOTDIR "/" DEFAULT_BOOTCODE);
100 	else if (*bootpath == '/')
101 		bp = strdup(bootpath);
102 	else {
103 		if (asprintf(&bp, "%s/%s", DEFAULT_BOOTDIR, bootpath) < 0)
104 			bp = NULL;
105 	}
106 
107 	if (bp == NULL) {
108 		gpt_warn(gpt, "Can't allocate memory for bootpath");
109 		goto fail;
110 	}
111 
112 	if ((buf = malloc((size_t)gpt->secsz)) == NULL) {
113 		gpt_warn(gpt, "Can't allocate memory for sector");
114 		goto fail;
115 	}
116 
117 
118 	if ((bfd = open(bp, O_RDONLY)) < 0 || fstat(bfd, &st) == -1) {
119 		gpt_warn(gpt, "Can't open `%s'", bp);
120 		goto fail;
121 	}
122 
123 	if (st.st_size != MBR_DSN_OFFSET) {
124 		gpt_warnx(gpt, "The bootcode in `%s' does not match the"
125 		    " expected size %u", bp, MBR_DSN_OFFSET);
126 		goto fail;
127 	}
128 
129 	if (read(bfd, buf, (size_t)st.st_size) != (ssize_t)st.st_size) {
130 		gpt_warn(gpt, "Error reading from `%s'", bp);
131 		goto fail;
132 	}
133 
134 	ret = 0;
135 fail:
136 	if (bfd != -1)
137 		close(bfd);
138 	if (ret == -1) {
139 		free(buf);
140 		buf = NULL;
141 	}
142 	free(bp);
143 	return buf;
144 }
145 
146 static int
147 set_bootable(gpt_t gpt, map_t map, map_t tbl, unsigned int i)
148 {
149 	unsigned int j;
150 	struct gpt_hdr *hdr = map->map_data;
151 	struct gpt_ent *ent;
152 	unsigned int ne = le32toh(hdr->hdr_entries);
153 
154 	for (j = 0; j < ne; j++) {
155 		ent = gpt_ent(map, tbl, j);
156 		ent->ent_attr &= ~GPT_ENT_ATTR_LEGACY_BIOS_BOOTABLE;
157 	}
158 
159 	ent = gpt_ent(map, tbl, i);
160 	ent->ent_attr |= GPT_ENT_ATTR_LEGACY_BIOS_BOOTABLE;
161 
162 	return gpt_write_crc(gpt, map, tbl);
163 }
164 
165 static int
166 biosboot(gpt_t gpt, daddr_t start, uint64_t size, u_int entry, uint8_t *label,
167     const char *bootpath, int active)
168 {
169 	map_t mbrmap, m;
170 	struct mbr *mbr, *bootcode;
171 	unsigned int i;
172 	struct gpt_ent *ent;
173 	uint8_t utfbuf[__arraycount(ent->ent_name) * 3 + 1];
174 
175 	/*
176 	 * Parse and validate partition maps
177 	 */
178 	if (gpt_hdr(gpt) == NULL)
179 		return -1;
180 
181 	mbrmap = map_find(gpt, MAP_TYPE_PMBR);
182 	if (mbrmap == NULL || mbrmap->map_start != 0) {
183 		gpt_warnx(gpt, "No valid Protective MBR found");
184 		return -1;
185 	}
186 
187 	mbr = mbrmap->map_data;
188 
189 	/*
190 	 * Update the boot code
191 	 */
192 	if ((bootcode = read_boot(gpt, bootpath)) == NULL) {
193 		gpt_warnx(gpt, "Error reading bootcode");
194 		return -1;
195 	}
196 	(void)memcpy(&mbr->mbr_code, &bootcode->mbr_code,
197 		sizeof(mbr->mbr_code));
198 	free(bootcode);
199 
200 	for (i = 0; i < __arraycount(mbr->mbr_part); i++)
201 		if (mbr->mbr_part[i].part_typ == MBR_PTYPE_PMBR)
202 			mbr->mbr_part[i].part_flag = active ? 0x80 : 0;
203 
204 	/*
205 	 * Walk through the GPT and see where we can boot from
206 	 */
207 	for (m = map_first(gpt); m != NULL; m = m->map_next) {
208 		if (m->map_type != MAP_TYPE_GPT_PART || m->map_index < 1)
209 			continue;
210 
211 		ent = m->map_data;
212 
213 		/* first, prefer user selection */
214 		if (entry > 0 && m->map_index == entry)
215 			break;
216 
217 		if (label != NULL) {
218 			utf16_to_utf8(ent->ent_name, utfbuf, sizeof(utfbuf));
219 			if (strcmp((char *)label, (char *)utfbuf) == 0)
220 				break;
221 		}
222 
223 		/* next, partition as could be specified by wedge */
224 		if (entry < 1 && label == NULL && size > 0 &&
225 		    m->map_start == start && m->map_size == (off_t)size)
226 			break;
227 	}
228 
229 	if (m == NULL) {
230 		gpt_warnx(gpt, "No bootable partition");
231 		return -1;
232 	}
233 
234 	i = m->map_index - 1;
235 
236 
237 	if (set_bootable(gpt, gpt->gpt, gpt->tbl, i) == -1)
238 		return -1;
239 
240 	if (set_bootable(gpt, gpt->tpg, gpt->lbt, i) == -1)
241 		return -1;
242 
243 	if (gpt_write(gpt, mbrmap) == -1) {
244 		gpt_warnx(gpt, "Cannot update Protective MBR");
245 		return -1;
246 	}
247 
248 	gpt_msg(gpt, "Partition %d marked as bootable", i + 1);
249 	return 0;
250 }
251 
252 static int
253 cmd_biosboot(gpt_t gpt, int argc, char *argv[])
254 {
255 #ifdef DIOCGWEDGEINFO
256 	struct dkwedge_info dkw;
257 #endif
258 	int ch;
259 	gpt_t ngpt = gpt;
260 	daddr_t start = 0;
261 	uint64_t size = 0;
262 	int active = 0;
263 	unsigned int entry = 0;
264 	uint8_t *label = NULL;
265 	char *bootpath = NULL;
266 
267 	while ((ch = getopt(argc, argv, "Ac:i:L:")) != -1) {
268 		switch(ch) {
269 		case 'A':
270 			active = 1;
271 			break;
272 		case 'c':
273 			if (gpt_name_get(gpt, &bootpath) == -1)
274 				goto usage;
275 			break;
276 		case 'i':
277 			if (gpt_uint_get(gpt, &entry) == -1)
278 				goto usage;
279 			break;
280 		case 'L':
281 			if (gpt_name_get(gpt, &label) == -1)
282 				goto usage;
283 			break;
284 		default:
285 			goto usage;
286 		}
287 	}
288 
289 	if (argc != optind)
290 		return usage();
291 
292 #ifdef DIOCGWEDGEINFO
293 	if ((gpt->sb.st_mode & S_IFMT) != S_IFREG &&
294 	    ioctl(gpt->fd, DIOCGWEDGEINFO, &dkw) != -1) {
295 		if (entry > 0)
296 			/* wedges and indexes are mutually exclusive */
297 			goto usage;
298 		start = dkw.dkw_offset;
299 		size = dkw.dkw_size;
300 		ngpt = gpt_open(dkw.dkw_parent, gpt->flags, gpt->verbose,
301 		    gpt->mediasz, gpt->secsz);
302 		if (ngpt == NULL)
303 			goto cleanup;
304 	}
305 #endif
306 	if (biosboot(ngpt, start, size, entry, label, bootpath, active) == -1)
307 		goto cleanup;
308 	if (ngpt != gpt)
309 		gpt_close(ngpt);
310 	return 0;
311 usage:
312 	usage();
313 cleanup:
314 	if (ngpt != gpt)
315 		gpt_close(ngpt);
316 	free(bootpath);
317 	free(label);
318 	return -1;
319 }
320