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biosboot.c revision 1.6 
      1 /*	$NetBSD: biosboot.c,v 1.6 2013/04/13 18:25:56 jakllsch 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 #include <sys/cdefs.h>
     35 #ifdef __RCSID
     36 __RCSID("$NetBSD: biosboot.c,v 1.6 2013/04/13 18:25:56 jakllsch Exp $");
     37 #endif
     38 
     39 #include <sys/stat.h>
     40 #include <sys/types.h>
     41 #include <sys/ioctl.h>
     42 #include <sys/disk.h>
     43 #include <sys/param.h>
     44 #include <sys/bootblock.h>
     45 
     46 #include <err.h>
     47 #include <fcntl.h>
     48 #include <inttypes.h>
     49 #include <paths.h>
     50 #include <stddef.h>
     51 #include <stdio.h>
     52 #include <stdlib.h>
     53 #include <string.h>
     54 #include <unistd.h>
     55 #include <util.h>
     56 
     57 #include "map.h"
     58 #include "gpt.h"
     59 
     60 #define DEFAULT_BOOTDIR		"/usr/mdec"
     61 #define DEFAULT_BOOTCODE	"gptmbr.bin"
     62 
     63 static daddr_t start;
     64 static uint64_t size;
     65 
     66 static char *bootpath;
     67 static unsigned int entry;
     68 
     69 const char biosbootmsg[] = "biosboot [-c bootcode] [-i index] device ...";
     70 
     71 __dead static void
     72 usage_biosboot(void)
     73 {
     74 	fprintf(stderr, "usage: %s %s\n", getprogname(), biosbootmsg);
     75 	exit(1);
     76 }
     77 
     78 static struct mbr*
     79 read_boot(void)
     80 {
     81 	int bfd, ret = 0;
     82 	struct mbr *buf;
     83 	struct stat st;
     84 
     85 	/* XXX how to do the following better? */
     86 	if (bootpath == NULL) {
     87 		bootpath = strdup(DEFAULT_BOOTDIR "/" DEFAULT_BOOTCODE);
     88 	} else {
     89 		if (strchr(bootpath, '/') == 0) {
     90 			char *p;
     91 			if ((p = strdup(bootpath)) == NULL)
     92 				err(1, "Malloc failed");
     93 			free(bootpath);
     94 			(void)asprintf(&bootpath, "%s/%s", DEFAULT_BOOTDIR, p);
     95 			free(p);
     96 		}
     97 	}
     98 	if (bootpath == NULL)
     99 		err(1, "Malloc failed");
    100 
    101 	if ((buf = malloc((size_t)secsz)) == NULL)
    102 		err(1, "Malloc failed");
    103 
    104 	if ((bfd = open(bootpath, O_RDONLY)) < 0 || fstat(bfd, &st) == -1) {
    105 		warn("%s", bootpath);
    106 		goto fail;
    107 	}
    108 
    109 	if (st.st_size != MBR_DSN_OFFSET) {
    110 		warnx("%s: the bootcode does not match expected size",
    111 			bootpath);
    112 		goto fail;
    113 	}
    114 
    115 	if (read(bfd, buf, st.st_size) != st.st_size) {
    116 		warn("%s", bootpath);
    117 		goto fail;
    118 	}
    119 
    120 	ret++;
    121 
    122     fail:
    123 	if (bfd >= 0)
    124 		close(bfd);
    125 	if (ret == 0) {
    126 		free(buf);
    127 		buf = NULL;
    128 	}
    129 	return buf;
    130 }
    131 
    132 static void
    133 biosboot(int fd)
    134 {
    135 	map_t *gpt, *tpg;
    136 	map_t *tbl, *lbt;
    137 	map_t *mbrmap, *m;
    138 	struct mbr *mbr, *bootcode;
    139 	struct gpt_hdr *hdr;
    140 	struct gpt_ent *ent;
    141 	int i;
    142 
    143 	/*
    144 	 * Parse and validate partition maps
    145 	 */
    146 	gpt = map_find(MAP_TYPE_PRI_GPT_HDR);
    147 	if (gpt == NULL) {
    148 		warnx("%s: error: no primary GPT header; run create or recover",
    149 		    device_name);
    150 		return;
    151 	}
    152 
    153 	tpg = map_find(MAP_TYPE_SEC_GPT_HDR);
    154 	if (tpg == NULL) {
    155 		warnx("%s: error: no secondary GPT header; run recover",
    156 		    device_name);
    157 		return;
    158 	}
    159 
    160 	tbl = map_find(MAP_TYPE_PRI_GPT_TBL);
    161 	lbt = map_find(MAP_TYPE_SEC_GPT_TBL);
    162 	if (tbl == NULL || lbt == NULL) {
    163 		warnx("%s: error: run recover -- trust me", device_name);
    164 		return;
    165 	}
    166 
    167 	mbrmap = map_find(MAP_TYPE_PMBR);
    168 	if (mbrmap == NULL || mbrmap->map_start != 0) {
    169 		warnx("%s: error: no valid Protective MBR found", device_name);
    170 		return;
    171 	}
    172 
    173 	mbr = mbrmap->map_data;
    174 
    175 	/*
    176 	 * Update the boot code
    177 	 */
    178 	if ((bootcode = read_boot()) == NULL) {
    179 		warnx("error reading bootcode");
    180 		return;
    181 	}
    182 	(void)memcpy(&mbr->mbr_code, &bootcode->mbr_code,
    183 		sizeof(mbr->mbr_code));
    184 	free(bootcode);
    185 
    186 	/*
    187 	 * Walk through the GPT and see where we can boot from
    188 	 */
    189 	for (m = map_first(); m != NULL; m = m->map_next) {
    190 		if (m->map_type != MAP_TYPE_GPT_PART || m->map_index < 1)
    191 			continue;
    192 
    193 		ent = m->map_data;
    194 
    195 		/* first, prefer user selection */
    196 		if (entry > 0 && m->map_index == entry)
    197 			break;
    198 
    199 		/* next, partition as could be specified by wedge */
    200 		if (entry < 1 && size > 0 &&
    201 		    m->map_start == start && m->map_size == (off_t)size)
    202 			break;
    203 	}
    204 
    205 	if (m == NULL) {
    206 		warnx("error: no bootable partition");
    207 		return;
    208 	}
    209 
    210 	i = m->map_index - 1;
    211 
    212 
    213 	hdr = gpt->map_data;
    214 
    215 	for (uint32_t j = 0; j < le32toh(hdr->hdr_entries); j++) {
    216 		ent = (void*)((char*)tbl->map_data + j * le32toh(hdr->hdr_entsz));
    217 		ent->ent_attr &= ~GPT_ENT_ATTR_LEGACY_BIOS_BOOTABLE;
    218 	}
    219 
    220 	ent = (void*)((char*)tbl->map_data + i * le32toh(hdr->hdr_entsz));
    221 	ent->ent_attr |= GPT_ENT_ATTR_LEGACY_BIOS_BOOTABLE;
    222 
    223 	hdr->hdr_crc_table = htole32(crc32(tbl->map_data,
    224 	    le32toh(hdr->hdr_entries) * le32toh(hdr->hdr_entsz)));
    225 	hdr->hdr_crc_self = 0;
    226 	hdr->hdr_crc_self = htole32(crc32(hdr, le32toh(hdr->hdr_size)));
    227 
    228 	gpt_write(fd, gpt);
    229 	gpt_write(fd, tbl);
    230 
    231 
    232 	hdr = tpg->map_data;
    233 
    234 	for (uint32_t j = 0; j < le32toh(hdr->hdr_entries); j++) {
    235 		ent = (void*)((char*)lbt->map_data + j * le32toh(hdr->hdr_entsz));
    236 		ent->ent_attr &= ~GPT_ENT_ATTR_LEGACY_BIOS_BOOTABLE;
    237 	}
    238 
    239 	ent = (void*)((char*)lbt->map_data + i * le32toh(hdr->hdr_entsz));
    240 	ent->ent_attr |= GPT_ENT_ATTR_LEGACY_BIOS_BOOTABLE;
    241 
    242 	hdr->hdr_crc_table = htole32(crc32(lbt->map_data,
    243 	    le32toh(hdr->hdr_entries) * le32toh(hdr->hdr_entsz)));
    244 	hdr->hdr_crc_self = 0;
    245 	hdr->hdr_crc_self = htole32(crc32(hdr, le32toh(hdr->hdr_size)));
    246 
    247 	gpt_write(fd, lbt);
    248 	gpt_write(fd, tpg);
    249 
    250 
    251 	if (gpt_write(fd, mbrmap) == -1) {
    252 		warnx("error: cannot update Protective MBR");
    253 		return;
    254 	}
    255 }
    256 
    257 int
    258 cmd_biosboot(int argc, char *argv[])
    259 {
    260 	struct dkwedge_info dkw;
    261 	struct stat sb;
    262 	char devpath[MAXPATHLEN];
    263 	char *dev, *p;
    264 	int ch, fd;
    265 
    266 	while ((ch = getopt(argc, argv, "c:i:")) != -1) {
    267 		switch(ch) {
    268 		case 'c':
    269 			if (bootpath != NULL)
    270 				usage_biosboot();
    271 			if ((bootpath = strdup(optarg)) == NULL)
    272 				err(1, "Malloc failed");
    273 			break;
    274 		case 'i':
    275 			if (entry > 0)
    276 				usage_biosboot();
    277 			entry = strtoul(optarg, &p, 10);
    278 			if (*p != 0 || entry < 1)
    279 				usage_biosboot();
    280 			break;
    281 		default:
    282 			usage_biosboot();
    283 		}
    284 	}
    285 
    286 	if (argc == optind)
    287 		usage_biosboot();
    288 
    289 	while (optind < argc) {
    290 		dev = argv[optind++];
    291 		start = 0;
    292 		size = 0;
    293 
    294 #ifdef __NetBSD__
    295 		/*
    296 		 * If a dk wedge was specified, loader should be
    297 		 * installed onto parent device
    298 		 */
    299 		if ((fd = opendisk(dev, O_RDONLY, devpath, sizeof(devpath), 0))
    300 				== -1)
    301 			goto next;
    302 		if (fstat(fd, &sb) == -1)
    303 			goto close;
    304 
    305 #ifdef DIOCGWEDGEINFO
    306 		if ((sb.st_mode & S_IFMT) != S_IFREG &&
    307 		    ioctl(fd, DIOCGWEDGEINFO, &dkw) != -1) {
    308 			if (entry > 0)
    309 				/* wedges and indexes are mutually exclusive */
    310 				usage_biosboot();
    311 			dev = dkw.dkw_parent;
    312 			start = dkw.dkw_offset;
    313 			size = dkw.dkw_size;
    314 		}
    315 #endif
    316 	close:
    317 		close(fd);
    318 #endif	/* __NetBSD__*/
    319 
    320 		fd = gpt_open(dev);
    321 	next:
    322 		if (fd == -1) {
    323 			warn("unable to open device '%s'", device_name);
    324 			continue;
    325 		}
    326 
    327 		biosboot(fd);
    328 
    329 		gpt_close(fd);
    330 	}
    331 
    332 	return (0);
    333 }
    334