Home | History | Annotate | Line # | Download | only in mdsetimage
mdsetimage.c revision 1.16
      1 /* $NetBSD: mdsetimage.c,v 1.16 2001/10/01 23:32:34 cgd Exp $ */
      2 
      3 /*
      4  * Copyright (c) 1996 Christopher G. Demetriou
      5  * 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  * 3. The name of the author may not be used to endorse or promote products
     16  *    derived from this software without specific prior written permission.
     17  *
     18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     21  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     23  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     28  *
     29  * <<Id: LICENSE_GC,v 1.1 2001/10/01 23:24:05 cgd Exp>>
     30  */
     31 
     32 #include <sys/cdefs.h>
     33 #ifndef lint
     34 __COPYRIGHT(
     35     "@(#) Copyright (c) 1996 Christopher G. Demetriou.\
     36   All rights reserved.\n");
     37 #endif /* not lint */
     38 
     39 #ifndef lint
     40 __RCSID("$NetBSD: mdsetimage.c,v 1.16 2001/10/01 23:32:34 cgd Exp $");
     41 #endif /* not lint */
     42 
     43 #include <sys/types.h>
     44 #include <sys/mman.h>
     45 #include <sys/stat.h>
     46 
     47 #include <err.h>
     48 #include <fcntl.h>
     49 #include <limits.h>
     50 #include <nlist.h>
     51 #include <stdio.h>
     52 #include <stdlib.h>
     53 #include <unistd.h>
     54 
     55 #include "extern.h"
     56 
     57 int		main __P((int, char *[]));
     58 static void	usage __P((void)) __attribute__((noreturn));
     59 static int	find_md_root __P((const char *, const char *, size_t,
     60 		    const struct nlist *, size_t *, u_int32_t *));
     61 
     62 static struct nlist md_root_nlist[] = {
     63 #define	X_MD_ROOT_IMAGE		0
     64 	{ "_md_root_image" },
     65 #define	X_MD_ROOT_SIZE		1
     66 	{ "_md_root_size" },
     67 	{ NULL }
     68 };
     69 
     70 int	verbose;
     71 #ifdef NLIST_AOUT
     72 /*
     73  * Since we can't get the text address from an a.out executable, we
     74  * need to be able to specify it.  Note: there's no way to test to
     75  * see if the user entered a valid address!
     76  */
     77 int	T_flag_specified;	/* the -T flag was specified */
     78 u_long	text_start;		/* Start of kernel text */
     79 #endif /* NLIST_AOUT */
     80 
     81 int
     82 main(argc, argv)
     83 	int argc;
     84 	char *argv[];
     85 {
     86 	struct stat ksb, fssb;
     87 	size_t md_root_offset;
     88 	u_int32_t md_root_size;
     89 	const char *kfile, *fsfile;
     90 	char *mappedkfile;
     91 	int ch, kfd, fsfd, rv;
     92 
     93 	setprogname(argv[0]);
     94 
     95 	while ((ch = getopt(argc, argv, "T:v")) != -1)
     96 		switch (ch) {
     97 		case 'v':
     98 			verbose = 1;
     99 			break;
    100 		case 'T':
    101 #ifdef NLIST_AOUT
    102 			T_flag_specified = 1;
    103 			text_start = strtoul(optarg, NULL, 0);
    104 			break;
    105 #endif /* NLIST_AOUT */
    106 			/* FALLTHROUGH */
    107 		case '?':
    108 		default:
    109 			usage();
    110 	}
    111 	argc -= optind;
    112 	argv += optind;
    113 
    114 	if (argc != 2)
    115 		usage();
    116 	kfile = argv[0];
    117 	fsfile = argv[1];
    118 
    119 	if ((kfd = open(kfile, O_RDWR, 0))  == -1)
    120 		err(1, "open %s", kfile);
    121 
    122 	if ((rv = __fdnlist(kfd, md_root_nlist)) != 0)
    123 		errx(1, "could not find symbols in %s", kfile);
    124 	if (verbose)
    125 		fprintf(stderr, "got symbols from %s\n", kfile);
    126 
    127 	if (fstat(kfd, &ksb) == -1)
    128 		err(1, "fstat %s", kfile);
    129 	if (ksb.st_size != (size_t)ksb.st_size)
    130 		errx(1, "%s too big to map", kfile);
    131 
    132 	if ((mappedkfile = mmap(NULL, ksb.st_size, PROT_READ | PROT_WRITE,
    133 	    MAP_FILE | MAP_SHARED, kfd, 0)) == (caddr_t)-1)
    134 		err(1, "mmap %s", kfile);
    135 	if (verbose)
    136 		fprintf(stderr, "mapped %s\n", kfile);
    137 
    138 	if (find_md_root(kfile, mappedkfile, ksb.st_size, md_root_nlist,
    139 	    &md_root_offset, &md_root_size) != 0)
    140 		errx(1, "could not find md root buffer in %s", kfile);
    141 
    142 	if ((fsfd = open(fsfile, O_RDONLY, 0)) == -1)
    143 		err(1, "open %s", fsfile);
    144 	if (fstat(fsfd, &fssb) == -1)
    145 		err(1, "fstat %s", fsfile);
    146 	if (fssb.st_size != (size_t)fssb.st_size)
    147 		errx(1, "fs image is too big");
    148 	if (fssb.st_size > md_root_size)
    149 		errx(1, "fs image (%lld bytes) too big for buffer (%lu bytes)",
    150 		    (long long)fssb.st_size, (unsigned long)md_root_size);
    151 
    152 	if (verbose)
    153 		fprintf(stderr, "copying image from %s into %s\n", fsfile,
    154 		    kfile);
    155 	if ((rv = read(fsfd, mappedkfile + md_root_offset,
    156 	    fssb.st_size)) != fssb.st_size) {
    157 		if (rv == -1)
    158 			err(1, "read %s", fsfile);
    159 		else
    160 			errx(1, "unexpected EOF reading %s", fsfile);
    161 	}
    162 	if (verbose)
    163 		fprintf(stderr, "done copying image\n");
    164 
    165 	close(fsfd);
    166 
    167 	munmap(mappedkfile, ksb.st_size);
    168 	close(kfd);
    169 
    170 	if (verbose)
    171 		fprintf(stderr, "exiting\n");
    172 	exit(0);
    173 }
    174 
    175 static void
    176 usage()
    177 {
    178 
    179 	fprintf(stderr,
    180 	    "usage: %s kernel_file fsimage_file\n",
    181 	    getprogname());
    182 	exit(1);
    183 }
    184 
    185 
    186 struct {
    187 	const char *name;
    188 	int	(*check) __P((const char *, size_t));
    189 	int	(*findoff) __P((const char *, size_t, u_long, size_t *));
    190 } exec_formats[] = {
    191 #ifdef NLIST_AOUT
    192 	{	"a.out",	check_aout,	findoff_aout,	},
    193 #endif
    194 #ifdef NLIST_ECOFF
    195 	{	"ECOFF",	check_ecoff,	findoff_ecoff,	},
    196 #endif
    197 #ifdef NLIST_ELF32
    198 	{	"ELF32",	check_elf32,	findoff_elf32,	},
    199 #endif
    200 #ifdef NLIST_ELF64
    201 	{	"ELF64",	check_elf64,	findoff_elf64,	},
    202 #endif
    203 #ifdef NLIST_COFF
    204 	{	"COFF",		check_coff,	findoff_coff,	},
    205 #endif
    206 };
    207 
    208 static int
    209 find_md_root(fname, mappedfile, mappedsize, nl, rootoffp, rootsizep)
    210 	const char *fname, *mappedfile;
    211 	size_t mappedsize;
    212 	const struct nlist *nl;
    213 	size_t *rootoffp;
    214 	u_int32_t *rootsizep;
    215 {
    216 	int i, n;
    217 	size_t rootsizeoff;
    218 
    219 	n = sizeof exec_formats / sizeof exec_formats[0];
    220 	for (i = 0; i < n; i++) {
    221 		if ((*exec_formats[i].check)(mappedfile, mappedsize) == 0)
    222 			break;
    223 	}
    224 	if (i == n) {
    225 		warnx("%s: unknown executable format", fname);
    226 		return (1);
    227 	}
    228 
    229 	if (verbose) {
    230 		fprintf(stderr, "%s is an %s binary\n", fname,
    231 		    exec_formats[i].name);
    232 #ifdef NLIST_AOUT
    233 		if (T_flag_specified)
    234 			fprintf(stderr, "kernel text loads at 0x%lx\n",
    235 			    text_start);
    236 #endif
    237 	}
    238 
    239 	if ((*exec_formats[i].findoff)(mappedfile, mappedsize,
    240 	    nl[X_MD_ROOT_SIZE].n_value, &rootsizeoff) != 0) {
    241 		warnx("couldn't find offset for %s in %s",
    242 		    nl[X_MD_ROOT_SIZE].n_name, fname);
    243 		return (1);
    244 	}
    245 	if (verbose)
    246 		fprintf(stderr, "%s is at offset %#lx in %s\n",
    247 			nl[X_MD_ROOT_SIZE].n_name,
    248 			(unsigned long)rootsizeoff, fname);
    249 	*rootsizep = *(u_int32_t *)&mappedfile[rootsizeoff];
    250 	if (verbose)
    251 		fprintf(stderr, "%s has value %#x\n",
    252 		    nl[X_MD_ROOT_SIZE].n_name, *rootsizep);
    253 
    254 	if ((*exec_formats[i].findoff)(mappedfile, mappedsize,
    255 	    nl[X_MD_ROOT_IMAGE].n_value, rootoffp) != 0) {
    256 		warnx("couldn't find offset for %s in %s",
    257 		    nl[X_MD_ROOT_IMAGE].n_name, fname);
    258 		return (1);
    259 	}
    260 	if (verbose)
    261 		fprintf(stderr, "%s is at offset %#lx in %s\n",
    262 			nl[X_MD_ROOT_IMAGE].n_name,
    263 			(unsigned long)(*rootoffp), fname);
    264 
    265 	return (0);
    266 }
    267