elf2aout.c revision 157928 
1/*-
2 * Copyright (c) 2002 Jake Burkholder
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD: head/usr.bin/elf2aout/elf2aout.c 157928 2006-04-21 09:39:51Z delphij $");
29
30#include <sys/types.h>
31#include <sys/elf64.h>
32#include <sys/endian.h>
33#include <sys/mman.h>
34#include <sys/stat.h>
35
36#include <err.h>
37#include <fcntl.h>
38#include <string.h>
39#include <unistd.h>
40
41#define	xe16toh(x)	((data == ELFDATA2MSB) ? be16toh(x) : le16toh(x))
42#define	xe32toh(x)	((data == ELFDATA2MSB) ? be32toh(x) : le32toh(x))
43#define	xe64toh(x)	((data == ELFDATA2MSB) ? be64toh(x) : le64toh(x))
44#define	htoxe32(x)	((data == ELFDATA2MSB) ? htobe32(x) : htole32(x))
45
46struct exec {
47	u_int32_t	a_magic;
48	u_int32_t	a_text;
49	u_int32_t	a_data;
50	u_int32_t	a_bss;
51	u_int32_t	a_syms;
52	u_int32_t	a_entry;
53	u_int32_t	a_trsize;
54	u_int32_t	a_drsize;
55};
56#define A_MAGIC 0x01030107
57
58static void usage(void);
59
60/*
61 * elf to a.out converter for freebsd/sparc64 bootblocks.
62 */
63int
64main(int ac, char **av)
65{
66	Elf64_Half phentsize;
67	Elf64_Half machine;
68	Elf64_Half phnum;
69	Elf64_Xword filesz;
70	Elf64_Xword memsz;
71	Elf64_Addr entry;
72	Elf64_Off offset;
73	Elf64_Off phoff;
74	Elf64_Word type;
75	unsigned char data;
76	struct stat sb;
77	struct exec a;
78	Elf64_Phdr *p;
79	Elf64_Ehdr *e;
80	void *v;
81	int efd;
82	int fd;
83	int c;
84	int i;
85
86	fd = STDIN_FILENO;
87	while ((c = getopt(ac, av, "o:")) != -1)
88		switch (c) {
89		case 'o':
90			if ((fd = open(optarg, O_CREAT|O_RDWR, 0644)) < 0)
91				err(1, "%s", optarg);
92			break;
93		case '?':
94		default:
95			usage();
96		}
97	ac -= optind;
98	av += optind;
99	if (ac == 0)
100		usage();
101
102	if ((efd = open(*av, O_RDONLY)) < 0 || fstat(efd, &sb) < 0)
103		err(1, NULL);
104	v = mmap(NULL, sb.st_size, PROT_READ, MAP_SHARED, efd, 0);
105	if ((e = v) == MAP_FAILED)
106		err(1, NULL);
107
108	if (!IS_ELF(*e))
109		errx(1, "not an elf file");
110	if (e->e_ident[EI_CLASS] != ELFCLASS64)
111		errx(1, "wrong class");
112	data = e->e_ident[EI_DATA];
113	if (data != ELFDATA2MSB && data != ELFDATA2LSB)
114		errx(1, "wrong data format");
115	if (e->e_ident[EI_VERSION] != EV_CURRENT)
116		errx(1, "wrong elf version");
117	machine = xe16toh(e->e_machine);
118	if (machine != EM_SPARCV9 && machine != EM_ALPHA)
119		errx(1, "wrong machine type");
120	phentsize = xe16toh(e->e_phentsize);
121	if (phentsize != sizeof(*p))
122		errx(1, "phdr size mismatch");
123
124	entry = xe64toh(e->e_entry);
125	phoff = xe64toh(e->e_phoff);
126	phnum = xe16toh(e->e_phnum);
127	p = (Elf64_Phdr *)((char *)e + phoff);
128	bzero(&a, sizeof(a));
129	for (i = 0; i < phnum; i++) {
130		type = xe32toh(p[i].p_type);
131		switch (type) {
132		case PT_LOAD:
133			if (a.a_magic != 0)
134				errx(1, "too many loadable segments");
135			filesz = xe64toh(p[i].p_filesz);
136			memsz = xe64toh(p[i].p_memsz);
137			offset = xe64toh(p[i].p_offset);
138			a.a_magic = htoxe32(A_MAGIC);
139			a.a_text = htoxe32(filesz);
140			a.a_bss = htoxe32(memsz - filesz);
141			a.a_entry = htoxe32(entry);
142			if (write(fd, &a, sizeof(a)) != sizeof(a) ||
143			    write(fd, (char *)e + offset, filesz) != (ssize_t)filesz)
144				err(1, NULL);
145			break;
146		default:
147			break;
148		}
149	}
150
151	return (0);
152}
153
154static void
155usage(void)
156{
157
158	errx(1, "usage: elf2aout [-o outfile] infile");
159}
160