elf2aout.c revision 108438 
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 108438 2002-12-30 09:58:20Z obrien $");
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
58extern char *optarg;
59extern int optind;
60
61static void usage(void);
62
63/*
64 * elf to a.out converter for freebsd/sparc64 bootblocks.
65 */
66int
67main(int ac, char **av)
68{
69	Elf64_Quarter phentsize;
70	Elf64_Quarter machine;
71	Elf64_Quarter phnum;
72	Elf64_Size filesz;
73	Elf64_Size memsz;
74	Elf64_Addr entry;
75	Elf64_Off offset;
76	Elf64_Off phoff;
77	Elf64_Half type;
78	unsigned char data;
79	struct stat sb;
80	struct exec a;
81	Elf64_Phdr *p;
82	Elf64_Ehdr *e;
83	void *v;
84	int efd;
85	int fd;
86	int c;
87	int i;
88
89	fd = STDIN_FILENO;
90	while ((c = getopt(ac, av, "o:")) != -1)
91		switch (c) {
92		case 'o':
93			if ((fd = open(optarg, O_CREAT|O_RDWR, 0644)) < 0)
94				err(1, "%s", optarg);
95			break;
96		case '?':
97		default:
98			usage();
99		}
100	ac -= optind;
101	av += optind;
102	if (ac == 0)
103		usage();
104
105	if ((efd = open(*av, O_RDONLY)) < 0 || fstat(efd, &sb) < 0)
106		err(1, NULL);
107	v = mmap(NULL, sb.st_size, PROT_READ, MAP_SHARED, efd, 0);
108	if ((e = v) == MAP_FAILED)
109		err(1, NULL);
110
111	if (!IS_ELF(*e))
112		errx(1, "not an elf file");
113	if (e->e_ident[EI_CLASS] != ELFCLASS64)
114		errx(1, "wrong class");
115	data = e->e_ident[EI_DATA];
116	if (data != ELFDATA2MSB && data != ELFDATA2LSB)
117		errx(1, "wrong data format");
118	if (e->e_ident[EI_VERSION] != EV_CURRENT)
119		errx(1, "wrong elf version");
120	machine = xe16toh(e->e_machine);
121	if (machine != EM_SPARCV9 && machine != EM_ALPHA)
122		errx(1, "wrong machine type");
123	phentsize = xe16toh(e->e_phentsize);
124	if (phentsize != sizeof(*p))
125		errx(1, "phdr size mismatch");
126
127	entry = xe64toh(e->e_entry);
128	phoff = xe64toh(e->e_phoff);
129	phnum = xe16toh(e->e_phnum);
130	p = (Elf64_Phdr *)((char *)e + phoff);
131	bzero(&a, sizeof(a));
132	for (i = 0; i < phnum; i++) {
133		type = xe32toh(p[i].p_type);
134		switch (type) {
135		case PT_LOAD:
136			if (a.a_magic != 0)
137				errx(1, "too many loadable segments");
138			filesz = xe64toh(p[i].p_filesz);
139			memsz = xe64toh(p[i].p_memsz);
140			offset = xe64toh(p[i].p_offset);
141			a.a_magic = htoxe32(A_MAGIC);
142			a.a_text = htoxe32(filesz);
143			a.a_bss = htoxe32(memsz - filesz);
144			a.a_entry = htoxe32(entry);
145			if (write(fd, &a, sizeof(a)) != sizeof(a) ||
146			    write(fd, (char *)e + offset, filesz) != (ssize_t)filesz)
147				err(1, NULL);
148			break;
149		default:
150			break;
151		}
152	}
153
154	return (0);
155}
156
157static void
158usage(void)
159{
160
161	errx(1, "usage: elf2aout [-o outfile] infile");
162}
163