freebsd-dev/usr.sbin/elf2aout/elf2aout.c
David E. O'Brien 5d5aa91800 Utility to create a.out [kernels] from an ELF one.
This is needed on sparc64 (and maybe all OpenFirmware based machines) as
most [all?] OpenBoot PROM's require either an a.out or FCode boot image.

Submitted by:	jake
2002-03-28 02:17:27 +00:00

157 lines
3.9 KiB
C

/*-
* Copyright (c) 2002 Jake Burkholder
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <sys/elf64.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <err.h>
#include <fcntl.h>
#define be16toh(x) (x)
#define be32toh(x) (x)
#define be64toh(x) (x)
#define htobe32(x) (x)
struct exec {
u_int a_magic;
u_int a_text;
u_int a_data;
u_int a_bss;
u_int a_syms;
u_int a_entry;
u_int a_trsize;
u_int a_drsize;
};
#define A_MAGIC 0x01030107
extern char *optarg;
extern int optind;
static void usage(void);
/*
* elf to a.out converter for freebsd/sparc64 bootblocks.
*/
int
main(int ac, char **av)
{
Elf64_Quarter phentsize;
Elf64_Quarter machine;
Elf64_Quarter phnum;
Elf64_Size filesz;
Elf64_Size memsz;
Elf64_Addr entry;
Elf64_Off offset;
Elf64_Off phoff;
Elf64_Half type;
struct stat sb;
struct exec a;
Elf64_Phdr *p;
Elf64_Ehdr *e;
void *v;
int efd;
int fd;
int c;
int i;
while ((c = getopt(ac, av, "o:")) != -1)
switch (c) {
case 'o':
if ((fd = open(optarg, O_CREAT|O_RDWR, 0644)) < 0)
err(1, "%s", optarg);
break;
case '?':
default:
usage();
}
ac -= optind;
av += optind;
if (ac == 0)
usage();
if ((efd = open(*av, O_RDONLY)) < 0 || fstat(efd, &sb) < 0)
err(1, NULL);
v = mmap(NULL, sb.st_size, PROT_READ, MAP_SHARED, efd, 0);
if ((e = v) == MAP_FAILED)
err(1, NULL);
if (!IS_ELF(*e))
errx(1, "not an elf file");
if (e->e_ident[EI_CLASS] != ELFCLASS64)
errx(1, "wrong class");
if (e->e_ident[EI_DATA] != ELFDATA2MSB)
errx(1, "wrong data format");
if (e->e_ident[EI_VERSION] != EV_CURRENT)
errx(1, "wrong elf version");
machine = be16toh(e->e_machine);
if (machine != EM_SPARCV9)
errx(1, "wrong machine type");
phentsize = be16toh(e->e_phentsize);
if (phentsize != sizeof(*p))
errx(1, "phdr size mismatch");
entry = be64toh(e->e_entry);
phoff = be64toh(e->e_phoff);
phnum = be16toh(e->e_phnum);
p = (Elf64_Phdr *)((char *)e + phoff);
bzero(&a, sizeof(a));
for (i = 0; i < phnum; i++) {
type = be32toh(p[i].p_type);
switch (type) {
case PT_LOAD:
if (a.a_magic != 0)
errx(1, "too many loadable segments");
filesz = be64toh(p[i].p_filesz);
memsz = be64toh(p[i].p_memsz);
offset = be64toh(p[i].p_offset);
a.a_magic = htobe32(A_MAGIC);
a.a_text = htobe32(filesz);
a.a_bss = htobe32(memsz - filesz);
a.a_entry = htobe32(entry);
if (write(fd, &a, sizeof(a)) != sizeof(a) ||
write(fd, (char *)e + offset, filesz) != filesz)
err(1, NULL);
break;
default:
break;
}
}
return (0);
}
static void
usage(void)
{
errx(1, "usage: elftoaout -o outfile infile");
}