- 根目录:
- arch
- alpha
- boot
- tools
- objstrip.c
/*
* arch/alpha/boot/tools/objstrip.c
*
* Strip the object file headers/trailers from an executable (ELF or ECOFF).
*
* Copyright (C) 1996 David Mosberger-Tang.
*/
/*
* Converts an ECOFF or ELF object file into a bootable file. The
* object file must be a OMAGIC file (i.e., data and bss follow immediately
* behind the text). See DEC "Assembly Language Programmer's Guide"
* documentation for details. The SRM boot process is documented in
* the Alpha AXP Architecture Reference Manual, Second Edition by
* Richard L. Sites and Richard T. Witek.
*/
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/fcntl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <linux/a.out.h>
#include <linux/coff.h>
#include <linux/param.h>
#ifdef __ELF__
# include <linux/elf.h>
# define elfhdr elf64_hdr
# define elf_phdr elf64_phdr
# define elf_check_arch(x) ((x)->e_machine == EM_ALPHA)
#endif
/* bootfile size must be multiple of BLOCK_SIZE: */
#define BLOCK_SIZE 512
const char * prog_name;
static void
usage (void)
{
fprintf(stderr,
"usage: %s [-v] -p file primary\n"
" %s [-vb] file [secondary]\n", prog_name, prog_name);
exit(1);
}
int
main (int argc, char *argv[])
{
size_t nwritten, tocopy, n, mem_size, fil_size, pad = 0;
int fd, ofd, i, j, verbose = 0, primary = 0;
char buf[8192], *inname;
struct exec * aout; /* includes file & aout header */
long offset;
#ifdef __ELF__
struct elfhdr *elf;
struct elf_phdr *elf_phdr; /* program header */
unsigned long long e_entry;
#endif
prog_name = argv[0];
for (i = 1; i < argc && argv[i][0] == '-'; ++i) {
for (j = 1; argv[i][j]; ++j) {
switch (argv[i][j]) {
case 'v':
verbose = ~verbose;
break;
case 'b':
pad = BLOCK_SIZE;
break;
case 'p':
primary = 1; /* make primary bootblock */
break;
}
}
}
if (i >= argc) {
usage();
}
inname = argv[i++];
fd = open(inname, O_RDONLY);
if (fd == -1) {
perror("open");
exit(1);
}
ofd = 1;
if (i < argc) {
ofd = open(argv[i++], O_WRONLY | O_CREAT | O_TRUNC, 0666);
if (ofd == -1) {
perror("open");
exit(1);
}
}
if (primary) {
/* generate bootblock for primary loader */
unsigned long bb[64], sum = 0;
struct stat st;
off_t size;
int i;
if (ofd == 1) {
usage();
}
if (fstat(fd, &st) == -1) {
perror("fstat");
exit(1);
}
size = (st.st_size + BLOCK_SIZE - 1) & ~(BLOCK_SIZE - 1);
memset(bb, 0, sizeof(bb));
strcpy((char *) bb, "Linux SRM bootblock");
bb[60] = size / BLOCK_SIZE; /* count */
bb[61] = 1; /* starting sector # */
bb[62] = 0; /* flags---must be 0 */
for (i = 0; i < 63; ++i) {
sum += bb[i];
}
bb[63] = sum;
if (write(ofd, bb, sizeof(bb)) != sizeof(bb)) {
perror("boot-block write");
exit(1);
}
printf("%lu\n", size);
return 0;
}
/* read and inspect exec header: */
if (read(fd, buf, sizeof(buf)) < 0) {
perror("read");
exit(1);
}
#ifdef __ELF__
elf = (struct elfhdr *) buf;
if (elf->e_ident[0] == 0x7f && strncmp((char *)elf->e_ident + 1, "ELF", 3) == 0) {
if (elf->e_type != ET_EXEC) {
fprintf(stderr, "%s: %s is not an ELF executable\n",
prog_name, inname);
exit(1);
}
if (!elf_check_arch(elf)) {
fprintf(stderr, "%s: is not for this processor (e_machine=%d)\n",
prog_name, elf->e_machine);
exit(1);
}
if (elf->e_phnum != 1) {
fprintf(stderr,
"%s: %d program headers (forgot to link with -N?)\n",
prog_name, elf->e_phnum);
}
e_entry = elf->e_entry;
lseek(fd, elf->e_phoff, SEEK_SET);
if (read(fd, buf, sizeof(*elf_phdr)) != sizeof(*elf_phdr)) {
perror("read");
exit(1);
}
elf_phdr = (struct elf_phdr *) buf;
offset = elf_phdr->p_offset;
mem_size = elf_phdr->p_memsz;
fil_size = elf_phdr->p_filesz;
/* work around ELF bug: */
if (elf_phdr->p_vaddr < e_entry) {
unsigned long delta = e_entry - elf_phdr->p_vaddr;
offset += delta;
mem_size -= delta;
fil_size -= delta;
elf_phdr->p_vaddr += delta;
}
if (verbose) {
fprintf(stderr, "%s: extracting %#016lx-%#016lx (at %lx)\n",
prog_name, (long) elf_phdr->p_vaddr,
elf_phdr->p_vaddr + fil_size, offset);
}
} else
#endif
{
aout = (struct exec *) buf;
if (!(aout->fh.f_flags & COFF_F_EXEC)) {
fprintf(stderr, "%s: %s is not in executable format\n",
prog_name, inname);
exit(1);
}
if (aout->fh.f_opthdr != sizeof(aout->ah)) {
fprintf(stderr, "%s: %s has unexpected optional header size\n",
prog_name, inname);
exit(1);
}
if (N_MAGIC(*aout) != OMAGIC) {
fprintf(stderr, "%s: %s is not an OMAGIC file\n",
prog_name, inname);
exit(1);
}
offset = N_TXTOFF(*aout);
fil_size = aout->ah.tsize + aout->ah.dsize;
mem_size = fil_size + aout->ah.bsize;
if (verbose) {
fprintf(stderr, "%s: extracting %#016lx-%#016lx (at %lx)\n",
prog_name, aout->ah.text_start,
aout->ah.text_start + fil_size, offset);
}
}
if (lseek(fd, offset, SEEK_SET) != offset) {
perror("lseek");
exit(1);
}
if (verbose) {
fprintf(stderr, "%s: copying %lu byte from %s\n",
prog_name, (unsigned long) fil_size, inname);
}
tocopy = fil_size;
while (tocopy > 0) {
n = tocopy;
if (n > sizeof(buf)) {
n = sizeof(buf);
}
tocopy -= n;
if ((size_t) read(fd, buf, n) != n) {
perror("read");
exit(1);
}
do {
nwritten = write(ofd, buf, n);
if ((ssize_t) nwritten == -1) {
perror("write");
exit(1);
}
n -= nwritten;
} while (n > 0);
}
if (pad) {
mem_size = ((mem_size + pad - 1) / pad) * pad;
}
tocopy = mem_size - fil_size;
if (tocopy > 0) {
fprintf(stderr,
"%s: zero-filling bss and aligning to %lu with %lu bytes\n",
prog_name, pad, (unsigned long) tocopy);
memset(buf, 0x00, sizeof(buf));
do {
n = tocopy;
if (n > sizeof(buf)) {
n = sizeof(buf);
}
nwritten = write(ofd, buf, n);
if ((ssize_t) nwritten == -1) {
perror("write");
exit(1);
}
tocopy -= nwritten;
} while (tocopy > 0);
}
return 0;
}