source: trunk/src/binutils/bfd/i386aoutemx.c@ 729

/* BFD back-end for emx a.out binaries, derived from i386aout.c and aout-target.h
   Copyright 1990, 1991, 1992 Free Software Foundation, Inc.

This file is part of BFD, the Binary File Descriptor library.

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */

#define EMX

#define ARCH_SIZE               32
#define DEFAULT_ARCH            bfd_arch_i386

#define TEXT_START_ADDR         0x10000
#define TARGET_PAGE_SIZE        0x1000
#define TARGET_SEGMENT_SIZE     0x10000
#define TARGET_STACK_END_ADDR   0x80000000

#define ZMAGIC_DISK_BLOCK_SIZE  1024
#define BYTES_IN_WORD           4
#define NO_CORE_COMMAND

#define MY(OP)                  CONCAT2(i386aout_emx_,OP)
#define TARGETNAME              "a.out-emx"

#define IS_STAB(flags) (((flags) & N_STAB) \
        && (flags) != (N_IMP1|N_EXT) && (flags) != (N_IMP2|N_EXT))

#include "aout/aoutemx.h"
#include "aoutx.h"

#define MY_object_p             MY(object_p)
#define MY_backend_data &MY(backend_data)

static bfd_boolean MY(set_sizes) PARAMS ((bfd *));
static const bfd_target *MY(object_p) PARAMS ((bfd *));

static CONST struct aout_backend_data MY(backend_data) = {
  0,                            /* zmagic contiguous */
  0,                            /* text incl header */
  0,                            /* entry is text address */
  0,                            /* exec_hdr_flags */
  0,                            /* text vma? */
  MY(set_sizes),
  1,                            /* exec header not counted */
  0,                            /* add_dynamic_symbols */
  0,                            /* add_one_symbol */
  0,                            /* link_dynamic_object */
  0,                            /* write_dynamic_symbol */
  0,                            /* check_dynamic_reloc */
  0                             /* finish_dynamic_link */
};

#include "aout-target.h"

#ifndef __EMX__

/* Cross-compilation support, borrowed from EMX C runtime library */
int _fseek_hdr PARAMS ((FILE *));

int _fseek_hdr (FILE *stream)
{
  struct
    {
      char magic[2];
      char fill1[6];
      unsigned short hdr_size;
    } exe_hdr;
  struct
    {
      char sig[16];
      char bound;
      char fill1;
      unsigned short hdr_loc_lo;      /* cannot use long, alignment! */
      unsigned short hdr_loc_hi;
    } patch;
  long original_pos;
  int saved_errno;

  original_pos = ftell (stream);
  if (fread (&exe_hdr, sizeof (exe_hdr), 1, stream) != 1)
    goto failure;
  if (memcmp (exe_hdr.magic, "MZ", 2) != 0)
    return (fseek (stream, original_pos, SEEK_SET) == -1 ? -1 : 0);
  if (fseek (stream, original_pos + 16 * exe_hdr.hdr_size, SEEK_SET) == -1)
    goto failure;
  if (fread (&patch, sizeof (patch), 1, stream) != 1)
    goto failure;
  if (memcmp (patch.sig, "emx", 3) != 0)
    goto failure;
  if (fseek (stream, original_pos + patch.hdr_loc_lo
             + 65536L * patch.hdr_loc_hi, SEEK_SET) == -1)
    goto failure;
  return 0;

failure:
  saved_errno = errno;
  fseek (stream, original_pos, SEEK_SET);
  errno = saved_errno;
  return -1;
}
#endif

/*
 * Finish up the reading of an a.out file header
 */
static const bfd_target *
MY(object_p) (abfd)
  bfd *abfd;
{
  struct external_exec exec_bytes;      /* Raw exec header from file */
  struct internal_exec exec;            /* Cleaned-up exec header */
  const bfd_target *target;
  size_t org_pos, add;

  org_pos = bfd_tell (abfd);
  (void)_fseek_hdr(bfd_cache_lookup(abfd));
  add = bfd_tell (abfd) - org_pos;

  if (bfd_bread ((PTR) &exec_bytes, EXEC_BYTES_SIZE, abfd)
      != EXEC_BYTES_SIZE)
  {
    if (bfd_get_error () != bfd_error_system_call)
      bfd_set_error (bfd_error_wrong_format);
    return 0;
  }

  exec.a_info = bfd_h_get_32 (abfd, exec_bytes.e_info);

  if (N_BADMAG (exec))
    return 0;

  NAME(aout,swap_exec_header_in)(abfd, &exec_bytes, &exec);
  exec.a_hdrofs = add;
  target = NAME(aout,some_aout_object_p) (abfd, &exec, MY(callback));
  return target;
}