elf32-mep.c   [plain text]

/* MeP-specific support for 32-bit ELF.
   Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006
   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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */

#include "bfd.h"
#include "sysdep.h"
#include "libbfd.h"
#include "elf-bfd.h"
#include "elf/mep.h"
#include "libiberty.h"

/* Forward declarations.  */

/* Private relocation functions.  */

#define MEPREL(type, size, bits, right, left, pcrel, overflow, mask) \
  {(unsigned)type, right, size, bits, pcrel, left, overflow, mep_reloc, #type, FALSE, 0, mask, 0 }

#define N complain_overflow_dont
#define S complain_overflow_signed
#define U complain_overflow_unsigned

static bfd_reloc_status_type mep_reloc (bfd *, arelent *, struct bfd_symbol *,
					void *, asection *, bfd *, char **);

static reloc_howto_type mep_elf_howto_table [] =
{
  /* type, size, bits, leftshift, rightshift, pcrel, OD/OS/OU, mask.  */
  MEPREL (R_MEP_NONE,     0,  0, 0, 0, 0, N, 0),
  MEPREL (R_RELC,         0,  0, 0, 0, 0, N, 0),
  /* MEPRELOC:HOWTO */
    /* This section generated from bfd/mep-relocs.pl from include/elf/mep.h.  */
  MEPREL (R_MEP_8,        0,  8, 0, 0, 0, U, 0xff),
  MEPREL (R_MEP_16,       1, 16, 0, 0, 0, U, 0xffff),
  MEPREL (R_MEP_32,       2, 32, 0, 0, 0, U, 0xffffffff),
  MEPREL (R_MEP_PCREL8A2, 1,  8, 1, 1, 1, S, 0x00fe),
  MEPREL (R_MEP_PCREL12A2,1, 12, 1, 1, 1, S, 0x0ffe),
  MEPREL (R_MEP_PCREL17A2,2, 17, 0, 1, 1, S, 0x0000ffff),
  MEPREL (R_MEP_PCREL24A2,2, 24, 0, 1, 1, S, 0x07f0ffff),
  MEPREL (R_MEP_PCABS24A2,2, 24, 0, 1, 0, U, 0x07f0ffff),
  MEPREL (R_MEP_LOW16,    2, 16, 0, 0, 0, N, 0x0000ffff),
  MEPREL (R_MEP_HI16U,    2, 32, 0,16, 0, N, 0x0000ffff),
  MEPREL (R_MEP_HI16S,    2, 32, 0,16, 0, N, 0x0000ffff),
  MEPREL (R_MEP_GPREL,    2, 16, 0, 0, 0, S, 0x0000ffff),
  MEPREL (R_MEP_TPREL,    2, 16, 0, 0, 0, S, 0x0000ffff),
  MEPREL (R_MEP_TPREL7,   1,  7, 0, 0, 0, U, 0x007f),
  MEPREL (R_MEP_TPREL7A2, 1,  7, 1, 1, 0, U, 0x007e),
  MEPREL (R_MEP_TPREL7A4, 1,  7, 2, 2, 0, U, 0x007c),
  MEPREL (R_MEP_UIMM24,   2, 24, 0, 0, 0, U, 0x00ffffff),
  MEPREL (R_MEP_ADDR24A4, 2, 24, 0, 2, 0, U, 0x00fcffff),
  MEPREL (R_MEP_GNU_VTINHERIT,1,  0,16,32, 0, N, 0x0000),
  MEPREL (R_MEP_GNU_VTENTRY,1,  0,16,32, 0, N, 0x0000),
  /* MEPRELOC:END */
};

#define VALID_MEP_RELOC(N) ((N) >= 0 \
  && (N) < ARRAY_SIZE (mep_elf_howto_table)

#undef N
#undef S
#undef U

static bfd_reloc_status_type
mep_reloc
    (bfd *               abfd ATTRIBUTE_UNUSED,
     arelent *           reloc_entry ATTRIBUTE_UNUSED,
     struct bfd_symbol * symbol ATTRIBUTE_UNUSED,
     void *              data ATTRIBUTE_UNUSED,
     asection *          input_section ATTRIBUTE_UNUSED,
     bfd *               output_bfd ATTRIBUTE_UNUSED,
     char **             error_message ATTRIBUTE_UNUSED)
{
  return bfd_reloc_ok;
}



#define BFD_RELOC_MEP_NONE BFD_RELOC_NONE
#if defined (__STDC__) || defined (ALMOST_STDC) || defined (HAVE_STRINGIZE)
#define MAP(n) case BFD_RELOC_MEP_##n: type = R_MEP_##n; break
#else
#define MAP(n) case BFD_RELOC_MEP_/**/n: type = R_MEP_/**/n; break
#endif

static reloc_howto_type *
mep_reloc_type_lookup
    (bfd * abfd ATTRIBUTE_UNUSED,
     bfd_reloc_code_real_type code)
{
  unsigned int type = 0;

  switch (code)
    {
    MAP(NONE);
    case BFD_RELOC_8:
      type = R_MEP_8;
      break;
    case BFD_RELOC_16:
      type = R_MEP_16;
      break;
    case BFD_RELOC_32:
      type = R_MEP_32;
      break;
    case BFD_RELOC_VTABLE_ENTRY:
      type = R_MEP_GNU_VTENTRY;
      break;
    case BFD_RELOC_VTABLE_INHERIT:
      type = R_MEP_GNU_VTINHERIT;
      break;
    case BFD_RELOC_RELC:
      type = R_RELC;
      break;

    /* MEPRELOC:MAP */
    /* This section generated from bfd/mep-relocs.pl from include/elf/mep.h.  */
    MAP(8);
    MAP(16);
    MAP(32);
    MAP(PCREL8A2);
    MAP(PCREL12A2);
    MAP(PCREL17A2);
    MAP(PCREL24A2);
    MAP(PCABS24A2);
    MAP(LOW16);
    MAP(HI16U);
    MAP(HI16S);
    MAP(GPREL);
    MAP(TPREL);
    MAP(TPREL7);
    MAP(TPREL7A2);
    MAP(TPREL7A4);
    MAP(UIMM24);
    MAP(ADDR24A4);
    MAP(GNU_VTINHERIT);
    MAP(GNU_VTENTRY);
    /* MEPRELOC:END */

    default:
      /* Pacify gcc -Wall.  */
      fprintf (stderr, "mep: no reloc for code %d\n", code);
      return NULL;
    }

  if (mep_elf_howto_table[type].type != type)
    {
      fprintf (stderr, "MeP: howto %d has type %d\n", type, mep_elf_howto_table[type].type);
      abort ();
    }

  return mep_elf_howto_table + type;
}

#undef MAP


/* Perform a single relocation.  */

static struct bfd_link_info *mep_info;
static int warn_tp = 0, warn_sda = 0;

static bfd_vma
mep_lookup_global
    (char *    name,
     bfd_vma   ofs,
     bfd_vma * cache,
     int *     warn)
{
  struct bfd_link_hash_entry *h;

  if (*cache || *warn)
    return *cache;

  h = bfd_link_hash_lookup (mep_info->hash, name, FALSE, FALSE, TRUE);
  if (h == 0 || h->type != bfd_link_hash_defined)
    {
      *warn = ofs + 1;
      return 0;
    }
  *cache = (h->u.def.value
	  + h->u.def.section->output_section->vma
	  + h->u.def.section->output_offset);
  return *cache;
}

static bfd_vma
mep_tpoff_base (bfd_vma ofs)
{
  static bfd_vma cache = 0;
  return mep_lookup_global ("__tpbase", ofs, &cache, &warn_tp);
}

static bfd_vma
mep_sdaoff_base (bfd_vma ofs)
{
  static bfd_vma cache = 0;
  return mep_lookup_global ("__sdabase", ofs, &cache, &warn_sda);
}

static bfd_reloc_status_type
mep_final_link_relocate
    (reloc_howto_type *  howto,
     bfd *               input_bfd,
     asection *          input_section,
     bfd_byte *          contents,
     Elf_Internal_Rela * rel,
     bfd_vma             relocation)
{
  unsigned long u;
  long s;
  unsigned char *byte;
  bfd_vma pc;
  bfd_reloc_status_type r = bfd_reloc_ok;
  int e2, e4;

  if (bfd_big_endian (input_bfd))
    {
      e2 = 0;
      e4 = 0;
    }
  else
    {
      e2 = 1;
      e4 = 3;
    }

  pc = (input_section->output_section->vma
	+ input_section->output_offset
	+ rel->r_offset);

  s = relocation + rel->r_addend;

  byte = (unsigned char *)contents + rel->r_offset;

  if (howto->type == R_MEP_PCREL24A2
      && s == 0
      && pc >= 0x800000)
    {
      /* This is an unreachable branch to an undefined weak function.
	 Silently ignore it, since the opcode can't do that but should
	 never be executed anyway.  */
      return bfd_reloc_ok;
    }

  if (howto->pc_relative)
    s -= pc;

  u = (unsigned long) s;

  switch (howto->type)
    {
    /* MEPRELOC:APPLY */
    /* This section generated from bfd/mep-relocs.pl from include/elf/mep.h.  */
    case R_MEP_8: /* 76543210 */
      if (u > 255) r = bfd_reloc_overflow;
      byte[0] = (u & 0xff);
      break;
    case R_MEP_16: /* fedcba9876543210 */
      if (u > 65535) r = bfd_reloc_overflow;
      byte[0^e2] = ((u >> 8) & 0xff);
      byte[1^e2] = (u & 0xff);
      break;
    case R_MEP_32: /* vutsrqponmlkjihgfedcba9876543210 */
      byte[0^e4] = ((u >> 24) & 0xff);
      byte[1^e4] = ((u >> 16) & 0xff);
      byte[2^e4] = ((u >> 8) & 0xff);
      byte[3^e4] = (u & 0xff);
      break;
    case R_MEP_PCREL8A2: /* --------7654321- */
      if (-128 > s || s > 127) r = bfd_reloc_overflow;
      byte[1^e2] = (byte[1^e2] & 0x01) | (s & 0xfe);
      break;
    case R_MEP_PCREL12A2: /* ----ba987654321- */
      if (-2048 > s || s > 2047) r = bfd_reloc_overflow;
      byte[0^e2] = (byte[0^e2] & 0xf0) | ((s >> 8) & 0x0f);
      byte[1^e2] = (byte[1^e2] & 0x01) | (s & 0xfe);
      break;
    case R_MEP_PCREL17A2: /* ----------------gfedcba987654321 */
      if (-65536 > s || s > 65535) r = bfd_reloc_overflow;
      byte[2^e2] = ((s >> 9) & 0xff);
      byte[3^e2] = ((s >> 1) & 0xff);
      break;
    case R_MEP_PCREL24A2: /* -----7654321----nmlkjihgfedcba98 */
      if (-8388608 > s || s > 8388607) r = bfd_reloc_overflow;
      byte[0^e2] = (byte[0^e2] & 0xf8) | ((s >> 5) & 0x07);
      byte[1^e2] = (byte[1^e2] & 0x0f) | ((s << 3) & 0xf0);
      byte[2^e2] = ((s >> 16) & 0xff);
      byte[3^e2] = ((s >> 8) & 0xff);
      break;
    case R_MEP_PCABS24A2: /* -----7654321----nmlkjihgfedcba98 */
      if (u > 16777215) r = bfd_reloc_overflow;
      byte[0^e2] = (byte[0^e2] & 0xf8) | ((u >> 5) & 0x07);
      byte[1^e2] = (byte[1^e2] & 0x0f) | ((u << 3) & 0xf0);
      byte[2^e2] = ((u >> 16) & 0xff);
      byte[3^e2] = ((u >> 8) & 0xff);
      break;
    case R_MEP_LOW16: /* ----------------fedcba9876543210 */
      byte[2^e2] = ((u >> 8) & 0xff);
      byte[3^e2] = (u & 0xff);
      break;
    case R_MEP_HI16U: /* ----------------vutsrqponmlkjihg */
      byte[2^e2] = ((u >> 24) & 0xff);
      byte[3^e2] = ((u >> 16) & 0xff);
      break;
    case R_MEP_HI16S: /* ----------------vutsrqponmlkjihg */
      byte[2^e2] = ((s >> 24) & 0xff);
      byte[3^e2] = ((s >> 16) & 0xff);
      break;
    case R_MEP_GPREL: /* ----------------fedcba9876543210 */
      s -= mep_sdaoff_base(rel->r_offset);
      if (-32768 > s || s > 32767) r = bfd_reloc_overflow;
      byte[2^e2] = ((s >> 8) & 0xff);
      byte[3^e2] = (s & 0xff);
      break;
    case R_MEP_TPREL: /* ----------------fedcba9876543210 */
      s -= mep_tpoff_base(rel->r_offset);
      if (-32768 > s || s > 32767) r = bfd_reloc_overflow;
      byte[2^e2] = ((s >> 8) & 0xff);
      byte[3^e2] = (s & 0xff);
      break;
    case R_MEP_TPREL7: /* ---------6543210 */
      u -= mep_tpoff_base(rel->r_offset);
      if (u > 127) r = bfd_reloc_overflow;
      byte[1^e2] = (byte[1^e2] & 0x80) | (u & 0x7f);
      break;
    case R_MEP_TPREL7A2: /* ---------654321- */
      u -= mep_tpoff_base(rel->r_offset);
      if (u > 127) r = bfd_reloc_overflow;
      byte[1^e2] = (byte[1^e2] & 0x81) | (u & 0x7e);
      break;
    case R_MEP_TPREL7A4: /* ---------65432-- */
      u -= mep_tpoff_base(rel->r_offset);
      if (u > 127) r = bfd_reloc_overflow;
      byte[1^e2] = (byte[1^e2] & 0x83) | (u & 0x7c);
      break;
    case R_MEP_UIMM24: /* --------76543210nmlkjihgfedcba98 */
      if (u > 16777215) r = bfd_reloc_overflow;
      byte[1^e2] = (u & 0xff);
      byte[2^e2] = ((u >> 16) & 0xff);
      byte[3^e2] = ((u >> 8) & 0xff);
      break;
    case R_MEP_ADDR24A4: /* --------765432--nmlkjihgfedcba98 */
      if (u > 16777215) r = bfd_reloc_overflow;
      byte[1^e2] = (byte[1^e2] & 0x03) | (u & 0xfc);
      byte[2^e2] = ((u >> 16) & 0xff);
      byte[3^e2] = ((u >> 8) & 0xff);
      break;
    case R_MEP_GNU_VTINHERIT: /* ---------------- */
      break;
    case R_MEP_GNU_VTENTRY: /* ---------------- */
      break;
    /* MEPRELOC:END */
    default:
      abort ();
    }

  return r;
}

/* Set the howto pointer for a MEP ELF reloc.  */

static void
mep_info_to_howto_rela
    (bfd *               abfd ATTRIBUTE_UNUSED,
     arelent *           cache_ptr,
     Elf_Internal_Rela * dst)
{
  unsigned int r_type;

  r_type = ELF32_R_TYPE (dst->r_info);
  cache_ptr->howto = & mep_elf_howto_table [r_type];
}

/* Look through the relocs for a section during the first phase.
   Since we don't do .gots or .plts, we just need to consider the
   virtual table relocs for gc.  */

static bfd_boolean
mep_elf_check_relocs
    (bfd *                     abfd,
     struct bfd_link_info *    info,
     asection *                sec,
     const Elf_Internal_Rela * relocs)
{
  Elf_Internal_Shdr *           symtab_hdr;
  struct elf_link_hash_entry ** sym_hashes;
  struct elf_link_hash_entry ** sym_hashes_end;
  const Elf_Internal_Rela *     rel;
  const Elf_Internal_Rela *     rel_end;

  if (info->relocatable)
    return TRUE;

  symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
  sym_hashes = elf_sym_hashes (abfd);
  sym_hashes_end = sym_hashes + symtab_hdr->sh_size / sizeof (Elf32_External_Sym);
  if (!elf_bad_symtab (abfd))
    sym_hashes_end -= symtab_hdr->sh_info;

  rel_end = relocs + sec->reloc_count;
  for (rel = relocs; rel < rel_end; rel++)
    {
      struct elf_link_hash_entry *h;
      unsigned long r_symndx;

      r_symndx = ELF32_R_SYM (rel->r_info);
      if (r_symndx < symtab_hdr->sh_info)
        h = NULL;
      else
        h = sym_hashes[r_symndx - symtab_hdr->sh_info];
    }
  return TRUE;
}


/* Relocate a MEP ELF section.
   There is some attempt to make this function usable for many architectures,
   both USE_REL and USE_RELA ['twould be nice if such a critter existed],
   if only to serve as a learning tool.

   The RELOCATE_SECTION function is called by the new ELF backend linker
   to handle the relocations for a section.

   The relocs are always passed as Rela structures; if the section
   actually uses Rel structures, the r_addend field will always be
   zero.

   This function is responsible for adjusting the section contents as
   necessary, and (if using Rela relocs and generating a relocatable
   output file) adjusting the reloc addend as necessary.

   This function does not have to worry about setting the reloc
   address or the reloc symbol index.

   LOCAL_SYMS is a pointer to the swapped in local symbols.

   LOCAL_SECTIONS is an array giving the section in the input file
   corresponding to the st_shndx field of each local symbol.

   The global hash table entry for the global symbols can be found
   via elf_sym_hashes (input_bfd).

   When generating relocatable output, this function must handle
   STB_LOCAL/STT_SECTION symbols specially.  The output symbol is
   going to be the section symbol corresponding to the output
   section, which means that the addend must be adjusted
   accordingly.  */

static bfd_boolean
mep_elf_relocate_section
    (bfd *                   output_bfd ATTRIBUTE_UNUSED,
     struct bfd_link_info *  info,
     bfd *                   input_bfd,
     asection *              input_section,
     bfd_byte *              contents,
     Elf_Internal_Rela *     relocs,
     Elf_Internal_Sym *      local_syms,
     asection **             local_sections)
{
  Elf_Internal_Shdr *           symtab_hdr;
  struct elf_link_hash_entry ** sym_hashes;
  Elf_Internal_Rela *           rel;
  Elf_Internal_Rela *           relend;

  symtab_hdr = & elf_tdata (input_bfd)->symtab_hdr;
  sym_hashes = elf_sym_hashes (input_bfd);
  relend     = relocs + input_section->reloc_count;

  mep_info = info;

  for (rel = relocs; rel < relend; rel ++)
    {
      reloc_howto_type *           howto;
      unsigned long                r_symndx;
      Elf_Internal_Sym *           sym;
      asection *                   sec;
      struct elf_link_hash_entry * h;
      bfd_vma                      relocation;
      bfd_reloc_status_type        r;
      const char *                 name = NULL;
      int                          r_type;

      r_type = ELF32_R_TYPE (rel->r_info);

      r_symndx = ELF32_R_SYM (rel->r_info);

      if (info->relocatable)
	{
	  /* This is a relocatable link.  We don't have to change
             anything, unless the reloc is against a section symbol,
             in which case we have to adjust according to where the
             section symbol winds up in the output section.  */
	  if (r_symndx < symtab_hdr->sh_info)
	    {
	      sym = local_syms + r_symndx;

	      if (ELF_ST_TYPE (sym->st_info) == STT_SECTION)
		{
		  sec = local_sections [r_symndx];
		  rel->r_addend += sec->output_offset + sym->st_value;
		}
	    }

	  continue;
	}

      /* Is this a complex relocation?  */
      if (ELF32_R_TYPE (rel->r_info) == R_RELC)
	{
	  bfd_elf_perform_complex_relocation (output_bfd, info,
					      input_bfd, input_section, contents,
					      rel, local_syms, local_sections);
	  continue;
	}

      /* This is a final link.  */
      howto  = mep_elf_howto_table + ELF32_R_TYPE (rel->r_info);
      h      = NULL;
      sym    = NULL;
      sec    = NULL;

      if (r_symndx < symtab_hdr->sh_info)
	{
	  sym = local_syms + r_symndx;
	  sec = local_sections [r_symndx];
	  relocation = _bfd_elf_rela_local_sym (output_bfd, sym, &sec, rel);

	  name = bfd_elf_string_from_elf_section
	    (input_bfd, symtab_hdr->sh_link, sym->st_name);
	  name = (name == NULL) ? bfd_section_name (input_bfd, sec) : name;
#if 0
	  fprintf (stderr, "local: sec: %s, sym: %s (%d), value: %x + %x + %x addend %x\n",
		   sec->name, name, sym->st_name,
		   sec->output_section->vma, sec->output_offset,
		   sym->st_value, rel->r_addend);
#endif
	}
      else
	{
	  h = sym_hashes [r_symndx];

	  while (h->root.type == bfd_link_hash_indirect
		 || h->root.type == bfd_link_hash_warning)
	    h = (struct elf_link_hash_entry *) h->root.u.i.link;

	  name = h->root.root.string;

	  if (h->root.type == bfd_link_hash_defined
	      || h->root.type == bfd_link_hash_defweak)
	    {
	      sec = h->root.u.def.section;
	      relocation = (h->root.u.def.value
			    + sec->output_section->vma
			    + sec->output_offset);
#if 0
	      fprintf (stderr,
		       "defined: sec: %s, name: %s, value: %x + %x + %x gives: %x\n",
		       sec->name, name, h->root.u.def.value,
		       sec->output_section->vma, sec->output_offset, relocation);
#endif
	    }
	  else if (h->root.type == bfd_link_hash_undefweak)
	    {
#if 0
	      fprintf (stderr, "undefined: sec: %s, name: %s\n",
		       sec->name, name);
#endif
	      relocation = 0;
	    }
	  else
	    {
	      if (! ((*info->callbacks->undefined_symbol)
		     (info, h->root.root.string, input_bfd,
		      input_section, rel->r_offset,
		      (!info->shared && info->unresolved_syms_in_objects == RM_GENERATE_ERROR))))
		return FALSE;
#if 0
	      fprintf (stderr, "unknown: name: %s\n", name);
#endif
	      relocation = 0;
	    }
	}

      switch (r_type)
	{
	default:
	  r = mep_final_link_relocate (howto, input_bfd, input_section,
					 contents, rel, relocation);
	  break;
	}

      if (r != bfd_reloc_ok)
	{
	  const char * msg = (const char *) NULL;

	  switch (r)
	    {
	    case bfd_reloc_overflow:
	      r = info->callbacks->reloc_overflow
		(info, (h ? &h->root : NULL), name, howto->name, (bfd_vma) 0,
		 input_bfd, input_section, rel->r_offset);
	      break;

	    case bfd_reloc_undefined:
	      r = info->callbacks->undefined_symbol
		(info, name, input_bfd, input_section, rel->r_offset, TRUE);
	      break;

	    case bfd_reloc_outofrange:
	      msg = _("internal error: out of range error");
	      break;

	    case bfd_reloc_notsupported:
	      msg = _("internal error: unsupported relocation error");
	      break;

	    case bfd_reloc_dangerous:
	      msg = _("internal error: dangerous relocation");
	      break;

	    default:
	      msg = _("internal error: unknown error");
	      break;
	    }

	  if (msg)
	    r = info->callbacks->warning
	      (info, msg, name, input_bfd, input_section, rel->r_offset);

	  if (! r)
	    return FALSE;
	}
    }

  if (warn_tp)
    info->callbacks->undefined_symbol
      (info, "__tpbase", input_bfd, input_section, warn_tp-1, TRUE);
  if (warn_sda)
    info->callbacks->undefined_symbol
      (info, "__sdabase", input_bfd, input_section, warn_sda-1, TRUE);
  if (warn_sda || warn_tp)
    return FALSE;

  return TRUE;
}


/* Update the got entry reference counts for the section being
   removed.  */

static bfd_boolean
mep_elf_gc_sweep_hook
    (bfd *                     abfd ATTRIBUTE_UNUSED,
     struct bfd_link_info *    info ATTRIBUTE_UNUSED,
     asection *                sec ATTRIBUTE_UNUSED,
     const Elf_Internal_Rela * relocs ATTRIBUTE_UNUSED)
{
  return TRUE;
}

/* Return the section that should be marked against GC for a given
   relocation.  */

static asection *
mep_elf_gc_mark_hook
    (asection *                   sec,
     struct bfd_link_info *       info ATTRIBUTE_UNUSED,
     Elf_Internal_Rela *          rel,
     struct elf_link_hash_entry * h,
     Elf_Internal_Sym *           sym)
{
  if (h != NULL)
    {
      switch (ELF32_R_TYPE (rel->r_info))
	{
	default:
	  switch (h->root.type)
	    {
	    case bfd_link_hash_defined:
	    case bfd_link_hash_defweak:
	      return h->root.u.def.section;

	    case bfd_link_hash_common:
	      return h->root.u.c.p->section;

	    default:
	      break;
	    }
	}
    }
  else
    {
      if (!(elf_bad_symtab (sec->owner)
	    && ELF_ST_BIND (sym->st_info) != STB_LOCAL)
	  && ! ((sym->st_shndx <= 0 || sym->st_shndx >= SHN_LORESERVE)
		&& sym->st_shndx != SHN_COMMON))
	return bfd_section_from_elf_index (sec->owner, sym->st_shndx);
    }

  return NULL;
}


/* Function to set the ELF flag bits.  */

static bfd_boolean
mep_elf_set_private_flags (bfd *    abfd,
			   flagword flags)
{
  elf_elfheader (abfd)->e_flags = flags;
  elf_flags_init (abfd) = TRUE;
  return TRUE;
}

static bfd_boolean
mep_elf_copy_private_bfd_data (bfd * ibfd, bfd * obfd)
{
  if (bfd_get_flavour (ibfd) != bfd_target_elf_flavour
      || bfd_get_flavour (obfd) != bfd_target_elf_flavour)
    return TRUE;

  elf_elfheader (obfd)->e_flags = elf_elfheader (ibfd)->e_flags;
  elf_flags_init (obfd) = TRUE;
  return TRUE;
}

/* Merge backend specific data from an object file to the output
   object file when linking.  */

static bfd_boolean
mep_elf_merge_private_bfd_data (bfd * ibfd, bfd * obfd)
{
  static bfd *last_ibfd = 0;
  flagword old_flags, new_flags;
  flagword old_partial, new_partial;

  /* Check if we have the same endianess.  */
  if (_bfd_generic_verify_endian_match (ibfd, obfd) == FALSE)
    return FALSE;

  new_flags = elf_elfheader (ibfd)->e_flags;
  old_flags = elf_elfheader (obfd)->e_flags;

#ifdef DEBUG
  _bfd_error_handler ("%B: old_flags = 0x%.8lx, new_flags = 0x%.8lx, init = %s",
		      ibfd, old_flags, new_flags, elf_flags_init (obfd) ? "yes" : "no");
#endif

    /* First call, no flags set.  */
    if (!elf_flags_init (obfd))
    {
      elf_flags_init (obfd) = TRUE;
      old_flags = new_flags;
    }
  else if ((new_flags | old_flags) & EF_MEP_LIBRARY)
    {
      /* Non-library flags trump library flags.  The choice doesn't really
	 matter if both OLD_FLAGS and NEW_FLAGS have EF_MEP_LIBRARY set.  */
      if (old_flags & EF_MEP_LIBRARY)
	old_flags = new_flags;
    }
  else
    {
      /* Make sure they're for the same mach.  Allow upgrade from the "mep"
	 mach.  */
      new_partial = (new_flags & EF_MEP_CPU_MASK);
      old_partial = (old_flags & EF_MEP_CPU_MASK);
      if (new_partial == old_partial)
	;
      else if (new_partial == EF_MEP_CPU_MEP)
	;
      else if (old_partial == EF_MEP_CPU_MEP)
	old_flags = (old_flags & ~EF_MEP_CPU_MASK) | new_partial;
      else
	{
	  _bfd_error_handler (_("%B and %B are for different cores"), last_ibfd, ibfd);
	  bfd_set_error (bfd_error_invalid_target);
	  return FALSE;
	}

      /* Make sure they're for the same me_module.  Allow basic config to
	 mix with any other.  */
      new_partial = (new_flags & EF_MEP_INDEX_MASK);
      old_partial = (old_flags & EF_MEP_INDEX_MASK);
      if (new_partial == old_partial)
	;
      else if (new_partial == 0)
	;
      else if (old_partial == 0)
	old_flags = (old_flags & ~EF_MEP_INDEX_MASK) | new_partial;
      else
	{
	  _bfd_error_handler (_("%B and %B are for different configurations"), last_ibfd, ibfd);
	  bfd_set_error (bfd_error_invalid_target);
	  return FALSE;
	}
    }

  elf_elfheader (obfd)->e_flags = old_flags;
  last_ibfd = ibfd;
  return TRUE;
}

/* This will be edited by the MeP configration tool.  */
static const char * config_names[] =
{
  "basic"
  /* start-mepcfgtool */
  ,"simple"
  ,"fmax"
  /* end-mepcfgtool */
};

static const char * core_names[] =
{
  "MeP", "MeP-c2", "MeP-c3", "MeP-h1"
};

static bfd_boolean
mep_elf_print_private_bfd_data (bfd * abfd, void * ptr)
{
  FILE *   file = (FILE *) ptr;
  flagword flags, partial_flags;

  BFD_ASSERT (abfd != NULL && ptr != NULL);

  /* Print normal ELF private data.  */
  _bfd_elf_print_private_bfd_data (abfd, ptr);

  flags = elf_elfheader (abfd)->e_flags;
  fprintf (file, _("private flags = 0x%lx"), (long)flags);

  partial_flags = (flags & EF_MEP_CPU_MASK) >> 24;
  if (partial_flags < ARRAY_SIZE (core_names))
    fprintf (file, "  core: %s", core_names[(long)partial_flags]);

  partial_flags = flags & EF_MEP_INDEX_MASK;
  if (partial_flags < ARRAY_SIZE (config_names))
    fprintf (file, "  me_module: %s", config_names[(long)partial_flags]);

  fputc ('\n', file);

  return TRUE;
}

/* Return the machine subcode from the ELF e_flags header.  */

static int
elf32_mep_machine (bfd * abfd)
{
  switch (elf_elfheader (abfd)->e_flags & EF_MEP_CPU_MASK)
    {
    default: break;
    case EF_MEP_CPU_C2: return bfd_mach_mep;
    case EF_MEP_CPU_C3: return bfd_mach_mep;
    case EF_MEP_CPU_C4: return bfd_mach_mep;
    case EF_MEP_CPU_H1: return bfd_mach_mep_h1;
    }

  return bfd_mach_mep;
}

static bfd_boolean
mep_elf_object_p (bfd * abfd)
{
  /* Irix 5 and 6 is broken.  Object file symbol tables are not always
     sorted correctly such that local symbols preceed global symbols,
     and the sh_info field in the symbol table is not always right.  */
  /* This is needed for the RELC support code.  */
  elf_bad_symtab (abfd) = TRUE;
  bfd_default_set_arch_mach (abfd, bfd_arch_mep, elf32_mep_machine (abfd));
  return TRUE;
}

static bfd_boolean
mep_elf_section_flags (flagword * flags, const Elf_Internal_Shdr * hdr)
{
  if (hdr->sh_flags & SHF_MEP_VLIW)
    * flags |= SEC_MEP_VLIW;
  return TRUE;
}

static bfd_boolean
mep_elf_fake_sections (bfd *               abfd ATTRIBUTE_UNUSED,
		       Elf_Internal_Shdr * hdr,
		       asection *          sec)
{
  if (sec->flags & SEC_MEP_VLIW)
    hdr->sh_flags |= SHF_MEP_VLIW;
  return TRUE;
}


#define ELF_ARCH		bfd_arch_mep
#define ELF_MACHINE_CODE	EM_CYGNUS_MEP
#define ELF_MAXPAGESIZE		0x1000

#define TARGET_BIG_SYM		bfd_elf32_mep_vec
#define TARGET_BIG_NAME		"elf32-mep"

#define TARGET_LITTLE_SYM	bfd_elf32_mep_little_vec
#define TARGET_LITTLE_NAME	"elf32-mep-little"

#define elf_info_to_howto_rel			NULL
#define elf_info_to_howto			mep_info_to_howto_rela
#define elf_backend_relocate_section		mep_elf_relocate_section
#define elf_backend_gc_mark_hook		mep_elf_gc_mark_hook
#define elf_backend_gc_sweep_hook		mep_elf_gc_sweep_hook
#define elf_backend_check_relocs                mep_elf_check_relocs
#define elf_backend_object_p		        mep_elf_object_p
#define elf_backend_section_flags		mep_elf_section_flags
#define elf_backend_fake_sections		mep_elf_fake_sections

#define elf_backend_can_gc_sections		1

#define bfd_elf32_bfd_reloc_type_lookup		mep_reloc_type_lookup
#define bfd_elf32_bfd_set_private_flags		mep_elf_set_private_flags
#define bfd_elf32_bfd_copy_private_bfd_data	mep_elf_copy_private_bfd_data
#define bfd_elf32_bfd_merge_private_bfd_data	mep_elf_merge_private_bfd_data
#define bfd_elf32_bfd_print_private_bfd_data	mep_elf_print_private_bfd_data

/* We use only the RELA entries.  */
#define USE_RELA

#include "elf32-target.h"