elf64-mips.c

基于4个mips核的noc设计

			     (const Elf64_Mips_External_Rela *) src,
			     &mirela);

  dst[0].r_offset = mirela.r_offset;
  dst[0].r_info = ELF32_R_INFO (mirela.r_sym, mirela.r_type);
  dst[0].r_addend = mirela.r_addend;
  dst[1].r_offset = mirela.r_offset;
  dst[1].r_info = ELF32_R_INFO (mirela.r_ssym, mirela.r_type2);
  dst[1].r_addend = 0;
  dst[2].r_offset = mirela.r_offset;
  dst[2].r_info = ELF32_R_INFO (STN_UNDEF, mirela.r_type3);
  dst[2].r_addend = 0;
}

/* Swap out a MIPS 64-bit Rel reloc.  */

static void
mips_elf64_be_swap_reloc_out (abfd, src, dst)
     bfd *abfd;
     const Elf_Internal_Rel *src;
     bfd_byte *dst;
{
  Elf64_Mips_Internal_Rel mirel;

  mirel.r_offset = src->r_offset;
  mirel.r_type = ELF32_R_TYPE (src->r_info);
  mirel.r_sym = ELF32_R_SYM (src->r_info);
  mirel.r_type2 = R_MIPS_NONE;
  mirel.r_ssym = STN_UNDEF;
  mirel.r_type3 = R_MIPS_NONE;

  mips_elf64_swap_reloc_out (abfd, &mirel,
			     (Elf64_Mips_External_Rel *) dst);
}

/* Swap out a MIPS 64-bit Rela reloc.  */

static void
mips_elf64_be_swap_reloca_out (abfd, src, dst)
     bfd *abfd;
     const Elf_Internal_Rela *src;
     bfd_byte *dst;
{
  Elf64_Mips_Internal_Rela mirela;

  mirela.r_offset = src->r_offset;
  mirela.r_type = ELF32_R_TYPE (src->r_info);
  mirela.r_addend = src->r_addend;
  mirela.r_sym = ELF32_R_SYM (src->r_info);
  mirela.r_type2 = R_MIPS_NONE;
  mirela.r_ssym = STN_UNDEF;
  mirela.r_type3 = R_MIPS_NONE;

  mips_elf64_swap_reloca_out (abfd, &mirela,
			      (Elf64_Mips_External_Rela *) dst);
}

/* A mapping from BFD reloc types to MIPS ELF reloc types.  */

struct elf_reloc_map
{
  bfd_reloc_code_real_type bfd_reloc_val;
  enum elf_mips_reloc_type elf_reloc_val;
};

static CONST struct elf_reloc_map mips_reloc_map[] =
{
  { BFD_RELOC_NONE, R_MIPS_NONE, },
  { BFD_RELOC_16, R_MIPS_16 },
  { BFD_RELOC_32, R_MIPS_32 },
  { BFD_RELOC_64, R_MIPS_64 },
  { BFD_RELOC_CTOR, R_MIPS_64 },
  { BFD_RELOC_32_PCREL, R_MIPS_REL32 },
  { BFD_RELOC_MIPS_JMP, R_MIPS_26 },
  { BFD_RELOC_HI16_S, R_MIPS_HI16 },
  { BFD_RELOC_LO16, R_MIPS_LO16 },
  { BFD_RELOC_MIPS_GPREL, R_MIPS_GPREL16 },
  { BFD_RELOC_MIPS_LITERAL, R_MIPS_LITERAL },
  { BFD_RELOC_MIPS_GOT16, R_MIPS_GOT16 },
  { BFD_RELOC_16_PCREL, R_MIPS_PC16 },
  { BFD_RELOC_MIPS_CALL16, R_MIPS_CALL16 },
  { BFD_RELOC_MIPS_GPREL32, R_MIPS_GPREL32 },
  { BFD_RELOC_MIPS_GOT_HI16, R_MIPS_GOT_HI16 },
  { BFD_RELOC_MIPS_GOT_LO16, R_MIPS_GOT_LO16 },
  { BFD_RELOC_MIPS_CALL_HI16, R_MIPS_CALL_HI16 },
  { BFD_RELOC_MIPS_CALL_LO16, R_MIPS_CALL_LO16 },
  { BFD_RELOC_MIPS_SUB, R_MIPS_SUB },
  { BFD_RELOC_MIPS_GOT_PAGE, R_MIPS_GOT_PAGE },
  { BFD_RELOC_MIPS_GOT_OFST, R_MIPS_GOT_OFST },
  { BFD_RELOC_MIPS_GOT_DISP, R_MIPS_GOT_DISP }
};

/* Given a BFD reloc type, return a howto structure.  */

static reloc_howto_type *
mips_elf64_reloc_type_lookup (abfd, code)
     bfd *abfd ATTRIBUTE_UNUSED;
     bfd_reloc_code_real_type code;
{
  unsigned int i;

  for (i = 0; i < sizeof (mips_reloc_map) / sizeof (struct elf_reloc_map); i++)
    {
      if (mips_reloc_map[i].bfd_reloc_val == code)
	{
	  int v;

	  v = (int) mips_reloc_map[i].elf_reloc_val;
	  return &mips_elf64_howto_table_rel[v];
	}
    }

  return NULL;
}

/* Since each entry in an SHT_REL or SHT_RELA section can represent up
   to three relocs, we must tell the user to allocate more space.  */

static long
mips_elf64_get_reloc_upper_bound (abfd, sec)
     bfd *abfd ATTRIBUTE_UNUSED;
     asection *sec;
{
  return (sec->reloc_count * 3 + 1) * sizeof (arelent *);
}

/* Read the relocations from one reloc section.  */

static boolean
mips_elf64_slurp_one_reloc_table (abfd, asect, symbols, rel_hdr)
     bfd *abfd;
     asection *asect;
     asymbol **symbols;
     const Elf_Internal_Shdr *rel_hdr;
{
  PTR allocated = NULL;
  bfd_byte *native_relocs;
  arelent *relents;
  arelent *relent;
  unsigned int count;
  unsigned int i;
  int entsize;
  reloc_howto_type *howto_table;

  allocated = (PTR) bfd_malloc (rel_hdr->sh_size);
  if (allocated == NULL)
    goto error_return;

  if (bfd_seek (abfd, rel_hdr->sh_offset, SEEK_SET) != 0
      || (bfd_read (allocated, 1, rel_hdr->sh_size, abfd) != rel_hdr->sh_size))
    goto error_return;

  native_relocs = (bfd_byte *) allocated;

  relents = asect->relocation + asect->reloc_count;

  entsize = rel_hdr->sh_entsize;
  BFD_ASSERT (entsize == sizeof (Elf64_Mips_External_Rel)
	      || entsize == sizeof (Elf64_Mips_External_Rela));

  count = rel_hdr->sh_size / entsize;

  if (entsize == sizeof (Elf64_Mips_External_Rel))
    howto_table = mips_elf64_howto_table_rel;
  else
    howto_table = mips_elf64_howto_table_rela;

  relent = relents;
  for (i = 0; i < count; i++, native_relocs += entsize)
    {
      Elf64_Mips_Internal_Rela rela;
      boolean used_sym, used_ssym;
      int ir;

      if (entsize == sizeof (Elf64_Mips_External_Rela))
	mips_elf64_swap_reloca_in (abfd,
				   (Elf64_Mips_External_Rela *) native_relocs,
				   &rela);
      else
	{
	  Elf64_Mips_Internal_Rel rel;

	  mips_elf64_swap_reloc_in (abfd,
				    (Elf64_Mips_External_Rel *) native_relocs,
				    &rel);
	  rela.r_offset = rel.r_offset;
	  rela.r_sym = rel.r_sym;
	  rela.r_ssym = rel.r_ssym;
	  rela.r_type3 = rel.r_type3;
	  rela.r_type2 = rel.r_type2;
	  rela.r_type = rel.r_type;
	  rela.r_addend = 0;
	}

      /* Each entry represents up to three actual relocations.  */

      used_sym = false;
      used_ssym = false;
      for (ir = 0; ir < 3; ir++)
	{
	  enum elf_mips_reloc_type type;

	  switch (ir)
	    {
	    default:
	      abort ();
	    case 0:
	      type = (enum elf_mips_reloc_type) rela.r_type;
	      break;
	    case 1:
	      type = (enum elf_mips_reloc_type) rela.r_type2;
	      break;
	    case 2:
	      type = (enum elf_mips_reloc_type) rela.r_type3;
	      break;
	    }

	  if (type == R_MIPS_NONE)
	    {
	      /* There are no more relocations in this entry.  If this
                 is the first entry, we need to generate a dummy
                 relocation so that the generic linker knows that
                 there has been a break in the sequence of relocations
                 applying to a particular address.  */
	      if (ir == 0)
		{
		  relent->sym_ptr_ptr = bfd_abs_section_ptr->symbol_ptr_ptr;
		  if ((abfd->flags & (EXEC_P | DYNAMIC)) == 0)
		    relent->address = rela.r_offset;
		  else
		    relent->address = rela.r_offset - asect->vma;
		  relent->addend = 0;
		  relent->howto = &howto_table[(int) R_MIPS_NONE];
		  ++relent;
		}
	      break;
	    }

	  /* Some types require symbols, whereas some do not.  */
	  switch (type)
	    {
	    case R_MIPS_NONE:
	    case R_MIPS_LITERAL:
	    case R_MIPS_INSERT_A:
	    case R_MIPS_INSERT_B:
	    case R_MIPS_DELETE:
	      relent->sym_ptr_ptr = bfd_abs_section_ptr->symbol_ptr_ptr;
	      break;

	    default:
	      if (! used_sym)
		{
		  if (rela.r_sym == 0)
		    relent->sym_ptr_ptr = bfd_abs_section_ptr->symbol_ptr_ptr;
		  else
		    {
		      asymbol **ps, *s;

		      ps = symbols + rela.r_sym - 1;
		      s = *ps;
		      if ((s->flags & BSF_SECTION_SYM) == 0)
			relent->sym_ptr_ptr = ps;
		      else
			relent->sym_ptr_ptr = s->section->symbol_ptr_ptr;
		    }

		  used_sym = true;
		}
	      else if (! used_ssym)
		{
		  switch (rela.r_ssym)
		    {
		    case RSS_UNDEF:
		      relent->sym_ptr_ptr =
			bfd_abs_section_ptr->symbol_ptr_ptr;
		      break;

		    case RSS_GP:
		    case RSS_GP0:
		    case RSS_LOC:
		      /* FIXME: I think these need to be handled using
                         special howto structures.  */
		      BFD_ASSERT (0);
		      break;

		    default:
		      BFD_ASSERT (0);
		      break;
		    }

		  used_ssym = true;
		}
	      else
		relent->sym_ptr_ptr = bfd_abs_section_ptr->symbol_ptr_ptr;

	      break;
	    }

	  /* The address of an ELF reloc is section relative for an
	     object file, and absolute for an executable file or
	     shared library.  The address of a BFD reloc is always
	     section relative.  */
	  if ((abfd->flags & (EXEC_P | DYNAMIC)) == 0)
	    relent->address = rela.r_offset;
	  else
	    relent->address = rela.r_offset - asect->vma;

	  relent->addend = rela.r_addend;

	  relent->howto = &howto_table[(int) type];

	  ++relent;
	}
    }

  asect->reloc_count += relent - relents;

  if (allocated != NULL)
    free (allocated);

  return true;

 error_return:
  if (allocated != NULL)
    free (allocated);
  return false;
}

/* Read the relocations.  On Irix 6, there can be two reloc sections
   associated with a single data section.  */

static boolean
mips_elf64_slurp_reloc_table (abfd, asect, symbols, dynamic)
     bfd *abfd;
     asection *asect;
     asymbol **symbols;
     boolean dynamic;
{
  struct bfd_elf_section_data * const d = elf_section_data (asect);

  if (dynamic)
    {
      bfd_set_error (bfd_error_invalid_operation);
      return false;
    }

  if (asect->relocation != NULL
      || (asect->flags & SEC_RELOC) == 0
      || asect->reloc_count == 0)
    return true;

  /* Allocate space for 3 arelent structures for each Rel structure.  */
  asect->relocation = ((arelent *)
		       bfd_alloc (abfd,
				  asect->reloc_count * 3 * sizeof (arelent)));
  if (asect->relocation == NULL)
    return false;

  /* The slurp_one_reloc_table routine increments reloc_count.  */
  asect->reloc_count = 0;

  if (! mips_elf64_slurp_one_reloc_table (abfd, asect, symbols, &d->rel_hdr))
    return false;
  if (d->rel_hdr2 != NULL)
    {
      if (! mips_elf64_slurp_one_reloc_table (abfd, asect, symbols,
					      d->rel_hdr2))
	return false;
    }

  return true;
}

/* Write out the relocations.  */

static void
mips_elf64_write_relocs (abfd, sec, data)
     bfd *abfd;
     asection *sec;
     PTR data;
{
  boolean *failedp = (boolean *) data;
  unsigned int count;
  Elf_Internal_Shdr *rela_hdr;
  Elf64_Mips_External_Rela *ext_rela;
  unsigned int idx;
  asymbol *last_sym = 0;
  int last_sym_idx = 0;

  /* If we have already failed, don't do anything.  */
  if (*failedp)
    return;

  if ((sec->flags & SEC_RELOC) == 0)
    return;

  /* The linker backend writes the relocs out itself, and sets the
     reloc_count field to zero to inhibit writing them here.  Also,
     sometimes the SEC_RELOC flag gets set even when there aren't any
     relocs.  */
  if (sec->reloc_count == 0)
    return;

  /* We can combine up to three relocs that refer to the same address
     if the latter relocs have no associated symbol.  */
  count = 0;
  for (idx = 0; idx < sec->reloc_count; idx++)
    {
      bfd_vma addr;
      unsigned int i;

      ++count;

      addr = sec->orelocation[idx]->address;
      for (i = 0; i < 2; i++)
	{
	  arelent *r;

	  if (idx + 1 >= sec->reloc_count)
	    break;
	  r = sec->orelocation[idx + 1];
	  if (r->address != addr
	      || ! bfd_is_abs_section ((*r->sym_ptr_ptr)->section)
	      || (*r->sym_ptr_ptr)->value != 0)
	    break;

	  /* We can merge the reloc at IDX + 1 with the reloc at IDX.  */

	  ++idx;
	}
    }