elf32-avr.c

基于4个mips核的noc设计

        h = NULL;
      else
        h = sym_hashes[r_symndx - symtab_hdr->sh_info];
    }

  return true;
}

/* Perform a single relocation.  By default we use the standard BFD
   routines, but a few relocs, we have to do them ourselves.  */

static bfd_reloc_status_type
avr_final_link_relocate (howto, input_bfd, input_section,
			 contents, rel, relocation)
     reloc_howto_type *  howto;
     bfd *               input_bfd;
     asection *          input_section;
     bfd_byte *          contents;
     Elf_Internal_Rela * rel;
     bfd_vma             relocation;
{
  bfd_reloc_status_type r = bfd_reloc_ok;
  bfd_vma               x;
  bfd_signed_vma	srel;

  switch (howto->type)
    {
    case R_AVR_7_PCREL:
      contents += rel->r_offset;
      srel = (bfd_signed_vma) relocation;
      srel += rel->r_addend;
      srel -= rel->r_offset;
      srel -= 2;	/* Branch instructions add 2 to the PC...  */
      srel -= (input_section->output_section->vma +
	       input_section->output_offset);

      if (srel & 1)
	return bfd_reloc_outofrange;
      if (srel > ((1 << 7) - 1) || (srel < - (1 << 7)))
	return bfd_reloc_overflow;
      x = bfd_get_16 (input_bfd, contents);
      x = (x & 0xfc07) | (((srel >> 1) << 3) & 0x3f8);
      bfd_put_16 (input_bfd, x, contents);
      break;

    case R_AVR_13_PCREL:
      contents   += rel->r_offset;
      srel = (bfd_signed_vma) relocation;
      srel += rel->r_addend;
      srel -= rel->r_offset;
      srel -= 2;	/* Branch instructions add 2 to the PC...  */
      srel -= (input_section->output_section->vma +
	       input_section->output_offset);

      if (srel & 1)
	return bfd_reloc_outofrange;

      /* AVR addresses commands as words.  */
      srel >>= 1;

      /* Check for overflow.  */
      if (srel < -2048 || srel > 2047)
	{
	  /* Apply WRAPAROUND if possible.  */
	  switch (bfd_get_mach (input_bfd))
	    {
	    case bfd_mach_avr2:
	    case bfd_mach_avr4:
	      break;

	    default:
	      return bfd_reloc_overflow;
	    }
	}

      x = bfd_get_16 (input_bfd, contents);
      x = (x & 0xf000) | (srel & 0xfff);
      bfd_put_16 (input_bfd, x, contents);
      break;

    case R_AVR_LO8_LDI:
      contents += rel->r_offset;
      srel = (bfd_signed_vma) relocation + rel->r_addend;
      x = bfd_get_16 (input_bfd, contents);
      x = (x & 0xf0f0) | (srel & 0xf) | ((srel << 4) & 0xf00);
      bfd_put_16 (input_bfd, x, contents);
      break;

    case R_AVR_HI8_LDI:
      contents += rel->r_offset;
      srel = (bfd_signed_vma) relocation + rel->r_addend;
      srel = (srel >> 8) & 0xff;
      x = bfd_get_16 (input_bfd, contents);
      x = (x & 0xf0f0) | (srel & 0xf) | ((srel << 4) & 0xf00);
      bfd_put_16 (input_bfd, x, contents);
      break;

    case R_AVR_HH8_LDI:
      contents += rel->r_offset;
      srel = (bfd_signed_vma) relocation + rel->r_addend;
      srel = (srel >> 16) & 0xff;
      x = bfd_get_16 (input_bfd, contents);
      x = (x & 0xf0f0) | (srel & 0xf) | ((srel << 4) & 0xf00);
      bfd_put_16 (input_bfd, x, contents);
      break;

    case R_AVR_LO8_LDI_NEG:
      contents += rel->r_offset;
      srel = (bfd_signed_vma) relocation + rel->r_addend;
      srel = -srel;
      x = bfd_get_16 (input_bfd, contents);
      x = (x & 0xf0f0) | (srel & 0xf) | ((srel << 4) & 0xf00);
      bfd_put_16 (input_bfd, x, contents);
      break;

    case R_AVR_HI8_LDI_NEG:
      contents += rel->r_offset;
      srel = (bfd_signed_vma) relocation + rel->r_addend;
      srel = -srel;
      srel = (srel >> 8) & 0xff;
      x = bfd_get_16 (input_bfd, contents);
      x = (x & 0xf0f0) | (srel & 0xf) | ((srel << 4) & 0xf00);
      bfd_put_16 (input_bfd, x, contents);
      break;

    case R_AVR_HH8_LDI_NEG:
      contents += rel->r_offset;
      srel = (bfd_signed_vma) relocation + rel->r_addend;
      srel = -srel;
      srel = (srel >> 16) & 0xff;
      x = bfd_get_16 (input_bfd, contents);
      x = (x & 0xf0f0) | (srel & 0xf) | ((srel << 4) & 0xf00);
      bfd_put_16 (input_bfd, x, contents);
      break;

    case R_AVR_LO8_LDI_PM:
      contents += rel->r_offset;
      srel = (bfd_signed_vma) relocation + rel->r_addend;
      if (srel & 1)
	return bfd_reloc_outofrange;
      srel = srel >> 1;
      x = bfd_get_16 (input_bfd, contents);
      x = (x & 0xf0f0) | (srel & 0xf) | ((srel << 4) & 0xf00);
      bfd_put_16 (input_bfd, x, contents);
      break;

    case R_AVR_HI8_LDI_PM:
      contents += rel->r_offset;
      srel = (bfd_signed_vma) relocation + rel->r_addend;
      if (srel & 1)
	return bfd_reloc_outofrange;
      srel = srel >> 1;
      srel = (srel >> 8) & 0xff;
      x = bfd_get_16 (input_bfd, contents);
      x = (x & 0xf0f0) | (srel & 0xf) | ((srel << 4) & 0xf00);
      bfd_put_16 (input_bfd, x, contents);
      break;

    case R_AVR_HH8_LDI_PM:
      contents += rel->r_offset;
      srel = (bfd_signed_vma) relocation + rel->r_addend;
      if (srel & 1)
	return bfd_reloc_outofrange;
      srel = srel >> 1;
      srel = (srel >> 16) & 0xff;
      x = bfd_get_16 (input_bfd, contents);
      x = (x & 0xf0f0) | (srel & 0xf) | ((srel << 4) & 0xf00);
      bfd_put_16 (input_bfd, x, contents);
      break;

    case R_AVR_LO8_LDI_PM_NEG:
      contents += rel->r_offset;
      srel = (bfd_signed_vma) relocation + rel->r_addend;
      srel = -srel;
      if (srel & 1)
	return bfd_reloc_outofrange;
      srel = srel >> 1;
      x = bfd_get_16 (input_bfd, contents);
      x = (x & 0xf0f0) | (srel & 0xf) | ((srel << 4) & 0xf00);
      bfd_put_16 (input_bfd, x, contents);
      break;

    case R_AVR_HI8_LDI_PM_NEG:
      contents += rel->r_offset;
      srel = (bfd_signed_vma) relocation + rel->r_addend;
      srel = -srel;
      if (srel & 1)
	return bfd_reloc_outofrange;
      srel = srel >> 1;
      srel = (srel >> 8) & 0xff;
      x = bfd_get_16 (input_bfd, contents);
      x = (x & 0xf0f0) | (srel & 0xf) | ((srel << 4) & 0xf00);
      bfd_put_16 (input_bfd, x, contents);
      break;

    case R_AVR_HH8_LDI_PM_NEG:
      contents += rel->r_offset;
      srel = (bfd_signed_vma) relocation + rel->r_addend;
      srel = -srel;
      if (srel & 1)
	return bfd_reloc_outofrange;
      srel = srel >> 1;
      srel = (srel >> 16) & 0xff;
      x = bfd_get_16 (input_bfd, contents);
      x = (x & 0xf0f0) | (srel & 0xf) | ((srel << 4) & 0xf00);
      bfd_put_16 (input_bfd, x, contents);
      break;

    case R_AVR_CALL:
      contents += rel->r_offset;
      srel = (bfd_signed_vma) relocation + rel->r_addend;
      if (srel & 1)
	return bfd_reloc_outofrange;
      srel = srel >> 1;
      x = bfd_get_16 (input_bfd, contents);
      x |= ((srel & 0x10000) | ((srel << 3) & 0x1f00000)) >> 16;
      bfd_put_16 (input_bfd, x, contents);
      bfd_put_16 (input_bfd, srel & 0xffff, contents+2);
      break;

    default:
      r = _bfd_final_link_relocate (howto, input_bfd, input_section,
				    contents, rel->r_offset,
				    relocation, rel->r_addend);
    }

  return r;
}

/* Relocate an AVR ELF section.  */
static boolean
elf32_avr_relocate_section (output_bfd, info, input_bfd, input_section,
			    contents, relocs, local_syms, local_sections)
     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;

  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->relocateable)
	{
	  /* This is a relocateable 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;
	}

      /* This is a final link.  */
      howto  = elf_avr_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 = (sec->output_section->vma
			+ sec->output_offset
			+ sym->st_value);

	  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;
	}
      else
	{
	  h = sym_hashes [r_symndx - symtab_hdr->sh_info];

	  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);
	    }
	  else if (h->root.type == bfd_link_hash_undefweak)
	    {
	      relocation = 0;
	    }
	  else
	    {
	      if (! ((*info->callbacks->undefined_symbol)
		     (info, h->root.root.string, input_bfd,
		      input_section, rel->r_offset, true)))
		return false;
	      relocation = 0;
	    }
	}

      r = avr_final_link_relocate (howto, input_bfd, input_section,
				   contents, rel, relocation);

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

	  switch (r)
	    {
	    case bfd_reloc_overflow:
	      r = info->callbacks->reloc_overflow
		(info, 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;
	}
    }

  return true;
}

/* The final processing done just before writing out a AVR ELF object
   file.  This gets the AVR architecture right based on the machine
   number.  */

static void
bfd_elf_avr_final_write_processing (abfd, linker)
     bfd *abfd;
     boolean linker ATTRIBUTE_UNUSED;
{
  unsigned long val;

  switch (bfd_get_mach (abfd))
    {
    default:
    case bfd_mach_avr2:
      val = E_AVR_MACH_AVR2;
      break;

    case bfd_mach_avr1:
      val = E_AVR_MACH_AVR1;
      break;

    case bfd_mach_avr3:
      val = E_AVR_MACH_AVR3;
      break;

    case bfd_mach_avr4:
      val = E_AVR_MACH_AVR4;
      break;

    case bfd_mach_avr5:
      val = E_AVR_MACH_AVR5;
      break;
    }

  elf_elfheader (abfd)->e_machine = EM_AVR;
  elf_elfheader (abfd)->e_flags &= ~ EF_AVR_MACH;
  elf_elfheader (abfd)->e_flags |= val;
}

/* Set the right machine number.  */

static boolean
elf32_avr_object_p (abfd)
     bfd *abfd;
{
  int e_set = bfd_mach_avr2;
  if (elf_elfheader (abfd)->e_machine == EM_AVR)
    {
      int e_mach = elf_elfheader (abfd)->e_flags & EF_AVR_MACH;
      switch (e_mach)
	{
	default:
	case E_AVR_MACH_AVR2:
	  e_set = bfd_mach_avr2;
	  break;

	case E_AVR_MACH_AVR1:
	  e_set = bfd_mach_avr1;
	  break;

	case E_AVR_MACH_AVR3:
	  e_set = bfd_mach_avr3;
	  break;

	case E_AVR_MACH_AVR4:
	  e_set = bfd_mach_avr4;
	  break;

	case E_AVR_MACH_AVR5:
	  e_set = bfd_mach_avr5;
	  break;
	}
    }
  return bfd_default_set_arch_mach (abfd, bfd_arch_avr,
				    e_set);
}

#define ELF_ARCH		bfd_arch_avr
#define ELF_MACHINE_CODE	EM_AVR
#define ELF_MAXPAGESIZE		1

#define TARGET_LITTLE_SYM       bfd_elf32_avr_vec
#define TARGET_LITTLE_NAME	"elf32-avr"

#define elf_info_to_howto	             avr_info_to_howto_rela
#define elf_info_to_howto_rel	             NULL
#define elf_backend_relocate_section         elf32_avr_relocate_section
#define elf_backend_gc_mark_hook             elf32_avr_gc_mark_hook
#define elf_backend_gc_sweep_hook            elf32_avr_gc_sweep_hook
#define elf_backend_check_relocs             elf32_avr_check_relocs
#define elf_backend_can_gc_sections          1
#define elf_backend_final_write_processing \
					bfd_elf_avr_final_write_processing
#define elf_backend_object_p		elf32_avr_object_p

#include "elf32-target.h"