elf32-ppc.c

来自「基于4个mips核的noc设计」· C语言 代码 · 共 1,931 行 · 第 1/5 页

                    }
                }
              else if ((insn & 0xFc00Fffe) == 0x4c000420)
                {
                  /* Instruction is BCCTRx */
                  if ((!BO0(insn) || !BO2(insn)) && !BO4(insn))
		    {
		      /* This branch is predicted as not-taken.
		      If this is a forward branch, it is problematic.
                      Since we can't tell statically if it will branch forward,
                      always set the prediction bit.  */
                      insn |= 0x00200000;   /* set the prediction bit */
                      modified = true;
		    }
                }
              else if ((insn & 0xFc00Fffe) == 0x4c000020)
                {
                  /* Instruction is BCLRx */
                  if ((!BO0(insn) || !BO2(insn)) && !BO4(insn))
		    {
		      /* This branch is predicted as not-taken.
		      If this is a forward branch, it is problematic.
                      Since we can't tell statically if it will branch forward,
                      always set the prediction bit.  */
                      insn |= 0x00200000;   /* set the prediction bit */
                      modified = true;
		    }
                }
#undef BO0
#undef BO2
#undef BO4
              if (modified)
	        {
                  bfd_put_32 (abfd, insn, contents + isec_offset);
		  section_modified = true;
	        }
            }
        }
      if (section_modified)
	{
	  elf_section_data (isec)->this_hdr.contents = contents;
	  free_contents = NULL;
	}
    }

  if (rela_comb != NULL)
    {
      free (rela_comb);
      rela_comb = NULL;
    }

  if (free_relocs != NULL)
    {
      free (free_relocs);
      free_relocs = NULL;
    }

  if (free_contents != NULL)
    {
      if (! link_info->keep_memory)
	free (free_contents);
      else
	{
	  /* Cache the section contents for elf_link_input_bfd.  */
	  elf_section_data (isec)->this_hdr.contents = contents;
	}
      free_contents = NULL;
    }

  return true;

error_return:
  if (rela_comb != NULL)
    free (rela_comb);
  if (free_relocs != NULL)
    free (free_relocs);
  if (free_contents != NULL)
    free (free_contents);
  return false;
}

static reloc_howto_type *
ppc_elf_reloc_type_lookup (abfd, code)
     bfd *abfd ATTRIBUTE_UNUSED;
     bfd_reloc_code_real_type code;
{
  enum elf_ppc_reloc_type ppc_reloc = R_PPC_NONE;

  if (!ppc_elf_howto_table[R_PPC_ADDR32])
    /* Initialize howto table if needed.  */
    ppc_elf_howto_init ();

  switch ((int) code)
    {
    default:
      return (reloc_howto_type *) NULL;

    case BFD_RELOC_NONE:		ppc_reloc = R_PPC_NONE;			break;
    case BFD_RELOC_32:			ppc_reloc = R_PPC_ADDR32;		break;
    case BFD_RELOC_PPC_BA26:		ppc_reloc = R_PPC_ADDR24;		break;
    case BFD_RELOC_16:			ppc_reloc = R_PPC_ADDR16;		break;
    case BFD_RELOC_LO16:		ppc_reloc = R_PPC_ADDR16_LO;		break;
    case BFD_RELOC_HI16:		ppc_reloc = R_PPC_ADDR16_HI;		break;
    case BFD_RELOC_HI16_S:		ppc_reloc = R_PPC_ADDR16_HA;		break;
    case BFD_RELOC_PPC_BA16:		ppc_reloc = R_PPC_ADDR14;		break;
    case BFD_RELOC_PPC_BA16_BRTAKEN:	ppc_reloc = R_PPC_ADDR14_BRTAKEN;	break;
    case BFD_RELOC_PPC_BA16_BRNTAKEN:	ppc_reloc = R_PPC_ADDR14_BRNTAKEN;	break;
    case BFD_RELOC_PPC_B26:		ppc_reloc = R_PPC_REL24;		break;
    case BFD_RELOC_PPC_B16:		ppc_reloc = R_PPC_REL14;		break;
    case BFD_RELOC_PPC_B16_BRTAKEN:	ppc_reloc = R_PPC_REL14_BRTAKEN;	break;
    case BFD_RELOC_PPC_B16_BRNTAKEN:	ppc_reloc = R_PPC_REL14_BRNTAKEN;	break;
    case BFD_RELOC_16_GOTOFF:		ppc_reloc = R_PPC_GOT16;		break;
    case BFD_RELOC_LO16_GOTOFF:		ppc_reloc = R_PPC_GOT16_LO;		break;
    case BFD_RELOC_HI16_GOTOFF:		ppc_reloc = R_PPC_GOT16_HI;		break;
    case BFD_RELOC_HI16_S_GOTOFF:	ppc_reloc = R_PPC_GOT16_HA;		break;
    case BFD_RELOC_24_PLT_PCREL:	ppc_reloc = R_PPC_PLTREL24;		break;
    case BFD_RELOC_PPC_COPY:		ppc_reloc = R_PPC_COPY;			break;
    case BFD_RELOC_PPC_GLOB_DAT:	ppc_reloc = R_PPC_GLOB_DAT;		break;
    case BFD_RELOC_PPC_LOCAL24PC:	ppc_reloc = R_PPC_LOCAL24PC;		break;
    case BFD_RELOC_32_PCREL:		ppc_reloc = R_PPC_REL32;		break;
    case BFD_RELOC_32_PLTOFF:		ppc_reloc = R_PPC_PLT32;		break;
    case BFD_RELOC_32_PLT_PCREL:	ppc_reloc = R_PPC_PLTREL32;		break;
    case BFD_RELOC_LO16_PLTOFF:		ppc_reloc = R_PPC_PLT16_LO;		break;
    case BFD_RELOC_HI16_PLTOFF:		ppc_reloc = R_PPC_PLT16_HI;		break;
    case BFD_RELOC_HI16_S_PLTOFF:	ppc_reloc = R_PPC_PLT16_HA;		break;
    case BFD_RELOC_GPREL16:		ppc_reloc = R_PPC_SDAREL16;		break;
    case BFD_RELOC_32_BASEREL:		ppc_reloc = R_PPC_SECTOFF;		break;
    case BFD_RELOC_LO16_BASEREL:	ppc_reloc = R_PPC_SECTOFF_LO;		break;
    case BFD_RELOC_HI16_BASEREL:	ppc_reloc = R_PPC_SECTOFF_HI;		break;
    case BFD_RELOC_HI16_S_BASEREL:	ppc_reloc = R_PPC_SECTOFF_HA;		break;
    case BFD_RELOC_CTOR:		ppc_reloc = R_PPC_ADDR32;		break;
    case BFD_RELOC_PPC_TOC16:		ppc_reloc = R_PPC_TOC16;		break;
    case BFD_RELOC_PPC_EMB_NADDR32:	ppc_reloc = R_PPC_EMB_NADDR32;		break;
    case BFD_RELOC_PPC_EMB_NADDR16:	ppc_reloc = R_PPC_EMB_NADDR16;		break;
    case BFD_RELOC_PPC_EMB_NADDR16_LO:	ppc_reloc = R_PPC_EMB_NADDR16_LO;	break;
    case BFD_RELOC_PPC_EMB_NADDR16_HI:	ppc_reloc = R_PPC_EMB_NADDR16_HI;	break;
    case BFD_RELOC_PPC_EMB_NADDR16_HA:	ppc_reloc = R_PPC_EMB_NADDR16_HA;	break;
    case BFD_RELOC_PPC_EMB_SDAI16:	ppc_reloc = R_PPC_EMB_SDAI16;		break;
    case BFD_RELOC_PPC_EMB_SDA2I16:	ppc_reloc = R_PPC_EMB_SDA2I16;		break;
    case BFD_RELOC_PPC_EMB_SDA2REL:	ppc_reloc = R_PPC_EMB_SDA2REL;		break;
    case BFD_RELOC_PPC_EMB_SDA21:	ppc_reloc = R_PPC_EMB_SDA21;		break;
    case BFD_RELOC_PPC_EMB_MRKREF:	ppc_reloc = R_PPC_EMB_MRKREF;		break;
    case BFD_RELOC_PPC_EMB_RELSEC16:	ppc_reloc = R_PPC_EMB_RELSEC16;		break;
    case BFD_RELOC_PPC_EMB_RELST_LO:	ppc_reloc = R_PPC_EMB_RELST_LO;		break;
    case BFD_RELOC_PPC_EMB_RELST_HI:	ppc_reloc = R_PPC_EMB_RELST_HI;		break;
    case BFD_RELOC_PPC_EMB_RELST_HA:	ppc_reloc = R_PPC_EMB_RELST_HA;		break;
    case BFD_RELOC_PPC_EMB_BIT_FLD:	ppc_reloc = R_PPC_EMB_BIT_FLD;		break;
    case BFD_RELOC_PPC_EMB_RELSDA:	ppc_reloc = R_PPC_EMB_RELSDA;		break;
    case BFD_RELOC_VTABLE_INHERIT:	ppc_reloc = R_PPC_GNU_VTINHERIT;	break;
    case BFD_RELOC_VTABLE_ENTRY:	ppc_reloc = R_PPC_GNU_VTENTRY;		break;
    }

  return ppc_elf_howto_table[(int) ppc_reloc];
};

/* Set the howto pointer for a PowerPC ELF reloc.  */

static void
ppc_elf_info_to_howto (abfd, cache_ptr, dst)
     bfd *abfd ATTRIBUTE_UNUSED;
     arelent *cache_ptr;
     Elf32_Internal_Rela *dst;
{
  if (!ppc_elf_howto_table[R_PPC_ADDR32])
    /* Initialize howto table if needed.  */
    ppc_elf_howto_init ();

  BFD_ASSERT (ELF32_R_TYPE (dst->r_info) < (unsigned int) R_PPC_max);
  cache_ptr->howto = ppc_elf_howto_table[ELF32_R_TYPE (dst->r_info)];
}

/* Handle the R_PPC_ADDR16_HA reloc.  */

static bfd_reloc_status_type
ppc_elf_addr16_ha_reloc (abfd, reloc_entry, symbol, data, input_section,
			 output_bfd, error_message)
     bfd *abfd ATTRIBUTE_UNUSED;
     arelent *reloc_entry;
     asymbol *symbol;
     PTR data ATTRIBUTE_UNUSED;
     asection *input_section;
     bfd *output_bfd;
     char **error_message ATTRIBUTE_UNUSED;
{
  bfd_vma relocation;

  if (output_bfd != NULL)
    {
      reloc_entry->address += input_section->output_offset;
      return bfd_reloc_ok;
    }

  if (reloc_entry->address > input_section->_cooked_size)
    return bfd_reloc_outofrange;

  if (bfd_is_com_section (symbol->section))
    relocation = 0;
  else
    relocation = symbol->value;

  relocation += symbol->section->output_section->vma;
  relocation += symbol->section->output_offset;
  relocation += reloc_entry->addend;

  reloc_entry->addend += (relocation & 0x8000) << 1;

  return bfd_reloc_continue;
}

/* Function to set whether a module needs the -mrelocatable bit set.  */

static boolean
ppc_elf_set_private_flags (abfd, flags)
     bfd *abfd;
     flagword flags;
{
  BFD_ASSERT (!elf_flags_init (abfd)
	      || elf_elfheader (abfd)->e_flags == flags);

  elf_elfheader (abfd)->e_flags = flags;
  elf_flags_init (abfd) = true;
  return true;
}

/* Copy backend specific data from one object module to another */
static boolean
ppc_elf_copy_private_bfd_data (ibfd, obfd)
     bfd *ibfd;
     bfd *obfd;
{
  if (bfd_get_flavour (ibfd) != bfd_target_elf_flavour
      || bfd_get_flavour (obfd) != bfd_target_elf_flavour)
    return true;

  BFD_ASSERT (!elf_flags_init (obfd)
	      || elf_elfheader (obfd)->e_flags == elf_elfheader (ibfd)->e_flags);

  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 boolean
ppc_elf_merge_private_bfd_data (ibfd, obfd)
     bfd *ibfd;
     bfd *obfd;
{
  flagword old_flags;
  flagword new_flags;
  boolean error;

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

  if (bfd_get_flavour (ibfd) != bfd_target_elf_flavour
      || bfd_get_flavour (obfd) != bfd_target_elf_flavour)
    return true;

  new_flags = elf_elfheader (ibfd)->e_flags;
  old_flags = elf_elfheader (obfd)->e_flags;
  if (!elf_flags_init (obfd))	/* First call, no flags set */
    {
      elf_flags_init (obfd) = true;
      elf_elfheader (obfd)->e_flags = new_flags;
    }

  else if (new_flags == old_flags)	/* Compatible flags are ok */
    ;

  else					/* Incompatible flags */
    {
      /* Warn about -mrelocatable mismatch.  Allow -mrelocatable-lib to be linked
         with either.  */
      error = false;
      if ((new_flags & EF_PPC_RELOCATABLE) != 0
	  && (old_flags & (EF_PPC_RELOCATABLE | EF_PPC_RELOCATABLE_LIB)) == 0)
	{
	  error = true;
	  (*_bfd_error_handler)
	    (_("%s: compiled with -mrelocatable and linked with modules compiled normally"),
	     bfd_get_filename (ibfd));
	}
      else if ((new_flags & (EF_PPC_RELOCATABLE | EF_PPC_RELOCATABLE_LIB)) == 0
	       && (old_flags & EF_PPC_RELOCATABLE) != 0)
	{
	  error = true;
	  (*_bfd_error_handler)
	    (_("%s: compiled normally and linked with modules compiled with -mrelocatable"),
	     bfd_get_filename (ibfd));
	}

      /* The output is -mrelocatable-lib iff both the input files are.  */
      if (! (new_flags & EF_PPC_RELOCATABLE_LIB))
	elf_elfheader (obfd)->e_flags &= ~EF_PPC_RELOCATABLE_LIB;

      /* The output is -mrelocatable iff it can't be -mrelocatable-lib,
         but each input file is either -mrelocatable or -mrelocatable-lib.  */
      if (! (elf_elfheader (obfd)->e_flags & EF_PPC_RELOCATABLE_LIB)
	  && (new_flags & (EF_PPC_RELOCATABLE_LIB | EF_PPC_RELOCATABLE))
	  && (old_flags & (EF_PPC_RELOCATABLE_LIB | EF_PPC_RELOCATABLE)))
	elf_elfheader (obfd)->e_flags |= EF_PPC_RELOCATABLE;

      /* Do not warn about eabi vs. V.4 mismatch, just or in the bit if any module uses it */
      elf_elfheader (obfd)->e_flags |= (new_flags & EF_PPC_EMB);

      new_flags &= ~ (EF_PPC_RELOCATABLE | EF_PPC_RELOCATABLE_LIB | EF_PPC_EMB);
      old_flags &= ~ (EF_PPC_RELOCATABLE | EF_PPC_RELOCATABLE_LIB | EF_PPC_EMB);

      /* Warn about any other mismatches */
      if (new_flags != old_flags)
	{
	  error = true;
	  (*_bfd_error_handler)
	    (_("%s: uses different e_flags (0x%lx) fields than previous modules (0x%lx)"),
	     bfd_get_filename (ibfd), (long) new_flags, (long) old_flags);
	}

      if (error)
	{
	  bfd_set_error (bfd_error_bad_value);
	  return false;
	}
    }

  return true;
}

/* Handle a PowerPC specific section when reading an object file.  This
   is called when elfcode.h finds a section with an unknown type.  */

static boolean
ppc_elf_section_from_shdr (abfd, hdr, name)
     bfd *abfd;
     Elf32_Internal_Shdr *hdr;
     char *name;
{
  asection *newsect;
  flagword flags;

  if (! _bfd_elf_make_section_from_shdr (abfd, hdr, name))
    return false;

  newsect = hdr->bfd_section;
  flags = bfd_get_section_flags (abfd, newsect);
  if (hdr->sh_flags & SHF_EXCLUDE)
    flags |= SEC_EXCLUDE;

  if (hdr->sh_type == SHT_ORDERED)
    flags |= SEC_SORT_ENTRIES;

  bfd_set_section_flags (abfd, newsect, flags);
  return true;
}

/* Set up any other section flags and such that may be necessary.  */

static boolean
ppc_elf_fake_sections (abfd, shdr, asect)
     bfd *abfd ATTRIBUTE_UNUSED;
     Elf32_Internal_Shdr *shdr;
     asection *asect;
{
  if ((asect->flags & SEC_EXCLUDE) != 0)
    shdr->sh_flags |= SHF_EXCLUDE;

  if ((asect->flags & SEC_SORT_ENTRIES) != 0)
    shdr->sh_type = SHT_ORDERED;

  return true;
}

/* Create a special linker section */
static elf_linker_section_t *
ppc_elf_create_linker_section (abfd, info, which)
     bfd *abfd;
     struct bfd_link_info *info;
     enum elf_linker_section_enum which;
{
  bfd *dynobj = elf_hash_table (info)->dynobj;
  elf_linker_section_t *lsect;

  /* Record the first bfd section that needs the special section */
  if (!dynobj)
    dynobj = elf_hash_table (info)->dynobj = abfd;