elf32-avr.c

基于4个mips核的noc设计

/* AVR-specific support for 32-bit ELF
   Copyright 1999, 2000 Free Software Foundation, Inc.
   Contributed by Denis Chertykov <[e-mail]>

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.  */

#include "bfd.h"
#include "sysdep.h"
#include "libbfd.h"
#include "elf-bfd.h"
#include "elf/avr.h"

static reloc_howto_type *bfd_elf32_bfd_reloc_type_lookup
  PARAMS ((bfd *abfd, bfd_reloc_code_real_type code));
static void avr_info_to_howto_rela
  PARAMS ((bfd *, arelent *, Elf32_Internal_Rela *));
static asection *elf32_avr_gc_mark_hook
  PARAMS ((bfd *, struct bfd_link_info *, Elf_Internal_Rela *,
	   struct elf_link_hash_entry *, Elf_Internal_Sym *));
static boolean elf32_avr_gc_sweep_hook
  PARAMS ((bfd *, struct bfd_link_info *, asection *,
	   const Elf_Internal_Rela *));
static boolean elf32_avr_check_relocs
  PARAMS ((bfd *, struct bfd_link_info *, asection *,
	   const Elf_Internal_Rela *));
static bfd_reloc_status_type avr_final_link_relocate
  PARAMS ((reloc_howto_type *, bfd *, asection *, bfd_byte *,
	   Elf_Internal_Rela *, bfd_vma));
static boolean elf32_avr_relocate_section
  PARAMS ((bfd *, struct bfd_link_info *, bfd *, asection *, bfd_byte *,
	   Elf_Internal_Rela *, Elf_Internal_Sym *, asection **));
static void bfd_elf_avr_final_write_processing PARAMS ((bfd *, boolean));
static boolean elf32_avr_object_p PARAMS ((bfd *));

/* Use RELA instead of REL */
#undef USE_REL

static reloc_howto_type elf_avr_howto_table[] =
{
  HOWTO (R_AVR_NONE,		/* type */
	 0,			/* rightshift */
	 2,			/* size (0 = byte, 1 = short, 2 = long) */
	 32,			/* bitsize */
	 false,			/* pc_relative */
	 0,			/* bitpos */
	 complain_overflow_bitfield, /* complain_on_overflow */
	 bfd_elf_generic_reloc,	/* special_function */
	 "R_AVR_NONE",		/* name */
	 false,			/* partial_inplace */
	 0,			/* src_mask */
	 0,			/* dst_mask */
	 false),		/* pcrel_offset */

  HOWTO (R_AVR_32,		/* type */
	 0,			/* rightshift */
	 2,			/* size (0 = byte, 1 = short, 2 = long) */
	 32,			/* bitsize */
	 false,			/* pc_relative */
	 0,			/* bitpos */
	 complain_overflow_bitfield, /* complain_on_overflow */
	 bfd_elf_generic_reloc,	/* special_function */
	 "R_AVR_32",		/* name */
	 false,			/* partial_inplace */
	 0xffffffff,		/* src_mask */
	 0xffffffff,		/* dst_mask */
	 false),		/* pcrel_offset */

  /* A 7 bit PC relative relocation.  */
  HOWTO (R_AVR_7_PCREL,		/* type */
	 1,			/* rightshift */
	 1,			/* size (0 = byte, 1 = short, 2 = long) */
	 7,			/* bitsize */
	 true,			/* pc_relative */
	 3,			/* bitpos */
	 complain_overflow_bitfield, /* complain_on_overflow */
	 bfd_elf_generic_reloc, /* special_function */
	 "R_AVR_7_PCREL",	/* name */
	 false,			/* partial_inplace */
	 0xffff,		/* src_mask */
	 0xffff,		/* dst_mask */
	 true),			/* pcrel_offset */

  /* A 13 bit PC relative relocation.  */
  HOWTO (R_AVR_13_PCREL,	/* type */
	 1,			/* rightshift */
	 1,			/* size (0 = byte, 1 = short, 2 = long) */
	 13,			/* bitsize */
	 true,			/* pc_relative */
	 0,			/* bitpos */
	 complain_overflow_bitfield, /* complain_on_overflow */
	 bfd_elf_generic_reloc, /* special_function */
	 "R_AVR_13_PCREL",	/* name */
	 false,			/* partial_inplace */
	 0xfff,			/* src_mask */
	 0xfff,			/* dst_mask */
	 true),			/* pcrel_offset */

  /* A 16 bit absolute relocation.  */
  HOWTO (R_AVR_16,		/* type */
	 0,			/* rightshift */
	 1,			/* size (0 = byte, 1 = short, 2 = long) */
	 16,			/* bitsize */
	 false,			/* pc_relative */
	 0,			/* bitpos */
	 complain_overflow_dont, /* complain_on_overflow */
	 bfd_elf_generic_reloc,	/* special_function */
	 "R_AVR_16",		/* name */
	 false,			/* partial_inplace */
	 0xffff,		/* src_mask */
	 0xffff,		/* dst_mask */
	 false),		/* pcrel_offset */

  /* A 16 bit absolute relocation for command address.  */
  HOWTO (R_AVR_16_PM,		/* type */
	 1,			/* rightshift */
	 1,			/* size (0 = byte, 1 = short, 2 = long) */
	 16,			/* bitsize */
	 false,			/* pc_relative */
	 0,			/* bitpos */
	 complain_overflow_bitfield, /* complain_on_overflow */
	 bfd_elf_generic_reloc,	/* special_function */
	 "R_AVR_16_PM",		/* name */
	 false,			/* partial_inplace */
	 0xffff,		/* src_mask */
	 0xffff,		/* dst_mask */
	 false),		/* pcrel_offset */
  /* A low 8 bit absolute relocation of 16 bit address.
     For LDI command.  */
  HOWTO (R_AVR_LO8_LDI,		/* type */
	 0,			/* rightshift */
	 1,			/* size (0 = byte, 1 = short, 2 = long) */
	 8,			/* bitsize */
	 false,			/* pc_relative */
	 0,			/* bitpos */
	 complain_overflow_dont, /* complain_on_overflow */
	 bfd_elf_generic_reloc,	/* special_function */
	 "R_AVR_LO8_LDI",	/* name */
	 false,			/* partial_inplace */
	 0xffff,		/* src_mask */
	 0xffff,		/* dst_mask */
	 false),		/* pcrel_offset */
  /* A high 8 bit absolute relocation of 16 bit address.
     For LDI command.  */
  HOWTO (R_AVR_HI8_LDI,		/* type */
	 8,			/* rightshift */
	 1,			/* size (0 = byte, 1 = short, 2 = long) */
	 8,			/* bitsize */
	 false,			/* pc_relative */
	 0,			/* bitpos */
	 complain_overflow_dont, /* complain_on_overflow */
	 bfd_elf_generic_reloc,	/* special_function */
	 "R_AVR_HI8_LDI",	/* name */
	 false,			/* partial_inplace */
	 0xffff,		/* src_mask */
	 0xffff,		/* dst_mask */
	 false),		/* pcrel_offset */
  /* A high 6 bit absolute relocation of 22 bit address.
     For LDI command.  */
  HOWTO (R_AVR_HH8_LDI,		/* type */
	 16,			/* rightshift */
	 1,			/* size (0 = byte, 1 = short, 2 = long) */
	 8,			/* bitsize */
	 false,			/* pc_relative */
	 0,			/* bitpos */
	 complain_overflow_dont, /* complain_on_overflow */
	 bfd_elf_generic_reloc,	/* special_function */
	 "R_AVR_HH8_LDI",	/* name */
	 false,			/* partial_inplace */
	 0xffff,		/* src_mask */
	 0xffff,		/* dst_mask */
	 false),		/* pcrel_offset */
  /* A negative low 8 bit absolute relocation of 16 bit address.
     For LDI command.  */
  HOWTO (R_AVR_LO8_LDI_NEG,	/* type */
	 0,			/* rightshift */
	 1,			/* size (0 = byte, 1 = short, 2 = long) */
	 8,			/* bitsize */
	 false,			/* pc_relative */
	 0,			/* bitpos */
	 complain_overflow_dont, /* complain_on_overflow */
	 bfd_elf_generic_reloc,	/* special_function */
	 "R_AVR_LO8_LDI_NEG",	/* name */
	 false,			/* partial_inplace */
	 0xffff,		/* src_mask */
	 0xffff,		/* dst_mask */
	 false),		/* pcrel_offset */
  /* A hegative high 8 bit absolute relocation of 16 bit address.
     For LDI command.  */
  HOWTO (R_AVR_HI8_LDI_NEG,	/* type */
	 8,			/* rightshift */
	 1,			/* size (0 = byte, 1 = short, 2 = long) */
	 8,			/* bitsize */
	 false,			/* pc_relative */
	 0,			/* bitpos */
	 complain_overflow_dont, /* complain_on_overflow */
	 bfd_elf_generic_reloc,	/* special_function */
	 "R_AVR_HI8_LDI_NEG",	/* name */
	 false,			/* partial_inplace */
	 0xffff,		/* src_mask */
	 0xffff,		/* dst_mask */
	 false),		/* pcrel_offset */
  /* A hegative high 6 bit absolute relocation of 22 bit address.
     For LDI command.  */
  HOWTO (R_AVR_HH8_LDI_NEG,	/* type */
	 16,			/* rightshift */
	 1,			/* size (0 = byte, 1 = short, 2 = long) */
	 8,			/* bitsize */
	 false,			/* pc_relative */
	 0,			/* bitpos */
	 complain_overflow_dont, /* complain_on_overflow */
	 bfd_elf_generic_reloc,	/* special_function */
	 "R_AVR_HH8_LDI_NEG",	/* name */
	 false,			/* partial_inplace */
	 0xffff,		/* src_mask */
	 0xffff,		/* dst_mask */
	 false),		/* pcrel_offset */
  /* A low 8 bit absolute relocation of 24 bit program memory address.
     For LDI command.  */
  HOWTO (R_AVR_LO8_LDI_PM,	/* type */
	 1,			/* rightshift */
	 1,			/* size (0 = byte, 1 = short, 2 = long) */
	 8,			/* bitsize */
	 false,			/* pc_relative */
	 0,			/* bitpos */
	 complain_overflow_dont, /* complain_on_overflow */
	 bfd_elf_generic_reloc,	/* special_function */
	 "R_AVR_LO8_LDI_PM",	/* name */
	 false,			/* partial_inplace */
	 0xffff,		/* src_mask */
	 0xffff,		/* dst_mask */
	 false),		/* pcrel_offset */
  /* A high 8 bit absolute relocation of 16 bit program memory address.
     For LDI command.  */
  HOWTO (R_AVR_HI8_LDI_PM,	/* type */
	 9,			/* rightshift */
	 1,			/* size (0 = byte, 1 = short, 2 = long) */
	 8,			/* bitsize */
	 false,			/* pc_relative */
	 0,			/* bitpos */
	 complain_overflow_dont, /* complain_on_overflow */
	 bfd_elf_generic_reloc,	/* special_function */
	 "R_AVR_HI8_LDI_PM",	/* name */
	 false,			/* partial_inplace */
	 0xffff,		/* src_mask */
	 0xffff,		/* dst_mask */
	 false),		/* pcrel_offset */
  /* A high 8 bit absolute relocation of 24 bit program memory address.
     For LDI command.  */
  HOWTO (R_AVR_HH8_LDI_PM,	/* type */
	 17,			/* rightshift */
	 1,			/* size (0 = byte, 1 = short, 2 = long) */
	 8,			/* bitsize */
	 false,			/* pc_relative */
	 0,			/* bitpos */
	 complain_overflow_dont, /* complain_on_overflow */
	 bfd_elf_generic_reloc,	/* special_function */
	 "R_AVR_HH8_LDI_PM",	/* name */
	 false,			/* partial_inplace */
	 0xffff,		/* src_mask */
	 0xffff,		/* dst_mask */
	 false),		/* pcrel_offset */
  /* A low 8 bit absolute relocation of a negative 24 bit
     program memory address.  For LDI command.  */
  HOWTO (R_AVR_LO8_LDI_PM_NEG,	/* type */
	 1,			/* rightshift */
	 1,			/* size (0 = byte, 1 = short, 2 = long) */
	 8,			/* bitsize */
	 false,			/* pc_relative */
	 0,			/* bitpos */
	 complain_overflow_dont, /* complain_on_overflow */
	 bfd_elf_generic_reloc,	/* special_function */
	 "R_AVR_LO8_LDI_PM_NEG", /* name */
	 false,			/* partial_inplace */
	 0xffff,		/* src_mask */
	 0xffff,		/* dst_mask */
	 false),		/* pcrel_offset */
  /* A high 8 bit absolute relocation of a negative 16 bit
     program memory address.  For LDI command.  */
  HOWTO (R_AVR_HI8_LDI_PM_NEG,	/* type */
	 9,			/* rightshift */
	 1,			/* size (0 = byte, 1 = short, 2 = long) */
	 8,			/* bitsize */
	 false,			/* pc_relative */
	 0,			/* bitpos */
	 complain_overflow_dont, /* complain_on_overflow */
	 bfd_elf_generic_reloc,	/* special_function */
	 "R_AVR_HI8_LDI_PM_NEG", /* name */
	 false,			/* partial_inplace */
	 0xffff,		/* src_mask */
	 0xffff,		/* dst_mask */
	 false),		/* pcrel_offset */
  /* A high 8 bit absolute relocation of a negative 24 bit
     program memory address.  For LDI command.  */
  HOWTO (R_AVR_HH8_LDI_PM_NEG,	/* type */
	 17,			/* rightshift */
	 1,			/* size (0 = byte, 1 = short, 2 = long) */
	 8,			/* bitsize */
	 false,			/* pc_relative */
	 0,			/* bitpos */
	 complain_overflow_dont, /* complain_on_overflow */
	 bfd_elf_generic_reloc,	/* special_function */
	 "R_AVR_HH8_LDI_PM_NEG", /* name */
	 false,			/* partial_inplace */
	 0xffff,		/* src_mask */
	 0xffff,		/* dst_mask */
	 false),		/* pcrel_offset */
  /* Relocation for CALL command in ATmega.  */
  HOWTO (R_AVR_CALL,		/* type */
	 1,			/* rightshift */
	 2,			/* size (0 = byte, 1 = short, 2 = long) */
	 23,			/* bitsize */
	 false,			/* pc_relative */
	 0,			/* bitpos */
	 complain_overflow_dont, /* complain_on_overflow */
	 bfd_elf_generic_reloc,	/* special_function */
	 "R_AVR_CALL",		/* name */
	 false,			/* partial_inplace */
	 0xffffffff,		/* src_mask */
	 0xffffffff,		/* dst_mask */
	 false)			/* pcrel_offset */
};

/* Map BFD reloc types to AVR ELF reloc types.  */

struct avr_reloc_map
{
  bfd_reloc_code_real_type bfd_reloc_val;
  unsigned int elf_reloc_val;
};

 static const struct avr_reloc_map avr_reloc_map[] =
{
  { BFD_RELOC_NONE,                 R_AVR_NONE },
  { BFD_RELOC_32,                   R_AVR_32 },
  { BFD_RELOC_AVR_7_PCREL,          R_AVR_7_PCREL },
  { BFD_RELOC_AVR_13_PCREL,         R_AVR_13_PCREL },
  { BFD_RELOC_16,                   R_AVR_16 },
  { BFD_RELOC_AVR_16_PM,            R_AVR_16_PM },
  { BFD_RELOC_AVR_LO8_LDI,          R_AVR_LO8_LDI},
  { BFD_RELOC_AVR_HI8_LDI,          R_AVR_HI8_LDI },
  { BFD_RELOC_AVR_HH8_LDI,          R_AVR_HH8_LDI },
  { BFD_RELOC_AVR_LO8_LDI_NEG,      R_AVR_LO8_LDI_NEG },
  { BFD_RELOC_AVR_HI8_LDI_NEG,      R_AVR_HI8_LDI_NEG },
  { BFD_RELOC_AVR_HH8_LDI_NEG,      R_AVR_HH8_LDI_NEG },
  { BFD_RELOC_AVR_LO8_LDI_PM,       R_AVR_LO8_LDI_PM },
  { BFD_RELOC_AVR_HI8_LDI_PM,       R_AVR_HI8_LDI_PM },
  { BFD_RELOC_AVR_HH8_LDI_PM,       R_AVR_HH8_LDI_PM },
  { BFD_RELOC_AVR_LO8_LDI_PM_NEG,   R_AVR_LO8_LDI_PM_NEG },
  { BFD_RELOC_AVR_HI8_LDI_PM_NEG,   R_AVR_HI8_LDI_PM_NEG },
  { BFD_RELOC_AVR_HH8_LDI_PM_NEG,   R_AVR_HH8_LDI_PM_NEG },
  { BFD_RELOC_AVR_CALL,             R_AVR_CALL }
};

static reloc_howto_type *
bfd_elf32_bfd_reloc_type_lookup (abfd, code)
     bfd *abfd ATTRIBUTE_UNUSED;
     bfd_reloc_code_real_type code;
{
  unsigned int i;

  for (i = 0;
       i < sizeof (avr_reloc_map) / sizeof (struct avr_reloc_map);
       i++)
    {
      if (avr_reloc_map[i].bfd_reloc_val == code)
	return &elf_avr_howto_table[avr_reloc_map[i].elf_reloc_val];
    }

  return NULL;
}

/* Set the howto pointer for an AVR ELF reloc.  */

static void
avr_info_to_howto_rela (abfd, cache_ptr, dst)
     bfd *abfd ATTRIBUTE_UNUSED;
     arelent *cache_ptr;
     Elf32_Internal_Rela *dst;
{
  unsigned int r_type;

  r_type = ELF32_R_TYPE (dst->r_info);
  BFD_ASSERT (r_type < (unsigned int) R_AVR_max);
  cache_ptr->howto = &elf_avr_howto_table[r_type];
}

static asection *
elf32_avr_gc_mark_hook (abfd, info, rel, h, sym)
     bfd *abfd;
     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 (abfd)
	    && 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 (abfd, sym->st_shndx);
	}
    }
  return NULL;
}

static boolean
elf32_avr_gc_sweep_hook (abfd, info, sec, relocs)
     bfd *abfd ATTRIBUTE_UNUSED;
     struct bfd_link_info *info ATTRIBUTE_UNUSED;
     asection *sec ATTRIBUTE_UNUSED;
     const Elf_Internal_Rela *relocs ATTRIBUTE_UNUSED;
{
  /* We don't use got and plt entries for avr.  */
  return true;
}

/* 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 boolean
elf32_avr_check_relocs (abfd, info, sec, 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, **sym_hashes_end;
  const Elf_Internal_Rela *rel;
  const Elf_Internal_Rela *rel_end;

  if (info->relocateable)
    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)