binutils-gdb/bfd/elf32-mn10300.c

/* Matsushita 10300 specific support for 32-bit ELF
   Copyright (C) 1996 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */

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

static reloc_howto_type *bfd_elf32_bfd_reloc_type_lookup
  PARAMS ((bfd *abfd, bfd_reloc_code_real_type code));
static void mn10300_info_to_howto
  PARAMS ((bfd *, arelent *, Elf32_Internal_Rela *));
static bfd_reloc_status_type bfd_elf32_mn10300_reloc
  PARAMS ((bfd *, arelent *, asymbol *, PTR, asection *, bfd *, char **));


/* We have to use RELA instructions since md_apply_fix3 in the assembler
   does absolutely nothing.  */
#define USE_RELA

enum reloc_type
{
  R_MN10300_NONE = 0,
  R_MN10300_32,
  R_MN10300_16,
  R_MN10300_8,
  R_MN10300_32B,
  R_MN10300_16B,
  R_MN10300_PCREL32_1BYTE,
  R_MN10300_PCREL16_1BYTE,
  R_MN10300_PCREL8_1BYTE,
  R_MN10300_PCREL32_2BYTE,
  R_MN10300_PCREL16_2BYTE,
  R_MN10300_MAX
};

static reloc_howto_type elf_mn10300_howto_table[] =
{
  /* Dummy relocation.  Does nothing.  */
  HOWTO (R_MN10300_NONE,
	 0,
	 2,
	 16,
	 false,
	 0,
	 complain_overflow_bitfield,
	 bfd_elf_generic_reloc,
	 "R_MN10300_NONE",
	 false,
	 0,
	 0,
	 false),
  /* Standard 32 bit reloc.  */
  HOWTO (R_MN10300_32,
	 0,
	 2,
	 32,
	 false,
	 0,
	 complain_overflow_bitfield,
	 bfd_elf_generic_reloc,
	 "R_MN10300_32",
	 false,
	 0xffffffff,
	 0xffffffff,
	 false),
  /* Standard 16 bit reloc.  */
  HOWTO (R_MN10300_16,
	 0,
	 1,
	 16,
	 false,
	 0,
	 complain_overflow_bitfield,
	 bfd_elf_generic_reloc,
	 "R_MN10300_16",
	 false,
	 0xffff,
	 0xffff,
	 false),
  /* Standard 8 bit reloc.  */
  HOWTO (R_MN10300_8,
	 0,
	 0,
	 8,
	 false,
	 0,
	 complain_overflow_bitfield,
	 bfd_elf_generic_reloc,
	 "R_MN10300_8",
	 false,
	 0xff,
	 0xff,
	 false),
  /* Standard 32 bit reloc, except it explicitly writes big-endian format.  */
  HOWTO (R_MN10300_32B,
	 0,
	 2,
	 32,
	 false,
	 0,
	 complain_overflow_bitfield,
	 bfd_elf32_mn10300_reloc,
	 "R_MN10300_32B",
	 false,
	 0xffffffff,
	 0xffffffff,
	 false),
  /* Standard 16 bit reloc, except it explicitly writes big-endian format.  */
  HOWTO (R_MN10300_16B,
	 0,
	 1,
	 16,
	 false,
	 0,
	 complain_overflow_bitfield,
	 bfd_elf32_mn10300_reloc,
	 "R_MN10300_16B",
	 false,
	 0xffff,
	 0xffff,
	 false),
  /* Simple 32bit pc-relative reloc with a 1 byte adjustment
     to get the pc-relative offset correct.  */
  HOWTO (R_MN10300_PCREL32_1BYTE,
	 0,
	 2,
	 32,
	 true,
	 0,
	 complain_overflow_bitfield,
	 bfd_elf32_mn10300_reloc,
	 "R_MN10300_PCREL32_1BYTE",
	 true,
	 0xffffffff,
	 0xffffffff,
	 false),
  /* Simple 16bit pc-relative reloc with a 1 byte adjustment
     to get the pc-relative offset correct.  */
  HOWTO (R_MN10300_PCREL16_1BYTE,
	 0,
	 1,
	 16,
	 true,
	 0,
	 complain_overflow_bitfield,
	 bfd_elf32_mn10300_reloc,
	 "R_MN10300_PCREL16_1BYTE",
	 true,
	 0xffff,
	 0xffff,
	 false),
  /* Simple 8 pc-relative reloc with a 1 byte adjustment
     to get the pc-relative offset correct.  */
  HOWTO (R_MN10300_PCREL8_1BYTE,
	 0,
	 0,
	 8,
	 true,
	 0,
	 complain_overflow_bitfield,
	 bfd_elf32_mn10300_reloc,
	 "R_MN10300_PCREL8_1BYTE",
	 true,
	 0xff,
	 0xff,
	 true),
  /* Simple 32 pc-relative reloc with a 2 byte adjustment
     to get the pc-relative offset correct.  */
  HOWTO (R_MN10300_PCREL32_2BYTE,
	 0,
	 2,
	 32,
	 true,
	 0,
	 complain_overflow_bitfield,
	 bfd_elf32_mn10300_reloc,
	 "R_MN10300_PCREL32_2BYTE",
	 true,
	 0xffffffff,
	 0xffffffff,
	 true),
  /* Simple 16 pc-relative reloc with a 2 byte adjustment
     to get the pc-relative offset correct.  */
  HOWTO (R_MN10300_PCREL16_2BYTE,
	 0,
	 1,
	 16,
	 true,
	 0,
	 complain_overflow_bitfield,
	 bfd_elf32_mn10300_reloc,
	 "R_MN10300_PCREL16_2BYTE",
	 true,
	 0xffff,
	 0xffff,
	 true),
};

struct mn10300_reloc_map
{
  unsigned char bfd_reloc_val;
  unsigned char elf_reloc_val;
};

static const struct mn10300_reloc_map mn10300_reloc_map[] =
{
  { BFD_RELOC_NONE, R_MN10300_NONE, },
  { BFD_RELOC_32, R_MN10300_32, },
  { BFD_RELOC_16, R_MN10300_16, },
  { BFD_RELOC_8, R_MN10300_8, },
  { BFD_RELOC_MN10300_32B, R_MN10300_32B, },
  { BFD_RELOC_MN10300_16B, R_MN10300_16B, },
  { BFD_RELOC_32_PCREL, R_MN10300_PCREL32_1BYTE, },
  { BFD_RELOC_16_PCREL, R_MN10300_PCREL16_1BYTE, },
  { BFD_RELOC_8_PCREL, R_MN10300_PCREL8_1BYTE, },
  { BFD_RELOC_MN10300_32_PCREL, R_MN10300_PCREL32_2BYTE, },
  { BFD_RELOC_MN10300_16_PCREL, R_MN10300_PCREL16_2BYTE, },
};

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

  for (i = 0;
       i < sizeof (mn10300_reloc_map) / sizeof (struct mn10300_reloc_map);
       i++)
    {
      if (mn10300_reloc_map[i].bfd_reloc_val == code)
	return &elf_mn10300_howto_table[mn10300_reloc_map[i].elf_reloc_val];
    }

  return NULL;
}

/* Set the howto pointer for an MN10300 ELF reloc.  */

static void
mn10300_info_to_howto (abfd, cache_ptr, dst)
     bfd *abfd;
     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_MN10300_MAX);
  cache_ptr->howto = &elf_mn10300_howto_table[r_type];
}

static bfd_reloc_status_type
bfd_elf32_mn10300_reloc (abfd, reloc, symbol, data, isection, obfd, err)
     bfd *abfd;
     arelent *reloc;
     asymbol *symbol;
     PTR data;
     asection *isection;
     bfd *obfd;
     char **err;
{
  if (obfd != (bfd *) NULL
      && (symbol->flags & BSF_SECTION_SYM) == 0
      && (! reloc->howto->partial_inplace
	  || reloc->addend == 0))
    {
      reloc->address += isection->output_offset;
      return bfd_reloc_ok;
    }
  else if (obfd != NULL)
    {
      return bfd_reloc_continue;
    }

  /* Catch relocs involving undefined symbols.  */
  if (bfd_is_und_section (symbol->section)
      && (symbol->flags & BSF_WEAK) == 0
      && obfd == NULL)
    return bfd_reloc_undefined;

  /* We handle final linking of some relocs ourselves.  */
    {
      long relocation;

      /* Is the address of the relocation really within the section?  */
      if (reloc->address > isection->_cooked_size)
	return bfd_reloc_outofrange;

      /* Work out which section the relocation is targetted at and the
	 initial relocation command value.  */

      /* Get symbol value.  (Common symbols are special.)  */
      if (bfd_is_com_section (symbol->section))
	relocation = 0;
      else
	relocation = symbol->value;

      /* Convert input-section-relative symbol value to absolute + addend.  */
      relocation += symbol->section->output_section->vma;
      relocation += symbol->section->output_offset;
      relocation += reloc->addend;

      if (reloc->howto->pc_relative == true)
	{
	  /* Here the variable relocation holds the final address of the
	     symbol we are relocating against, plus any addend.  */
	  relocation -= isection->output_section->vma + isection->output_offset;

	  /* Deal with pcrel_offset */
	  relocation -= reloc->address;

	  if (reloc->howto->type == R_MN10300_PCREL32_1BYTE
	      || reloc->howto->type == R_MN10300_PCREL16_1BYTE
	      || reloc->howto->type == R_MN10300_PCREL8_1BYTE)
            relocation += 1;
	  else if (reloc->howto->type == R_MN10300_PCREL32_2BYTE
	      || reloc->howto->type == R_MN10300_PCREL16_2BYTE)
            relocation += 2;
	}

      /* I've got no clue... */
      reloc->addend = 0;	

      if (reloc->howto->size == 0)
	{
	  if (relocation > 0x7f || relocation < -0x80)
	    return bfd_reloc_overflow;

	  bfd_put_8 (abfd, relocation & 0xff,
		     (bfd_byte *)data + reloc->address);
	}
      else if (reloc->howto->size == 1)
	{
	  if (relocation > 0x7fff || relocation < -0x8000)
	    return bfd_reloc_overflow;

	  bfd_putb16 (relocation & 0xffff, (bfd_byte *)data + reloc->address);
 	}
      else if (reloc->howto->size == 2)
	bfd_putb32 (relocation, (bfd_byte *)data + reloc->address);
      return bfd_reloc_ok;
    }

  return bfd_reloc_continue;
}

#define TARGET_LITTLE_SYM	bfd_elf32_mn10300_vec
#define TARGET_LITTLE_NAME	"elf32-mn10300"
#define ELF_ARCH		bfd_arch_mn10300
#define ELF_MACHINE_CODE	EM_CYGNUS_MN10300
#define ELF_MAXPAGESIZE		0x1000

#define elf_info_to_howto	mn10300_info_to_howto
#define elf_info_to_howto_rel	0

#define elf_symbol_leading_char '_'

#include "elf32-target.h"