xref: /src/external/gpl3/binutils/dist/bfd/elf32-arc.c

/* ARC-specific support for 32-bit ELF
   Copyright 1994, 1995, 1997, 1999, 2001, 2002, 2005, 2007
   Free Software Foundation, Inc.
   Contributed by Doug Evans (dje (at) cygnus.com).

   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 3 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., 51 Franklin Street - Fifth Floor, Boston,
   MA 02110-1301, USA.  */

#include "sysdep.h"
#include "bfd.h"
#include "libbfd.h"
#include "elf-bfd.h"
#include "elf/arc.h"
#include "libiberty.h"

/* Try to minimize the amount of space occupied by relocation tables
   on the ROM (not that the ROM won't be swamped by other ELF overhead).  */

#define USE_REL	1

static bfd_reloc_status_type
arc_elf_b22_pcrel (bfd * abfd,
		   arelent * reloc_entry,
		   asymbol * symbol,
		   void * data,
		   asection * input_section,
		   bfd * output_bfd,
		   char ** error_message)
{
  /* If linking, back up the final symbol address by the address of the
     reloc.  This cannot be accomplished by setting the pcrel_offset
     field to TRUE, as bfd_install_relocation will detect this and refuse
     to install the offset in the first place, but bfd_perform_relocation
     will still insist on removing it.  */
  if (output_bfd == NULL)
    reloc_entry->addend -= reloc_entry->address;

  /* Fall through to the default elf reloc handler.  */
  return bfd_elf_generic_reloc (abfd, reloc_entry, symbol, data,
				input_section, output_bfd, error_message);
}

static reloc_howto_type elf_arc_howto_table[] =
{
  /* This reloc does nothing.  */
  HOWTO (R_ARC_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_ARC_NONE",		/* Name.  */
	 TRUE,			/* Partial_inplace.  */
	 0,			/* Src_mask.  */
	 0,			/* Dst_mask.  */
	 FALSE),		/* PCrel_offset.  */

  /* A standard 32 bit relocation.  */
  HOWTO (R_ARC_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_ARC_32",		/* Name.  */
	 TRUE,			/* Partial_inplace.  */
	 0xffffffff,		/* Src_mask.  */
	 0xffffffff,		/* Dst_mask.  */
	 FALSE),		/* PCrel_offset.  */

  /* A 26 bit absolute branch, right shifted by 2.  */
  HOWTO (R_ARC_B26,		/* Type.  */
	 2,			/* Rightshift.  */
	 2,			/* Size (0 = byte, 1 = short, 2 = long).  */
	 26,			/* Bitsize.  */
	 FALSE,			/* PC_relative.  */
	 0,			/* Bitpos.  */
	 complain_overflow_bitfield, /* Complain_on_overflow.  */
	 bfd_elf_generic_reloc,	/* Special_function.  */
	 "R_ARC_B26",		/* Name.  */
	 TRUE,			/* Partial_inplace.  */
	 0x00ffffff,		/* Src_mask.  */
	 0x00ffffff,		/* Dst_mask.  */
	 FALSE),		/* PCrel_offset.  */

  /* A relative 22 bit branch; bits 21-2 are stored in bits 26-7.  */
  HOWTO (R_ARC_B22_PCREL,	/* Type.  */
	 2,			/* Rightshift.  */
	 2,			/* Size (0 = byte, 1 = short, 2 = long).  */
	 22,			/* Bitsize.  */
	 TRUE,			/* PC_relative.  */
	 7,			/* Bitpos.  */
	 complain_overflow_signed, /* Complain_on_overflow.  */
	 arc_elf_b22_pcrel,	/* Special_function.  */
	 "R_ARC_B22_PCREL",	/* Name.  */
	 TRUE,			/* Partial_inplace.  */
	 0x07ffff80,		/* Src_mask.  */
	 0x07ffff80,		/* Dst_mask.  */
	 FALSE),		/* PCrel_offset.  */
};

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

struct arc_reloc_map
{
  bfd_reloc_code_real_type bfd_reloc_val;
  unsigned char elf_reloc_val;
};

static const struct arc_reloc_map arc_reloc_map[] =
{
  { BFD_RELOC_NONE, R_ARC_NONE, },
  { BFD_RELOC_32, R_ARC_32 },
  { BFD_RELOC_CTOR, R_ARC_32 },
  { BFD_RELOC_ARC_B26, R_ARC_B26 },
  { BFD_RELOC_ARC_B22_PCREL, R_ARC_B22_PCREL },
};

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

  for (i = ARRAY_SIZE (arc_reloc_map); i--;)
    if (arc_reloc_map[i].bfd_reloc_val == code)
      return elf_arc_howto_table + arc_reloc_map[i].elf_reloc_val;

  return NULL;
}

static reloc_howto_type *
bfd_elf32_bfd_reloc_name_lookup (bfd *abfd ATTRIBUTE_UNUSED,
				 const char *r_name)
{
  unsigned int i;

  for (i = 0;
       i < sizeof (elf_arc_howto_table) / sizeof (elf_arc_howto_table[0]);
       i++)
    if (elf_arc_howto_table[i].name != NULL
	&& strcasecmp (elf_arc_howto_table[i].name, r_name) == 0)
      return &elf_arc_howto_table[i];

  return NULL;
}

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

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

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

/* Set the right machine number for an ARC ELF file.  */

static bfd_boolean
arc_elf_object_p (bfd *abfd)
{
  unsigned int mach = bfd_mach_arc_6;

  if (elf_elfheader(abfd)->e_machine == EM_ARC)
    {
      unsigned long arch = elf_elfheader (abfd)->e_flags & EF_ARC_MACH;

      switch (arch)
	{
	case E_ARC_MACH_ARC5:
	  mach = bfd_mach_arc_5;
	  break;
	default:
	case E_ARC_MACH_ARC6:
	  mach = bfd_mach_arc_6;
	  break;
	case E_ARC_MACH_ARC7:
	  mach = bfd_mach_arc_7;
	  break;
	case E_ARC_MACH_ARC8:
	  mach = bfd_mach_arc_8;
	  break;
	}
    }
  return bfd_default_set_arch_mach (abfd, bfd_arch_arc, mach);
}

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

static void
arc_elf_final_write_processing (bfd *abfd,
				bfd_boolean linker ATTRIBUTE_UNUSED)
{
  unsigned long val;

  switch (bfd_get_mach (abfd))
    {
    case bfd_mach_arc_5:
      val = E_ARC_MACH_ARC5;
      break;
    default:
    case bfd_mach_arc_6:
      val = E_ARC_MACH_ARC6;
      break;
    case bfd_mach_arc_7:
      val = E_ARC_MACH_ARC7;
      break;
    case bfd_mach_arc_8:
      val = E_ARC_MACH_ARC8;
      break;
    }
  elf_elfheader (abfd)->e_flags &=~ EF_ARC_MACH;
  elf_elfheader (abfd)->e_flags |= val;
}

#define TARGET_LITTLE_SYM   bfd_elf32_littlearc_vec
#define TARGET_LITTLE_NAME  "elf32-littlearc"
#define TARGET_BIG_SYM      bfd_elf32_bigarc_vec
#define TARGET_BIG_NAME	    "elf32-bigarc"
#define ELF_ARCH            bfd_arch_arc
#define ELF_MACHINE_CODE    EM_ARC
#define ELF_MAXPAGESIZE     0x1000

#define elf_info_to_howto                   0
#define elf_info_to_howto_rel               arc_info_to_howto_rel
#define elf_backend_object_p                arc_elf_object_p
#define elf_backend_final_write_processing  arc_elf_final_write_processing

#include "elf32-target.h"