bfd/aout-arm.c

/* BFD back-end for raw ARM a.out binaries.
   Copyright (C) 1994-2016 Free Software Foundation, Inc.
   Contributed by Richard Earnshaw (rwe@pegasus.esprit.ec.org)

   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"

/* Avoid multiple definitions from aoutx if supporting standard a.out
   as well as our own.  */
/* Do not "beautify" the CONCAT* macro args.  Traditional C will not
   remove whitespace added here, and thus will fail to concatenate
   the tokens.  */
#define NAME(x,y) CONCAT3 (aoutarm,_32_,y)

#define N_TXTADDR(x)						\
  ((N_MAGIC (x) == NMAGIC)					\
   ? (bfd_vma) 0x8000						\
   : ((N_MAGIC (x) != ZMAGIC)					\
      ? (bfd_vma) 0						\
      : ((N_SHARED_LIB (x))					\
	 ? ((x)->a_entry & ~(bfd_vma) (TARGET_PAGE_SIZE - 1))	\
	 : (bfd_vma) TEXT_START_ADDR)))

#define TEXT_START_ADDR 0x8000
#define TARGET_PAGE_SIZE 0x8000
#define SEGMENT_SIZE TARGET_PAGE_SIZE
#define DEFAULT_ARCH bfd_arch_arm

#define MY(OP) CONCAT2 (arm_aout_,OP)
#define N_BADMAG(x) ((((x)->a_info & ~007200) != ZMAGIC) && \
                     (((x)->a_info & ~006000) != OMAGIC) && \
                     ((x)->a_info != NMAGIC))
#define N_MAGIC(x) ((x)->a_info & ~07200)

#define MY_bfd_reloc_type_lookup arm_aout_bfd_reloc_type_lookup
#define MY_bfd_reloc_name_lookup arm_aout_bfd_reloc_name_lookup

#include "libaout.h"
#include "aout/aout64.h"


static bfd_reloc_status_type
  MY (fix_pcrel_26) (bfd *, arelent *, asymbol *, void *, asection *, bfd *, char **);
static bfd_reloc_status_type
  MY (fix_pcrel_26_done) (bfd *, arelent *, asymbol *, void *, asection *, bfd *, char **);

reloc_howto_type MY (howto_table)[] =
{
  /* Type rs size bsz pcrel bitpos ovrf sf name part_inpl
     readmask setmask pcdone.  */
  HOWTO (0, 0, 0, 8, FALSE, 0, complain_overflow_bitfield, 0, "8", TRUE,
	 0x000000ff, 0x000000ff, FALSE),
  HOWTO (1, 0, 1, 16, FALSE, 0, complain_overflow_bitfield, 0, "16", TRUE,
	 0x0000ffff, 0x0000ffff, FALSE),
  HOWTO (2, 0, 2, 32, FALSE, 0, complain_overflow_bitfield, 0, "32", TRUE,
	 0xffffffff, 0xffffffff, FALSE),
  HOWTO (3, 2, 2, 26, TRUE, 0, complain_overflow_signed, MY (fix_pcrel_26),
	 "ARM26", TRUE, 0x00ffffff, 0x00ffffff, TRUE),
  HOWTO (4, 0, 0, 8, TRUE, 0, complain_overflow_signed, 0, "DISP8", TRUE,
	 0x000000ff, 0x000000ff, TRUE),
  HOWTO (5, 0, 1, 16, TRUE, 0, complain_overflow_signed, 0, "DISP16", TRUE,
	 0x0000ffff, 0x0000ffff, TRUE),
  HOWTO (6, 0, 2, 32, TRUE, 0, complain_overflow_signed, 0, "DISP32", TRUE,
	 0xffffffff, 0xffffffff, TRUE),
  HOWTO (7, 2, 2, 26, FALSE, 0, complain_overflow_signed,
	 MY (fix_pcrel_26_done), "ARM26D", TRUE, 0x0, 0x0,
	 FALSE),
  EMPTY_HOWTO (-1),
  HOWTO (9, 0, -1, 16, FALSE, 0, complain_overflow_bitfield, 0, "NEG16", TRUE,
	 0x0000ffff, 0x0000ffff, FALSE),
  HOWTO (10, 0, -2, 32, FALSE, 0, complain_overflow_bitfield, 0, "NEG32", TRUE,
	 0xffffffff, 0xffffffff, FALSE)
};

#define RELOC_ARM_BITS_NEG_BIG      ((unsigned int) 0x08)
#define RELOC_ARM_BITS_NEG_LITTLE   ((unsigned int) 0x10)

static reloc_howto_type *
MY (reloc_howto) (bfd *abfd,
		  struct reloc_std_external *rel,
		  int *r_index,
		  int *r_extern,
		  int *r_pcrel)
{
  unsigned int r_length;
  unsigned int r_pcrel_done;
  unsigned int r_neg;
  int howto_index;

  *r_pcrel = 0;
  if (bfd_header_big_endian (abfd))
    {
      *r_index     =  ((rel->r_index[0] << 16)
		       | (rel->r_index[1] << 8)
		       | rel->r_index[2]);
      *r_extern    = (0 != (rel->r_type[0] & RELOC_STD_BITS_EXTERN_BIG));
      r_pcrel_done = (0 != (rel->r_type[0] & RELOC_STD_BITS_PCREL_BIG));
      r_neg 	   = (0 != (rel->r_type[0] & RELOC_ARM_BITS_NEG_BIG));
      r_length     = ((rel->r_type[0] & RELOC_STD_BITS_LENGTH_BIG)
		      >> RELOC_STD_BITS_LENGTH_SH_BIG);
    }
  else
    {
      *r_index     = ((rel->r_index[2] << 16)
		      | (rel->r_index[1] << 8)
		      | rel->r_index[0]);
      *r_extern    = (0 != (rel->r_type[0] & RELOC_STD_BITS_EXTERN_LITTLE));
      r_pcrel_done = (0 != (rel->r_type[0] & RELOC_STD_BITS_PCREL_LITTLE));
      r_neg 	   = (0 != (rel->r_type[0] & RELOC_ARM_BITS_NEG_LITTLE));
      r_length     = ((rel->r_type[0] & RELOC_STD_BITS_LENGTH_LITTLE)
		      >> RELOC_STD_BITS_LENGTH_SH_LITTLE);
    }
  howto_index = r_length + 4 * r_pcrel_done + 8 * r_neg;
  if (howto_index == 3)
    *r_pcrel = 1;

  return MY (howto_table) + howto_index;
}

#define MY_reloc_howto(BFD, REL, IN, EX, PC) \
	MY (reloc_howto) (BFD, REL, &IN, &EX, &PC)

static void
MY (put_reloc) (bfd *abfd,
		int r_extern,
		int r_index,
		bfd_vma value,
		reloc_howto_type *howto,
		struct reloc_std_external *reloc)
{
  unsigned int r_length;
  int r_pcrel;
  int r_neg;

  PUT_WORD (abfd, value, reloc->r_address);
  /* Size as a power of two.  */
  r_length = howto->size;

  /* Special case for branch relocations.  */
  if (howto->type == 3 || howto->type == 7)
    r_length = 3;

  r_pcrel  = howto->type & 4; 	/* PC Relative done?  */
  r_neg = howto->type & 8;	/* Negative relocation.  */

  if (bfd_header_big_endian (abfd))
    {
      reloc->r_index[0] = r_index >> 16;
      reloc->r_index[1] = r_index >> 8;
      reloc->r_index[2] = r_index;
      reloc->r_type[0] =
	((r_extern ?     RELOC_STD_BITS_EXTERN_BIG : 0)
	 | (r_pcrel ?    RELOC_STD_BITS_PCREL_BIG : 0)
	 | (r_neg ?	 RELOC_ARM_BITS_NEG_BIG : 0)
	 | (r_length <<  RELOC_STD_BITS_LENGTH_SH_BIG));
    }
  else
    {
      reloc->r_index[2] = r_index >> 16;
      reloc->r_index[1] = r_index >> 8;
      reloc->r_index[0] = r_index;
      reloc->r_type[0] =
	((r_extern ?     RELOC_STD_BITS_EXTERN_LITTLE : 0)
	 | (r_pcrel ?    RELOC_STD_BITS_PCREL_LITTLE : 0)
	 | (r_neg ?	 RELOC_ARM_BITS_NEG_LITTLE : 0)
	 | (r_length <<  RELOC_STD_BITS_LENGTH_SH_LITTLE));
    }
}

#define MY_put_reloc(BFD, EXT, IDX, VAL, HOWTO, RELOC) \
  MY (put_reloc) (BFD, EXT, IDX, VAL, HOWTO, RELOC)

static void
MY (relocatable_reloc) (reloc_howto_type *howto,
			bfd *abfd,
			struct reloc_std_external *reloc,
			bfd_vma *amount,
			bfd_vma r_addr)
{
  if (howto->type == 3)
    {
      if (reloc->r_type[0]
	  & (bfd_header_big_endian (abfd)
	     ? RELOC_STD_BITS_EXTERN_BIG : RELOC_STD_BITS_EXTERN_LITTLE))
	/* The reloc is still external, so don't modify anything.  */
	*amount = 0;
      else
	{
	  *amount -= r_addr;
	  /* Change the r_pcrel value -- on the ARM, this bit is set once the
	     relocation is done.  */
	  if (bfd_header_big_endian (abfd))
	    reloc->r_type[0] |= RELOC_STD_BITS_PCREL_BIG;
	  else
	    reloc->r_type[0] |= RELOC_STD_BITS_PCREL_LITTLE;
	}
    }
  else if (howto->type == 7)
    *amount = 0;
}

#define MY_relocatable_reloc(HOW, BFD, REL, AMOUNT, ADDR) \
  MY (relocatable_reloc) (HOW, BFD, REL, &(AMOUNT), ADDR)

static bfd_reloc_status_type
MY (fix_pcrel_26_done) (bfd *abfd ATTRIBUTE_UNUSED,
			arelent *reloc_entry ATTRIBUTE_UNUSED,
			asymbol *symbol ATTRIBUTE_UNUSED,
			void * data ATTRIBUTE_UNUSED,
			asection *input_section ATTRIBUTE_UNUSED,
			bfd *output_bfd ATTRIBUTE_UNUSED,
			char **error_message ATTRIBUTE_UNUSED)
{
  /* This is dead simple at present.  */
  return bfd_reloc_ok;
}

static bfd_reloc_status_type
MY (fix_pcrel_26) (bfd *abfd,
		   arelent *reloc_entry,
		   asymbol *symbol,
		   void * data,
		   asection *input_section,
		   bfd *output_bfd,
		   char **error_message ATTRIBUTE_UNUSED)
{
  bfd_vma relocation;
  bfd_size_type addr = reloc_entry->address;
  bfd_vma target = bfd_get_32 (abfd, (bfd_byte *) data + addr);
  bfd_reloc_status_type flag = bfd_reloc_ok;

  /* If this is an undefined symbol, return error.  */
  if (bfd_is_und_section (symbol->section)
      && (symbol->flags & BSF_WEAK) == 0)
    return output_bfd ? bfd_reloc_ok : bfd_reloc_undefined;

  /* If the sections are different, and we are doing a partial relocation,
     just ignore it for now.  */
  if (symbol->section->name != input_section->name
      && output_bfd != NULL)
    return bfd_reloc_ok;

  relocation = (target & 0x00ffffff) << 2;
  relocation = (relocation ^ 0x02000000) - 0x02000000; /* Sign extend.  */
  relocation += symbol->value;
  relocation += symbol->section->output_section->vma;
  relocation += symbol->section->output_offset;
  relocation += reloc_entry->addend;
  relocation -= input_section->output_section->vma;
  relocation -= input_section->output_offset;
  relocation -= addr;
  if (relocation & 3)
    return bfd_reloc_overflow;

  /* Check for overflow.  */
  if (relocation & 0x02000000)
    {
      if ((relocation & ~ (bfd_vma) 0x03ffffff) != ~ (bfd_vma) 0x03ffffff)
	flag = bfd_reloc_overflow;
    }
  else if (relocation & ~ (bfd_vma) 0x03ffffff)
    flag = bfd_reloc_overflow;

  target &= ~ (bfd_vma) 0x00ffffff;
  target |= (relocation >> 2) & 0x00ffffff;
  bfd_put_32 (abfd, target, (bfd_byte *) data + addr);

  /* Now the ARM magic... Change the reloc type so that it is marked as done.
     Strictly this is only necessary if we are doing a partial relocation.  */
  reloc_entry->howto = &MY (howto_table)[7];

  return flag;
}

static reloc_howto_type *
MY (bfd_reloc_type_lookup) (bfd *abfd,
			    bfd_reloc_code_real_type code)
{
#define ASTD(i,j)       case i: return & MY (howto_table)[j]

  if (code == BFD_RELOC_CTOR)
    switch (bfd_arch_bits_per_address (abfd))
      {
      case 32:
        code = BFD_RELOC_32;
        break;
      default:
	return NULL;
      }

  switch (code)
    {
      ASTD (BFD_RELOC_16, 1);
      ASTD (BFD_RELOC_32, 2);
      ASTD (BFD_RELOC_ARM_PCREL_BRANCH, 3);
      ASTD (BFD_RELOC_8_PCREL, 4);
      ASTD (BFD_RELOC_16_PCREL, 5);
      ASTD (BFD_RELOC_32_PCREL, 6);
    default:
      return NULL;
    }
}

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

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

  return NULL;
}

#define MY_swap_std_reloc_in     MY (swap_std_reloc_in)
#define MY_swap_std_reloc_out    MY (swap_std_reloc_out)
#define MY_get_section_contents  _bfd_generic_get_section_contents

void MY_swap_std_reloc_in (bfd *, struct reloc_std_external *, arelent *, asymbol **, bfd_size_type);
void MY_swap_std_reloc_out (bfd *, arelent *, struct reloc_std_external *);

#include "aoutx.h"

void
MY_swap_std_reloc_in (bfd *abfd,
		      struct reloc_std_external *bytes,
		      arelent *cache_ptr,
		      asymbol **symbols,
		      bfd_size_type symcount ATTRIBUTE_UNUSED)
{
  int r_index;
  int r_extern;
  int r_pcrel;
  struct aoutdata *su = &(abfd->tdata.aout_data->a);

  cache_ptr->address = H_GET_32 (abfd, bytes->r_address);

  cache_ptr->howto = MY_reloc_howto (abfd, bytes, r_index, r_extern, r_pcrel);

  MOVE_ADDRESS (0);
}

void
MY_swap_std_reloc_out (bfd *abfd,
		       arelent *g,
		       struct reloc_std_external *natptr)
{
  int r_index;
  asymbol *sym = *(g->sym_ptr_ptr);
  int r_extern;
  int r_length;
  int r_pcrel;
  int r_neg = 0;	/* Negative relocs use the BASEREL bit.  */
  asection *output_section = sym->section->output_section;

  PUT_WORD (abfd, g->address, natptr->r_address);

  r_length = g->howto->size ;   /* Size as a power of two.  */
  if (r_length < 0)
    {
      r_length = -r_length;
      r_neg = 1;
    }

  r_pcrel  = (int) g->howto->pc_relative; /* Relative to PC?  */

  /* For RISC iX, in pc-relative relocs the r_pcrel bit means that the
     relocation has been done already (Only for the 26-bit one I think).  */
  if (g->howto->type == 3)
    {
      r_length = 3;
      r_pcrel = 0;
    }
  else if (g->howto->type == 7)
    {
      r_length = 3;
      r_pcrel = 1;
    }

  /* Name was clobbered by aout_write_syms to be symbol index.  */

  /* If this relocation is relative to a symbol then set the
     r_index to the symbols index, and the r_extern bit.

     Absolute symbols can come in in two ways, either as an offset
     from the abs section, or as a symbol which has an abs value.
     check for that here.  */

  if (bfd_is_com_section (output_section)
      || bfd_is_abs_section (output_section)
      || bfd_is_und_section (output_section))
    {
      if (bfd_abs_section_ptr->symbol == sym)
	{
	  /* Whoops, looked like an abs symbol, but is really an offset
	     from the abs section.  */
	  r_index = 0;
	  r_extern = 0;
	}
      else
	{
	  /* Fill in symbol.  */
	  r_extern = 1;
	  r_index = (*(g->sym_ptr_ptr))->KEEPIT;
	}
    }
  else
    {
      /* Just an ordinary section.  */
      r_extern = 0;
      r_index  = output_section->target_index;
    }

  /* Now the fun stuff.  */
  if (bfd_header_big_endian (abfd))
    {
      natptr->r_index[0] = r_index >> 16;
      natptr->r_index[1] = r_index >> 8;
      natptr->r_index[2] = r_index;
      natptr->r_type[0] =
	(  (r_extern ?   RELOC_STD_BITS_EXTERN_BIG: 0)
	 | (r_pcrel  ?   RELOC_STD_BITS_PCREL_BIG: 0)
	 | (r_neg    ?   RELOC_ARM_BITS_NEG_BIG: 0)
	 | (r_length <<  RELOC_STD_BITS_LENGTH_SH_BIG));
    }
  else
    {
      natptr->r_index[2] = r_index >> 16;
      natptr->r_index[1] = r_index >> 8;
      natptr->r_index[0] = r_index;
      natptr->r_type[0] =
	(  (r_extern ?   RELOC_STD_BITS_EXTERN_LITTLE: 0)
	 | (r_pcrel  ?   RELOC_STD_BITS_PCREL_LITTLE: 0)
	 | (r_neg    ?   RELOC_ARM_BITS_NEG_LITTLE: 0)
	 | (r_length <<  RELOC_STD_BITS_LENGTH_SH_LITTLE));
    }
}

#define MY_BFD_TARGET

#include "aout-target.h"

extern const bfd_target arm_aout_be_vec;

const bfd_target arm_aout_le_vec =
{
  "a.out-arm-little",           /* Name.  */
  bfd_target_aout_flavour,
  BFD_ENDIAN_LITTLE,            /* Target byte order (little).  */
  BFD_ENDIAN_LITTLE,            /* Target headers byte order (little).  */
  (HAS_RELOC | EXEC_P |         /* Object flags.  */
   HAS_LINENO | HAS_DEBUG |
   HAS_SYMS | HAS_LOCALS | DYNAMIC | WP_TEXT | D_PAGED),
  (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_RELOC | SEC_CODE | SEC_DATA),
  MY_symbol_leading_char,
  AR_PAD_CHAR,                  /* AR_pad_char.  */
  15,                           /* AR_max_namelen.  */
  0,				/* match priority.  */
  bfd_getl64, bfd_getl_signed_64, bfd_putl64,
  bfd_getl32, bfd_getl_signed_32, bfd_putl32,
  bfd_getl16, bfd_getl_signed_16, bfd_putl16,	/* Data.  */
  bfd_getl64, bfd_getl_signed_64, bfd_putl64,
  bfd_getl32, bfd_getl_signed_32, bfd_putl32,
  bfd_getl16, bfd_getl_signed_16, bfd_putl16,	/* Headers.  */
  {_bfd_dummy_target, MY_object_p,		/* bfd_check_format.  */
   bfd_generic_archive_p, MY_core_file_p},
  {bfd_false, MY_mkobject,			/* bfd_set_format.  */
   _bfd_generic_mkarchive, bfd_false},
  {bfd_false, MY_write_object_contents,		/* bfd_write_contents.  */
   _bfd_write_archive_contents, bfd_false},

  BFD_JUMP_TABLE_GENERIC (MY),
  BFD_JUMP_TABLE_COPY (MY),
  BFD_JUMP_TABLE_CORE (MY),
  BFD_JUMP_TABLE_ARCHIVE (MY),
  BFD_JUMP_TABLE_SYMBOLS (MY),
  BFD_JUMP_TABLE_RELOCS (MY),
  BFD_JUMP_TABLE_WRITE (MY),
  BFD_JUMP_TABLE_LINK (MY),
  BFD_JUMP_TABLE_DYNAMIC (MY),

  & arm_aout_be_vec,

  (void *) MY_backend_data,
};

const bfd_target arm_aout_be_vec =
{
  "a.out-arm-big",              /* Name.  */
  bfd_target_aout_flavour,
  BFD_ENDIAN_BIG,               /* Target byte order (big).  */
  BFD_ENDIAN_BIG,               /* Target headers byte order (big).  */
  (HAS_RELOC | EXEC_P |         /* Object flags.  */
   HAS_LINENO | HAS_DEBUG |
   HAS_SYMS | HAS_LOCALS | DYNAMIC | WP_TEXT | D_PAGED),
  (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_RELOC | SEC_CODE | SEC_DATA),
  MY_symbol_leading_char,
  AR_PAD_CHAR,			/* AR_pad_char.  */
  15,				/* AR_max_namelen.  */
  0,				/* match priority.  */
  bfd_getb64, bfd_getb_signed_64, bfd_putb64,
  bfd_getb32, bfd_getb_signed_32, bfd_putb32,
  bfd_getb16, bfd_getb_signed_16, bfd_putb16,	/* Data.  */
  bfd_getb64, bfd_getb_signed_64, bfd_putb64,
  bfd_getb32, bfd_getb_signed_32, bfd_putb32,
  bfd_getb16, bfd_getb_signed_16, bfd_putb16,	/* Headers.  */
  {_bfd_dummy_target, MY_object_p,		/* bfd_check_format.  */
   bfd_generic_archive_p, MY_core_file_p},
  {bfd_false, MY_mkobject,			/* bfd_set_format.  */
   _bfd_generic_mkarchive, bfd_false},
  {bfd_false, MY_write_object_contents,		/* bfd_write_contents.  */
   _bfd_write_archive_contents, bfd_false},

  BFD_JUMP_TABLE_GENERIC (MY),
  BFD_JUMP_TABLE_COPY (MY),
  BFD_JUMP_TABLE_CORE (MY),
  BFD_JUMP_TABLE_ARCHIVE (MY),
  BFD_JUMP_TABLE_SYMBOLS (MY),
  BFD_JUMP_TABLE_RELOCS (MY),
  BFD_JUMP_TABLE_WRITE (MY),
  BFD_JUMP_TABLE_LINK (MY),
  BFD_JUMP_TABLE_DYNAMIC (MY),

  & arm_aout_le_vec,

  (void *) MY_backend_data,
};