binutils-gdb/bfd/coff-arm.c

/* BFD back-end for Intel arm COFF files.
   Copyright 1990, 1991, 1992, 1993, 1994, 1995 Free Software Foundation, Inc.
   Written by Cygnus Support.

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 "obstack.h"

#include "coff/arm.h"

#include "coff/internal.h"

#ifdef COFF_WITH_PE
#include "coff/pe.h"
#endif

#include "libcoff.h"

static bfd_reloc_status_type
aoutarm_fix_pcrel_26_done PARAMS ((bfd *, arelent *, asymbol *, PTR,
				  asection *, bfd *, char **));

static bfd_reloc_status_type
aoutarm_fix_pcrel_26 PARAMS ((bfd *, arelent *, asymbol *, PTR,
			     asection *, bfd *, char **));


static bfd_reloc_status_type coff_arm_reloc 
  PARAMS ((bfd *, arelent *, asymbol *, PTR, asection *, bfd *, char **));

static bfd_reloc_status_type
coff_arm_reloc (abfd, reloc_entry, symbol, data, input_section, output_bfd,
		 error_message)
     bfd *abfd;
     arelent *reloc_entry;
     asymbol *symbol;
     PTR data;
     asection *input_section;
     bfd *output_bfd;
     char **error_message;
{
  symvalue diff;

  if (output_bfd == (bfd *) NULL)
    return bfd_reloc_continue;

  if (bfd_is_com_section (symbol->section))
    {
      /* We are relocating a common symbol.  The current value in the
	 object file is ORIG + OFFSET, where ORIG is the value of the
	 common symbol as seen by the object file when it was compiled
	 (this may be zero if the symbol was undefined) and OFFSET is
	 the offset into the common symbol (normally zero, but may be
	 non-zero when referring to a field in a common structure).
	 ORIG is the negative of reloc_entry->addend, which is set by
	 the CALC_ADDEND macro below.  We want to replace the value in
	 the object file with NEW + OFFSET, where NEW is the value of
	 the common symbol which we are going to put in the final
	 object file.  NEW is symbol->value.  */
      diff = symbol->value + reloc_entry->addend;
    }
  else
    {
      /* For some reason bfd_perform_relocation always effectively
	 ignores the addend for a COFF target when producing
	 relocateable output.  This seems to be always wrong for 386
	 COFF, so we handle the addend here instead.  */
      diff = reloc_entry->addend;
    }

#define DOIT(x) \
  x = ((x & ~howto->dst_mask) | (((x & howto->src_mask) + diff) & howto->dst_mask))

  if (diff != 0)
    {
      reloc_howto_type *howto = reloc_entry->howto;
      unsigned char *addr = (unsigned char *) data + reloc_entry->address;

      switch (howto->size)
	{
	case 0:
	  {
	    char x = bfd_get_8 (abfd, addr);
	    DOIT (x);
	    bfd_put_8 (abfd, x, addr);
	  }
	  break;

	case 1:
	  {
	    short x = bfd_get_16 (abfd, addr);
	    DOIT (x);
	    bfd_put_16 (abfd, x, addr);
	  }
	  break;

	case 2:
	  {
	    long x = bfd_get_32 (abfd, addr);
	    DOIT (x);
	    bfd_put_32 (abfd, x, addr);
	  }
	  break;

	default:
	  abort ();
	}
    }

  /* Now let bfd_perform_relocation finish everything up.  */
  return bfd_reloc_continue;
}

static reloc_howto_type aoutarm_std_reloc_howto[] = 
{
  /* type              rs size bsz  pcrel bitpos ovrf                     sf name     part_inpl readmask  setmask    pcdone */
  HOWTO(0,			/* type */
	0,			/* rs */
	0,			/* size */
	8,			/* bsz */
	false,			/* pcrel */
	0,			/* bitpos */
	complain_overflow_bitfield, /* ovf */
	coff_arm_reloc,		/* sf */
	"8",			/*name */
        true,			/* partial */
	0x000000ff,		/*read mask */
	0x000000ff,		/* setmask */
	PCRELOFFSET		/* pcdone */),
  HOWTO(1,  
	0, 
	1, 
	16, 
	false,
	0,
	complain_overflow_bitfield,
	coff_arm_reloc,
	"16", 
	true,
	0x0000ffff,
	0x0000ffff, 
	PCRELOFFSET),
  HOWTO( 2, 
	0,
	2, 
	32,
	false,
	0,
	complain_overflow_bitfield,
	coff_arm_reloc,
	"32",
        true,
	0xffffffff,
	0xffffffff,
	PCRELOFFSET),
  HOWTO( 3,
	2,
	3, 
	26,
	true,
	0,
	complain_overflow_signed,
	aoutarm_fix_pcrel_26 ,
	"ARM26",
	true, 
	0x00ffffff,
	0x00ffffff, 
	PCRELOFFSET),
  HOWTO( 4,        
	0,
	0,
	8, 
	true,
	0,
	complain_overflow_signed, 
	coff_arm_reloc,
	"DISP8",  
	true,
	0x000000ff,
	0x000000ff,
	true),
  HOWTO( 5, 
	0,
	1,
	16,
	true,
	0,
	complain_overflow_signed, 
	coff_arm_reloc,
	"DISP16",
	true,
	0x0000ffff,
	0x0000ffff,
	true),
  HOWTO( 6,
	0,
	2,
	32,
	true,
	0,
	complain_overflow_signed, 
 	coff_arm_reloc,
	"DISP32",
	true,
	0xffffffff,
	0xffffffff,
	true),
  HOWTO( 7,  
	2, 
	3,   
	26,
	false,
	0,
	complain_overflow_signed,
	aoutarm_fix_pcrel_26_done, 
	"ARM26D",
	true,
	0x00ffffff,
	0x00ffffff, 
	false),
  {-1},
  HOWTO( 9,
	0,
	-1,
	16,
	false,
	0, 
	complain_overflow_bitfield,
	coff_arm_reloc,
	"NEG16",
        true, 
	0x0000ffff,
	0x0000ffff, 
	false),
  HOWTO( 10, 
	0, 
	-2,
	32,
	false,
	0,
	complain_overflow_bitfield,
	coff_arm_reloc,
	"NEG32",
        true,
	0xffffffff,
	0xffffffff,
	false)
};



#define RTYPE2HOWTO(cache_ptr, dst) \
	    (cache_ptr)->howto = aoutarm_std_reloc_howto + (dst)->r_type;

static bfd_reloc_status_type
aoutarm_fix_pcrel_26_done (abfd, reloc_entry, symbol, data, input_section,
			  output_bfd, error_message)
     bfd *abfd;
     arelent *reloc_entry;
     asymbol *symbol;
     PTR data;
     asection *input_section;
     bfd *output_bfd;
     char **error_message;
{
  /* This is dead simple at present.  */
  return bfd_reloc_ok;
}

static bfd_reloc_status_type
aoutarm_fix_pcrel_26 (abfd, reloc_entry, symbol, data, input_section,
		     output_bfd, error_message)
     bfd *abfd;
     arelent *reloc_entry;
     asymbol *symbol;
     PTR data;
     asection *input_section;
     bfd *output_bfd;
     char **error_message;
{
  bfd_vma relocation;
  bfd_size_type addr = reloc_entry->address;
  long 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 (symbol->section == &bfd_und_section
      && (symbol->flags & BSF_WEAK) == 0)
    return output_bfd ? bfd_reloc_continue : 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 != (bfd *)NULL)
    return bfd_reloc_continue;

  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 & ~0x03ffffff) != ~0x03ffffff)
	flag = bfd_reloc_overflow;
    }
  else if (relocation & ~0x03ffffff)
    flag = bfd_reloc_overflow;

  target &= ~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 = &aoutarm_std_reloc_howto[7];
  
  return flag;
}

static CONST struct reloc_howto_struct *
arm_reloc_type_lookup(abfd,code)
      bfd *abfd;
      bfd_reloc_code_real_type code;
{
#define ASTD(i,j)       case i: return &aoutarm_std_reloc_howto[j]
  if (code == BFD_RELOC_CTOR)
    switch (bfd_get_arch_info (abfd)->bits_per_address)
      {
      case 32:
        code = BFD_RELOC_32;
        break;
      default: return (CONST struct reloc_howto_struct *) 0;
      }

  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 (CONST struct reloc_howto_struct *) 0;
    }
}


#define coff_bfd_reloc_type_lookup arm_reloc_type_lookup

#define COFF_DEFAULT_SECTION_ALIGNMENT_POWER (2)
/* The page size is a guess based on ELF.  */
#define COFF_PAGE_SIZE 0x1000

/* For some reason when using arm COFF the value stored in the .text
   section for a reference to a common symbol is the value itself plus
   any desired offset.  Ian Taylor, Cygnus Support.  */

/* If we are producing relocateable output, we need to do some
   adjustments to the object file that are not done by the
   bfd_perform_relocation function.  This function is called by every
   reloc type to make any required adjustments.  */

static bfd_reloc_status_type
aacoff_arm_reloc (abfd, reloc_entry, symbol, data, input_section, output_bfd,
		 error_message)
     bfd *abfd;
     arelent *reloc_entry;
     asymbol *symbol;
     PTR data;
     asection *input_section;
     bfd *output_bfd;
     char **error_message;
{
  symvalue diff;

  if (output_bfd == (bfd *) NULL)
    return bfd_reloc_continue;

  if (bfd_is_com_section (symbol->section))
    {
      /* We are relocating a common symbol.  The current value in the
	 object file is ORIG + OFFSET, where ORIG is the value of the
	 common symbol as seen by the object file when it was compiled
	 (this may be zero if the symbol was undefined) and OFFSET is
	 the offset into the common symbol (normally zero, but may be
	 non-zero when referring to a field in a common structure).
	 ORIG is the negative of reloc_entry->addend, which is set by
	 the CALC_ADDEND macro below.  We want to replace the value in
	 the object file with NEW + OFFSET, where NEW is the value of
	 the common symbol which we are going to put in the final
	 object file.  NEW is symbol->value.  */
      diff = symbol->value + reloc_entry->addend;
    }
  else
    {
      /* For some reason bfd_perform_relocation always effectively
	 ignores the addend for a COFF target when producing
	 relocateable output.  This seems to be always wrong for arm
	 COFF, so we handle the addend here instead.  */
      diff = reloc_entry->addend;
    }

#define DOIT(x) \
  x = ((x & ~howto->dst_mask) | (((x & howto->src_mask) + diff) & howto->dst_mask))

  if (diff != 0)
    {
      reloc_howto_type *howto = reloc_entry->howto;
      unsigned char *addr = (unsigned char *) data + reloc_entry->address;

      switch (howto->size)
	{
	case 0:
	  {
	    char x = bfd_get_8 (abfd, addr);
	    DOIT (x);
	    bfd_put_8 (abfd, x, addr);
	  }
	  break;

	case 1:
	  {
	    short x = bfd_get_16 (abfd, addr);
	    DOIT (x);
	    bfd_put_16 (abfd, x, addr);
	  }
	  break;

	case 2:
	  {
	    long x = bfd_get_32 (abfd, addr);
	    DOIT (x);
	    bfd_put_32 (abfd, x, addr);
	  }
	  break;

	default:
	  abort ();
	}
    }

  /* Now let bfd_perform_relocation finish everything up.  */
  return bfd_reloc_continue;
}





/* Turn a howto into a reloc  nunmber */

#define SELECT_RELOC(x,howto) { x.r_type = howto->type; }
#define BADMAG(x) ARMBADMAG(x)
#define ARM 1			/* Customize coffcode.h */


/* On SCO Unix 3.2.2 the native assembler generates two .data
   sections.  We handle that by renaming the second one to .data2.  It
   does no harm to do this for any arm COFF target.  */
#define TWO_DATA_SECS

/* For arm COFF a STYP_NOLOAD | STYP_BSS section is part of a shared
   library.  On some other COFF targets STYP_BSS is normally
   STYP_NOLOAD.  */
#define BSS_NOLOAD_IS_SHARED_LIBRARY


/* We use the special COFF backend linker.  */
#define coff_relocate_section _bfd_coff_generic_relocate_section



#include "coffcode.h"

static const bfd_target *
i3coff_object_p(a)
     bfd *a;
{
  return coff_object_p(a);
}

const bfd_target
#ifdef TARGET_SYM
  TARGET_SYM =
#else
  armcoff_vec =
#endif
{
#ifdef TARGET_NAME
  TARGET_NAME,
#else
  "coff-arm",			/* name */
#endif
  bfd_target_coff_flavour,
  false,			/* data byte order is little */
  false,			/* header byte order is little */

  (HAS_RELOC | EXEC_P |		/* object flags */
   HAS_LINENO | HAS_DEBUG |
   HAS_SYMS | HAS_LOCALS | WP_TEXT | D_PAGED),

  (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_RELOC), /* section flags */
#ifdef TARGET_UNDERSCORE
  TARGET_UNDERSCORE,		/* leading underscore */
#else
  0,				/* leading underscore */
#endif
  '/',				/* ar_pad_char */
  15,				/* ar_max_namelen */

  2,				/* minimum alignment power */
  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, /* hdrs */

/* Note that we allow an object file to be treated as a core file as well. */
    {_bfd_dummy_target, i3coff_object_p, /* bfd_check_format */
       bfd_generic_archive_p, i3coff_object_p},
    {bfd_false, coff_mkobject, _bfd_generic_mkarchive, /* bfd_set_format */
       bfd_false},
    {bfd_false, coff_write_object_contents, /* bfd_write_contents */
       _bfd_write_archive_contents, bfd_false},

     BFD_JUMP_TABLE_GENERIC (coff),
     BFD_JUMP_TABLE_COPY (coff),
     BFD_JUMP_TABLE_CORE (_bfd_nocore),
     BFD_JUMP_TABLE_ARCHIVE (_bfd_archive_coff),
     BFD_JUMP_TABLE_SYMBOLS (coff),
     BFD_JUMP_TABLE_RELOCS (coff),
     BFD_JUMP_TABLE_WRITE (coff),
     BFD_JUMP_TABLE_LINK (coff),
     BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic),

  COFF_SWAP_TABLE,
};