bout.c

早期freebsd实现

}

static int 
DEFUN(b_out_sizeof_headers,(ignore_abfd, ignore),
      bfd *ignore_abfd AND
      boolean ignore)
{
  return sizeof(struct internal_exec);
}



/************************************************************************/
static bfd_vma 
DEFUN(get_value,(reloc, seclet),
      arelent  *reloc AND
      bfd_seclet_type *seclet)
{
  bfd_vma value;
  asymbol *symbol = *(reloc->sym_ptr_ptr);

  /* A symbol holds a pointer to a section, and an offset from the
     base of the section.  To relocate, we find where the section will
     live in the output and add that in */

  if (symbol->section == &bfd_und_section)
  {
    /* Ouch, this is an undefined symbol.. */
    bfd_error_vector.undefined_symbol(reloc, seclet);
    value = symbol->value;
  }
  else 
  {
    value = symbol->value +
     symbol->section->output_offset +
      symbol->section->output_section->vma;
  }

  /* Add the value contained in the relocation */
  value += (short)((reloc->addend) & 0xffff);
  
  return value;
}

static void
DEFUN(perform_slip,(s, slip, input_section, value),
      asymbol **s AND
      unsigned int slip AND
      asection *input_section AND
      bfd_vma value)
{
  
  /* Find all symbols past this point, and make them know
     what's happened */
  while (*s) 
  {
    asymbol *p = *s;
    if (p->section == input_section) 
    {
      /* This was pointing into this section, so mangle it */
      if (p->value > value)
      {
	p->value -=slip;
      }
    }
    s++;
	
  }    
}
#if 1
/* This routine works out if the thing we want to get to can be
   reached with a 24bit offset instead of a 32 bit one.
   If it can, then it changes the amode */

static int 
DEFUN(abs32code,(input_section, symbols, r, shrink),
      asection *input_section AND
      asymbol **symbols AND
      arelent *r AND
      unsigned int shrink) 
{
  bfd_vma value = get_value(r,0);
  bfd_vma dot = input_section->output_section->vma +  input_section->output_offset + r->address;	
  bfd_vma gap;
  
  /* See if the address we're looking at within 2^23 bytes of where
     we are, if so then we can use a small branch rather than the
     jump we were going to */

  gap = value - (dot - shrink);
  

  if (-1<<23 < (long)gap && (long)gap < 1<<23 )
  { 
    /* Change the reloc type from 32bitcode possible 24, to 24bit
       possible 32 */

    r->howto = &howto_reloc_abs32codeshrunk;
    /* The place to relc moves back by four bytes */
    r->address -=4;
	  
    /* This will be four bytes smaller in the long run */
    shrink += 4 ;
    perform_slip(symbols, 4, input_section, r->address-shrink +4);
  }      
  return shrink;      
}

static int 
DEFUN(aligncode,(input_section, symbols, r, shrink),
      asection *input_section AND
      asymbol **symbols AND
      arelent *r AND
      unsigned int shrink) 
{
  bfd_vma dot = input_section->output_section->vma +  input_section->output_offset + r->address;	
  bfd_vma gap;
  bfd_vma old_end;
  bfd_vma new_end;
  int shrink_delta;
  int size = r->howto->size;

  /* Reduce the size of the alignment so that it's still aligned but
     smaller  - the current size is already the same size as or bigger
     than the alignment required.  */

  /* calculate the first byte following the padding before we optimize */
  old_end = ((dot + size ) & ~size) + size+1;
  /* work out where the new end will be - remember that we're smaller
     than we used to be */
  new_end = ((dot - shrink + size) & ~size);

  /* This is the new end */
  gap = old_end - ((dot + size) & ~size);

  shrink_delta = (old_end - new_end) - shrink;

  if (shrink_delta)
  { 
    /* Change the reloc so that it knows how far to align to */
    r->howto = howto_done_align_table + (r->howto - howto_align_table);

    /* Encode the stuff into the addend - for future use we need to
       know how big the reloc used to be */
    r->addend = old_end ;

    /* This will be N bytes smaller in the long run, adjust all the symbols */
    perform_slip(symbols, shrink_delta, input_section, r->address - shrink );
    shrink += shrink_delta;
  }      
  return shrink;      
}


static boolean 
DEFUN(b_out_relax_section,(abfd, i, symbols),
      bfd *abfd AND
      asection *i AND
      asymbol **symbols)
{
  
  /* Get enough memory to hold the stuff */
  bfd *input_bfd = i->owner;
  asection *input_section = i;
  int shrink = 0 ;
  boolean new = false;
  
  bfd_size_type reloc_size = bfd_get_reloc_upper_bound(input_bfd,
						       input_section);
  arelent **reloc_vector = (arelent **)alloca(reloc_size);

  /* Get the relocs and think about them */
  if (bfd_canonicalize_reloc(input_bfd, 
			     input_section,
			     reloc_vector,
			     symbols))
  {
    arelent **parent;
    for (parent = reloc_vector; *parent; parent++) 
    {
      arelent *r = *parent;
      switch (r->howto->type) {
       case ALIGNER:
	/* An alignment reloc */
	shrink = aligncode(input_section, symbols, r,shrink);
	new=true;
	break;
       case ABS32CODE:
	/* A 32bit reloc in an addressing mode */
	shrink = abs32code(input_section, symbols, r,shrink);
	new=true;
	break;
       case ABS32CODE_SHRUNK:
	shrink+=4;
	break;
      }
    }
  }
  input_section->_cooked_size = input_section->_raw_size - shrink;  

  return new;
}

#endif
static bfd_byte *
DEFUN(b_out_get_relocated_section_contents,(in_abfd, seclet, data),
      bfd *in_abfd AND
      bfd_seclet_type *seclet AND
      bfd_byte *data)

{
  /* Get enough memory to hold the stuff */
  bfd *input_bfd = seclet->u.indirect.section->owner;
  asection *input_section = seclet->u.indirect.section;
  bfd_size_type reloc_size = bfd_get_reloc_upper_bound(input_bfd,
						       input_section);
  arelent **reloc_vector = (arelent **)alloca(reloc_size);
  
  /* read in the section */
  bfd_get_section_contents(input_bfd,
			   input_section,
			   data,
			   0,
			   input_section->_raw_size);
  
  
  if (bfd_canonicalize_reloc(input_bfd, 
			     input_section,
			     reloc_vector,
			     seclet->u.indirect.symbols) )
  {
    arelent **parent = reloc_vector;
    arelent *reloc ;
    


    unsigned int dst_address = 0;
    unsigned int src_address = 0;
    unsigned int run;
    unsigned int idx;
    
    /* Find how long a run we can do */
    while (dst_address < seclet->size) 
    {
      
      reloc = *parent;
      if (reloc) 
      {
	/* Note that the relaxing didn't tie up the addresses in the
	   relocation, so we use the original address to work out the
	   run of non-relocated data */
	run = reloc->address - src_address;
	parent++;
	
      }
      else 
      {
	run = seclet->size - dst_address;
      }
      /* Copy the bytes */
      for (idx = 0; idx < run; idx++)
      {
	data[dst_address++] = data[src_address++];
      }
    
      /* Now do the relocation */
    
      if (reloc) 
      {
	switch (reloc->howto->type) 
	{
	 case ABS32CODE:
	  calljx_callback(in_abfd, reloc, src_address + data, dst_address+data, input_section);
	  src_address+=4;
	  dst_address+=4;
	  break;
	 case ABS32:
	  bfd_put_32(in_abfd, get_value(reloc, seclet), data+dst_address);
	  src_address+=4;
	  dst_address+=4;
	  break;
	 case CALLJ:
	  callj_callback(in_abfd, reloc ,data,src_address,dst_address,input_section);
	  src_address+=4;
	  dst_address+=4;
	  break;
	 case ALIGNDONE:
	  src_address = reloc->addend;
	  dst_address = (dst_address + reloc->howto->size) & ~reloc->howto->size;
	  break;
	 case ABS32CODE_SHRUNK: 
	  /* This used to be a callx, but we've found out that a
	     callj will reach, so do the right thing */
	  callj_callback(in_abfd, reloc,data,src_address+4, dst_address,input_section);

	  dst_address+=4;
	  src_address+=8;
	  break;
	 case PCREL24:
	 {
	   long int word = bfd_get_32(in_abfd, data+src_address);
	   asymbol *symbol = *(reloc->sym_ptr_ptr);
	   word = (word & ~BAL_MASK) |
	    (((word & BAL_MASK) +
	      symbol->section->output_offset +
	      symbol->section->output_section->vma+
	      symbol->value + reloc->addend - dst_address -
	      ( input_section->output_section->vma + input_section->output_offset))
	     & BAL_MASK);

	   bfd_put_32(in_abfd,word,  data+dst_address);
	   dst_address+=4;
	   src_address+=4;

	 }
	  break;

	 case PCREL13:
	 {
	   long int word = bfd_get_32(in_abfd, data+src_address);
	   asymbol *symbol = *(reloc->sym_ptr_ptr);
	   word = (word & ~PCREL13_MASK) |
	    (((word & PCREL13_MASK) +
	      symbol->section->output_offset +
	      symbol->section->output_section->vma+
	      symbol->value + reloc->addend - dst_address -
	      ( input_section->output_section->vma + input_section->output_offset))
	     & PCREL13_MASK);

	   bfd_put_32(in_abfd,word,  data+dst_address);
	   dst_address+=4;
	   src_address+=4;

	 }
	  break;

	 default:

	  abort();
	}
      }    
    }
  }
  return data;
}
/***********************************************************************/

/* Build the transfer vectors for Big and Little-Endian B.OUT files.  */

/* We don't have core files.  */
#define	aout_32_core_file_failing_command _bfd_dummy_core_file_failing_command
#define	aout_32_core_file_failing_signal _bfd_dummy_core_file_failing_signal
#define	aout_32_core_file_matches_executable_p	\
				_bfd_dummy_core_file_matches_executable_p

/* We use BSD-Unix generic archive files.  */
#define	aout_32_openr_next_archived_file	bfd_generic_openr_next_archived_file
#define	aout_32_generic_stat_arch_elt	bfd_generic_stat_arch_elt
#define	aout_32_slurp_armap		bfd_slurp_bsd_armap
#define	aout_32_slurp_extended_name_table	bfd_true
#define	aout_32_write_armap		bsd_write_armap
#define	aout_32_truncate_arname		bfd_bsd_truncate_arname

/* We override these routines from the usual a.out file routines.  */
#define	aout_32_canonicalize_reloc	b_out_canonicalize_reloc
#define	aout_32_get_reloc_upper_bound	b_out_get_reloc_upper_bound
#define	aout_32_set_section_contents	b_out_set_section_contents
#define	aout_32_set_arch_mach		b_out_set_arch_mach
#define	aout_32_sizeof_headers		b_out_sizeof_headers

#define aout_32_bfd_debug_info_start		bfd_void
#define aout_32_bfd_debug_info_end		bfd_void
#define aout_32_bfd_debug_info_accumulate	(PROTO(void,(*),(bfd*, struct sec *))) bfd_void

#define aout_32_bfd_get_relocated_section_contents  b_out_get_relocated_section_contents
#define aout_32_bfd_relax_section                   b_out_relax_section

bfd_target b_out_vec_big_host =
{
  "b.out.big",			/* name */
  bfd_target_aout_flavour,
  false,			/* data byte order is little */
  true,				/* hdr byte order is big */
  (HAS_RELOC | EXEC_P |		/* object flags */
   HAS_LINENO | HAS_DEBUG |
   HAS_SYMS | HAS_LOCALS | DYNAMIC | WP_TEXT ),
  (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_RELOC), /* section flags */
  '_',				/* symbol leading char */
  ' ',				/* ar_pad_char */
  16,				/* ar_max_namelen */
  2,				/* minumum alignment power */

  _do_getl64, _do_putl64,  _do_getl32, _do_putl32, _do_getl16, _do_putl16, /* data */
  _do_getb64, _do_putb64,  _do_getb32, _do_putb32, _do_getb16, _do_putb16, /* hdrs */
 {_bfd_dummy_target, b_out_object_p, /* bfd_check_format */
   bfd_generic_archive_p, _bfd_dummy_target},
 {bfd_false, b_out_mkobject,	/* bfd_set_format */
   _bfd_generic_mkarchive, bfd_false},
 {bfd_false, b_out_write_object_contents, /* bfd_write_contents */
   _bfd_write_archive_contents, bfd_false},

  JUMP_TABLE(aout_32),
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0,	/* COFF stuff?! */
  b_out_reloc_type_lookup,
};


bfd_target b_out_vec_little_host =
{
  "b.out.little",		/* name */
  bfd_target_aout_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 | DYNAMIC | WP_TEXT ),
  (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_RELOC), /* section flags */
    '_',			/* symbol leading char */
  ' ',				/* ar_pad_char */
  16,				/* ar_max_namelen */
     2,				/* minum align */
_do_getl64, _do_putl64, _do_getl32, _do_putl32, _do_getl16, _do_putl16, /* data */
_do_getl64, _do_putl64, _do_getl32, _do_putl32, _do_getl16, _do_putl16, /* hdrs */
	 
    {_bfd_dummy_target, b_out_object_p, /* bfd_check_format */
       bfd_generic_archive_p, _bfd_dummy_target},
    {bfd_false, b_out_mkobject,	/* bfd_set_format */
       _bfd_generic_mkarchive, bfd_false},
    {bfd_false, b_out_write_object_contents,	/* bfd_write_contents */
       _bfd_write_archive_contents, bfd_false},
  JUMP_TABLE(aout_32),
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0,	/* COFF stuff?! */
  b_out_reloc_type_lookup,
};