coff-a29k.c

来自「基于4个mips核的noc设计」· C语言 代码 · 共 604 行 · 第 1/2 页

/* BFD back-end for AMD 29000 COFF binaries.
   Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1997, 1999, 2000, 2001
   Free Software Foundation, Inc.
   Contributed by David Wood at New York University 7/8/91.

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.  */

#define A29K 1

#include "bfd.h"
#include "sysdep.h"
#include "libbfd.h"
#include "coff/a29k.h"
#include "coff/internal.h"
#include "libcoff.h"

static long get_symbol_value PARAMS ((asymbol *));
static bfd_reloc_status_type a29k_reloc
  PARAMS ((bfd *, arelent *, asymbol *, PTR, asection *, bfd *, char **));
static boolean coff_a29k_relocate_section
  PARAMS ((bfd *, struct bfd_link_info *, bfd *, asection *, bfd_byte *,
	   struct internal_reloc *, struct internal_syment *, asection **));
static boolean coff_a29k_adjust_symndx
  PARAMS ((bfd *, struct bfd_link_info *, bfd *, asection *,
	   struct internal_reloc *, boolean *));

#define COFF_DEFAULT_SECTION_ALIGNMENT_POWER (2)

#define INSERT_HWORD(WORD,HWORD)	\
    (((WORD) & 0xff00ff00) | (((HWORD) & 0xff00) << 8) | ((HWORD)& 0xff))
#define EXTRACT_HWORD(WORD) \
    ((((WORD) & 0x00ff0000) >> 8) | ((WORD) & 0xff))
#define SIGN_EXTEND_HWORD(HWORD) \
    (((HWORD) ^ 0x8000) - 0x8000)

/* Provided the symbol, returns the value reffed */
static long
get_symbol_value (symbol)
     asymbol *symbol;
{
  long relocation = 0;

  if (bfd_is_com_section (symbol->section))
    {
      relocation = 0;
    }
  else
    {
      relocation = symbol->value +
	symbol->section->output_section->vma +
	symbol->section->output_offset;
    }

  return(relocation);
}

/* this function is in charge of performing all the 29k relocations */

static bfd_reloc_status_type
a29k_reloc (abfd, reloc_entry, symbol_in, data, input_section, output_bfd,
	    error_message)
     bfd *abfd;
     arelent *reloc_entry;
     asymbol *symbol_in;
     PTR data;
     asection *input_section;
     bfd *output_bfd;
     char **error_message;
{
  /* the consth relocation comes in two parts, we have to remember
     the state between calls, in these variables */
  static boolean part1_consth_active = false;
  static unsigned long part1_consth_value;

  unsigned long insn;
  unsigned long sym_value;
  unsigned long unsigned_value;
  unsigned short r_type;
  long signed_value;

  unsigned long addr = reloc_entry->address ; /*+ input_section->vma*/
  bfd_byte  *hit_data =addr + (bfd_byte *) (data);

  r_type = reloc_entry->howto->type;

  if (output_bfd)
    {
      /* Partial linking - do nothing */
      reloc_entry->address += input_section->output_offset;
      return bfd_reloc_ok;

    }

  if (symbol_in != NULL
      && bfd_is_und_section (symbol_in->section))
    {
      /* Keep the state machine happy in case we're called again */
      if (r_type == R_IHIHALF)
	{
	  part1_consth_active = true;
	  part1_consth_value  = 0;
	}
      return(bfd_reloc_undefined);
    }

  if ((part1_consth_active) && (r_type != R_IHCONST))
    {
      part1_consth_active = false;
      *error_message = (char *) _("Missing IHCONST");
      return(bfd_reloc_dangerous);
    }

  sym_value = get_symbol_value(symbol_in);

  switch (r_type)
    {
    case R_IREL:
      insn = bfd_get_32 (abfd, hit_data);
      /* Take the value in the field and sign extend it */
      signed_value = EXTRACT_HWORD(insn);
      signed_value = SIGN_EXTEND_HWORD(signed_value);
      signed_value <<= 2;

      /* See the note on the R_IREL reloc in coff_a29k_relocate_section.  */
      if (signed_value == - (long) reloc_entry->address)
	signed_value = 0;

      signed_value += sym_value + reloc_entry->addend;
      if ((signed_value & ~0x3ffff) == 0)
	{				/* Absolute jmp/call */
	  insn |= (1<<24);		/* Make it absolute */
	  /* FIXME: Should we change r_type to R_IABS */
	}
      else
	{
	  /* Relative jmp/call, so subtract from the value the
	     address of the place we're coming from */
	  signed_value -= (reloc_entry->address
			   + input_section->output_section->vma
			   + input_section->output_offset);
	  if (signed_value>0x1ffff || signed_value<-0x20000)
	    return(bfd_reloc_overflow);
	}
      signed_value >>= 2;
      insn = INSERT_HWORD(insn, signed_value);
      bfd_put_32 (abfd, insn ,hit_data);
      break;
    case R_ILOHALF:
      insn = bfd_get_32 (abfd, hit_data);
      unsigned_value = EXTRACT_HWORD(insn);
      unsigned_value +=  sym_value + reloc_entry->addend;
      insn = INSERT_HWORD(insn, unsigned_value);
      bfd_put_32 (abfd, insn, hit_data);
      break;
    case R_IHIHALF:
      insn = bfd_get_32 (abfd, hit_data);
      /* consth, part 1
	 Just get the symbol value that is referenced */
      part1_consth_active = true;
      part1_consth_value = sym_value + reloc_entry->addend;
      /* Don't modify insn until R_IHCONST */
      break;
    case R_IHCONST:
      insn = bfd_get_32 (abfd, hit_data);
      /* consth, part 2
	 Now relocate the reference */
      if (part1_consth_active == false)
	{
	  *error_message = (char *) _("Missing IHIHALF");
	  return(bfd_reloc_dangerous);
	}
      /* sym_ptr_ptr = r_symndx, in coff_slurp_reloc_table() */
      unsigned_value = 0;		/*EXTRACT_HWORD(insn) << 16;*/
      unsigned_value += reloc_entry->addend; /* r_symndx */
      unsigned_value += part1_consth_value;
      unsigned_value = unsigned_value >> 16;
      insn = INSERT_HWORD(insn, unsigned_value);
      part1_consth_active = false;
      bfd_put_32 (abfd, insn, hit_data);
      break;
    case R_BYTE:
      insn = bfd_get_8 (abfd, hit_data);
      unsigned_value = insn + sym_value + reloc_entry->addend;
      if (unsigned_value & 0xffffff00)
	return(bfd_reloc_overflow);
      bfd_put_8 (abfd, unsigned_value, hit_data);
      break;
    case R_HWORD:
      insn = bfd_get_16 (abfd, hit_data);
      unsigned_value = insn + sym_value + reloc_entry->addend;
      if (unsigned_value & 0xffff0000)
	return(bfd_reloc_overflow);
      bfd_put_16 (abfd, insn, hit_data);
      break;
    case R_WORD:
      insn = bfd_get_32 (abfd, hit_data);
      insn += sym_value + reloc_entry->addend;
      bfd_put_32 (abfd, insn, hit_data);
      break;
    default:
      *error_message = _("Unrecognized reloc");
      return (bfd_reloc_dangerous);
    }

  return(bfd_reloc_ok);
}

/*      type	   rightshift
		       size
			  bitsize
			       pc-relative
				     bitpos
					 absolute
					     complain_on_overflow
						  special_function
						    relocation name
							       partial_inplace
								      src_mask
*/

/*FIXME: I'm not real sure about this table */
static reloc_howto_type howto_table[] =
{
  {R_ABS,     0, 3, 32, false, 0, complain_overflow_bitfield,a29k_reloc,"ABS",     true, 0xffffffff,0xffffffff, false},
  EMPTY_HOWTO (1),
  EMPTY_HOWTO (2),
  EMPTY_HOWTO (3),
  EMPTY_HOWTO (4),
  EMPTY_HOWTO (5),
  EMPTY_HOWTO (6),
  EMPTY_HOWTO (7),
  EMPTY_HOWTO (8),
  EMPTY_HOWTO (9),
  EMPTY_HOWTO (10),
  EMPTY_HOWTO (11),
  EMPTY_HOWTO (12),
  EMPTY_HOWTO (13),
  EMPTY_HOWTO (14),
  EMPTY_HOWTO (15),
  EMPTY_HOWTO (16),
  EMPTY_HOWTO (17),
  EMPTY_HOWTO (18),
  EMPTY_HOWTO (19),
  EMPTY_HOWTO (20),
  EMPTY_HOWTO (21),
  EMPTY_HOWTO (22),
  EMPTY_HOWTO (23),
  {R_IREL,    0, 3, 32, true,  0, complain_overflow_signed,a29k_reloc,"IREL",    true, 0xffffffff,0xffffffff, false},
  {R_IABS,    0, 3, 32, false, 0, complain_overflow_bitfield, a29k_reloc,"IABS",    true, 0xffffffff,0xffffffff, false},
  {R_ILOHALF, 0, 3, 16, true,  0, complain_overflow_signed, a29k_reloc,"ILOHALF", true, 0x0000ffff,0x0000ffff, false},
  {R_IHIHALF, 0, 3, 16, true,  16, complain_overflow_signed, a29k_reloc,"IHIHALF", true, 0xffff0000,0xffff0000, false},
  {R_IHCONST, 0, 3, 16, true,  0, complain_overflow_signed, a29k_reloc,"IHCONST", true, 0xffff0000,0xffff0000, false},
  {R_BYTE,    0, 0, 8, false, 0, complain_overflow_bitfield, a29k_reloc,"BYTE",    true, 0x000000ff,0x000000ff, false},
  {R_HWORD,   0, 1, 16, false, 0, complain_overflow_bitfield, a29k_reloc,"HWORD",   true, 0x0000ffff,0x0000ffff, false},
  {R_WORD,    0, 2, 32, false, 0, complain_overflow_bitfield, a29k_reloc,"WORD",    true, 0xffffffff,0xffffffff, false},
};

#define BADMAG(x) A29KBADMAG(x)

#define RELOC_PROCESSING(relent, reloc, symbols, abfd, section) \
 reloc_processing(relent, reloc, symbols, abfd, section)

static void
reloc_processing (relent,reloc, symbols, abfd, section)
     arelent *relent;
     struct internal_reloc *reloc;
     asymbol **symbols;
     bfd *abfd;
     asection *section;
{
  static bfd_vma ihihalf_vaddr = (bfd_vma) -1;

  relent->address = reloc->r_vaddr;
  relent->howto = howto_table + reloc->r_type;
  if (reloc->r_type == R_IHCONST)
    {
      /* The address of an R_IHCONST should always be the address of
	 the immediately preceding R_IHIHALF.  relocs generated by gas
	 are correct, but relocs generated by High C are different (I
	 can't figure out what the address means for High C).  We can
	 handle both gas and High C by ignoring the address here, and
	 simply reusing the address saved for R_IHIHALF.  */
      if (ihihalf_vaddr == (bfd_vma) -1)
	abort ();
      relent->address = ihihalf_vaddr;
      ihihalf_vaddr = (bfd_vma) -1;
      relent->addend = reloc->r_symndx;
      relent->sym_ptr_ptr= bfd_abs_section_ptr->symbol_ptr_ptr;