riscix.c

基于4个mips核的noc设计

/* BFD back-end for RISC iX (Acorn, arm) binaries.
   Copyright 1994, 1995, 1996, 1997, 1998, 2000, 2001
   Free Software Foundation, Inc.
   Contributed by Richard Earnshaw ([e-mail])

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.  */

/* RISC iX overloads the MAGIC field to indicate more than just the usual
   [ZNO]MAGIC values.  Also included are squeezing information and
   shared library usage.  */

/* The following come from the man page.  */
#define SHLIBLEN 60

#define MF_IMPURE       00200
#define MF_SQUEEZED     01000
#define MF_USES_SL      02000
#define MF_IS_SL        04000

/* Common combinations.  */
#define IMAGIC          (MF_IMPURE|ZMAGIC)      /* Demand load (impure text) */
#define SPOMAGIC        (MF_USES_SL|OMAGIC)     /* OMAGIC with large header */
                                        /* -- may contain a ref to a */
                                        /* shared lib required by the */
                                        /* object.  */
#define SLOMAGIC        (MF_IS_SL|OMAGIC) /* A reference to a shared library */
                                          /* The text portion of the object */
                                          /* contains "overflow text" from */
                                          /* the shared library to be linked */
                                          /* in with an object */
#define QMAGIC          (MF_SQUEEZED|ZMAGIC)    /* Sqeezed demand paged.  */
                                          /* NOTE: This interpretation of */
                                          /* QMAGIC seems to be at variance */
                                          /* With that used on other */
                                          /* architectures.  */
#define SPZMAGIC        (MF_USES_SL|ZMAGIC)     /* program which uses sl */
#define SPQMAGIC        (MF_USES_SL|QMAGIC)     /* sqeezed ditto */
#define SLZMAGIC        (MF_IS_SL|ZMAGIC)       /* shared lib part of prog */
#define SLPZMAGIC       (MF_USES_SL|SLZMAGIC)   /* sl which uses another */

#define N_SHARED_LIB(x) ((x).a_info & MF_USES_SL)

/* Only a pure OMAGIC file has the minimal header */
#define N_TXTOFF(x)                     \
 ((x).a_info == OMAGIC ? 32             \
  : (N_MAGIC(x) == ZMAGIC) ? TARGET_PAGE_SIZE  \
  : 999)

#define N_TXTADDR(x)                                                         \
  (N_MAGIC(x) != ZMAGIC ? 0 /* object file or NMAGIC */                      \
   /* Programs with shared libs are loaded at the first page after all the   \
      text segments of the shared library programs.  Without looking this    \
      up we can't know exactly what the address will be.  A reasonable guess \
      is that a_entry will be in the first page of the executable.  */       \
   : N_SHARED_LIB(x) ? ((x).a_entry & ~(TARGET_PAGE_SIZE - 1))                      \
   : TEXT_START_ADDR)

#define N_SYMOFF(x) \
  (N_TXTOFF (x) + (x).a_text + (x).a_data + (x).a_trsize + (x).a_drsize)

#define N_STROFF(x) (N_SYMOFF (x) + (x).a_syms)

#define TEXT_START_ADDR 32768
#define TARGET_PAGE_SIZE 32768
#define SEGMENT_SIZE TARGET_PAGE_SIZE
#define DEFAULT_ARCH bfd_arch_arm

#define MY(OP) CAT(riscix_,OP)
#define TARGETNAME "a.out-riscix"
#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)

#include "bfd.h"
#include "sysdep.h"
#include "libbfd.h"

#define WRITE_HEADERS(abfd, execp)					   \
  {									   \
    bfd_size_type text_size; /* dummy vars */				   \
    file_ptr text_end;							   \
    if (adata(abfd).magic == undecided_magic)				   \
      NAME(aout,adjust_sizes_and_vmas) (abfd, &text_size, &text_end);	   \
    									   \
    execp->a_syms = bfd_get_symcount (abfd) * EXTERNAL_NLIST_SIZE;	   \
    execp->a_entry = bfd_get_start_address (abfd);			   \
    									   \
    execp->a_trsize = ((obj_textsec (abfd)->reloc_count) *		   \
		       obj_reloc_entry_size (abfd));			   \
    execp->a_drsize = ((obj_datasec (abfd)->reloc_count) *		   \
		       obj_reloc_entry_size (abfd));			   \
    NAME(aout,swap_exec_header_out) (abfd, execp, &exec_bytes);		   \
    									   \
    if (bfd_seek (abfd, (file_ptr) 0, SEEK_SET) != 0) return false;	   \
    if (bfd_write ((PTR) &exec_bytes, 1, EXEC_BYTES_SIZE, abfd)		   \
	!= EXEC_BYTES_SIZE)						   \
      return false;							   \
    /* Now write out reloc info, followed by syms and strings */	   \
									   \
    if (bfd_get_outsymbols (abfd) != (asymbol **) NULL			   \
	&& bfd_get_symcount (abfd) != 0)				   \
      {									   \
	if (bfd_seek (abfd, (file_ptr) (N_SYMOFF(*execp)), SEEK_SET) != 0)  \
	  return false;							   \
									   \
	if (! NAME(aout,write_syms) (abfd)) return false;		   \
									   \
	if (bfd_seek (abfd, (file_ptr) (N_TRELOFF(*execp)), SEEK_SET) != 0) \
	  return false;							   \
									   \
	if (! riscix_squirt_out_relocs (abfd, obj_textsec (abfd)))	   \
	  return false;							   \
	if (bfd_seek (abfd, (file_ptr) (N_DRELOFF(*execp)), SEEK_SET) != 0) \
	  return false;							   \
									   \
	if (!NAME(aout,squirt_out_relocs) (abfd, obj_datasec (abfd)))	   \
	  return false;							   \
      }									   \
  }

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

static bfd_reloc_status_type
riscix_fix_pcrel_26_done PARAMS ((bfd *, arelent *, asymbol *, PTR,
				  asection *, bfd *, char **));

static bfd_reloc_status_type
riscix_fix_pcrel_26 PARAMS ((bfd *, arelent *, asymbol *, PTR,
			     asection *, bfd *, char **));

static reloc_howto_type riscix_std_reloc_howto[] = {
  /* 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,  3,   26, true, 0, complain_overflow_signed,  riscix_fix_pcrel_26 , "ARM26",      true, 0x00ffffff,0x00ffffff, false),
  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,  3,   26, false, 0, complain_overflow_signed,  riscix_fix_pcrel_26_done, "ARM26D",true,0x00ffffff,0x00ffffff, 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 RISCIX_TABLE_SIZE \
  (sizeof (riscix_std_reloc_howto) / sizeof (reloc_howto_type))

static bfd_reloc_status_type
riscix_fix_pcrel_26_done (abfd, reloc_entry, symbol, data, input_section,
			  output_bfd, error_message)
     bfd *abfd ATTRIBUTE_UNUSED;
     arelent *reloc_entry ATTRIBUTE_UNUSED;
     asymbol *symbol ATTRIBUTE_UNUSED;
     PTR 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
riscix_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 ATTRIBUTE_UNUSED;
{
  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 & ~ (bfd_vma) 0x03ffffff) != ~ (bfd_vma) 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 = &riscix_std_reloc_howto[7];

  return flag;
}

reloc_howto_type *
riscix_reloc_type_lookup (abfd, code)
     bfd *abfd;
     bfd_reloc_code_real_type code;
{
#define ASTD(i,j)       case i: return &riscix_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 (reloc_howto_type *) 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 (reloc_howto_type *) NULL;
    }
}

#define MY_bfd_link_hash_table_create _bfd_generic_link_hash_table_create
#define MY_bfd_link_add_symbols _bfd_generic_link_add_symbols
#define MY_final_link_callback should_not_be_used
#define MY_bfd_final_link _bfd_generic_final_link

#define MY_bfd_reloc_type_lookup riscix_reloc_type_lookup
#define MY_canonicalize_reloc riscix_canonicalize_reloc
#define MY_object_p riscix_object_p

static const bfd_target *riscix_callback PARAMS ((bfd *));

void
riscix_swap_std_reloc_out (abfd, g, natptr)
     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 (r_length == 3)
    r_pcrel = r_pcrel ? 0 : 1;

#if 0
  /* For a standard reloc, the addend is in the object file.  */
  r_addend = g->addend + (*(g->sym_ptr_ptr))->section->output_section->vma;
#endif

  /* 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.