/* BFD back-end for Intel 960 COFF files.
   Copyright (C) 1990, 1991, 1992, 1993, 1994 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., 675 Mass Ave, Cambridge, MA 02139, USA.  */

#define I960 1
#define BADMAG(x) I960BADMAG(x)

#include "bfd.h"
#include "sysdep.h"
#include "libbfd.h"
#include "obstack.h"
#include "coff/i960.h"
#include "coff/internal.h"
#include "libcoff.h"		/* to allow easier abstraction-breaking */

static bfd_reloc_status_type optcall_callback
  PARAMS ((bfd *, arelent *, asymbol *, PTR, asection *, bfd *, char **));
static bfd_reloc_status_type coff_i960_relocate
  PARAMS ((bfd *, arelent *, asymbol *, PTR, asection *, bfd *, char **));

#define COFF_DEFAULT_SECTION_ALIGNMENT_POWER (3)

#define COFF_LONG_FILENAMES

#define CALLS	 0x66003800	/* Template for 'calls' instruction	*/
#define BAL	 0x0b000000	/* Template for 'bal' instruction	*/
#define BAL_MASK 0x00ffffff

static bfd_reloc_status_type 
optcall_callback (abfd, reloc_entry, symbol_in, data,
		  ignore_input_section, ignore_bfd, error_message)
     bfd *abfd;
     arelent *reloc_entry;
     asymbol *symbol_in;
     PTR data;
     asection *ignore_input_section;
     bfd *ignore_bfd;
     char **error_message;
{
  /* This item has already been relocated correctly, but we may be
   * able to patch in yet better code - done by digging out the
   * correct info on this symbol */
  bfd_reloc_status_type result;
  coff_symbol_type *cs = coffsymbol(symbol_in);

  /* So the target symbol has to be of coff type, and the symbol 
     has to have the correct native information within it */
  if ((bfd_asymbol_flavour(&cs->symbol) != bfd_target_coff_flavour)
      || (cs->native == (combined_entry_type *)NULL))
    {
      /* This is interesting, consider the case where we're outputting coff
	 from a mix n match input, linking from coff to a symbol defined in a
	 bout file will cause this match to be true. Should I complain?  This
	 will only work if the bout symbol is non leaf.  */
      *error_message =
	(char *) "uncertain calling convention for non-COFF symbol";
      result = bfd_reloc_dangerous;
    }
  else
    {
    switch (cs->native->u.syment.n_sclass) 
      {
      case C_LEAFSTAT:
      case C_LEAFEXT:
  	/* This is a call to a leaf procedure, replace instruction with a bal
	   to the correct location.  */
	{
	  union internal_auxent *aux = &((cs->native+2)->u.auxent);
	  int word = bfd_get_32(abfd, (bfd_byte *)data + reloc_entry->address);
	  int olf = (aux->x_bal.x_balntry - cs->native->u.syment.n_value);
	  BFD_ASSERT(cs->native->u.syment.n_numaux==2);

	  /* We replace the original call instruction with a bal to
	     the bal entry point - the offset of which is described in
	     the 2nd auxent of the original symbol. We keep the native
	     sym and auxents untouched, so the delta between the two
	     is the offset of the bal entry point.  */
	  word = ((word +  olf)  & BAL_MASK) | BAL;
  	  bfd_put_32(abfd, word, (bfd_byte *) data + reloc_entry->address);
  	}
	result = bfd_reloc_ok;
	break;
      case C_SCALL:
	/* This is a call to a system call, replace with a calls to # */
	BFD_ASSERT(0);
	result = bfd_reloc_ok;
	break;
      default:
	result = bfd_reloc_ok;
	break;
      }
  }
  return result;
}

/* i960 COFF is used by VxWorks 5.1.  However, VxWorks 5.1 does not
   appear to correctly handle a reloc against a symbol defined in the
   same object file.  It appears to simply discard such relocs, rather
   than adding their values into the object file.  We handle this here
   by converting all relocs against defined symbols into relocs
   against the section symbol, when generating a relocateable output
   file.  */

static bfd_reloc_status_type 
coff_i960_relocate (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;
{
  const char *sec_name;
  asymbol **syms, **sym_end;

  if (output_bfd == NULL)
    {
      /* Not generating relocateable output file.  */
      return bfd_reloc_continue;
    }

  if (bfd_is_und_section (bfd_get_section (symbol)))
    {
      /* Symbol is not defined, so no need to worry about it.  */
      return bfd_reloc_continue;
    }

  if (bfd_is_com_section (bfd_get_section (symbol)))
    {
      /* I don't really know what the right action is for a common
         symbol.  */
      return bfd_reloc_continue;
    }

  /* Convert the reloc to use the section symbol.  FIXME: This method
     is ridiculous.  */
  sec_name = bfd_get_section_name (output_bfd,
				   bfd_get_section (symbol)->output_section);
  syms = bfd_get_outsymbols (output_bfd);
  sym_end = syms + bfd_get_symcount (output_bfd);
  for (; syms < sym_end; syms++)
    {
      if (bfd_asymbol_name (*syms) != NULL
	  && strcmp (bfd_asymbol_name (*syms), sec_name) == 0
	  && (*syms)->value == 0)
	{
	  reloc_entry->sym_ptr_ptr = syms;
	  break;
	}
    }

  if (syms >= sym_end)
    abort ();

  /* Let bfd_perform_relocation do its thing, which will include
     stuffing the symbol addend into the object file.  */
  return bfd_reloc_continue;
}

static reloc_howto_type howto_rellong =
  HOWTO ((unsigned int) R_RELLONG, 0, 2, 32,false, 0,
	 complain_overflow_bitfield, coff_i960_relocate,"rellong", true,
	 0xffffffff, 0xffffffff, 0);
static reloc_howto_type howto_iprmed =
  HOWTO (R_IPRMED, 0, 2, 24,true,0, complain_overflow_signed,
	 coff_i960_relocate, "iprmed ", true, 0x00ffffff, 0x00ffffff, 0);
static reloc_howto_type howto_optcall =
  HOWTO (R_OPTCALL, 0,2,24,true,0, complain_overflow_signed,
	 optcall_callback, "optcall", true, 0x00ffffff, 0x00ffffff, 0);

static const reloc_howto_type *
coff_i960_reloc_type_lookup (abfd, code)
     bfd *abfd;
     bfd_reloc_code_real_type code;
{
  switch (code)
    {
    default:
      return 0;
    case BFD_RELOC_I960_CALLJ:
      return &howto_optcall;
    case BFD_RELOC_32:
    case BFD_RELOC_CTOR:
      return &howto_rellong;
    case BFD_RELOC_24_PCREL:
      return &howto_iprmed;
    }
}

/* The real code is in coffcode.h */

#define RTYPE2HOWTO(cache_ptr, dst) \
{							\
   reloc_howto_type *howto_ptr;				\
   switch ((dst)->r_type) {				\
     case 17: howto_ptr = &howto_rellong; break;	\
     case 25: howto_ptr = &howto_iprmed; break;		\
     case 27: howto_ptr = &howto_optcall; break;	\
     default: howto_ptr = 0; break;			\
     }							\
   (cache_ptr)->howto = howto_ptr;			\
 }

#include "coffcode.h"

#undef coff_bfd_reloc_type_lookup
#define coff_bfd_reloc_type_lookup coff_i960_reloc_type_lookup

const bfd_target icoff_little_vec =
{
  "coff-Intel-little",		/* name */
  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),

  (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_RELOC), /* section flags */
  '_',				/* leading underscore */
  '/',				/* ar_pad_char */
  15,				/* ar_max_namelen */

  3,				/* 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 */

 {_bfd_dummy_target, coff_object_p, /* bfd_check_format */
   bfd_generic_archive_p, _bfd_dummy_target},
 {bfd_false, coff_mkobject,	/* bfd_set_format */
   _bfd_generic_mkarchive, 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,
};


const bfd_target icoff_big_vec =
{
  "coff-Intel-big",		/* name */
  bfd_target_coff_flavour,
  false,			/* data byte order is little */
  true,				/* header byte order is big */

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

  (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_RELOC), /* section flags */
  '_',				/* leading underscore */
  '/',				/* ar_pad_char */
  15,				/* ar_max_namelen */

  3,				/* 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_getb64, bfd_getb_signed_64, bfd_putb64,
     bfd_getb32, bfd_getb_signed_32, bfd_putb32,
     bfd_getb16, bfd_getb_signed_16, bfd_putb16, /* hdrs */

  {_bfd_dummy_target, coff_object_p, /* bfd_check_format */
     bfd_generic_archive_p, _bfd_dummy_target},
  {bfd_false, coff_mkobject,	/* bfd_set_format */
     _bfd_generic_mkarchive, 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,
};
