/* BFD back-end for OpenRISC 1000 COFF binaries.
   Copyright 2002 Free Software Foundation, Inc.
   Contributed by Ivan Guzvinec  <ivang@opencores.org>

   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 OR32 1

#include "bfd.h"
#include "sysdep.h"
#include "libbfd.h"
#include "coff/or32.h"
#include "coff/internal.h"
#include "libcoff.h"

static long                   get_symbol_value           PARAMS ((asymbol *));
static bfd_reloc_status_type  or32_reloc                 PARAMS ((bfd *, arelent *, asymbol *, PTR, asection *, bfd *, char **));
static boolean                coff_or32_relocate_section PARAMS ((bfd *, struct bfd_link_info *, bfd *, asection *, bfd_byte *, struct internal_reloc *, struct internal_syment *, asection **));
static boolean                coff_or32_adjust_symndx    PARAMS ((bfd *, struct bfd_link_info *, bfd *, asection *, struct internal_reloc *, boolean *));
static void                   reloc_processing           PARAMS ((arelent *, struct internal_reloc *, asymbol **, bfd *, asection *));

#define COFF_DEFAULT_SECTION_ALIGNMENT_POWER (2)

#define INSERT_HWORD(WORD,HWORD)              \
    (((WORD) & 0xffff0000) | ((HWORD)& 0x0000ffff))
#define EXTRACT_HWORD(WORD)                   \
    ((WORD) & 0x0000ffff)
#define SIGN_EXTEND_HWORD(HWORD)              \
    ((HWORD) & 0x8000 ? (HWORD)|(~0xffffL) : (HWORD))

#define INSERT_JUMPTARG(WORD,JT)              \
    (((WORD) & 0xfc000000) | ((JT)& 0x03ffffff))
#define EXTRACT_JUMPTARG(WORD)                   \
    ((WORD) & 0x03ffffff)
#define SIGN_EXTEND_JUMPTARG(JT)              \
    ((JT) & 0x04000000 ? (JT)|(~0x03ffffffL) : (JT))

/* 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 or32 relocations.  */

static bfd_reloc_status_type
or32_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_JUMPTARG (insn);
      signed_value = SIGN_EXTEND_JUMPTARG (signed_value);
      signed_value <<= 2;

      /* See the note on the R_IREL reloc in coff_or32_relocate_section.  */
      if (signed_value == - (long) reloc_entry->address)
        signed_value = 0;

      signed_value += sym_value + reloc_entry->addend;
#if 0
      if ((signed_value & ~0x3ffff) == 0)
        {                     /* Absolute jmp/call.  */
          insn |= (1<<24);    /* Make it absolute.  */
          /* FIXME: Should we change r_type to R_IABS.  */
        } 
      else 
#endif
        {
          /* 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 > 0x7ffffff || signed_value < -0x8000000) 
            return bfd_reloc_overflow;
        }
      signed_value >>= 2;
      insn = INSERT_JUMPTARG (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,  or32_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,    or32_reloc, "IREL",    true, 0xffffffff,0xffffffff, false },
  { R_IABS,     0, 3, 32, false,  0, complain_overflow_bitfield,  or32_reloc, "IABS",    true, 0xffffffff,0xffffffff, false },
  { R_ILOHALF,  0, 3, 16, true,   0, complain_overflow_signed,    or32_reloc, "ILOHALF", true, 0x0000ffff,0x0000ffff, false },
  { R_IHIHALF,  0, 3, 16, true,   16,complain_overflow_signed,    or32_reloc, "IHIHALF", true, 0xffff0000,0xffff0000, false },
  { R_IHCONST,  0, 3, 16, true,   0, complain_overflow_signed,    or32_reloc, "IHCONST", true, 0xffff0000,0xffff0000, false },
  { R_BYTE,     0, 0, 8,  false,  0, complain_overflow_bitfield,  or32_reloc, "BYTE",    true, 0x000000ff,0x000000ff, false },
  { R_HWORD,    0, 1, 16, false,  0, complain_overflow_bitfield,  or32_reloc, "HWORD",   true, 0x0000ffff,0x0000ffff, false },
  { R_WORD,     0, 2, 32, false,  0, complain_overflow_bitfield,  or32_reloc, "WORD",    true, 0xffffffff,0xffffffff, false },
};

#define BADMAG(x) OR32BADMAG (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;
    }
  else
    {
      asymbol *ptr;
      relent->sym_ptr_ptr = symbols + obj_convert (abfd)[reloc->r_symndx];

      ptr = *(relent->sym_ptr_ptr);

      relent->addend = 0;
      relent->address-= section->vma;

      if (reloc->r_type == R_IHIHALF)
	ihihalf_vaddr = relent->address;
      else if (ihihalf_vaddr != (bfd_vma) -1)
	abort ();
    }
}

/* The reloc processing routine for the optimized COFF linker.  */

static boolean
coff_or32_relocate_section (output_bfd, info, input_bfd, input_section,
                            contents, relocs, syms, sections)
     bfd *output_bfd ATTRIBUTE_UNUSED;
     struct bfd_link_info *info;
     bfd *input_bfd;
     asection *input_section;
     bfd_byte *contents;
     struct internal_reloc *relocs;
     struct internal_syment *syms;
     asection **sections;
{
  struct internal_reloc *rel;
  struct internal_reloc *relend;
  boolean hihalf;
  bfd_vma hihalf_val;

  /* If we are performing a relocateable link, we don't need to do a
     thing.  The caller will take care of adjusting the reloc
     addresses and symbol indices.  */
  if (info->relocateable)
    return true;

  hihalf = false;
  hihalf_val = 0;

  rel = relocs;
  relend = rel + input_section->reloc_count;

  for (; rel < relend; rel++)
    {
      long symndx;
      bfd_byte *loc;
      struct coff_link_hash_entry *h;
      struct internal_syment *sym;
      asection *sec;
      bfd_vma val;
      boolean overflow;
      unsigned long insn;
      long signed_value;
      unsigned long unsigned_value;
      bfd_reloc_status_type rstat;

      symndx = rel->r_symndx;
      loc = contents + rel->r_vaddr - input_section->vma;

      if (symndx == -1 || rel->r_type == R_IHCONST)
        h = NULL;
      else
        h = obj_coff_sym_hashes (input_bfd)[symndx];

      sym = NULL;
      sec = NULL;
      val = 0;

      /* An R_IHCONST reloc does not have a symbol.  Instead, the
         symbol index is an addend.  R_IHCONST is always used in
         conjunction with R_IHHALF.  */
      if (rel->r_type != R_IHCONST)
        {
          if (h == NULL)
            {
              if (symndx == -1)
                sec = bfd_abs_section_ptr;
              else
                {
                  sym = syms + symndx;
                  sec = sections[symndx];
                  val = (sec->output_section->vma
                         + sec->output_offset
                         + sym->n_value
                         - sec->vma);
                }
            }
          else
            {
              if (h->root.type == bfd_link_hash_defined
                  || h->root.type == bfd_link_hash_defweak)
                {
                  sec = h->root.u.def.section;
                  val = (h->root.u.def.value
                         + sec->output_section->vma
                         + sec->output_offset);
                }
              else
                {
                  if (! ((*info->callbacks->undefined_symbol)
                         (info, h->root.root.string, input_bfd, input_section,
                          rel->r_vaddr - input_section->vma, true)))
                    return false;
                }
            }

          if (hihalf)
            {
              if (! ((*info->callbacks->reloc_dangerous)
                     (info, "missing IHCONST reloc", input_bfd,
                      input_section, rel->r_vaddr - input_section->vma)))
                return false;
              hihalf = false;
            }
        }

      overflow = false;

      switch (rel->r_type)
        {
        default:
          bfd_set_error (bfd_error_bad_value);
          return false;

        case R_IREL:
          insn = bfd_get_32 (input_bfd, loc);

          /* Extract the addend.  */
          signed_value = EXTRACT_JUMPTARG (insn);
          signed_value = SIGN_EXTEND_JUMPTARG (signed_value);
          signed_value <<= 2;

          /* Determine the destination of the jump.  */
          signed_value += val;

#if 0
          if ((signed_value & ~0x3ffff) == 0)
            {
              /* We can use an absolute jump.  */
              insn |= (1 << 24);
            }
          else
#endif
            {
              /* Make the destination PC relative.  */
              signed_value -= (input_section->output_section->vma
                               + input_section->output_offset
                               + (rel->r_vaddr - input_section->vma));
              if (signed_value > 0x7ffffff || signed_value < - 0x8000000)
                {
                  overflow = true;
                  signed_value = 0;
                }
            }

          /* Put the adjusted value back into the instruction.  */
          signed_value >>= 2;
          insn = INSERT_JUMPTARG(insn, signed_value);

          bfd_put_32 (input_bfd, (bfd_vma) insn, loc);
          break;

        case R_ILOHALF:
          insn = bfd_get_32 (input_bfd, loc);
          unsigned_value = EXTRACT_HWORD (insn);
          unsigned_value += val;
          insn = INSERT_HWORD (insn, unsigned_value);
          bfd_put_32 (input_bfd, insn, loc);
          break;

        case R_IHIHALF:
          /* Save the value for the R_IHCONST reloc.  */
          hihalf = true;
          hihalf_val = val;
          break;

        case R_IHCONST:
          if (! hihalf)
            {
              if (! ((*info->callbacks->reloc_dangerous)
                     (info, "missing IHIHALF reloc", input_bfd,
                      input_section, rel->r_vaddr - input_section->vma)))
                return false;
              hihalf_val = 0;
            }

          insn = bfd_get_32 (input_bfd, loc);
          unsigned_value = rel->r_symndx + hihalf_val;
          unsigned_value >>= 16;
          insn = INSERT_HWORD (insn, unsigned_value);
          bfd_put_32 (input_bfd, (bfd_vma) insn, loc);

          hihalf = false;
          break;

        case R_BYTE:
        case R_HWORD:
        case R_WORD:
          rstat = _bfd_relocate_contents (howto_table + rel->r_type,
                                          input_bfd, val, loc);
          if (rstat == bfd_reloc_overflow)
            overflow = true;
          else if (rstat != bfd_reloc_ok)
            abort ();
          break;
        }

      if (overflow)
        {
          const char *name;
          char buf[SYMNMLEN + 1];

          if (symndx == -1)
            name = "*ABS*";
          else if (h != NULL)
            name = h->root.root.string;
          else if (sym == NULL)
            name = "*unknown*";
          else if (sym->_n._n_n._n_zeroes == 0
                   && sym->_n._n_n._n_offset != 0)
            name = obj_coff_strings (input_bfd) + sym->_n._n_n._n_offset;
          else
            {
              strncpy (buf, sym->_n._n_name, SYMNMLEN);
              buf[SYMNMLEN] = '\0';
              name = buf;
            }

          if (! ((*info->callbacks->reloc_overflow)
                 (info, name, howto_table[rel->r_type].name, (bfd_vma) 0,
                  input_bfd, input_section,
                  rel->r_vaddr - input_section->vma)))
            return false;
        }
    }   

  return true;
}

#define coff_relocate_section coff_or32_relocate_section

/* We don't want to change the symndx of a R_IHCONST reloc, since it
   is actually an addend, not a symbol index at all.  */

static boolean
coff_or32_adjust_symndx (obfd, info, ibfd, sec, irel, adjustedp)
     bfd *obfd ATTRIBUTE_UNUSED;
     struct bfd_link_info *info ATTRIBUTE_UNUSED;
     bfd *ibfd ATTRIBUTE_UNUSED;
     asection *sec ATTRIBUTE_UNUSED;
     struct internal_reloc *irel;
     boolean *adjustedp;
{
  if (irel->r_type == R_IHCONST)
    *adjustedp = true;
  else
    *adjustedp = false;
  return true;
}

#define coff_adjust_symndx coff_or32_adjust_symndx

#include "coffcode.h"

const bfd_target or32coff_big_vec =
{
  "coff-or32-big",  /* Name.  */
  bfd_target_coff_flavour,
  BFD_ENDIAN_BIG,   /* Data byte order is big.  */
  BFD_ENDIAN_BIG,   /* 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 | /* Section flags.  */
   SEC_LOAD | SEC_RELOC | 
   SEC_READONLY ),
  '_',        /* Leading underscore.  */
  '/',        /* ar_pad_char.  */
  15,         /* ar_max_namelen.  */

  /* 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,

  /* Headers.  */
  bfd_getb64, bfd_getb_signed_64, bfd_putb64,
  bfd_getb32, bfd_getb_signed_32, bfd_putb32,
  bfd_getb16, bfd_getb_signed_16, bfd_putb16,

  { 
    _bfd_dummy_target,
    coff_object_p,
    bfd_generic_archive_p,
    _bfd_dummy_target
  },
  {
    bfd_false,
    coff_mkobject,
    _bfd_generic_mkarchive,
    bfd_false
  },
  {
    bfd_false,
    coff_write_object_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),
   
 /* Alternative_target.  */
#ifdef TARGET_LITTLE_SYM
  & TARGET_LITTLE_SYM,
#else
  NULL,
#endif

  COFF_SWAP_TABLE
};