/* AVR-specific support for 32-bit ELF
   Copyright 1999, 2000, 2001, 2002, 2003, 2004
   Free Software Foundation, Inc.
   Contributed by Denis Chertykov <denisc@overta.ru>

   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.  */

#include "bfd.h"
#include "sysdep.h"
#include "libbfd.h"
#include "elf-bfd.h"
#include "elf/blarg.h"

static reloc_howto_type *bfd_elf32_bfd_reloc_type_lookup
  PARAMS ((bfd *abfd, bfd_reloc_code_real_type code));
static void blarg_info_to_howto_rela
  PARAMS ((bfd *, arelent *, Elf_Internal_Rela *));
static asection *elf32_blarg_gc_mark_hook
  PARAMS ((asection *, struct bfd_link_info *, Elf_Internal_Rela *,
	   struct elf_link_hash_entry *, Elf_Internal_Sym *));
static bfd_boolean elf32_blarg_gc_sweep_hook
  PARAMS ((bfd *, struct bfd_link_info *, asection *,
	   const Elf_Internal_Rela *));
static bfd_boolean elf32_blarg_check_relocs
  PARAMS ((bfd *, struct bfd_link_info *, asection *,
	   const Elf_Internal_Rela *));
static bfd_reloc_status_type blarg_final_link_relocate
  PARAMS ((reloc_howto_type *, bfd *, asection *, bfd_byte *,
	   Elf_Internal_Rela *, bfd_vma));
static bfd_boolean elf32_blarg_relocate_section
  PARAMS ((bfd *, struct bfd_link_info *, bfd *, asection *, bfd_byte *,
	   Elf_Internal_Rela *, Elf_Internal_Sym *, asection **));
static void bfd_elf_blarg_final_write_processing PARAMS ((bfd *, bfd_boolean));
static bfd_boolean elf32_blarg_object_p PARAMS ((bfd *));

static reloc_howto_type elf_blarg_howto_table[] =
{
  HOWTO (R_BLARG_NONE,		/* type */
	 0,			/* rightshift */
	 2,			/* size (0 = byte, 1 = short, 2 = long) */
	 32,			/* bitsize */
	 FALSE,			/* pc_relative */
	 0,			/* bitpos */
	 complain_overflow_bitfield, /* complain_on_overflow */
	 bfd_elf_generic_reloc,	/* special_function */
	 "R_BLARG_NONE",	/* name */
	 FALSE,			/* partial_inplace */
	 0,			/* src_mask */
	 0,			/* dst_mask */
	 FALSE),		/* pcrel_offset */

  /* A 16 bit absolute relocation.  */
  HOWTO (R_BLARG_16,		/* type */
	 1,			/* rightshift */
	 1,			/* size (0 = byte, 1 = short, 2 = long) */
	 16,			/* bitsize */
	 FALSE,			/* pc_relative */
	 0,			/* bitpos */
	 complain_overflow_dont, /* complain_on_overflow */
	 bfd_elf_generic_reloc,	/* special_function */
	 "R_BLARG_16",		/* name */
	 FALSE,			/* partial_inplace */
	 0xffff,		/* src_mask */
	 0xffff,		/* dst_mask */
	 FALSE),		/* pcrel_offset */

};

/* Map BFD reloc types to AVR ELF reloc types.  */

struct blarg_reloc_map
{
  bfd_reloc_code_real_type bfd_reloc_val;
  unsigned int elf_reloc_val;
};

 static const struct blarg_reloc_map blarg_reloc_map[] =
{
  { BFD_RELOC_NONE,                 R_BLARG_NONE },
  { BFD_RELOC_16,                   R_BLARG_16 }
};

static reloc_howto_type *
bfd_elf32_bfd_reloc_type_lookup (abfd, code)
     bfd *abfd ATTRIBUTE_UNUSED;
     bfd_reloc_code_real_type code;
{
  unsigned int i;

  for (i = 0;
       i < sizeof (blarg_reloc_map) / sizeof (struct blarg_reloc_map);
       i++)
    {
      if (blarg_reloc_map[i].bfd_reloc_val == code)
	return &elf_blarg_howto_table[blarg_reloc_map[i].elf_reloc_val];
    }

  return NULL;
}

/* Set the howto pointer for an AVR ELF reloc.  */

static void
blarg_info_to_howto_rela (abfd, cache_ptr, dst)
     bfd *abfd ATTRIBUTE_UNUSED;
     arelent *cache_ptr;
     Elf_Internal_Rela *dst;
{
  unsigned int r_type;

  r_type = ELF32_R_TYPE (dst->r_info);
  BFD_ASSERT (r_type < (unsigned int) R_BLARG_max);
  cache_ptr->howto = &elf_blarg_howto_table[r_type];
}

static asection *
elf32_blarg_gc_mark_hook (sec, info, rel, h, sym)
     asection *sec;
     struct bfd_link_info *info ATTRIBUTE_UNUSED;
     Elf_Internal_Rela *rel;
     struct elf_link_hash_entry *h;
     Elf_Internal_Sym *sym;
{
  if (h != NULL)
    {
      switch (ELF32_R_TYPE (rel->r_info))
	{
	default:
	  switch (h->root.type)
	    {
	    case bfd_link_hash_defined:
	    case bfd_link_hash_defweak:
	      return h->root.u.def.section;

	    case bfd_link_hash_common:
	      return h->root.u.c.p->section;

	    default:
	      break;
	    }
	}
    }
  else
    return bfd_section_from_elf_index (sec->owner, sym->st_shndx);

  return NULL;
}

static bfd_boolean
elf32_blarg_gc_sweep_hook (abfd, info, sec, relocs)
     bfd *abfd ATTRIBUTE_UNUSED;
     struct bfd_link_info *info ATTRIBUTE_UNUSED;
     asection *sec ATTRIBUTE_UNUSED;
     const Elf_Internal_Rela *relocs ATTRIBUTE_UNUSED;
{
  /* We don't use got and plt entries for blarg.  */
  return TRUE;
}

/* Look through the relocs for a section during the first phase.
   Since we don't do .gots or .plts, we just need to consider the
   virtual table relocs for gc.  */

static bfd_boolean
elf32_blarg_check_relocs (abfd, info, sec, relocs)
     bfd *abfd;
     struct bfd_link_info *info;
     asection *sec;
     const Elf_Internal_Rela *relocs;
{
  Elf_Internal_Shdr *symtab_hdr;
  struct elf_link_hash_entry **sym_hashes, **sym_hashes_end;
  const Elf_Internal_Rela *rel;
  const Elf_Internal_Rela *rel_end;

  if (info->relocatable)
    return TRUE;

  symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
  sym_hashes = elf_sym_hashes (abfd);
  sym_hashes_end = sym_hashes + symtab_hdr->sh_size/sizeof (Elf32_External_Sym);
  if (!elf_bad_symtab (abfd))
    sym_hashes_end -= symtab_hdr->sh_info;

  rel_end = relocs + sec->reloc_count;
  for (rel = relocs; rel < rel_end; rel++)
    {
      struct elf_link_hash_entry *h;
      unsigned long r_symndx;

      r_symndx = ELF32_R_SYM (rel->r_info);
      if (r_symndx < symtab_hdr->sh_info)
        h = NULL;
      else
      	{
	  h = sym_hashes[r_symndx - symtab_hdr->sh_info];
	  while (h->root.type == bfd_link_hash_indirect
		 || h->root.type == bfd_link_hash_warning)
	    h = (struct elf_link_hash_entry *) h->root.u.i.link;
	}
    }

  return TRUE;
}

/* Perform a single relocation.  By default we use the standard BFD
   routines, but a few relocs, we have to do them ourselves.  */

static bfd_reloc_status_type
blarg_final_link_relocate (howto, input_bfd, input_section,
			 contents, rel, relocation)
     reloc_howto_type *  howto;
     bfd *               input_bfd;
     asection *          input_section;
     bfd_byte *          contents;
     Elf_Internal_Rela * rel;
     bfd_vma             relocation;
{
  bfd_reloc_status_type r = bfd_reloc_ok;

  switch (howto->type)
    {
    default:
      r = _bfd_final_link_relocate (howto, input_bfd, input_section,
				    contents, rel->r_offset,
				    relocation, rel->r_addend);
    }
  return r;
}

/* Relocate an AVR ELF section.  */
static bfd_boolean
elf32_blarg_relocate_section (output_bfd, info, input_bfd, input_section,
			    contents, relocs, local_syms, local_sections)
     bfd *output_bfd ATTRIBUTE_UNUSED;
     struct bfd_link_info *info;
     bfd *input_bfd;
     asection *input_section;
     bfd_byte *contents;
     Elf_Internal_Rela *relocs;
     Elf_Internal_Sym *local_syms;
     asection **local_sections;
{
  Elf_Internal_Shdr *           symtab_hdr;
  struct elf_link_hash_entry ** sym_hashes;
  Elf_Internal_Rela *           rel;
  Elf_Internal_Rela *           relend;

  if (info->relocatable)
    return TRUE;

  symtab_hdr = & elf_tdata (input_bfd)->symtab_hdr;
  sym_hashes = elf_sym_hashes (input_bfd);
  relend     = relocs + input_section->reloc_count;

  for (rel = relocs; rel < relend; rel ++)
    {
      reloc_howto_type *           howto;
      unsigned long                r_symndx;
      Elf_Internal_Sym *           sym;
      asection *                   sec;
      struct elf_link_hash_entry * h;
      bfd_vma                      relocation;
      bfd_reloc_status_type        r;
      const char *                 name;
      int                          r_type;

      /* This is a final link.  */
      r_type = ELF32_R_TYPE (rel->r_info);
      r_symndx = ELF32_R_SYM (rel->r_info);
      howto  = elf_blarg_howto_table + ELF32_R_TYPE (rel->r_info);
      h      = NULL;
      sym    = NULL;
      sec    = NULL;

      if (r_symndx < symtab_hdr->sh_info)
	{
	  sym = local_syms + r_symndx;
	  sec = local_sections [r_symndx];
	  relocation = _bfd_elf_rela_local_sym (output_bfd, sym, &sec, rel);

	  name = bfd_elf_string_from_elf_section
	    (input_bfd, symtab_hdr->sh_link, sym->st_name);
	  name = (name == NULL) ? bfd_section_name (input_bfd, sec) : name;
	}
      else
	{
	  bfd_boolean unresolved_reloc, warned;

	  RELOC_FOR_GLOBAL_SYMBOL (info, input_bfd, input_section, rel,
				   r_symndx, symtab_hdr, sym_hashes,
				   h, sec, relocation,
				   unresolved_reloc, warned);

	  name = h->root.root.string;
	}

      r = blarg_final_link_relocate (howto, input_bfd, input_section,
				   contents, rel, relocation);

      if (r != bfd_reloc_ok)
	{
	  const char * msg = (const char *) NULL;

	  switch (r)
	    {
	    case bfd_reloc_overflow:
	      r = info->callbacks->reloc_overflow
		(info, (h ? &h->root : NULL),
		 name, howto->name, (bfd_vma) 0,
		 input_bfd, input_section, rel->r_offset);
	      break;

	    case bfd_reloc_undefined:
	      r = info->callbacks->undefined_symbol
		(info, name, input_bfd, input_section, rel->r_offset, TRUE);
	      break;

	    case bfd_reloc_outofrange:
	      msg = _("internal error: out of range error");
	      break;

	    case bfd_reloc_notsupported:
	      msg = _("internal error: unsupported relocation error");
	      break;

	    case bfd_reloc_dangerous:
	      msg = _("internal error: dangerous relocation");
	      break;

	    default:
	      msg = _("internal error: unknown error");
	      break;
	    }

	  if (msg)
	    r = info->callbacks->warning
	      (info, msg, name, input_bfd, input_section, rel->r_offset);

	  if (! r)
	    return FALSE;
	}
    }

  return TRUE;
}

/* The final processing done just before writing out a AVR ELF object
   file.  This gets the AVR architecture right based on the machine
   number.  */

static void
bfd_elf_blarg_final_write_processing (abfd, linker)
     bfd *abfd;
     bfd_boolean linker ATTRIBUTE_UNUSED;
{
  unsigned long val;

  switch (bfd_get_mach (abfd))
    {
    default:
    case bfd_mach_blarg:
      val = E_BLARG_MACH_BLARG;
      break;
    }

  elf_elfheader (abfd)->e_machine = EM_BLARG;
  elf_elfheader (abfd)->e_flags &= ~ EF_BLARG_MACH;
  elf_elfheader (abfd)->e_flags |= val;
}

/* Set the right machine number.  */

static bfd_boolean
elf32_blarg_object_p (abfd)
     bfd *abfd;
{
  unsigned int e_set = bfd_mach_blarg;
  if (elf_elfheader (abfd)->e_machine == EM_BLARG)
    {
      int e_mach = elf_elfheader (abfd)->e_flags & EF_BLARG_MACH;
      switch (e_mach)
	{
	default:
	case E_BLARG_MACH_BLARG:
	  e_set = bfd_mach_blarg;
	  break;
	}
    }
  return bfd_default_set_arch_mach (abfd, bfd_arch_blarg,
				    e_set);
}

#define ELF_ARCH		bfd_arch_blarg
#define ELF_MACHINE_CODE	EM_BLARG
//#define ELF_MACHINE_ALT1	EM_AVR_OLD
#define ELF_MAXPAGESIZE		1

#define TARGET_LITTLE_SYM       bfd_elf32_blarg_vec
#define TARGET_LITTLE_NAME	"elf32-blarg"

#define elf_info_to_howto	             blarg_info_to_howto_rela
#define elf_info_to_howto_rel	             NULL
#define elf_backend_relocate_section         elf32_blarg_relocate_section
#define elf_backend_gc_mark_hook             elf32_blarg_gc_mark_hook
#define elf_backend_gc_sweep_hook            elf32_blarg_gc_sweep_hook
#define elf_backend_check_relocs             elf32_blarg_check_relocs
#define elf_backend_can_gc_sections          1
#define elf_backend_rela_normal		     1
#define elf_backend_final_write_processing \
					bfd_elf_blarg_final_write_processing
#define elf_backend_object_p		elf32_blarg_object_p

#include "elf32-target.h"