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/* OpenRISC-specific support for 32-bit ELF.

   Copyright 2001, 2002, 2003, 2004, 2005, 2006, 2007

   Free Software Foundation, Inc.

   Contributed by Johan Rydberg, jrydberg@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 3 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., 51 Franklin Street - Fifth Floor, Boston,

   MA 02110-1301, USA.  */

#include "sysdep.h"

#include "bfd.h"

#include "libbfd.h"

#include "elf-bfd.h"

#include "elf/openrisc.h"

#include "libiberty.h"

static reloc_howto_type openrisc_elf_howto_table[] =

{

  /* This reloc does nothing.  */

  HOWTO (R_OPENRISC_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_OPENRISC_NONE",     /* name */

         FALSE,                 /* partial_inplace */

         0,                      /* src_mask */

         0,                      /* dst_mask */

         FALSE),                /* pcrel_offset */

  /* A PC relative 26 bit relocation, right shifted by 2.  */

  HOWTO (R_OPENRISC_INSN_REL_26, /* type */

         2,                     /* rightshift */

         2,                     /* size (0 = byte, 1 = short, 2 = long) */

         26,                    /* bitsize */

         TRUE,                  /* pc_relative */

         0,                      /* bitpos */

         complain_overflow_signed, /* complain_on_overflow */

         bfd_elf_generic_reloc, /* special_function */

         "R_OPENRISC_INSN_REL_26", /* name */

         FALSE,                 /* partial_inplace */

         0x00000000,            /* src_mask */

         0x03ffffff,            /* dst_mask */

         FALSE),                /* pcrel_offset */

  /* A absolute 26 bit relocation, right shifted by 2.  */

  HOWTO (R_OPENRISC_INSN_ABS_26, /* type */

         2,                     /* rightshift */

         2,                     /* size (0 = byte, 1 = short, 2 = long) */

         26,                    /* bitsize */

         FALSE,                 /* pc_relative */

         0,                      /* bitpos */

         complain_overflow_signed, /* complain_on_overflow */

         bfd_elf_generic_reloc, /* special_function */

         "R_OPENRISC_INSN_ABS_26", /* name */

         FALSE,                 /* partial_inplace */

         0x00000000,            /* src_mask */

         0x03ffffff,            /* dst_mask */

         FALSE),                /* pcrel_offset */

  HOWTO (R_OPENRISC_LO_16_IN_INSN, /* type */

         0,                      /* 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_OPENRISC_LO_16_IN_INSN", /* name */

         FALSE,                 /* partial_inplace */

         0,                      /* src_mask */

         0x0000ffff,            /* dst_mask */

         FALSE),                /* pcrel_offset */

  HOWTO (R_OPENRISC_HI_16_IN_INSN, /* type */

         16,                    /* 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_OPENRISC_HI_16_IN_INSN",    /* name */

         FALSE,                 /* partial_inplace */

         0,                      /* src_mask */

         0x0000ffff,            /* dst_mask */

         FALSE),                /* pcrel_offset */

  /* An 8 bit absolute relocation.  */

  HOWTO (R_OPENRISC_8,          /* type */

         0,                      /* rightshift */

         0,                      /* size (0 = byte, 1 = short, 2 = long) */

         8,                     /* bitsize */

         FALSE,                 /* pc_relative */

         0,                      /* bitpos */

         complain_overflow_bitfield, /* complain_on_overflow */

         bfd_elf_generic_reloc, /* special_function */

         "R_OPENRISC_8",        /* name */

         TRUE,                  /* partial_inplace */

         0x0000,                /* src_mask */

         0x00ff,                /* dst_mask */

         FALSE),                /* pcrel_offset */

  /* A 16 bit absolute relocation.  */

  HOWTO (R_OPENRISC_16,         /* type */

         0,                      /* rightshift */

         1,                     /* size (0 = byte, 1 = short, 2 = long) */

         16,                    /* bitsize */

         FALSE,                 /* pc_relative */

         0,                      /* bitpos */

         complain_overflow_bitfield, /* complain_on_overflow */

         bfd_elf_generic_reloc, /* special_function */

         "R_OPENRISC_16",       /* name */

         TRUE,                  /* partial_inplace */

         0x00000000,            /* src_mask */

         0x0000ffff,            /* dst_mask */

         FALSE),                /* pcrel_offset */

  /* A 32 bit absolute relocation.  */

  HOWTO (R_OPENRISC_32,         /* 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_OPENRISC_32",       /* name */

         TRUE,                  /* partial_inplace */

         0x00000000,            /* src_mask */

         0xffffffff,            /* dst_mask */

         FALSE),                /* pcrel_offset */

  /* GNU extension to record C++ vtable hierarchy.  */

  HOWTO (R_OPENRISC_GNU_VTINHERIT, /* type */

         0,                      /* rightshift */

         2,                     /* size (0 = byte, 1 = short, 2 = long) */

         0,                      /* bitsize */

         FALSE,                 /* pc_relative */

         0,                      /* bitpos */

         complain_overflow_dont, /* complain_on_overflow */

         NULL,                  /* special_function */

         "R_OPENRISC_GNU_VTINHERIT", /* name */

         FALSE,                 /* partial_inplace */

         0,                      /* src_mask */

         0,                      /* dst_mask */

         FALSE),                /* pcrel_offset */

  /* GNU extension to record C++ vtable member usage.  */

  HOWTO (R_OPENRISC_GNU_VTENTRY, /* type */

         0,                      /* rightshift */

         2,                     /* size (0 = byte, 1 = short, 2 = long) */

         0,                      /* bitsize */

         FALSE,                 /* pc_relative */

         0,                      /* bitpos */

         complain_overflow_dont, /* complain_on_overflow */

         _bfd_elf_rel_vtable_reloc_fn, /* special_function */

         "R_OPENRISC_GNU_VTENTRY", /* name */

         FALSE,                 /* partial_inplace */

         0,                      /* src_mask */

         0,                      /* dst_mask */

         FALSE),                /* pcrel_offset */

};

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

struct openrisc_reloc_map

{

  bfd_reloc_code_real_type bfd_reloc_val;

  unsigned int openrisc_reloc_val;

};

static const struct openrisc_reloc_map openrisc_reloc_map[] =

{

  { BFD_RELOC_NONE,             R_OPENRISC_NONE },

  { BFD_RELOC_32,               R_OPENRISC_32 },

  { BFD_RELOC_16,               R_OPENRISC_16 },

  { BFD_RELOC_8,                R_OPENRISC_8 },

  { BFD_RELOC_OPENRISC_REL_26,  R_OPENRISC_INSN_REL_26 },

  { BFD_RELOC_OPENRISC_ABS_26,  R_OPENRISC_INSN_ABS_26 },

  { BFD_RELOC_HI16,             R_OPENRISC_HI_16_IN_INSN },

  { BFD_RELOC_LO16,             R_OPENRISC_LO_16_IN_INSN },

  { BFD_RELOC_VTABLE_INHERIT,   R_OPENRISC_GNU_VTINHERIT },

  { BFD_RELOC_VTABLE_ENTRY,     R_OPENRISC_GNU_VTENTRY }

};

static reloc_howto_type *

openrisc_reloc_type_lookup (bfd * abfd ATTRIBUTE_UNUSED,

                            bfd_reloc_code_real_type code)

{

  unsigned int i;

  for (i = ARRAY_SIZE (openrisc_reloc_map); --i;)

    if (openrisc_reloc_map[i].bfd_reloc_val == code)

      return & openrisc_elf_howto_table[openrisc_reloc_map[i].

                                       openrisc_reloc_val];

  return NULL;

}

static reloc_howto_type *

openrisc_reloc_name_lookup (bfd *abfd ATTRIBUTE_UNUSED,

                            const char *r_name)

{

  unsigned int i;

  for (i = 0;

       i < (sizeof (openrisc_elf_howto_table)

            / sizeof (openrisc_elf_howto_table[0]));

       i++)

    if (openrisc_elf_howto_table[i].name != NULL

        && strcasecmp (openrisc_elf_howto_table[i].name, r_name) == 0)

      return &openrisc_elf_howto_table[i];

  return NULL;

}

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

static void

openrisc_info_to_howto_rela (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_OPENRISC_max);

  cache_ptr->howto = & openrisc_elf_howto_table[r_type];

}

/* 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

openrisc_final_link_relocate (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)

    {

    case R_OPENRISC_LO_16_IN_INSN:

      relocation &= 0xffff;

      r = _bfd_final_link_relocate (howto, input_bfd, input_section,

                                    contents, rel->r_offset,

                                    relocation, rel->r_addend);

      break;

    default:

      r = _bfd_final_link_relocate (howto, input_bfd, input_section,

                                    contents, rel->r_offset,

                                    relocation, rel->r_addend);

    }

  return r;

}

/* Relocate an OpenRISC ELF section.

   The RELOCATE_SECTION function is called by the new ELF backend linker

   to handle the relocations for a section.

   The relocs are always passed as Rela structures; if the section

   actually uses Rel structures, the r_addend field will always be

   zero.

   This function is responsible for adjusting the section contents as

   necessary, and (if using Rela relocs and generating a relocatable

   output file) adjusting the reloc addend as necessary.

   This function does not have to worry about setting the reloc

   address or the reloc symbol index.

   LOCAL_SYMS is a pointer to the swapped in local symbols.

   LOCAL_SECTIONS is an array giving the section in the input file

   corresponding to the st_shndx field of each local symbol.

   The global hash table entry for the global symbols can be found

   via elf_sym_hashes (input_bfd).

   When generating relocatable output, this function must handle

   STB_LOCAL/STT_SECTION symbols specially.  The output symbol is

   going to be the section symbol corresponding to the output

   section, which means that the addend must be adjusted

   accordingly.  */

static bfd_boolean

openrisc_elf_relocate_section (bfd *output_bfd,

                               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;

  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 = NULL;

      int r_type;

      r_type = ELF32_R_TYPE (rel->r_info);

      r_symndx = ELF32_R_SYM (rel->r_info);

      if (r_type == R_OPENRISC_GNU_VTINHERIT

          || r_type == R_OPENRISC_GNU_VTENTRY)

        continue;

      if ((unsigned int) r_type >

          (sizeof openrisc_elf_howto_table / sizeof (reloc_howto_type)))

        abort ();

      howto = openrisc_elf_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);

        }

      if (sec != NULL && elf_discarded_section (sec))

        {

          /* For relocs against symbols from removed linkonce sections,

             or sections discarded by a linker script, we just want the

             section contents zeroed.  Avoid any special processing.  */

          _bfd_clear_contents (howto, input_bfd, contents + rel->r_offset);

          rel->r_info = 0;

          rel->r_addend = 0;

          continue;

        }

      if (info->relocatable)

        continue;

      r = openrisc_final_link_relocate (howto, input_bfd, input_section,

                                        contents, rel, relocation);

      if (r != bfd_reloc_ok)

        {

          const char *msg = 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;

}

/* Return the section that should be marked against GC for a given

   relocation.  */

static asection *

openrisc_elf_gc_mark_hook (asection *sec,

                           struct bfd_link_info *info,

                           Elf_Internal_Rela *rel,

                           struct elf_link_hash_entry *h,

                           Elf_Internal_Sym *sym)

{

  if (h != NULL)

    switch (ELF32_R_TYPE (rel->r_info))

      {

      case R_OPENRISC_GNU_VTINHERIT:

      case R_OPENRISC_GNU_VTENTRY:

        return NULL;

      }

  return _bfd_elf_gc_mark_hook (sec, info, rel, h, sym);

}

/* 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

openrisc_elf_check_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;

  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);

  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;

        }

      switch (ELF32_R_TYPE (rel->r_info))

        {

          /* This relocation describes the C++ object vtable hierarchy.

             Reconstruct it for later use during GC.  */

        case R_OPENRISC_GNU_VTINHERIT:

          if (!bfd_elf_gc_record_vtinherit (abfd, sec, h, rel->r_offset))

            return FALSE;

          break;

          /* This relocation describes which C++ vtable entries are actually

             used.  Record for later use during GC.  */

        case R_OPENRISC_GNU_VTENTRY:

          BFD_ASSERT (h != NULL);

          if (h != NULL

              && !bfd_elf_gc_record_vtentry (abfd, sec, h, rel->r_addend))

            return FALSE;

          break;

        }

    }

  return TRUE;

}

/* Set the right machine number.  */

static bfd_boolean

openrisc_elf_object_p (bfd *abfd)

{

  bfd_default_set_arch_mach (abfd, bfd_arch_openrisc, 0);

  return TRUE;

}

/* Store the machine number in the flags field.  */

static void

openrisc_elf_final_write_processing (bfd *abfd,

                                     bfd_boolean linker ATTRIBUTE_UNUSED)

{

  unsigned long val;

  switch (bfd_get_mach (abfd))

    {

    default:

      val = 0;

      break;

    }

  elf_elfheader (abfd)->e_flags &= ~0xf;

  elf_elfheader (abfd)->e_flags |= val;

}

#define ELF_ARCH                        bfd_arch_openrisc

#define ELF_MACHINE_CODE                EM_OPENRISC

#define ELF_MACHINE_ALT1                EM_OPENRISC_OLD

#define ELF_MAXPAGESIZE                 0x1000

#define TARGET_BIG_SYM                  bfd_elf32_openrisc_vec

#define TARGET_BIG_NAME                 "elf32-openrisc"

#define elf_info_to_howto_rel           NULL

#define elf_info_to_howto               openrisc_info_to_howto_rela

#define elf_backend_relocate_section    openrisc_elf_relocate_section

#define elf_backend_gc_mark_hook        openrisc_elf_gc_mark_hook

#define elf_backend_check_relocs        openrisc_elf_check_relocs

#define elf_backend_can_gc_sections     1

#define elf_backend_rela_normal         1

#define bfd_elf32_bfd_reloc_type_lookup openrisc_reloc_type_lookup

#define bfd_elf32_bfd_reloc_name_lookup openrisc_reloc_name_lookup

#define elf_backend_object_p                openrisc_elf_object_p

#define elf_backend_final_write_processing  openrisc_elf_final_write_processing

#include "elf32-target.h"