elf32-msp430.c   [plain text]

/*  MSP430-specific support for 32-bit ELF
    Copyright (C) 2002 Free Software Foundation, Inc.
    Contributed by Dmitry Diky <diwil@mail.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 "libiberty.h"
#include "libbfd.h"
#include "elf-bfd.h"
#include "elf/msp430.h"

static reloc_howto_type *bfd_elf32_bfd_reloc_type_lookup
  PARAMS ((bfd *, bfd_reloc_code_real_type));

static void msp430_info_to_howto_rela
  PARAMS ((bfd *, arelent *, Elf_Internal_Rela *));

static asection *elf32_msp430_gc_mark_hook
  PARAMS ((asection *, struct bfd_link_info *, Elf_Internal_Rela *,
	   struct elf_link_hash_entry *, Elf_Internal_Sym *));

static bfd_boolean elf32_msp430_gc_sweep_hook
  PARAMS ((bfd *, struct bfd_link_info *, asection *,
	   const Elf_Internal_Rela *));

static bfd_boolean elf32_msp430_check_relocs
  PARAMS ((bfd *, struct bfd_link_info *, asection *,
	   const Elf_Internal_Rela *));

static bfd_reloc_status_type msp430_final_link_relocate
  PARAMS ((reloc_howto_type *, bfd *, asection *, bfd_byte *,
	   Elf_Internal_Rela *, bfd_vma));

static bfd_boolean elf32_msp430_relocate_section
  PARAMS ((bfd *, struct bfd_link_info *, bfd *, asection *, bfd_byte *,
	   Elf_Internal_Rela *, Elf_Internal_Sym *, asection **));

static void bfd_elf_msp430_final_write_processing
  PARAMS ((bfd *, bfd_boolean));

static bfd_boolean elf32_msp430_object_p
  PARAMS ((bfd *));

static void elf32_msp430_post_process_headers
  PARAMS ((bfd *, struct bfd_link_info *));

/* Use RELA instead of REL.  */
#undef USE_REL

static reloc_howto_type elf_msp430_howto_table[] =
{
  HOWTO (R_MSP430_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_MSP430_NONE",	/* name */
	 FALSE,			/* partial_inplace */
	 0,			/* src_mask */
	 0,			/* dst_mask */
	 FALSE),		/* pcrel_offset */

  HOWTO (R_MSP430_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_MSP430_32",		/* name */
	 FALSE,			/* partial_inplace */
	 0xffffffff,		/* src_mask */
	 0xffffffff,		/* dst_mask */
	 FALSE),		/* pcrel_offset */

  /* A 13 bit PC relative relocation.  */
  HOWTO (R_MSP430_10_PCREL,	/* type */
	 1,			/* rightshift */
	 1,			/* size (0 = byte, 1 = short, 2 = long) */
	 10,			/* bitsize */
	 TRUE,			/* pc_relative */
	 0,			/* bitpos */
	 complain_overflow_bitfield,	/* complain_on_overflow */
	 bfd_elf_generic_reloc,	/* special_function */
	 "R_MSP430_13_PCREL",	/* name */
	 FALSE,			/* partial_inplace */
	 0xfff,			/* src_mask */
	 0xfff,			/* dst_mask */
	 TRUE),			/* pcrel_offset */

  /* A 16 bit absolute relocation.  */
  HOWTO (R_MSP430_16,		/* 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_MSP430_16",		/* name */
	 FALSE,			/* partial_inplace */
	 0xffff,		/* src_mask */
	 0xffff,		/* dst_mask */
	 FALSE),		/* pcrel_offset */

  /* A 16 bit absolute relocation for command address.  */
  HOWTO (R_MSP430_16_PCREL,	/* type */
	 1,			/* rightshift */
	 1,			/* size (0 = byte, 1 = short, 2 = long) */
	 16,			/* bitsize */
	 TRUE,			/* pc_relative */
	 0,			/* bitpos */
	 complain_overflow_dont,/* complain_on_overflow */
	 bfd_elf_generic_reloc,	/* special_function */
	 "R_MSP430_16_PCREL",	/* name */
	 FALSE,			/* partial_inplace */
	 0xffff,		/* src_mask */
	 0xffff,		/* dst_mask */
	 TRUE),			/* pcrel_offset */

  /* A 16 bit absolute relocation, byte operations.  */
  HOWTO (R_MSP430_16_BYTE,	/* 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_MSP430_16_BYTE",	/* name */
	 FALSE,			/* partial_inplace */
	 0xffff,		/* src_mask */
	 0xffff,		/* dst_mask */
	 FALSE),		/* pcrel_offset */

  /* A 16 bit absolute relocation for command address.  */
  HOWTO (R_MSP430_16_PCREL_BYTE,/* type */
	 1,			/* rightshift */
	 1,			/* size (0 = byte, 1 = short, 2 = long) */
	 16,			/* bitsize */
	 TRUE,			/* pc_relative */
	 0,			/* bitpos */
	 complain_overflow_dont,/* complain_on_overflow */
	 bfd_elf_generic_reloc,	/* special_function */
	 "R_MSP430_16_PCREL_BYTE",	/* name */
	 FALSE,			/* partial_inplace */
	 0xffff,		/* src_mask */
	 0xffff,		/* dst_mask */
	 TRUE)			/* pcrel_offset */
};

/* Map BFD reloc types to MSP430 ELF reloc types.  */

struct msp430_reloc_map
{
  bfd_reloc_code_real_type bfd_reloc_val;
  unsigned int elf_reloc_val;
};

static const struct msp430_reloc_map msp430_reloc_map[] =
  {
    {BFD_RELOC_NONE, R_MSP430_NONE},
    {BFD_RELOC_32, R_MSP430_32},
    {BFD_RELOC_MSP430_10_PCREL, R_MSP430_10_PCREL},
    {BFD_RELOC_16, R_MSP430_16_BYTE},
    {BFD_RELOC_MSP430_16_PCREL, R_MSP430_16_PCREL},
    {BFD_RELOC_MSP430_16, R_MSP430_16},
    {BFD_RELOC_MSP430_16_PCREL_BYTE, R_MSP430_16_PCREL_BYTE},
    {BFD_RELOC_MSP430_16_BYTE, R_MSP430_16_BYTE}
  };

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 < ARRAY_SIZE (msp430_reloc_map); i++)
    if (msp430_reloc_map[i].bfd_reloc_val == code)
      return &elf_msp430_howto_table[msp430_reloc_map[i].elf_reloc_val];

  return NULL;
}

/* Set the howto pointer for an MSP430 ELF reloc.  */

static void
msp430_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_MSP430_max);
  cache_ptr->howto = &elf_msp430_howto_table[r_type];
}

static asection *
elf32_msp430_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_msp430_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 msp430.  */
  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_msp430_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->relocateable)
    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];
    }

  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
msp430_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;
  bfd_vma x;
  bfd_signed_vma srel;

  switch (howto->type)
    {
    case R_MSP430_10_PCREL:
      contents += rel->r_offset;
      srel = (bfd_signed_vma) relocation;
      srel += rel->r_addend;
      srel -= rel->r_offset;
      srel -= 2;		/* Branch instructions add 2 to the PC...  */
      srel -= (input_section->output_section->vma +
	       input_section->output_offset);

      if (srel & 1)
	return bfd_reloc_outofrange;

      /* MSP430 addresses commands as words.  */
      srel >>= 1;

      /* Check for an overflow.  */
      if (srel < -512 || srel > 511)
	return bfd_reloc_overflow;

      x = bfd_get_16 (input_bfd, contents);
      x = (x & 0xfc00) | (srel & 0x3ff);
      bfd_put_16 (input_bfd, x, contents);
      break;

    case R_MSP430_16_PCREL:
      contents += rel->r_offset;
      srel = (bfd_signed_vma) relocation;
      srel += rel->r_addend;
      srel -= rel->r_offset;
      /* Only branch instructions add 2 to the PC...  */
      srel -= (input_section->output_section->vma +
	       input_section->output_offset);

      if (srel & 1)
	return bfd_reloc_outofrange;

      bfd_put_16 (input_bfd, srel & 0xffff, contents);
      break;

    case R_MSP430_16_PCREL_BYTE:
      contents += rel->r_offset;
      srel = (bfd_signed_vma) relocation;
      srel += rel->r_addend;
      srel -= rel->r_offset;
      /* Only branch instructions add 2 to the PC...  */
      srel -= (input_section->output_section->vma +
	       input_section->output_offset);

      bfd_put_16 (input_bfd, srel & 0xffff, contents);
      break;

    case R_MSP430_16_BYTE:
      contents += rel->r_offset;
      srel = (bfd_signed_vma) relocation;
      srel += rel->r_addend;
      bfd_put_16 (input_bfd, srel & 0xffff, contents);
      break;

    case R_MSP430_16:
      contents += rel->r_offset;
      srel = (bfd_signed_vma) relocation;
      srel += rel->r_addend;

      if (srel & 1)
	return bfd_reloc_notsupported;

      bfd_put_16 (input_bfd, srel & 0xffff, contents);
      break;

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

  return r;
}

/* Relocate an MSP430 ELF section.  */

static bfd_boolean
elf32_msp430_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;

  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;

      /* This is a final link.  */

      r_type = ELF32_R_TYPE (rel->r_info);
      r_symndx = ELF32_R_SYM (rel->r_info);
      howto = elf_msp430_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
	{
	  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;

	  name = h->root.root.string;

	  if (h->root.type == bfd_link_hash_defined
	      || h->root.type == bfd_link_hash_defweak)
	    {
	      sec = h->root.u.def.section;
	      relocation = (h->root.u.def.value
			    + sec->output_section->vma + sec->output_offset);
	    }
	  else if (h->root.type == bfd_link_hash_undefweak)
	    {
	      relocation = 0;
	    }
	  else
	    {
	      if (!((*info->callbacks->undefined_symbol)
		    (info, h->root.root.string, input_bfd,
		     input_section, rel->r_offset, TRUE)))
		return FALSE;
	      relocation = 0;
	    }
	}

      r = msp430_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, 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 MSP430 ELF object
   file.  This gets the MSP430 architecture right based on the machine
   number.  */

static void
bfd_elf_msp430_final_write_processing (abfd, linker)
     bfd *abfd;
     bfd_boolean linker ATTRIBUTE_UNUSED;
{
  unsigned long val;

  switch (bfd_get_mach (abfd))
    {
    default:
    case bfd_mach_msp12:
      val = E_MSP430_MACH_MSP430x12;
      break;

    case bfd_mach_msp110:
      val = E_MSP430_MACH_MSP430x11x1;
      break;

    case bfd_mach_msp11:
      val = E_MSP430_MACH_MSP430x11;
      break;

    case bfd_mach_msp13:
      val = E_MSP430_MACH_MSP430x13;
      break;

    case bfd_mach_msp14:
      val = E_MSP430_MACH_MSP430x14;
      break;

    case bfd_mach_msp41:
      val = E_MSP430_MACH_MSP430x41;
      break;

    case bfd_mach_msp43:
      val = E_MSP430_MACH_MSP430x43;
      break;

    case bfd_mach_msp44:
      val = E_MSP430_MACH_MSP430x44;
      break;

    case bfd_mach_msp31:
      val = E_MSP430_MACH_MSP430x31;
      break;

    case bfd_mach_msp32:
      val = E_MSP430_MACH_MSP430x32;
      break;

    case bfd_mach_msp33:
      val = E_MSP430_MACH_MSP430x33;
      break;

    case bfd_mach_msp15:
      val = E_MSP430_MACH_MSP430x15;
      break;

    case bfd_mach_msp16:
      val = E_MSP430_MACH_MSP430x16;
      break;
    }

  elf_elfheader (abfd)->e_machine = EM_MSP430;
  elf_elfheader (abfd)->e_flags &= ~EF_MSP430_MACH;
  elf_elfheader (abfd)->e_flags |= val;
}

/* Set the right machine number.  */

static bfd_boolean
elf32_msp430_object_p (abfd)
     bfd *abfd;
{
  int e_set = bfd_mach_msp14;

  if (elf_elfheader (abfd)->e_machine == EM_MSP430
      || elf_elfheader (abfd)->e_machine == EM_MSP430_OLD)
    {
      int e_mach = elf_elfheader (abfd)->e_flags & EF_MSP430_MACH;

      switch (e_mach)
	{
	default:
	case E_MSP430_MACH_MSP430x12:
	  e_set = bfd_mach_msp12;
	  break;

	case E_MSP430_MACH_MSP430x11:
	  e_set = bfd_mach_msp11;
	  break;

	case E_MSP430_MACH_MSP430x11x1:
	  e_set = bfd_mach_msp110;
	  break;

	case E_MSP430_MACH_MSP430x13:
	  e_set = bfd_mach_msp13;
	  break;

	case E_MSP430_MACH_MSP430x14:
	  e_set = bfd_mach_msp14;
	  break;

	case E_MSP430_MACH_MSP430x41:
	  e_set = bfd_mach_msp41;
	  break;

	case E_MSP430_MACH_MSP430x31:
	  e_set = bfd_mach_msp31;
	  break;

	case E_MSP430_MACH_MSP430x32:
	  e_set = bfd_mach_msp32;
	  break;

	case E_MSP430_MACH_MSP430x33:
	  e_set = bfd_mach_msp33;
	  break;

	case E_MSP430_MACH_MSP430x43:
	  e_set = bfd_mach_msp43;
	  break;

	case E_MSP430_MACH_MSP430x44:
	  e_set = bfd_mach_msp44;
	  break;

	case E_MSP430_MACH_MSP430x15:
	  e_set = bfd_mach_msp15;
	  break;

	case E_MSP430_MACH_MSP430x16:
	  e_set = bfd_mach_msp16;
	  break;
	}
    }

  return bfd_default_set_arch_mach (abfd, bfd_arch_msp430, e_set);
}

static void
elf32_msp430_post_process_headers (abfd, link_info)
     bfd *abfd;
     struct bfd_link_info *link_info ATTRIBUTE_UNUSED;
{
  Elf_Internal_Ehdr *i_ehdrp;	/* ELF file header, internal form.  */

  i_ehdrp = elf_elfheader (abfd);

#ifndef ELFOSABI_STANDALONE
#define ELFOSABI_STANDALONE	255
#endif

  i_ehdrp->e_ident[EI_OSABI] = ELFOSABI_STANDALONE;
}


#define ELF_ARCH		bfd_arch_msp430
#define ELF_MACHINE_CODE	EM_MSP430
#define ELF_MACHINE_ALT1	EM_MSP430_OLD
#define ELF_MAXPAGESIZE		1

#define TARGET_LITTLE_SYM       bfd_elf32_msp430_vec
#define TARGET_LITTLE_NAME	"elf32-msp430"

#define elf_info_to_howto	             msp430_info_to_howto_rela
#define elf_info_to_howto_rel	             NULL
#define elf_backend_relocate_section         elf32_msp430_relocate_section
#define elf_backend_gc_mark_hook             elf32_msp430_gc_mark_hook
#define elf_backend_gc_sweep_hook            elf32_msp430_gc_sweep_hook
#define elf_backend_check_relocs             elf32_msp430_check_relocs
#define elf_backend_can_gc_sections          1
#define elf_backend_final_write_processing   bfd_elf_msp430_final_write_processing
#define elf_backend_object_p		     elf32_msp430_object_p
#define elf_backend_post_process_headers     elf32_msp430_post_process_headers

#include "elf32-target.h"