path: root/ld/emultempl/armelf.em

# This shell script emits a C file. -*- C -*-
#   Copyright 1991, 1993, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003,
#   2004, 2005
#   Free Software Foundation, Inc.
#
# This file is part of GLD, the Gnu Linker.
#
# 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., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA.
#

# This file is sourced from elf32.em, and defines extra arm-elf
# specific routines.
#
test -z $TARGET2_TYPE && TARGET2_TYPE="rel"
cat >>e${EMULATION_NAME}.c <<EOF

static char *thumb_entry_symbol = NULL;
static bfd *bfd_for_interwork;
static int byteswap_code = 0;
static int target1_is_rel = 0${TARGET1_IS_REL};
static char *target2_type = "${TARGET2_TYPE}";
static int fix_v4bx = 0;
static int use_blx = 0;

static void
gld${EMULATION_NAME}_before_parse (void)
{
#ifndef TARGET_			/* I.e., if not generic.  */
  ldfile_set_output_arch ("`echo ${ARCH}`", bfd_arch_unknown);
#endif /* not TARGET_ */
  config.dynamic_link = ${DYNAMIC_LINK-TRUE};
  config.has_shared = `if test -n "$GENERATE_SHLIB_SCRIPT" ; then echo TRUE ; else echo FALSE ; fi`;
}

static void
arm_elf_after_open (void)
{
  if (strstr (bfd_get_target (output_bfd), "arm") == NULL)
    {
      /* The arm backend needs special fields in the output hash structure.
	 These will only be created if the output format is an arm format,
	 hence we do not support linking and changing output formats at the
	 same time.  Use a link followed by objcopy to change output formats.  */
      einfo ("%F%X%P: error: cannot change output format whilst linking ARM binaries\n");
      return;
    }

  {
    LANG_FOR_EACH_INPUT_STATEMENT (is)
      {
	bfd_elf32_arm_add_glue_sections_to_bfd (is->the_bfd, & link_info);
      }
  }

  /* Call the standard elf routine.  */
  gld${EMULATION_NAME}_after_open ();
}

static void
arm_elf_set_bfd_for_interworking (lang_statement_union_type *statement)
{
  if (statement->header.type == lang_input_section_enum
      && !statement->input_section.ifile->just_syms_flag
      && (statement->input_section.section->flags & SEC_EXCLUDE) == 0)
    {
      asection *i = statement->input_section.section;
      asection *output_section = i->output_section;

      ASSERT (output_section->owner == output_bfd);

      /* Don't attach the interworking stubs to a dynamic object, to
	 an empty section, etc.  */
      if ((output_section->flags & SEC_HAS_CONTENTS) != 0
	  && (i->flags & SEC_NEVER_LOAD) == 0
	  && ! (i->owner->flags & DYNAMIC)
	  && ! i->owner->output_has_begun)
	{
	  bfd_for_interwork = i->owner;
	  bfd_for_interwork->output_has_begun = TRUE;
	}
    }
}

static void
arm_elf_before_allocation (void)
{
  bfd *tem;

  /* Call the standard elf routine.  */
  gld${EMULATION_NAME}_before_allocation ();

  if (link_info.input_bfds != NULL)
    {
      /* The interworking bfd must be the last one in the link.  */
      bfd_for_interwork = NULL;
      for (tem = link_info.input_bfds; tem != NULL; tem = tem->link_next)
	tem->output_has_begun = FALSE;

      lang_for_each_statement (arm_elf_set_bfd_for_interworking);
      for (tem = link_info.input_bfds; tem != NULL; tem = tem->link_next)
	tem->output_has_begun = FALSE;

      /* If bfd_for_interwork is NULL, then there are no loadable sections
	 with real contents to be linked, so we are not going to have to
	 create any interworking stubs, so it is OK not to call
	 bfd_elf32_arm_get_bfd_for_interworking.  */
      if (bfd_for_interwork != NULL)
	bfd_elf32_arm_get_bfd_for_interworking (bfd_for_interwork, &link_info);
    }
  /* We should be able to set the size of the interworking stub section.  */

  /* Here we rummage through the found bfds to collect glue information.  */
  /* FIXME: should this be based on a command line option? krk@cygnus.com  */
  {
    LANG_FOR_EACH_INPUT_STATEMENT (is)
      {
	if (!bfd_elf32_arm_process_before_allocation (is->the_bfd, & link_info,
						      byteswap_code))
	  {
	    /* xgettext:c-format */
	    einfo (_("Errors encountered processing file %s"), is->filename);
	  }
      }
  }

  /* We have seen it all. Allocate it, and carry on.  */
  bfd_elf32_arm_allocate_interworking_sections (& link_info);
}

static void
arm_elf_finish (void)
{
  struct bfd_link_hash_entry * h;

  /* Call the elf32.em routine.  */
  gld${EMULATION_NAME}_finish ();

  if (thumb_entry_symbol == NULL)
    return;

  h = bfd_link_hash_lookup (link_info.hash, thumb_entry_symbol,
			    FALSE, FALSE, TRUE);

  if (h != (struct bfd_link_hash_entry *) NULL
      && (h->type == bfd_link_hash_defined
	  || h->type == bfd_link_hash_defweak)
      && h->u.def.section->output_section != NULL)
    {
      static char buffer[32];
      bfd_vma val;

      /* Special procesing is required for a Thumb entry symbol.  The
	 bottom bit of its address must be set.  */
      val = (h->u.def.value
	     + bfd_get_section_vma (output_bfd,
				    h->u.def.section->output_section)
	     + h->u.def.section->output_offset);

      val |= 1;

      /* Now convert this value into a string and store it in entry_symbol
	 where the lang_finish() function will pick it up.  */
      buffer[0] = '0';
      buffer[1] = 'x';

      sprintf_vma (buffer + 2, val);

      if (entry_symbol.name != NULL && entry_from_cmdline)
	einfo (_("%P: warning: '--thumb-entry %s' is overriding '-e %s'\n"),
	       thumb_entry_symbol, entry_symbol.name);
      entry_symbol.name = buffer;
    }
  else
    einfo (_("%P: warning: connot find thumb start symbol %s\n"),
	   thumb_entry_symbol);
}

/* This is a convenitent point to tell BFD about target specific flags.
   After the output has been created, but before inputs are read.  */
static void
arm_elf_create_output_section_statements (void)
{
  bfd_elf32_arm_set_target_relocs (&link_info, target1_is_rel, target2_type,
                                   fix_v4bx, use_blx);
}

EOF

# Define some shell vars to insert bits of code into the standard elf
# parse_args and list_options functions.
#
PARSE_AND_LIST_PROLOGUE='
#define OPTION_THUMB_ENTRY		301
#define OPTION_BE8			302
#define OPTION_TARGET1_REL		303
#define OPTION_TARGET1_ABS		304
#define OPTION_TARGET2			305
#define OPTION_FIX_V4BX			306
#define OPTION_USE_BLX			307
'

PARSE_AND_LIST_SHORTOPTS=p

PARSE_AND_LIST_LONGOPTS='
  { "no-pipeline-knowledge", no_argument, NULL, '\'p\''},
  { "thumb-entry", required_argument, NULL, OPTION_THUMB_ENTRY},
  { "be8", no_argument, NULL, OPTION_BE8},
  { "target1-rel", no_argument, NULL, OPTION_TARGET1_REL},
  { "target1-abs", no_argument, NULL, OPTION_TARGET1_ABS},
  { "target2", required_argument, NULL, OPTION_TARGET2},
  { "fix-v4bx", no_argument, NULL, OPTION_FIX_V4BX},
  { "use-blx", no_argument, NULL, OPTION_USE_BLX},
'

PARSE_AND_LIST_OPTIONS='
  fprintf (file, _("     --thumb-entry=<sym>      Set the entry point to be Thumb symbol <sym>\n"));
  fprintf (file, _("     --be8                    Oputput BE8 format image\n"));
  fprintf (file, _("     --target1=rel            Interpret R_ARM_TARGET1 as R_ARM_REL32\n"));
  fprintf (file, _("     --target1=abs            Interpret R_ARM_TARGET1 as R_ARM_ABS32\n"));
  fprintf (file, _("     --target2=<type>         Specify definition of R_ARM_TARGET2\n"));
  fprintf (file, _("     --fix-v4bx               Rewrite BX rn as MOV pc, rn for ARMv4\n"));
  fprintf (file, _("     --use-blx                Enable use of BLX instructions\n"));
'

PARSE_AND_LIST_ARGS_CASES='
    case '\'p\'':
      /* Only here for backwards compatibility.  */
      break;

    case OPTION_THUMB_ENTRY:
      thumb_entry_symbol = optarg;
      break;

    case OPTION_BE8:
      byteswap_code = 1;
      break;

    case OPTION_TARGET1_REL:
      target1_is_rel = 1;
      break;

    case OPTION_TARGET1_ABS:
      target1_is_rel = 0;
      break;

    case OPTION_TARGET2:
      target2_type = optarg;
      break;

    case OPTION_FIX_V4BX:
      fix_v4bx = 1;
      break;

    case OPTION_USE_BLX:
      use_blx = 1;
      break;
'

# We have our own after_open and before_allocation functions, but they call
# the standard routines, so give them a different name.
LDEMUL_AFTER_OPEN=arm_elf_after_open
LDEMUL_BEFORE_ALLOCATION=arm_elf_before_allocation
LDEMUL_CREATE_OUTPUT_SECTION_STATEMENTS=arm_elf_create_output_section_statements

# Replace the elf before_parse function with our own.
LDEMUL_BEFORE_PARSE=gld"${EMULATION_NAME}"_before_parse

# Call the extra arm-elf function
LDEMUL_FINISH=arm_elf_finish