path: root/ld/emultempl/armelf.em

# This shell script emits a C file. -*- C -*-
#   Copyright 1991, 1993, 1996, 1997, 1998, 1999, 2000, 2002
#   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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
#

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

#include "elf-bfd.h"
#include "elf/arm.h"

static int    no_pipeline_knowledge = 0;
static char * thumb_entry_symbol = NULL;
static bfd *  bfd_for_interwork;

static void  arm_elf_after_open                PARAMS ((void));
static void  arm_elf_set_bfd_for_interworking  PARAMS ((lang_statement_union_type *));
static void  arm_elf_before_allocation         PARAMS ((void));
static void  arm_elf_stringify_thumb_address   PARAMS ((struct bfd_link_hash_entry *, char *));
static void  arm_elf_finish                    PARAMS ((void));


static void
gld${EMULATION_NAME}_before_parse ()
{
#ifndef TARGET_			/* I.e., if not generic.  */
  ldfile_set_output_arch ("`echo ${ARCH}`");
#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 ()
{
  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 (statement)
     lang_statement_union_type * statement;
{
  if (statement->header.type == lang_input_section_enum
      && statement->input_section.ifile->just_syms_flag == false)
    {
      asection * i = statement->input_section.section;
      asection * output_section = i->output_section;

      ASSERT (output_section->owner == output_bfd);

      if ((output_section->flags & SEC_HAS_CONTENTS) != 0
	  && (i->flags & SEC_NEVER_LOAD) == 0
	  && ! i->owner->output_has_begun)
	{
	  bfd_for_interwork = i->owner;
	  bfd_for_interwork->output_has_begun = true;
	}
    }
}

static void
arm_elf_before_allocation ()
{
  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);
      ASSERT (bfd_for_interwork != NULL);
      for (tem = link_info.input_bfds; tem != NULL; tem = tem->link_next)
	tem->output_has_begun = false;

      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,
						      no_pipeline_knowledge))
	  {
	    /* 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);
}

void
arm_elf_stringify_thumb_address (h, buffer)
     struct bfd_link_hash_entry * h;
     char * buffer;
{
  bfd_vma val;
      
  /* Get the address of the symbol.  */
  val = (h->u.def.value
	 + bfd_get_section_vma (output_bfd,
				h->u.def.section->output_section)
	 + h->u.def.section->output_offset);
  /* This is a thumb address, so the bottom bit of its address must be set.  */
  val |= 1;

  /* Now convert this value into a string.  */
  buffer[0] = '0';
  buffer[1] = 'x';

  sprintf_vma (buffer + 2, val);
}

static void
arm_elf_finish ()
{
  struct bfd_link_hash_entry * h;

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

  if (thumb_entry_symbol != NULL)
    {
      static char buffer[32];

      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)
	{
	  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);
	  
	  arm_elf_stringify_thumb_address (h, buffer);
	  entry_symbol.name = buffer;
	}
      else
	einfo (_("%P: warning: cannot find thumb start symbol %s\n"),
	       thumb_entry_symbol);
    }

  /* If init is a Thumb function set the LSB.  */
  h = bfd_link_hash_lookup (link_info.hash, link_info.init_function, false,
			    false, true);

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

      arm_elf_stringify_thumb_address (h, buffer);
      link_info.init_function = buffer;
    }

  /* If fini is a Thumb function set the LSB.  */
  h = bfd_link_hash_lookup (link_info.hash, link_info.fini_function, false,
			    false, true);

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

      arm_elf_stringify_thumb_address (h, buffer);
      link_info.fini_function = buffer;
    }
}

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
'

# Note we add 'n' to the short option list in order to prevent
# getopt_long_only from thinking that -n is a unique abbreviation
# for --no-pipeline-knowledge.  There is no case to handle 'n' here
# however, so instead it will be passed back to parse_args() in
# lexsup.c where it will be handled.
PARSE_AND_LIST_SHORTOPTS=pn

PARSE_AND_LIST_LONGOPTS='
  { "no-pipeline-knowledge", no_argument, NULL, '\'p\''},
  { "thumb-entry", required_argument, NULL, OPTION_THUMB_ENTRY},
'

PARSE_AND_LIST_OPTIONS='
  fprintf (file, _("  -p --no-pipeline-knowledge  Stop the linker knowing about the pipeline length\n"));
  fprintf (file, _("     --thumb-entry=<sym>      Set the entry point to be Thumb symbol <sym>\n"));
'

PARSE_AND_LIST_ARGS_CASES='
    case '\'p\'':
      no_pipeline_knowledge = 1;
      break;

    case OPTION_THUMB_ENTRY:
      thumb_entry_symbol = optarg;
      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

# 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