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# This shell script emits a C file. -*- C -*-

#   Copyright 2006, 2007, 2008, 2009

#   Free Software Foundation, Inc.

#

# This file is part of the GNU Binutils.

#

# 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.

# This file is sourced from elf32.em, and defines extra avr-elf specific

# routines.  It is used to generate the trampolines for the avr6 family

# of devices where one needs to address the issue that it is not possible

# to reach the whole program memory by using 16 bit pointers.

fragment <

#include "elf32-avr.h"

#include "ldctor.h"

/* The fake file and it's corresponding section meant to hold

   the linker stubs if needed.  */

static lang_input_statement_type *stub_file;

static asection *avr_stub_section;

/* Variables set by the command-line parameters and transfered

   to the bfd without use of global shared variables.  */

static bfd_boolean avr_no_stubs = FALSE;

static bfd_boolean avr_debug_relax = FALSE;

static bfd_boolean avr_debug_stubs = FALSE;

static bfd_boolean avr_replace_call_ret_sequences = TRUE;

static bfd_vma avr_pc_wrap_around = 0x10000000;

/* Transfers information to the bfd frontend.  */

static void

avr_elf_set_global_bfd_parameters (void)

{

  elf32_avr_setup_params (& link_info,

                          stub_file->the_bfd,

                          avr_stub_section,

                          avr_no_stubs,

                          avr_debug_stubs,

                          avr_debug_relax,

                          avr_pc_wrap_around,

                          avr_replace_call_ret_sequences);

}

/* Makes a conservative estimate of the trampoline section size that could

   be corrected later on.  */

static void

avr_elf_${EMULATION_NAME}_before_allocation (void)

{

  int ret;

  gld${EMULATION_NAME}_before_allocation ();

  /* We only need stubs for the avr6 family.  */

  if (strcmp ("${EMULATION_NAME}","avr6"))

    avr_no_stubs = TRUE;

  avr_elf_set_global_bfd_parameters ();

  /* If generating a relocatable output file, then

     we don't  have to generate the trampolines.  */

  if (link_info.relocatable)

    avr_no_stubs = TRUE;

  if (avr_no_stubs)

    return;

  ret = elf32_avr_setup_section_lists (link_info.output_bfd, &link_info);

  if (ret < 0)

    einfo ("%X%P: can not setup the input section list: %E\n");

  if (ret <= 0)

    return;

  /* Call into the BFD backend to do the real "stub"-work.  */

  if (! elf32_avr_size_stubs (link_info.output_bfd, &link_info, TRUE))

    einfo ("%X%P: can not size stub section: %E\n");

}

/* This is called before the input files are opened.  We create a new

   fake input file to hold the stub section and generate the section itself.  */

static void

avr_elf_create_output_section_statements (void)

{

  flagword flags;

  stub_file = lang_add_input_file ("linker stubs",

                                   lang_input_file_is_fake_enum,

                                   NULL);

  stub_file->the_bfd = bfd_create ("linker stubs", link_info.output_bfd);

  if (stub_file->the_bfd == NULL

      || !bfd_set_arch_mach (stub_file->the_bfd,

                             bfd_get_arch (link_info.output_bfd),

                             bfd_get_mach (link_info.output_bfd)))

    {

      einfo ("%X%P: can not create stub BFD %E\n");

      return;

    }

  /* Now we add the stub section.  */

  flags = (SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE

           | SEC_HAS_CONTENTS | SEC_RELOC | SEC_IN_MEMORY | SEC_KEEP);

  avr_stub_section = bfd_make_section_anyway_with_flags (stub_file->the_bfd,

                                                         ".trampolines",

                                                         flags);

  if (avr_stub_section == NULL)

    goto err_ret;

  avr_stub_section->alignment_power = 1;

  ldlang_add_file (stub_file);

  return;

  err_ret:

   einfo ("%X%P: can not make stub section: %E\n");

   return;

}

/* Re-calculates the size of the stubs so that we won't waste space.  */

static void

avr_elf_after_allocation (void)

{

  if (!avr_no_stubs && !command_line.relax)

    {

      /* If relaxing, elf32_avr_size_stubs will be called from

         elf32_avr_relax_section.  */

      if (!elf32_avr_size_stubs (link_info.output_bfd, &link_info, FALSE))

        einfo ("%X%P: can not size stub section: %E\n");

    }

  gld${EMULATION_NAME}_after_allocation ();

  /* Now build the linker stubs.  */

  if (!avr_no_stubs)

    {

      if (!elf32_avr_build_stubs (&link_info))

        einfo ("%X%P: can not build stubs: %E\n");

    }

}

EOF

PARSE_AND_LIST_PROLOGUE='

#define OPTION_NO_CALL_RET_REPLACEMENT 301

#define OPTION_PMEM_WRAP_AROUND        302

#define OPTION_NO_STUBS                303

#define OPTION_DEBUG_STUBS             304

#define OPTION_DEBUG_RELAX             305

'

PARSE_AND_LIST_LONGOPTS='

  { "no-call-ret-replacement", no_argument,

     NULL, OPTION_NO_CALL_RET_REPLACEMENT},

  { "pmem-wrap-around", required_argument,

    NULL, OPTION_PMEM_WRAP_AROUND},

  { "no-stubs", no_argument,

    NULL, OPTION_NO_STUBS},

  { "debug-stubs", no_argument,

    NULL, OPTION_DEBUG_STUBS},

  { "debug-relax", no_argument,

    NULL, OPTION_DEBUG_RELAX},

'

PARSE_AND_LIST_OPTIONS='

  fprintf (file, _("  --pmem-wrap-around=    "

                   "Make the linker relaxation machine assume that a\n"

                   "                              "

                   "  program counter wrap-around occures at address\n"

                   "                              "

                   "  .  Supported values: 8k, 16k, 32k and 64k.\n"));

  fprintf (file, _("  --no-call-ret-replacement   "

                   "The relaxation machine normally will\n"

                   "                              "

                   "  substitute two immediately following call/ret\n"

                   "                              "

                   "  instructions by a single jump instruction.\n"

                   "                              "

                   "  This option disables this optimization.\n"));

  fprintf (file, _("  --no-stubs                  "

                   "If the linker detects to attempt to access\n"

                   "                              "

                   "  an instruction beyond 128k by a reloc that\n"

                   "                              "

                   "  is limited to 128k max, it inserts a jump\n"

                   "                              "

                   "  stub. You can de-active this with this switch.\n"));

  fprintf (file, _("  --debug-stubs               "

                   "Used for debugging avr-ld.\n"));

  fprintf (file, _("  --debug-relax               "

                   "Used for debugging avr-ld.\n"));

'

PARSE_AND_LIST_ARGS_CASES='

    case OPTION_PMEM_WRAP_AROUND:

      {

        /* This variable is defined in the bfd library.  */

        if ((!strcmp (optarg,"32k"))      || (!strcmp (optarg,"32K")))

          avr_pc_wrap_around = 32768;

        else if ((!strcmp (optarg,"8k")) || (!strcmp (optarg,"8K")))

          avr_pc_wrap_around = 8192;

        else if ((!strcmp (optarg,"16k")) || (!strcmp (optarg,"16K")))

          avr_pc_wrap_around = 16384;

        else if ((!strcmp (optarg,"64k")) || (!strcmp (optarg,"64K")))

          avr_pc_wrap_around = 0x10000;

        else

          return FALSE;

      }

      break;

    case OPTION_DEBUG_STUBS:

      avr_debug_stubs = TRUE;

      break;

    case OPTION_DEBUG_RELAX:

      avr_debug_relax = TRUE;

      break;

    case OPTION_NO_STUBS:

      avr_no_stubs = TRUE;

      break;

    case OPTION_NO_CALL_RET_REPLACEMENT:

      {

        /* This variable is defined in the bfd library.  */

        avr_replace_call_ret_sequences = FALSE;

      }

      break;

'

#

# Put these extra avr-elf routines in ld_${EMULATION_NAME}_emulation

#

LDEMUL_BEFORE_ALLOCATION=avr_elf_${EMULATION_NAME}_before_allocation

LDEMUL_AFTER_ALLOCATION=avr_elf_after_allocation

LDEMUL_CREATE_OUTPUT_SECTION_STATEMENTS=avr_elf_create_output_section_statements