ld/emultempl/avrelf.em

   1 # This shell script emits a C file. -*- C -*-
   2 #   Copyright (C) 2006-2014 Free Software Foundation, Inc.
   3 #
   4 # This file is part of the GNU Binutils.
   5 #
   6 # This program is free software; you can redistribute it and/or modify
   7 # it under the terms of the GNU General Public License as published by
   8 # the Free Software Foundation; either version 3 of the License, or
   9 # (at your option) any later version.
  10 #
  11 # This program is distributed in the hope that it will be useful,
  12 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 # GNU General Public License for more details.
  15 #
  16 # You should have received a copy of the GNU General Public License
  17 # along with this program; if not, write to the Free Software
  18 # Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  19 # MA 02110-1301, USA.
  20
  21
  22 # This file is sourced from elf32.em, and defines extra avr-elf specific
  23 # routines.  It is used to generate the trampolines for the avr6 family
  24 # of devices where one needs to address the issue that it is not possible
  25 # to reach the whole program memory by using 16 bit pointers.
  26
  27 fragment <<EOF
  28
  29 #include "elf32-avr.h"
  30 #include "ldctor.h"
  31
  32 /* The fake file and it's corresponding section meant to hold
  33    the linker stubs if needed.  */
  34
  35 static lang_input_statement_type *stub_file;
  36 static asection *avr_stub_section;
  37
  38 /* Variables set by the command-line parameters and transfered
  39    to the bfd without use of global shared variables.  */
  40
  41 static bfd_boolean avr_no_stubs = FALSE;
  42 static bfd_boolean avr_debug_relax = FALSE;
  43 static bfd_boolean avr_debug_stubs = FALSE;
  44 static bfd_boolean avr_replace_call_ret_sequences = TRUE;
  45 static bfd_vma avr_pc_wrap_around = 0x10000000;
  46
  47 /* Transfers information to the bfd frontend.  */
  48
  49 static void
  50 avr_elf_set_global_bfd_parameters (void)
  51 {
  52   elf32_avr_setup_params (& link_info,
  53                           stub_file->the_bfd,
  54                           avr_stub_section,
  55                           avr_no_stubs,
  56                           avr_debug_stubs,
  57                           avr_debug_relax,
  58                           avr_pc_wrap_around,
  59                           avr_replace_call_ret_sequences);
  60 }
  61
  62
  63 /* Makes a conservative estimate of the trampoline section size that could
  64    be corrected later on.  */
  65
  66 static void
  67 avr_elf_${EMULATION_NAME}_before_allocation (void)
  68 {
  69   int ret;
  70
  71   gld${EMULATION_NAME}_before_allocation ();
  72
  73   /* We only need stubs for avr6, avrxmega6, and avrxmega7. */
  74   if (strcmp ("${EMULATION_NAME}","avr6")
  75       && strcmp ("${EMULATION_NAME}","avrxmega6")
  76       && strcmp ("${EMULATION_NAME}","avrxmega7") )
  77     avr_no_stubs = TRUE;
  78
  79   avr_elf_set_global_bfd_parameters ();
  80
  81   /* If generating a relocatable output file, then
  82      we don't  have to generate the trampolines.  */
  83   if (link_info.relocatable)
  84     avr_no_stubs = TRUE;
  85
  86   if (avr_no_stubs)
  87     return;
  88
  89   ret = elf32_avr_setup_section_lists (link_info.output_bfd, &link_info);
  90
  91   if (ret < 0)
  92     einfo ("%X%P: can not setup the input section list: %E\n");
  93
  94   if (ret <= 0)
  95     return;
  96
  97   /* Call into the BFD backend to do the real "stub"-work.  */
  98   if (! elf32_avr_size_stubs (link_info.output_bfd, &link_info, TRUE))
  99     einfo ("%X%P: can not size stub section: %E\n");
 100 }
 101
 102 /* This is called before the input files are opened.  We create a new
 103    fake input file to hold the stub section and generate the section itself.  */
 104
 105 static void
 106 avr_elf_create_output_section_statements (void)
 107 {
 108   flagword flags;
 109
 110   stub_file = lang_add_input_file ("linker stubs",
 111                                    lang_input_file_is_fake_enum,
 112                                    NULL);
 113
 114   stub_file->the_bfd = bfd_create ("linker stubs", link_info.output_bfd);
 115   if (stub_file->the_bfd == NULL
 116       || !bfd_set_arch_mach (stub_file->the_bfd,
 117                              bfd_get_arch (link_info.output_bfd),
 118                              bfd_get_mach (link_info.output_bfd)))
 119     {
 120       einfo ("%X%P: can not create stub BFD %E\n");
 121       return;
 122     }
 123
 124   /* Now we add the stub section.  */
 125
 126   flags = (SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE
 127            | SEC_HAS_CONTENTS | SEC_RELOC | SEC_IN_MEMORY | SEC_KEEP);
 128   avr_stub_section = bfd_make_section_anyway_with_flags (stub_file->the_bfd,
 129                                                          ".trampolines",
 130                                                          flags);
 131   if (avr_stub_section == NULL)
 132     goto err_ret;
 133
 134   avr_stub_section->alignment_power = 1;
 135
 136   ldlang_add_file (stub_file);
 137
 138   return;
 139
 140   err_ret:
 141    einfo ("%X%P: can not make stub section: %E\n");
 142    return;
 143 }
 144
 145 /* Re-calculates the size of the stubs so that we won't waste space.  */
 146
 147 static void
 148 avr_elf_after_allocation (void)
 149 {
 150   if (!avr_no_stubs && ! RELAXATION_ENABLED)
 151     {
 152       /* If relaxing, elf32_avr_size_stubs will be called from
 153          elf32_avr_relax_section.  */
 154       if (!elf32_avr_size_stubs (link_info.output_bfd, &link_info, TRUE))
 155         einfo ("%X%P: can not size stub section: %E\n");
 156     }
 157
 158   gld${EMULATION_NAME}_after_allocation ();
 159
 160   /* Now build the linker stubs.  */
 161   if (!avr_no_stubs)
 162     {
 163       if (!elf32_avr_build_stubs (&link_info))
 164         einfo ("%X%P: can not build stubs: %E\n");
 165     }
 166 }
 167
 168 static void
 169 avr_elf_before_parse (void)
 170 {
 171   /* Don't create a demand-paged executable, since this feature isn't
 172      meaningful in AVR. */
 173   config.magic_demand_paged = FALSE;
 174
 175   gld${EMULATION_NAME}_before_parse ();
 176 }
 177
 178 EOF
 179
 180
 181 PARSE_AND_LIST_PROLOGUE='
 182
 183 #define OPTION_NO_CALL_RET_REPLACEMENT 301
 184 #define OPTION_PMEM_WRAP_AROUND        302
 185 #define OPTION_NO_STUBS                303
 186 #define OPTION_DEBUG_STUBS             304
 187 #define OPTION_DEBUG_RELAX             305
 188 '
 189
 190 PARSE_AND_LIST_LONGOPTS='
 191   { "no-call-ret-replacement", no_argument,
 192      NULL, OPTION_NO_CALL_RET_REPLACEMENT},
 193   { "pmem-wrap-around", required_argument,
 194     NULL, OPTION_PMEM_WRAP_AROUND},
 195   { "no-stubs", no_argument,
 196     NULL, OPTION_NO_STUBS},
 197   { "debug-stubs", no_argument,
 198     NULL, OPTION_DEBUG_STUBS},
 199   { "debug-relax", no_argument,
 200     NULL, OPTION_DEBUG_RELAX},
 201 '
 202
 203 PARSE_AND_LIST_OPTIONS='
 204   fprintf (file, _("  --pmem-wrap-around=<val>    "
 205                    "Make the linker relaxation machine assume that a\n"
 206                    "                              "
 207                    "  program counter wrap-around occures at address\n"
 208                    "                              "
 209                    "  <val>.  Supported values: 8k, 16k, 32k and 64k.\n"));
 210   fprintf (file, _("  --no-call-ret-replacement   "
 211                    "The relaxation machine normally will\n"
 212                    "                              "
 213                    "  substitute two immediately following call/ret\n"
 214                    "                              "
 215                    "  instructions by a single jump instruction.\n"
 216                    "                              "
 217                    "  This option disables this optimization.\n"));
 218   fprintf (file, _("  --no-stubs                  "
 219                    "If the linker detects to attempt to access\n"
 220                    "                              "
 221                    "  an instruction beyond 128k by a reloc that\n"
 222                    "                              "
 223                    "  is limited to 128k max, it inserts a jump\n"
 224                    "                              "
 225                    "  stub. You can de-active this with this switch.\n"));
 226   fprintf (file, _("  --debug-stubs               "
 227                    "Used for debugging avr-ld.\n"));
 228   fprintf (file, _("  --debug-relax               "
 229                    "Used for debugging avr-ld.\n"));
 230 '
 231
 232 PARSE_AND_LIST_ARGS_CASES='
 233
 234     case OPTION_PMEM_WRAP_AROUND:
 235       {
 236         /* This variable is defined in the bfd library.  */
 237         if ((!strcmp (optarg,"32k"))      || (!strcmp (optarg,"32K")))
 238           avr_pc_wrap_around = 32768;
 239         else if ((!strcmp (optarg,"8k")) || (!strcmp (optarg,"8K")))
 240           avr_pc_wrap_around = 8192;
 241         else if ((!strcmp (optarg,"16k")) || (!strcmp (optarg,"16K")))
 242           avr_pc_wrap_around = 16384;
 243         else if ((!strcmp (optarg,"64k")) || (!strcmp (optarg,"64K")))
 244           avr_pc_wrap_around = 0x10000;
 245         else
 246           return FALSE;
 247       }
 248       break;
 249
 250     case OPTION_DEBUG_STUBS:
 251       avr_debug_stubs = TRUE;
 252       break;
 253
 254     case OPTION_DEBUG_RELAX:
 255       avr_debug_relax = TRUE;
 256       break;
 257
 258     case OPTION_NO_STUBS:
 259       avr_no_stubs = TRUE;
 260       break;
 261
 262     case OPTION_NO_CALL_RET_REPLACEMENT:
 263       {
 264         /* This variable is defined in the bfd library.  */
 265         avr_replace_call_ret_sequences = FALSE;
 266       }
 267       break;
 268 '
 269
 270 #
 271 # Put these extra avr-elf routines in ld_${EMULATION_NAME}_emulation
 272 #
 273 LDEMUL_BEFORE_PARSE=avr_elf_before_parse
 274 LDEMUL_BEFORE_ALLOCATION=avr_elf_${EMULATION_NAME}_before_allocation
 275 LDEMUL_AFTER_ALLOCATION=avr_elf_after_allocation
 276 LDEMUL_CREATE_OUTPUT_SECTION_STATEMENTS=avr_elf_create_output_section_statements