ld/emultempl/m68hc1xelf.em

   1 # This shell script emits a C file. -*- C -*-
   2 #   Copyright 1991, 1993, 1994, 1997, 1999, 2000, 2001, 2002, 2003
   3 #   Free Software Foundation, Inc.
   4 #
   5 # This file is part of GLD, the Gnu Linker.
   6 #
   7 # This program is free software; you can redistribute it and/or modify
   8 # it under the terms of the GNU General Public License as published by
   9 # the Free Software Foundation; either version 2 of the License, or
  10 # (at your option) any later version.
  11 #
  12 # This program is distributed in the hope that it will be useful,
  13 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 # GNU General Public License for more details.
  16 #
  17 # You should have received a copy of the GNU General Public License
  18 # along with this program; if not, write to the Free Software
  19 # Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  20 #
  21
  22 # This file is sourced from elf32.em, and defines extra m68hc12-elf
  23 # and m68hc11-elf specific routines.  It is used to generate the
  24 # HC11/HC12 trampolines to call a far function by using a normal 'jsr/bsr'.
  25 #
  26 # - The HC11/HC12 relocations are checked to see if there is a
  27 #   R_M68HC11_16 relocation to a symbol marked with STO_M68HC12_FAR.
  28 #   This relocation cannot be made on the symbol but must be made on
  29 #   its trampoline
  30 #   The trampolines to generate are collected during this pass
  31 #   (See elf32_m68hc11_size_stubs)
  32 #
  33 # - The trampolines are generated in a ".tramp" section.  The generation
  34 #   takes care of HC11 and HC12 specificities.
  35 #   (See elf32_m68hc11_build_stubs)
  36 #
  37 # - During relocation the R_M68HC11_16 relocation to the far symbols
  38 #   are redirected to the trampoline that was generated.
  39 #
  40 # Copied from hppaelf and adapted for M68HC11/M68HC12 specific needs.
  41 #
  42 cat >>e${EMULATION_NAME}.c <<EOF
  43
  44 #include "ldctor.h"
  45 #include "elf32-m68hc1x.h"
  46
  47 static asection *m68hc11elf_add_stub_section (const char *, asection *);
  48
  49 /* Fake input file for stubs.  */
  50 static lang_input_statement_type *stub_file;
  51
  52 /* By default the HC11/HC12 trampolines to call a far function using
  53    a normal 'bsr' and 'jsr' convention are generated during the link.
  54    The --no-trampoline option prevents that.  */
  55 static int no_trampoline = 0;
  56
  57 /* Name of memory bank window in the MEMORY description.
  58    This is set by --bank-window option.  */
  59 static const char* bank_window_name = 0;
  60
  61 static void
  62 m68hc11_elf_${EMULATION_NAME}_before_allocation (void)
  63 {
  64   lang_memory_region_type* region;
  65   int ret;
  66
  67   gld${EMULATION_NAME}_before_allocation ();
  68
  69   /* If generating a relocatable output file, then we don't
  70      have to generate the trampolines.  */
  71   if (link_info.relocatable)
  72     return;
  73
  74   ret = elf32_m68hc11_setup_section_lists (output_bfd, &link_info);
  75   if (ret != 0 && no_trampoline == 0)
  76     {
  77       if (ret < 0)
  78         {
  79           einfo ("%X%P: can not size stub section: %E\n");
  80           return;
  81         }
  82
  83       /* Call into the BFD backend to do the real work.  */
  84       if (!elf32_m68hc11_size_stubs (output_bfd,
  85                                      stub_file->the_bfd,
  86                                      &link_info,
  87                                      &m68hc11elf_add_stub_section))
  88         {
  89           einfo ("%X%P: can not size stub section: %E\n");
  90           return;
  91         }
  92     }
  93
  94   if (bank_window_name == 0)
  95     return;
  96
  97   /* The 'bank_window_name' memory region is a special region that describes
  98      the memory bank window to access to paged memory.  For 68HC12
  99      this is fixed and should be:
 100
 101      window (rx) : ORIGIN = 0x8000, LENGTH = 16K
 102
 103      But for 68HC11 this is board specific.  The definition of such
 104      memory region allows to control how this paged memory is accessed.  */
 105   region = lang_memory_region_lookup (bank_window_name, FALSE);
 106
 107   /* Check the length to see if it was defined in the script.  */
 108   if (region->length != 0)
 109     {
 110       struct m68hc11_page_info *pinfo;
 111       unsigned i;
 112
 113       /* Get default values  */
 114       m68hc11_elf_get_bank_parameters (&link_info);
 115       pinfo = &m68hc11_elf_hash_table (&link_info)->pinfo;
 116
 117       /* And override them with the region definition.  */
 118       pinfo->bank_size = region->length;
 119       pinfo->bank_shift = 0;
 120       for (i = pinfo->bank_size; i != 0; i >>= 1)
 121         pinfo->bank_shift++;
 122       pinfo->bank_shift--;
 123       pinfo->bank_size = 1L << pinfo->bank_shift;
 124       pinfo->bank_mask = (1 << pinfo->bank_shift) - 1;
 125       pinfo->bank_physical = region->origin;
 126       pinfo->bank_physical_end = region->origin + pinfo->bank_size;
 127
 128       if (pinfo->bank_size != region->length)
 129         {
 130           einfo (_("warning: the size of the 'window' memory region "
 131                    "is not a power of 2\n"));
 132           einfo (_("warning: its size %d is truncated to %d\n"),
 133                  region->length, pinfo->bank_size);
 134         }
 135     }
 136 }
 137
 138 /* This is called before the input files are opened.  We create a new
 139    fake input file to hold the stub sections.  */
 140
 141 static void
 142 m68hc11elf_create_output_section_statements (void)
 143 {
 144   stub_file = lang_add_input_file ("linker stubs",
 145                                    lang_input_file_is_fake_enum,
 146                                    NULL);
 147   stub_file->the_bfd = bfd_create ("linker stubs", output_bfd);
 148   if (stub_file->the_bfd == NULL
 149       || !bfd_set_arch_mach (stub_file->the_bfd,
 150                              bfd_get_arch (output_bfd),
 151                              bfd_get_mach (output_bfd)))
 152     {
 153       einfo ("%X%P: can not create BFD %E\n");
 154       return;
 155     }
 156
 157   ldlang_add_file (stub_file);
 158 }
 159
 160
 161 struct hook_stub_info
 162 {
 163   lang_statement_list_type add;
 164   asection *input_section;
 165 };
 166
 167 /* Traverse the linker tree to find the spot where the stub goes.  */
 168
 169 static bfd_boolean
 170 hook_in_stub (struct hook_stub_info *info, lang_statement_union_type **lp)
 171 {
 172   lang_statement_union_type *l;
 173   bfd_boolean ret;
 174
 175   for (; (l = *lp) != NULL; lp = &l->header.next)
 176     {
 177       switch (l->header.type)
 178         {
 179         case lang_constructors_statement_enum:
 180           ret = hook_in_stub (info, &constructor_list.head);
 181           if (ret)
 182             return ret;
 183           break;
 184
 185         case lang_output_section_statement_enum:
 186           ret = hook_in_stub (info,
 187                               &l->output_section_statement.children.head);
 188           if (ret)
 189             return ret;
 190           break;
 191
 192         case lang_wild_statement_enum:
 193           ret = hook_in_stub (info, &l->wild_statement.children.head);
 194           if (ret)
 195             return ret;
 196           break;
 197
 198         case lang_group_statement_enum:
 199           ret = hook_in_stub (info, &l->group_statement.children.head);
 200           if (ret)
 201             return ret;
 202           break;
 203
 204         case lang_input_section_enum:
 205           if (l->input_section.section == info->input_section
 206               || strcmp (bfd_get_section_name (output_section,
 207                                                l->input_section.section),
 208                          bfd_get_section_name (output_section,
 209                                                info->input_section)) == 0)
 210             {
 211               /* We've found our section.  Insert the stub immediately
 212                  before its associated input section.  */
 213               *lp = info->add.head;
 214               *(info->add.tail) = l;
 215               return TRUE;
 216             }
 217           break;
 218
 219         case lang_data_statement_enum:
 220         case lang_reloc_statement_enum:
 221         case lang_object_symbols_statement_enum:
 222         case lang_output_statement_enum:
 223         case lang_target_statement_enum:
 224         case lang_input_statement_enum:
 225         case lang_assignment_statement_enum:
 226         case lang_padding_statement_enum:
 227         case lang_address_statement_enum:
 228         case lang_fill_statement_enum:
 229           break;
 230
 231         default:
 232           FAIL ();
 233           break;
 234         }
 235     }
 236   return FALSE;
 237 }
 238
 239
 240 /* Call-back for elf32_m68hc11_size_stubs.  */
 241
 242 /* Create a new stub section, and arrange for it to be linked
 243    immediately before INPUT_SECTION.  */
 244
 245 static asection *
 246 m68hc11elf_add_stub_section (const char *stub_sec_name,
 247                              asection *tramp_section)
 248 {
 249   asection *stub_sec;
 250   flagword flags;
 251   asection *output_section;
 252   const char *secname;
 253   lang_output_section_statement_type *os;
 254   struct hook_stub_info info;
 255
 256   stub_sec = bfd_make_section_anyway (stub_file->the_bfd, stub_sec_name);
 257   if (stub_sec == NULL)
 258     goto err_ret;
 259
 260   flags = (SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE
 261            | SEC_HAS_CONTENTS | SEC_RELOC | SEC_IN_MEMORY | SEC_KEEP);
 262   if (!bfd_set_section_flags (stub_file->the_bfd, stub_sec, flags))
 263     goto err_ret;
 264
 265   output_section = tramp_section->output_section;
 266   secname = bfd_get_section_name (output_section->owner, output_section);
 267   os = lang_output_section_find (secname);
 268
 269   /* Try to put the new section at the same place as an existing
 270      .tramp section.  Such .tramp section exists in most cases and
 271      contains the trampoline code.  This way we put the generated trampoline
 272      at the correct place.  */
 273   info.input_section = tramp_section;
 274   lang_list_init (&info.add);
 275   lang_add_section (&info.add, stub_sec, os, stub_file);
 276
 277   if (info.add.head == NULL)
 278     goto err_ret;
 279
 280   if (hook_in_stub (&info, &os->children.head))
 281     return stub_sec;
 282
 283  err_ret:
 284   einfo ("%X%P: can not make stub section: %E\n");
 285   return NULL;
 286 }
 287
 288 /* Final emulation specific call.  For the 68HC12 we use this opportunity
 289    to build linker stubs.  */
 290
 291 static void
 292 gld${EMULATION_NAME}_finish (void)
 293 {
 294   /* Now build the linker stubs.  */
 295   if (stub_file->the_bfd->sections != NULL)
 296     {
 297       /* Call again the trampoline analyzer to initialize the trampoline
 298          stubs with the correct symbol addresses.  Since there could have
 299          been relaxation, the symbol addresses that were found during
 300          first call may no longer be correct.  */
 301       if (!elf32_m68hc11_size_stubs (output_bfd,
 302                                      stub_file->the_bfd,
 303                                      &link_info, 0))
 304         {
 305           einfo ("%X%P: can not size stub section: %E\n");
 306           return;
 307         }
 308       if (!elf32_m68hc11_build_stubs (output_bfd, &link_info))
 309         einfo ("%X%P: can not build stubs: %E\n");
 310     }
 311 }
 312
 313
 314 /* Avoid processing the fake stub_file in vercheck, stat_needed and
 315    check_needed routines.  */
 316
 317 static void (*real_func) (lang_input_statement_type *);
 318
 319 static void m68hc11_for_each_input_file_wrapper (lang_input_statement_type *l)
 320 {
 321   if (l != stub_file)
 322     (*real_func) (l);
 323 }
 324
 325 static void
 326 m68hc11_lang_for_each_input_file (void (*func) (lang_input_statement_type *))
 327 {
 328   real_func = func;
 329   lang_for_each_input_file (&m68hc11_for_each_input_file_wrapper);
 330 }
 331
 332 #define lang_for_each_input_file m68hc11_lang_for_each_input_file
 333
 334 EOF
 335
 336 # Define some shell vars to insert bits of code into the standard elf
 337 # parse_args and list_options functions.
 338 #
 339 PARSE_AND_LIST_PROLOGUE='
 340 #define OPTION_NO_TRAMPOLINE            300
 341 #define OPTION_BANK_WINDOW              301
 342 '
 343
 344 # The options are repeated below so that no abbreviations are allowed.
 345 # Otherwise -s matches stub-group-size
 346 PARSE_AND_LIST_LONGOPTS='
 347   { "no-trampoline", no_argument, NULL, OPTION_NO_TRAMPOLINE },
 348   { "bank-window",   required_argument, NULL, OPTION_BANK_WINDOW },
 349 '
 350
 351 PARSE_AND_LIST_OPTIONS='
 352   fprintf (file, _(""
 353 "  --no-trampoline         Do not generate the far trampolines used to call\n"
 354 "                          a far function using 'jsr' or 'bsr'.\n"
 355 "  --bank-window NAME      Specify the name of the memory region describing\n"
 356 "                          the layout of the memory bank window.\n"
 357                    ));
 358 '
 359
 360 PARSE_AND_LIST_ARGS_CASES='
 361     case OPTION_NO_TRAMPOLINE:
 362       no_trampoline = 1;
 363       break;
 364     case OPTION_BANK_WINDOW:
 365       bank_window_name = optarg;
 366       break;
 367 '
 368
 369 # Put these extra m68hc11elf routines in ld_${EMULATION_NAME}_emulation
 370 #
 371 LDEMUL_BEFORE_ALLOCATION=m68hc11_elf_${EMULATION_NAME}_before_allocation
 372 LDEMUL_FINISH=gld${EMULATION_NAME}_finish
 373 LDEMUL_CREATE_OUTPUT_SECTION_STATEMENTS=m68hc11elf_create_output_section_statements