ld/emultempl/m68hc1xelf.em

   1 # This shell script emits a C file. -*- C -*-
   2 #   Copyright (C) 1991-2021 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 elf.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 fragment <<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 (bfd_get_flavour (link_info.output_bfd) != bfd_target_elf_flavour)
  70     return;
  71
  72   /* If generating a relocatable output file, then we don't
  73      have to generate the trampolines.  */
  74   if (bfd_link_relocatable (&link_info))
  75     return;
  76
  77   ret = elf32_m68hc11_setup_section_lists (link_info.output_bfd, &link_info);
  78   if (ret != 0 && no_trampoline == 0)
  79     {
  80       if (ret < 0)
  81         {
  82           einfo (_("%X%P: can not size stub section: %E\n"));
  83           return;
  84         }
  85
  86       /* Call into the BFD backend to do the real work.  */
  87       if (!elf32_m68hc11_size_stubs (link_info.output_bfd,
  88                                      stub_file->the_bfd,
  89                                      &link_info,
  90                                      &m68hc11elf_add_stub_section))
  91         {
  92           einfo (_("%X%P: can not size stub section: %E\n"));
  93           return;
  94         }
  95     }
  96
  97   if (bank_window_name == 0)
  98     return;
  99
 100   /* The 'bank_window_name' memory region is a special region that describes
 101      the memory bank window to access to paged memory.  For 68HC12
 102      this is fixed and should be:
 103
 104      window (rx) : ORIGIN = 0x8000, LENGTH = 16K
 105
 106      But for 68HC11 this is board specific.  The definition of such
 107      memory region allows to control how this paged memory is accessed.  */
 108   region = lang_memory_region_lookup (bank_window_name, FALSE);
 109
 110   /* Check the length to see if it was defined in the script.  */
 111   if (region->length != 0)
 112     {
 113       struct m68hc11_page_info *pinfo;
 114       unsigned i;
 115
 116       /* Get default values  */
 117       m68hc11_elf_get_bank_parameters (&link_info);
 118       pinfo = &m68hc11_elf_hash_table (&link_info)->pinfo;
 119
 120       /* And override them with the region definition.  */
 121       pinfo->bank_size = region->length;
 122       pinfo->bank_shift = 0;
 123       for (i = pinfo->bank_size; i != 0; i >>= 1)
 124         pinfo->bank_shift++;
 125       pinfo->bank_shift--;
 126       pinfo->bank_size = 1L << pinfo->bank_shift;
 127       pinfo->bank_mask = (1 << pinfo->bank_shift) - 1;
 128       pinfo->bank_physical = region->origin;
 129       pinfo->bank_physical_end = region->origin + pinfo->bank_size;
 130
 131       if (pinfo->bank_size != region->length)
 132         {
 133           einfo (_("%P: warning: the size of the 'window' memory region "
 134                    "is not a power of 2; its size %d is truncated to %d\n"),
 135                  region->length, pinfo->bank_size);
 136         }
 137     }
 138 }
 139
 140 /* This is called before the input files are opened.  We create a new
 141    fake input file to hold the stub sections.  */
 142
 143 static void
 144 m68hc11elf_create_output_section_statements (void)
 145 {
 146   if (bfd_get_flavour (link_info.output_bfd) != bfd_target_elf_flavour)
 147     {
 148       einfo (_("%X%P: changing output format whilst linking "
 149                "is not supported\n"));
 150       return;
 151     }
 152
 153   stub_file = lang_add_input_file ("linker stubs",
 154                                    lang_input_file_is_fake_enum,
 155                                    NULL);
 156   stub_file->the_bfd = bfd_create ("linker stubs", link_info.output_bfd);
 157   if (stub_file->the_bfd == NULL
 158       || !bfd_set_arch_mach (stub_file->the_bfd,
 159                              bfd_get_arch (link_info.output_bfd),
 160                              bfd_get_mach (link_info.output_bfd)))
 161     {
 162       einfo (_("%F%P: can not create BFD: %E\n"));
 163       return;
 164     }
 165
 166   ldlang_add_file (stub_file);
 167 }
 168
 169
 170 struct hook_stub_info
 171 {
 172   lang_statement_list_type add;
 173   asection *input_section;
 174 };
 175
 176 /* Traverse the linker tree to find the spot where the stub goes.  */
 177
 178 static bfd_boolean
 179 hook_in_stub (struct hook_stub_info *info, lang_statement_union_type **lp)
 180 {
 181   lang_statement_union_type *l;
 182   bfd_boolean ret;
 183
 184   for (; (l = *lp) != NULL; lp = &l->header.next)
 185     {
 186       switch (l->header.type)
 187         {
 188         case lang_constructors_statement_enum:
 189           ret = hook_in_stub (info, &constructor_list.head);
 190           if (ret)
 191             return ret;
 192           break;
 193
 194         case lang_output_section_statement_enum:
 195           ret = hook_in_stub (info,
 196                               &l->output_section_statement.children.head);
 197           if (ret)
 198             return ret;
 199           break;
 200
 201         case lang_wild_statement_enum:
 202           ret = hook_in_stub (info, &l->wild_statement.children.head);
 203           if (ret)
 204             return ret;
 205           break;
 206
 207         case lang_group_statement_enum:
 208           ret = hook_in_stub (info, &l->group_statement.children.head);
 209           if (ret)
 210             return ret;
 211           break;
 212
 213         case lang_input_section_enum:
 214           if (l->input_section.section == info->input_section
 215               || strcmp (bfd_section_name (l->input_section.section),
 216                          bfd_section_name (info->input_section)) == 0)
 217             {
 218               /* We've found our section.  Insert the stub immediately
 219                  before its associated input section.  */
 220               *lp = info->add.head;
 221               *(info->add.tail) = l;
 222               return TRUE;
 223             }
 224           break;
 225
 226         case lang_data_statement_enum:
 227         case lang_reloc_statement_enum:
 228         case lang_object_symbols_statement_enum:
 229         case lang_output_statement_enum:
 230         case lang_target_statement_enum:
 231         case lang_input_statement_enum:
 232         case lang_assignment_statement_enum:
 233         case lang_padding_statement_enum:
 234         case lang_address_statement_enum:
 235         case lang_fill_statement_enum:
 236           break;
 237
 238         default:
 239           FAIL ();
 240           break;
 241         }
 242     }
 243   return FALSE;
 244 }
 245
 246
 247 /* Call-back for elf32_m68hc11_size_stubs.  */
 248
 249 /* Create a new stub section, and arrange for it to be linked
 250    immediately before INPUT_SECTION.  */
 251
 252 static asection *
 253 m68hc11elf_add_stub_section (const char *stub_sec_name,
 254                              asection *tramp_section)
 255 {
 256   asection *stub_sec;
 257   flagword flags;
 258   asection *output_section;
 259   lang_output_section_statement_type *os;
 260   struct hook_stub_info info;
 261
 262   flags = (SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE
 263            | SEC_HAS_CONTENTS | SEC_RELOC | SEC_IN_MEMORY | SEC_KEEP);
 264   stub_sec = bfd_make_section_anyway_with_flags (stub_file->the_bfd,
 265                                                  stub_sec_name, flags);
 266   if (stub_sec == NULL)
 267     goto err_ret;
 268
 269   output_section = tramp_section->output_section;
 270   os = lang_output_section_get (output_section);
 271
 272   /* Try to put the new section at the same place as an existing
 273      .tramp section.  Such .tramp section exists in most cases and
 274      contains the trampoline code.  This way we put the generated trampoline
 275      at the correct place.  */
 276   info.input_section = tramp_section;
 277   lang_list_init (&info.add);
 278   lang_add_section (&info.add, stub_sec, NULL, os);
 279
 280   if (info.add.head == NULL)
 281     goto err_ret;
 282
 283   if (hook_in_stub (&info, &os->children.head))
 284     return stub_sec;
 285
 286  err_ret:
 287   einfo (_("%X%P: can not make stub section: %E\n"));
 288   return NULL;
 289 }
 290
 291 /* For the 68HC12 we use this opportunity to build linker stubs.  */
 292
 293 static void
 294 m68hc11elf_after_allocation (void)
 295 {
 296   if (bfd_get_flavour (link_info.output_bfd) == bfd_target_elf_flavour)
 297     {
 298       /* Now build the linker stubs.  */
 299       if (stub_file->the_bfd->sections != NULL)
 300         {
 301           /* Call again the trampoline analyzer to initialize the trampoline
 302              stubs with the correct symbol addresses.  Since there could have
 303              been relaxation, the symbol addresses that were found during
 304              first call may no longer be correct.  */
 305           if (!elf32_m68hc11_size_stubs (link_info.output_bfd,
 306                                          stub_file->the_bfd,
 307                                          &link_info, 0))
 308             {
 309               einfo (_("%X%P: can not size stub section: %E\n"));
 310               return;
 311             }
 312           if (!elf32_m68hc11_build_stubs (link_info.output_bfd, &link_info))
 313             einfo (_("%X%P: can not build stubs: %E\n"));
 314         }
 315     }
 316
 317   gld${EMULATION_NAME}_after_allocation ();
 318 }
 319
 320 EOF
 321
 322 # Define some shell vars to insert bits of code into the standard elf
 323 # parse_args and list_options functions.
 324 #
 325 PARSE_AND_LIST_PROLOGUE='
 326 #define OPTION_NO_TRAMPOLINE            300
 327 #define OPTION_BANK_WINDOW              301
 328 '
 329
 330 # The options are repeated below so that no abbreviations are allowed.
 331 # Otherwise -s matches stub-group-size
 332 PARSE_AND_LIST_LONGOPTS='
 333   { "no-trampoline", no_argument, NULL, OPTION_NO_TRAMPOLINE },
 334   { "bank-window",   required_argument, NULL, OPTION_BANK_WINDOW },
 335 '
 336
 337 PARSE_AND_LIST_OPTIONS='
 338   fprintf (file, _(
 339 "  --no-trampoline             Do not generate the far trampolines used to call\n"
 340 "                                a far function using 'jsr' or 'bsr'\n"));
 341   fprintf (file, _(
 342 "  --bank-window NAME          Specify the name of the memory region describing\n"
 343 "                                the layout of the memory bank window\n"));
 344 '
 345
 346 PARSE_AND_LIST_ARGS_CASES='
 347     case OPTION_NO_TRAMPOLINE:
 348       no_trampoline = 1;
 349       break;
 350     case OPTION_BANK_WINDOW:
 351       bank_window_name = optarg;
 352       break;
 353 '
 354
 355 # Put these extra m68hc11elf routines in ld_${EMULATION_NAME}_emulation
 356 #
 357 LDEMUL_BEFORE_ALLOCATION=m68hc11_elf_${EMULATION_NAME}_before_allocation
 358 LDEMUL_AFTER_ALLOCATION=m68hc11elf_after_allocation
 359 LDEMUL_CREATE_OUTPUT_SECTION_STATEMENTS=m68hc11elf_create_output_section_statements