ld/emultempl/cr16elf.em

   1 # This shell script emits a C file. -*- C -*-
   2 # Copyright 2007, 2008 Free Software Foundation, Inc.
   3 # Contributed by M R Swami Reddy <MR.Swami.Reddy@nsc.com>
   4 #
   5 # This file is part of the GNU Binutils.
   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 3 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., 51 Franklin Street - Fifth Floor, Boston,
  20 # MA 02110-1301, USA.
  21 #
  22
  23 # This file is sourced from elf32.em, and defines extra cr16-elf
  24 # specific routines.
  25 #
  26 fragment <<EOF
  27
  28 #include "ldctor.h"
  29
  30 /* Flag for the emulation-specific "--no-relax" option.  */
  31 static bfd_boolean disable_relaxation = FALSE;
  32
  33 static void check_sections (bfd *, asection *, void *);
  34
  35
  36 /* This function is run after all the input files have been opened.  */
  37
  38 static void
  39 cr16_elf_after_open (void)
  40 {
  41   /* Call the standard elf routine.  */
  42   gld${EMULATION_NAME}_after_open ();
  43
  44    if (command_line.embedded_relocs
  45        && (! link_info.relocatable))
  46      {
  47        bfd *abfd;
  48
  49       /* In the embedded relocs mode we create a .emreloc section for each
  50          input file with a nonzero .data section.  The BFD backend will fill in
  51          these sections with magic numbers which can be used to relocate the
  52          data section at run time.  */
  53       for (abfd = link_info.input_bfds; abfd != NULL; abfd = abfd->link_next)
  54         {
  55           asection *datasec;
  56
  57           /* As first-order business, make sure that each input BFD is either
  58              COFF or ELF.  We need to call a special BFD backend function to
  59              generate the embedded relocs, and we have such functions only for
  60              COFF and ELF.  */
  61           if (bfd_get_flavour (abfd) != bfd_target_coff_flavour
  62               && bfd_get_flavour (abfd) != bfd_target_elf_flavour)
  63             einfo ("%F%B: all input objects must be COFF or ELF for --embedded-relocs\n");
  64
  65           datasec = bfd_get_section_by_name (abfd, ".data.rel");
  66
  67           /* Note that we assume that the reloc_count field has already
  68              been set up.  We could call bfd_get_reloc_upper_bound, but
  69              that returns the size of a memory buffer rather than a reloc
  70              count.  We do not want to call bfd_canonicalize_reloc,
  71              because although it would always work it would force us to
  72              read in the relocs into BFD canonical form, which would waste
  73              a significant amount of time and memory.  */
  74           if (datasec != NULL && datasec->reloc_count > 0)
  75             {
  76               asection *relsec;
  77
  78               relsec = bfd_make_section (abfd, ".emreloc");
  79               if (relsec == NULL
  80                   || ! bfd_set_section_flags (abfd, relsec,
  81                                               (SEC_ALLOC
  82                                                | SEC_LOAD
  83                                                | SEC_HAS_CONTENTS
  84                                                | SEC_IN_MEMORY))
  85                   || ! bfd_set_section_alignment (abfd, relsec, 2)
  86                   || ! bfd_set_section_size (abfd, relsec,
  87                                              datasec->reloc_count * 8))
  88                 einfo ("%F%B: can not create .emreloc section: %E\n");
  89             }
  90
  91           /* Double check that all other data sections are empty, as is
  92              required for embedded PIC code.  */
  93           bfd_map_over_sections (abfd, check_sections, datasec);
  94         }
  95     }
  96 }
  97
  98 /* Check that of the data sections, only the .data section has
  99    relocs.  This is called via bfd_map_over_sections.  */
 100
 101 static void
 102 check_sections (bfd *abfd, asection *sec, void *datasec)
 103 {
 104   if ((strncmp (bfd_get_section_name (abfd, sec), ".data.rel", 9) == 0)
 105      && sec != datasec
 106      && sec->reloc_count == 0 )
 107     einfo ("%B%X: section %s has relocs; can not use --embedded-relocs\n",
 108            abfd, bfd_get_section_name (abfd, sec));
 109 }
 110
 111 static void
 112 cr16elf_after_parse (void)
 113 {
 114   /* Always behave as if called with --sort-common command line
 115      option.
 116      This is to emulate the CRTools' method of keeping variables
 117      of different alignment in separate sections.  */
 118   config.sort_common = TRUE;
 119
 120   /* Don't create a demand-paged executable, since this feature isn't
 121      meaninful in CR16 embedded systems. Moreover, when magic_demand_paged
 122      is true the link sometimes fails.  */
 123   config.magic_demand_paged = FALSE;
 124 }
 125
 126 /* This is called after the sections have been attached to output
 127    sections, but before any sizes or addresses have been set.  */
 128
 129 static void
 130 cr16elf_before_allocation (void)
 131 {
 132   /* Call the default first.  */
 133   gld${EMULATION_NAME}_before_allocation ();
 134
 135    if (command_line.embedded_relocs
 136        && (! link_info.relocatable))
 137      {
 138
 139    bfd *abfd;
 140
 141    /* If we are generating embedded relocs, call a special BFD backend
 142          routine to do the work.  */
 143    for (abfd = link_info.input_bfds; abfd != NULL; abfd = abfd->link_next)
 144       {
 145           asection *datasec, *relsec;
 146           char *errmsg;
 147
 148           datasec = bfd_get_section_by_name (abfd, ".data.rel");
 149
 150           if (datasec == NULL || datasec->reloc_count == 0)
 151             continue;
 152
 153           relsec = bfd_get_section_by_name (abfd, ".emreloc");
 154           ASSERT (relsec != NULL);
 155
 156           if (! bfd_cr16_elf32_create_embedded_relocs (abfd, &link_info,
 157                                                            datasec, relsec,
 158                                                            &errmsg))
 159                 {
 160                   if (errmsg == NULL)
 161                     einfo ("%B%X: can not create runtime reloc information: %E\n",
 162                            abfd);
 163                   else
 164                     einfo ("%X%B: can not create runtime reloc information: %s\n",
 165                            abfd, errmsg);
 166                 }
 167        }
 168      }
 169
 170   /* Enable relaxation by default if the "--no-relax" option was not
 171      specified.  This is done here instead of in the before_parse hook
 172      because there is a check in main() to prohibit use of --relax and
 173      -r together.  */
 174
 175   if (!disable_relaxation)
 176     command_line.relax = TRUE;
 177 }
 178
 179 EOF
 180
 181 # Define some shell vars to insert bits of code into the standard elf
 182 # parse_args and list_options functions.
 183 #
 184 PARSE_AND_LIST_PROLOGUE='
 185 #define OPTION_NO_RELAX                 301
 186 '
 187
 188 PARSE_AND_LIST_LONGOPTS='
 189   { "no-relax", no_argument, NULL, OPTION_NO_RELAX},
 190 '
 191
 192 PARSE_AND_LIST_OPTIONS='
 193   fprintf (file, _("  --no-relax                  Do not relax branches\n"));
 194 '
 195
 196 PARSE_AND_LIST_ARGS_CASES='
 197     case OPTION_NO_RELAX:
 198       disable_relaxation = TRUE;
 199       break;
 200 '
 201
 202 # Put these extra cr16-elf routines in ld_${EMULATION_NAME}_emulation
 203 #
 204 LDEMUL_AFTER_OPEN=cr16_elf_after_open
 205 LDEMUL_AFTER_PARSE=cr16elf_after_parse
 206 LDEMUL_BEFORE_ALLOCATION=cr16elf_before_allocation