ld/emultempl/armelf.em

   1 # This shell script emits a C file. -*- C -*-
   2 #   Copyright 1991, 1993, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003,
   3 #   2004, 2005
   4 #   Free Software Foundation, Inc.
   5 #
   6 # This file is part of GLD, the Gnu Linker.
   7 #
   8 # This program is free software; you can redistribute it and/or modify
   9 # it under the terms of the GNU General Public License as published by
  10 # the Free Software Foundation; either version 2 of the License, or
  11 # (at your option) any later version.
  12 #
  13 # This program is distributed in the hope that it will be useful,
  14 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 # GNU General Public License for more details.
  17 #
  18 # You should have received a copy of the GNU General Public License
  19 # along with this program; if not, write to the Free Software
  20 # Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA.
  21 #
  22
  23 # This file is sourced from elf32.em, and defines extra arm-elf
  24 # specific routines.
  25 #
  26 test -z "$TARGET2_TYPE" && TARGET2_TYPE="rel"
  27 cat >>e${EMULATION_NAME}.c <<EOF
  28
  29 static char *thumb_entry_symbol = NULL;
  30 static bfd *bfd_for_interwork;
  31 static int byteswap_code = 0;
  32 static int target1_is_rel = 0${TARGET1_IS_REL};
  33 static char *target2_type = "${TARGET2_TYPE}";
  34 static int fix_v4bx = 0;
  35 static int use_blx = 0;
  36
  37 static void
  38 gld${EMULATION_NAME}_before_parse (void)
  39 {
  40 #ifndef TARGET_                 /* I.e., if not generic.  */
  41   ldfile_set_output_arch ("`echo ${ARCH}`", bfd_arch_unknown);
  42 #endif /* not TARGET_ */
  43   config.dynamic_link = ${DYNAMIC_LINK-TRUE};
  44   config.has_shared = `if test -n "$GENERATE_SHLIB_SCRIPT" ; then echo TRUE ; else echo FALSE ; fi`;
  45 }
  46
  47 static void
  48 arm_elf_after_open (void)
  49 {
  50   if (strstr (bfd_get_target (output_bfd), "arm") == NULL)
  51     {
  52       /* The arm backend needs special fields in the output hash structure.
  53          These will only be created if the output format is an arm format,
  54          hence we do not support linking and changing output formats at the
  55          same time.  Use a link followed by objcopy to change output formats.  */
  56       einfo ("%F%X%P: error: cannot change output format whilst linking ARM binaries\n");
  57       return;
  58     }
  59
  60   {
  61     LANG_FOR_EACH_INPUT_STATEMENT (is)
  62       {
  63         bfd_elf32_arm_add_glue_sections_to_bfd (is->the_bfd, & link_info);
  64       }
  65   }
  66
  67   /* Call the standard elf routine.  */
  68   gld${EMULATION_NAME}_after_open ();
  69 }
  70
  71 static void
  72 arm_elf_set_bfd_for_interworking (lang_statement_union_type *statement)
  73 {
  74   if (statement->header.type == lang_input_section_enum
  75       && !statement->input_section.ifile->just_syms_flag
  76       && (statement->input_section.section->flags & SEC_EXCLUDE) == 0)
  77     {
  78       asection *i = statement->input_section.section;
  79       asection *output_section = i->output_section;
  80
  81       ASSERT (output_section->owner == output_bfd);
  82
  83       /* Don't attach the interworking stubs to a dynamic object, to
  84          an empty section, etc.  */
  85       if ((output_section->flags & SEC_HAS_CONTENTS) != 0
  86           && (i->flags & SEC_NEVER_LOAD) == 0
  87           && ! (i->owner->flags & DYNAMIC)
  88           && ! i->owner->output_has_begun)
  89         {
  90           bfd_for_interwork = i->owner;
  91           bfd_for_interwork->output_has_begun = TRUE;
  92         }
  93     }
  94 }
  95
  96 static void
  97 arm_elf_before_allocation (void)
  98 {
  99   bfd *tem;
 100
 101   /* Call the standard elf routine.  */
 102   gld${EMULATION_NAME}_before_allocation ();
 103
 104   if (link_info.input_bfds != NULL)
 105     {
 106       /* The interworking bfd must be the last one in the link.  */
 107       bfd_for_interwork = NULL;
 108       for (tem = link_info.input_bfds; tem != NULL; tem = tem->link_next)
 109         tem->output_has_begun = FALSE;
 110
 111       lang_for_each_statement (arm_elf_set_bfd_for_interworking);
 112       for (tem = link_info.input_bfds; tem != NULL; tem = tem->link_next)
 113         tem->output_has_begun = FALSE;
 114
 115       /* If bfd_for_interwork is NULL, then there are no loadable sections
 116          with real contents to be linked, so we are not going to have to
 117          create any interworking stubs, so it is OK not to call
 118          bfd_elf32_arm_get_bfd_for_interworking.  */
 119       if (bfd_for_interwork != NULL)
 120         bfd_elf32_arm_get_bfd_for_interworking (bfd_for_interwork, &link_info);
 121     }
 122   /* We should be able to set the size of the interworking stub section.  */
 123
 124   /* Here we rummage through the found bfds to collect glue information.  */
 125   /* FIXME: should this be based on a command line option? krk@cygnus.com  */
 126   {
 127     LANG_FOR_EACH_INPUT_STATEMENT (is)
 128       {
 129         if (!bfd_elf32_arm_process_before_allocation (is->the_bfd, & link_info,
 130                                                       byteswap_code))
 131           {
 132             /* xgettext:c-format */
 133             einfo (_("Errors encountered processing file %s"), is->filename);
 134           }
 135       }
 136   }
 137
 138   /* We have seen it all. Allocate it, and carry on.  */
 139   bfd_elf32_arm_allocate_interworking_sections (& link_info);
 140 }
 141
 142 static void
 143 arm_elf_finish (void)
 144 {
 145   struct bfd_link_hash_entry * h;
 146
 147   /* Call the elf32.em routine.  */
 148   gld${EMULATION_NAME}_finish ();
 149
 150   if (thumb_entry_symbol == NULL)
 151     return;
 152
 153   h = bfd_link_hash_lookup (link_info.hash, thumb_entry_symbol,
 154                             FALSE, FALSE, TRUE);
 155
 156   if (h != (struct bfd_link_hash_entry *) NULL
 157       && (h->type == bfd_link_hash_defined
 158           || h->type == bfd_link_hash_defweak)
 159       && h->u.def.section->output_section != NULL)
 160     {
 161       static char buffer[32];
 162       bfd_vma val;
 163
 164       /* Special procesing is required for a Thumb entry symbol.  The
 165          bottom bit of its address must be set.  */
 166       val = (h->u.def.value
 167              + bfd_get_section_vma (output_bfd,
 168                                     h->u.def.section->output_section)
 169              + h->u.def.section->output_offset);
 170
 171       val |= 1;
 172
 173       /* Now convert this value into a string and store it in entry_symbol
 174          where the lang_finish() function will pick it up.  */
 175       buffer[0] = '0';
 176       buffer[1] = 'x';
 177
 178       sprintf_vma (buffer + 2, val);
 179
 180       if (entry_symbol.name != NULL && entry_from_cmdline)
 181         einfo (_("%P: warning: '--thumb-entry %s' is overriding '-e %s'\n"),
 182                thumb_entry_symbol, entry_symbol.name);
 183       entry_symbol.name = buffer;
 184     }
 185   else
 186     einfo (_("%P: warning: connot find thumb start symbol %s\n"),
 187            thumb_entry_symbol);
 188 }
 189
 190 /* This is a convenitent point to tell BFD about target specific flags.
 191    After the output has been created, but before inputs are read.  */
 192 static void
 193 arm_elf_create_output_section_statements (void)
 194 {
 195   bfd_elf32_arm_set_target_relocs (&link_info, target1_is_rel, target2_type,
 196                                    fix_v4bx, use_blx);
 197 }
 198
 199 EOF
 200
 201 # Define some shell vars to insert bits of code into the standard elf
 202 # parse_args and list_options functions.
 203 #
 204 PARSE_AND_LIST_PROLOGUE='
 205 #define OPTION_THUMB_ENTRY              301
 206 #define OPTION_BE8                      302
 207 #define OPTION_TARGET1_REL              303
 208 #define OPTION_TARGET1_ABS              304
 209 #define OPTION_TARGET2                  305
 210 #define OPTION_FIX_V4BX                 306
 211 #define OPTION_USE_BLX                  307
 212 '
 213
 214 PARSE_AND_LIST_SHORTOPTS=p
 215
 216 PARSE_AND_LIST_LONGOPTS='
 217   { "no-pipeline-knowledge", no_argument, NULL, '\'p\''},
 218   { "thumb-entry", required_argument, NULL, OPTION_THUMB_ENTRY},
 219   { "be8", no_argument, NULL, OPTION_BE8},
 220   { "target1-rel", no_argument, NULL, OPTION_TARGET1_REL},
 221   { "target1-abs", no_argument, NULL, OPTION_TARGET1_ABS},
 222   { "target2", required_argument, NULL, OPTION_TARGET2},
 223   { "fix-v4bx", no_argument, NULL, OPTION_FIX_V4BX},
 224   { "use-blx", no_argument, NULL, OPTION_USE_BLX},
 225 '
 226
 227 PARSE_AND_LIST_OPTIONS='
 228   fprintf (file, _("     --thumb-entry=<sym>      Set the entry point to be Thumb symbol <sym>\n"));
 229   fprintf (file, _("     --be8                    Oputput BE8 format image\n"));
 230   fprintf (file, _("     --target1=rel            Interpret R_ARM_TARGET1 as R_ARM_REL32\n"));
 231   fprintf (file, _("     --target1=abs            Interpret R_ARM_TARGET1 as R_ARM_ABS32\n"));
 232   fprintf (file, _("     --target2=<type>         Specify definition of R_ARM_TARGET2\n"));
 233   fprintf (file, _("     --fix-v4bx               Rewrite BX rn as MOV pc, rn for ARMv4\n"));
 234   fprintf (file, _("     --use-blx                Enable use of BLX instructions\n"));
 235 '
 236
 237 PARSE_AND_LIST_ARGS_CASES='
 238     case '\'p\'':
 239       /* Only here for backwards compatibility.  */
 240       break;
 241
 242     case OPTION_THUMB_ENTRY:
 243       thumb_entry_symbol = optarg;
 244       break;
 245
 246     case OPTION_BE8:
 247       byteswap_code = 1;
 248       break;
 249
 250     case OPTION_TARGET1_REL:
 251       target1_is_rel = 1;
 252       break;
 253
 254     case OPTION_TARGET1_ABS:
 255       target1_is_rel = 0;
 256       break;
 257
 258     case OPTION_TARGET2:
 259       target2_type = optarg;
 260       break;
 261
 262     case OPTION_FIX_V4BX:
 263       fix_v4bx = 1;
 264       break;
 265
 266     case OPTION_USE_BLX:
 267       use_blx = 1;
 268       break;
 269 '
 270
 271 # We have our own after_open and before_allocation functions, but they call
 272 # the standard routines, so give them a different name.
 273 LDEMUL_AFTER_OPEN=arm_elf_after_open
 274 LDEMUL_BEFORE_ALLOCATION=arm_elf_before_allocation
 275 LDEMUL_CREATE_OUTPUT_SECTION_STATEMENTS=arm_elf_create_output_section_statements
 276
 277 # Replace the elf before_parse function with our own.
 278 LDEMUL_BEFORE_PARSE=gld"${EMULATION_NAME}"_before_parse
 279
 280 # Call the extra arm-elf function
 281 LDEMUL_FINISH=arm_elf_finish