| 1 | # This shell script emits a C file. -*- C -*- |
| 2 | # Copyright (C) 2006-2018 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 | #include "elf/avr.h" |
| 32 | |
| 33 | /* The fake file and it's corresponding section meant to hold |
| 34 | the linker stubs if needed. */ |
| 35 | |
| 36 | static lang_input_statement_type *stub_file; |
| 37 | static asection *avr_stub_section; |
| 38 | |
| 39 | /* Variables set by the command-line parameters and transferred |
| 40 | to the bfd without use of global shared variables. */ |
| 41 | |
| 42 | static bfd_boolean avr_no_stubs = FALSE; |
| 43 | static bfd_boolean avr_debug_relax = FALSE; |
| 44 | static bfd_boolean avr_debug_stubs = FALSE; |
| 45 | static bfd_boolean avr_replace_call_ret_sequences = TRUE; |
| 46 | static bfd_vma avr_pc_wrap_around = 0x10000000; |
| 47 | |
| 48 | /* Transfers information to the bfd frontend. */ |
| 49 | |
| 50 | static void |
| 51 | avr_elf_set_global_bfd_parameters (void) |
| 52 | { |
| 53 | elf32_avr_setup_params (& link_info, |
| 54 | stub_file->the_bfd, |
| 55 | avr_stub_section, |
| 56 | avr_no_stubs, |
| 57 | avr_debug_stubs, |
| 58 | avr_debug_relax, |
| 59 | avr_pc_wrap_around, |
| 60 | avr_replace_call_ret_sequences); |
| 61 | } |
| 62 | |
| 63 | |
| 64 | /* Makes a conservative estimate of the trampoline section size that could |
| 65 | be corrected later on. */ |
| 66 | |
| 67 | static void |
| 68 | avr_elf_${EMULATION_NAME}_before_allocation (void) |
| 69 | { |
| 70 | int ret; |
| 71 | |
| 72 | gld${EMULATION_NAME}_before_allocation (); |
| 73 | |
| 74 | if (bfd_get_flavour (link_info.output_bfd) != bfd_target_elf_flavour) |
| 75 | { |
| 76 | avr_no_stubs = TRUE; |
| 77 | return; |
| 78 | } |
| 79 | |
| 80 | /* We only need stubs for avr6, avrxmega6, and avrxmega7. */ |
| 81 | if (strcmp ("${EMULATION_NAME}","avr6") |
| 82 | && strcmp ("${EMULATION_NAME}","avrxmega6") |
| 83 | && strcmp ("${EMULATION_NAME}","avrxmega7") ) |
| 84 | avr_no_stubs = TRUE; |
| 85 | |
| 86 | avr_elf_set_global_bfd_parameters (); |
| 87 | |
| 88 | /* If generating a relocatable output file, then |
| 89 | we don't have to generate the trampolines. */ |
| 90 | if (bfd_link_relocatable (&link_info)) |
| 91 | avr_no_stubs = TRUE; |
| 92 | |
| 93 | if (avr_no_stubs) |
| 94 | return; |
| 95 | |
| 96 | ret = elf32_avr_setup_section_lists (link_info.output_bfd, &link_info); |
| 97 | |
| 98 | if (ret < 0) |
| 99 | einfo (_("%X%P: can not setup the input section list: %E\n")); |
| 100 | |
| 101 | if (ret <= 0) |
| 102 | return; |
| 103 | |
| 104 | /* Call into the BFD backend to do the real "stub"-work. */ |
| 105 | if (! elf32_avr_size_stubs (link_info.output_bfd, &link_info, TRUE)) |
| 106 | einfo (_("%X%P: can not size stub section: %E\n")); |
| 107 | } |
| 108 | |
| 109 | /* This is called before the input files are opened. We create a new |
| 110 | fake input file to hold the stub section and generate the section itself. */ |
| 111 | |
| 112 | static void |
| 113 | avr_elf_create_output_section_statements (void) |
| 114 | { |
| 115 | flagword flags; |
| 116 | |
| 117 | if (bfd_get_flavour (link_info.output_bfd) != bfd_target_elf_flavour) |
| 118 | { |
| 119 | einfo (_("%F%P: error: cannot change output format " |
| 120 | "whilst linking %s binaries\n"), "AVR"); |
| 121 | return; |
| 122 | } |
| 123 | |
| 124 | stub_file = lang_add_input_file ("linker stubs", |
| 125 | lang_input_file_is_fake_enum, |
| 126 | NULL); |
| 127 | |
| 128 | stub_file->the_bfd = bfd_create ("linker stubs", link_info.output_bfd); |
| 129 | if (stub_file->the_bfd == NULL |
| 130 | || !bfd_set_arch_mach (stub_file->the_bfd, |
| 131 | bfd_get_arch (link_info.output_bfd), |
| 132 | bfd_get_mach (link_info.output_bfd))) |
| 133 | { |
| 134 | einfo (_("%X%P: can not create stub BFD: %E\n")); |
| 135 | return; |
| 136 | } |
| 137 | |
| 138 | /* Now we add the stub section. */ |
| 139 | |
| 140 | flags = (SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE |
| 141 | | SEC_HAS_CONTENTS | SEC_RELOC | SEC_IN_MEMORY | SEC_KEEP); |
| 142 | avr_stub_section = bfd_make_section_anyway_with_flags (stub_file->the_bfd, |
| 143 | ".trampolines", |
| 144 | flags); |
| 145 | if (avr_stub_section == NULL) |
| 146 | goto err_ret; |
| 147 | |
| 148 | avr_stub_section->alignment_power = 1; |
| 149 | |
| 150 | ldlang_add_file (stub_file); |
| 151 | |
| 152 | return; |
| 153 | |
| 154 | err_ret: |
| 155 | einfo (_("%X%P: can not make stub section: %E\n")); |
| 156 | return; |
| 157 | } |
| 158 | |
| 159 | /* Re-calculates the size of the stubs so that we won't waste space. */ |
| 160 | |
| 161 | static void |
| 162 | avr_elf_after_allocation (void) |
| 163 | { |
| 164 | if (!avr_no_stubs && ! RELAXATION_ENABLED) |
| 165 | { |
| 166 | /* If relaxing, elf32_avr_size_stubs will be called from |
| 167 | elf32_avr_relax_section. */ |
| 168 | if (!elf32_avr_size_stubs (link_info.output_bfd, &link_info, TRUE)) |
| 169 | einfo (_("%X%P: can not size stub section: %E\n")); |
| 170 | } |
| 171 | |
| 172 | gld${EMULATION_NAME}_after_allocation (); |
| 173 | |
| 174 | /* Now build the linker stubs. */ |
| 175 | if (!avr_no_stubs) |
| 176 | { |
| 177 | if (!elf32_avr_build_stubs (&link_info)) |
| 178 | einfo (_("%X%P: can not build stubs: %E\n")); |
| 179 | } |
| 180 | } |
| 181 | |
| 182 | static void |
| 183 | avr_elf_before_parse (void) |
| 184 | { |
| 185 | /* Don't create a demand-paged executable, since this feature isn't |
| 186 | meaningful in AVR. */ |
| 187 | config.magic_demand_paged = FALSE; |
| 188 | |
| 189 | gld${EMULATION_NAME}_before_parse (); |
| 190 | } |
| 191 | |
| 192 | static void |
| 193 | avr_finish (void) |
| 194 | { |
| 195 | bfd *abfd; |
| 196 | bfd_boolean avr_link_relax; |
| 197 | |
| 198 | if (bfd_link_relocatable (&link_info)) |
| 199 | { |
| 200 | avr_link_relax = TRUE; |
| 201 | for (abfd = link_info.input_bfds; abfd != NULL; abfd = abfd->link.next) |
| 202 | { |
| 203 | /* Don't let the linker stubs prevent the final object being |
| 204 | marked as link-relax ready. */ |
| 205 | if ((elf_elfheader (abfd)->e_flags |
| 206 | & EF_AVR_LINKRELAX_PREPARED) == 0 |
| 207 | && abfd != stub_file->the_bfd) |
| 208 | { |
| 209 | avr_link_relax = FALSE; |
| 210 | break; |
| 211 | } |
| 212 | } |
| 213 | } |
| 214 | else |
| 215 | { |
| 216 | avr_link_relax = RELAXATION_ENABLED; |
| 217 | } |
| 218 | |
| 219 | abfd = link_info.output_bfd; |
| 220 | |
| 221 | if (bfd_get_flavour (link_info.output_bfd) == bfd_target_elf_flavour) |
| 222 | { |
| 223 | if (avr_link_relax) |
| 224 | elf_elfheader (abfd)->e_flags |= EF_AVR_LINKRELAX_PREPARED; |
| 225 | else |
| 226 | elf_elfheader (abfd)->e_flags &= ~EF_AVR_LINKRELAX_PREPARED; |
| 227 | } |
| 228 | |
| 229 | finish_default (); |
| 230 | } |
| 231 | EOF |
| 232 | |
| 233 | |
| 234 | PARSE_AND_LIST_PROLOGUE=' |
| 235 | |
| 236 | #define OPTION_NO_CALL_RET_REPLACEMENT 301 |
| 237 | #define OPTION_PMEM_WRAP_AROUND 302 |
| 238 | #define OPTION_NO_STUBS 303 |
| 239 | #define OPTION_DEBUG_STUBS 304 |
| 240 | #define OPTION_DEBUG_RELAX 305 |
| 241 | ' |
| 242 | |
| 243 | PARSE_AND_LIST_LONGOPTS=' |
| 244 | { "no-call-ret-replacement", no_argument, |
| 245 | NULL, OPTION_NO_CALL_RET_REPLACEMENT}, |
| 246 | { "pmem-wrap-around", required_argument, |
| 247 | NULL, OPTION_PMEM_WRAP_AROUND}, |
| 248 | { "no-stubs", no_argument, |
| 249 | NULL, OPTION_NO_STUBS}, |
| 250 | { "debug-stubs", no_argument, |
| 251 | NULL, OPTION_DEBUG_STUBS}, |
| 252 | { "debug-relax", no_argument, |
| 253 | NULL, OPTION_DEBUG_RELAX}, |
| 254 | ' |
| 255 | |
| 256 | PARSE_AND_LIST_OPTIONS=' |
| 257 | fprintf (file, _(" --pmem-wrap-around=<val> " |
| 258 | "Make the linker relaxation machine assume that a\n" |
| 259 | " " |
| 260 | " program counter wrap-around occurs at address\n" |
| 261 | " " |
| 262 | " <val>. Supported values: 8k, 16k, 32k and 64k.\n")); |
| 263 | fprintf (file, _(" --no-call-ret-replacement " |
| 264 | "The relaxation machine normally will\n" |
| 265 | " " |
| 266 | " substitute two immediately following call/ret\n" |
| 267 | " " |
| 268 | " instructions by a single jump instruction.\n" |
| 269 | " " |
| 270 | " This option disables this optimization.\n")); |
| 271 | fprintf (file, _(" --no-stubs " |
| 272 | "If the linker detects to attempt to access\n" |
| 273 | " " |
| 274 | " an instruction beyond 128k by a reloc that\n" |
| 275 | " " |
| 276 | " is limited to 128k max, it inserts a jump\n" |
| 277 | " " |
| 278 | " stub. You can de-active this with this switch.\n")); |
| 279 | fprintf (file, _(" --debug-stubs " |
| 280 | "Used for debugging avr-ld.\n")); |
| 281 | fprintf (file, _(" --debug-relax " |
| 282 | "Used for debugging avr-ld.\n")); |
| 283 | ' |
| 284 | |
| 285 | PARSE_AND_LIST_ARGS_CASES=' |
| 286 | |
| 287 | case OPTION_PMEM_WRAP_AROUND: |
| 288 | { |
| 289 | /* This variable is defined in the bfd library. */ |
| 290 | if ((!strcmp (optarg,"32k")) || (!strcmp (optarg,"32K"))) |
| 291 | avr_pc_wrap_around = 32768; |
| 292 | else if ((!strcmp (optarg,"8k")) || (!strcmp (optarg,"8K"))) |
| 293 | avr_pc_wrap_around = 8192; |
| 294 | else if ((!strcmp (optarg,"16k")) || (!strcmp (optarg,"16K"))) |
| 295 | avr_pc_wrap_around = 16384; |
| 296 | else if ((!strcmp (optarg,"64k")) || (!strcmp (optarg,"64K"))) |
| 297 | avr_pc_wrap_around = 0x10000; |
| 298 | else |
| 299 | return FALSE; |
| 300 | } |
| 301 | break; |
| 302 | |
| 303 | case OPTION_DEBUG_STUBS: |
| 304 | avr_debug_stubs = TRUE; |
| 305 | break; |
| 306 | |
| 307 | case OPTION_DEBUG_RELAX: |
| 308 | avr_debug_relax = TRUE; |
| 309 | break; |
| 310 | |
| 311 | case OPTION_NO_STUBS: |
| 312 | avr_no_stubs = TRUE; |
| 313 | break; |
| 314 | |
| 315 | case OPTION_NO_CALL_RET_REPLACEMENT: |
| 316 | { |
| 317 | /* This variable is defined in the bfd library. */ |
| 318 | avr_replace_call_ret_sequences = FALSE; |
| 319 | } |
| 320 | break; |
| 321 | ' |
| 322 | |
| 323 | # |
| 324 | # Put these extra avr-elf routines in ld_${EMULATION_NAME}_emulation |
| 325 | # |
| 326 | LDEMUL_BEFORE_PARSE=avr_elf_before_parse |
| 327 | LDEMUL_BEFORE_ALLOCATION=avr_elf_${EMULATION_NAME}_before_allocation |
| 328 | LDEMUL_AFTER_ALLOCATION=avr_elf_after_allocation |
| 329 | LDEMUL_CREATE_OUTPUT_SECTION_STATEMENTS=avr_elf_create_output_section_statements |
| 330 | LDEMUL_FINISH=avr_finish |