1 # This shell script emits a C file. -*- C -*-
2 # Copyright (C) 2006-2017 Free Software Foundation, Inc.
4 # This file is part of the GNU Binutils.
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.
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.
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,
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.
29 #include "elf32-avr.h"
33 /* The fake file and it's corresponding section meant to hold
34 the linker stubs if needed. */
36 static lang_input_statement_type *stub_file;
37 static asection *avr_stub_section;
39 /* Variables set by the command-line parameters and transferred
40 to the bfd without use of global shared variables. */
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;
48 /* Transfers information to the bfd frontend. */
51 avr_elf_set_global_bfd_parameters (void)
53 elf32_avr_setup_params (& link_info,
60 avr_replace_call_ret_sequences);
64 /* Makes a conservative estimate of the trampoline section size that could
65 be corrected later on. */
68 avr_elf_${EMULATION_NAME}_before_allocation (void)
72 gld${EMULATION_NAME}_before_allocation ();
74 if (bfd_get_flavour (link_info.output_bfd) != bfd_target_elf_flavour)
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") )
86 avr_elf_set_global_bfd_parameters ();
88 /* If generating a relocatable output file, then
89 we don't have to generate the trampolines. */
90 if (bfd_link_relocatable (&link_info))
96 ret = elf32_avr_setup_section_lists (link_info.output_bfd, &link_info);
99 einfo ("%X%P: can not setup the input section list: %E\n");
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");
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. */
113 avr_elf_create_output_section_statements (void)
117 if (bfd_get_flavour (link_info.output_bfd) != bfd_target_elf_flavour)
119 einfo ("%X%P: changing output format whilst linking is not supported\n");
123 stub_file = lang_add_input_file ("linker stubs",
124 lang_input_file_is_fake_enum,
127 stub_file->the_bfd = bfd_create ("linker stubs", link_info.output_bfd);
128 if (stub_file->the_bfd == NULL
129 || !bfd_set_arch_mach (stub_file->the_bfd,
130 bfd_get_arch (link_info.output_bfd),
131 bfd_get_mach (link_info.output_bfd)))
133 einfo ("%X%P: can not create stub BFD %E\n");
137 /* Now we add the stub section. */
139 flags = (SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE
140 | SEC_HAS_CONTENTS | SEC_RELOC | SEC_IN_MEMORY | SEC_KEEP);
141 avr_stub_section = bfd_make_section_anyway_with_flags (stub_file->the_bfd,
144 if (avr_stub_section == NULL)
147 avr_stub_section->alignment_power = 1;
149 ldlang_add_file (stub_file);
154 einfo ("%X%P: can not make stub section: %E\n");
158 /* Re-calculates the size of the stubs so that we won't waste space. */
161 avr_elf_after_allocation (void)
163 if (!avr_no_stubs && ! RELAXATION_ENABLED)
165 /* If relaxing, elf32_avr_size_stubs will be called from
166 elf32_avr_relax_section. */
167 if (!elf32_avr_size_stubs (link_info.output_bfd, &link_info, TRUE))
168 einfo ("%X%P: can not size stub section: %E\n");
171 gld${EMULATION_NAME}_after_allocation ();
173 /* Now build the linker stubs. */
176 if (!elf32_avr_build_stubs (&link_info))
177 einfo ("%X%P: can not build stubs: %E\n");
182 avr_elf_before_parse (void)
184 /* Don't create a demand-paged executable, since this feature isn't
185 meaningful in AVR. */
186 config.magic_demand_paged = FALSE;
188 gld${EMULATION_NAME}_before_parse ();
195 bfd_boolean avr_link_relax;
197 if (bfd_link_relocatable (&link_info))
199 avr_link_relax = TRUE;
200 for (abfd = link_info.input_bfds; abfd != NULL; abfd = abfd->link.next)
202 /* Don't let the linker stubs prevent the final object being
203 marked as link-relax ready. */
204 if ((elf_elfheader (abfd)->e_flags
205 & EF_AVR_LINKRELAX_PREPARED) == 0
206 && abfd != stub_file->the_bfd)
208 avr_link_relax = FALSE;
215 avr_link_relax = RELAXATION_ENABLED;
218 abfd = link_info.output_bfd;
220 if (bfd_get_flavour (link_info.output_bfd) == bfd_target_elf_flavour)
223 elf_elfheader (abfd)->e_flags |= EF_AVR_LINKRELAX_PREPARED;
225 elf_elfheader (abfd)->e_flags &= ~EF_AVR_LINKRELAX_PREPARED;
233 PARSE_AND_LIST_PROLOGUE='
235 #define OPTION_NO_CALL_RET_REPLACEMENT 301
236 #define OPTION_PMEM_WRAP_AROUND 302
237 #define OPTION_NO_STUBS 303
238 #define OPTION_DEBUG_STUBS 304
239 #define OPTION_DEBUG_RELAX 305
242 PARSE_AND_LIST_LONGOPTS='
243 { "no-call-ret-replacement", no_argument,
244 NULL, OPTION_NO_CALL_RET_REPLACEMENT},
245 { "pmem-wrap-around", required_argument,
246 NULL, OPTION_PMEM_WRAP_AROUND},
247 { "no-stubs", no_argument,
248 NULL, OPTION_NO_STUBS},
249 { "debug-stubs", no_argument,
250 NULL, OPTION_DEBUG_STUBS},
251 { "debug-relax", no_argument,
252 NULL, OPTION_DEBUG_RELAX},
255 PARSE_AND_LIST_OPTIONS='
256 fprintf (file, _(" --pmem-wrap-around=<val> "
257 "Make the linker relaxation machine assume that a\n"
259 " program counter wrap-around occures at address\n"
261 " <val>. Supported values: 8k, 16k, 32k and 64k.\n"));
262 fprintf (file, _(" --no-call-ret-replacement "
263 "The relaxation machine normally will\n"
265 " substitute two immediately following call/ret\n"
267 " instructions by a single jump instruction.\n"
269 " This option disables this optimization.\n"));
270 fprintf (file, _(" --no-stubs "
271 "If the linker detects to attempt to access\n"
273 " an instruction beyond 128k by a reloc that\n"
275 " is limited to 128k max, it inserts a jump\n"
277 " stub. You can de-active this with this switch.\n"));
278 fprintf (file, _(" --debug-stubs "
279 "Used for debugging avr-ld.\n"));
280 fprintf (file, _(" --debug-relax "
281 "Used for debugging avr-ld.\n"));
284 PARSE_AND_LIST_ARGS_CASES='
286 case OPTION_PMEM_WRAP_AROUND:
288 /* This variable is defined in the bfd library. */
289 if ((!strcmp (optarg,"32k")) || (!strcmp (optarg,"32K")))
290 avr_pc_wrap_around = 32768;
291 else if ((!strcmp (optarg,"8k")) || (!strcmp (optarg,"8K")))
292 avr_pc_wrap_around = 8192;
293 else if ((!strcmp (optarg,"16k")) || (!strcmp (optarg,"16K")))
294 avr_pc_wrap_around = 16384;
295 else if ((!strcmp (optarg,"64k")) || (!strcmp (optarg,"64K")))
296 avr_pc_wrap_around = 0x10000;
302 case OPTION_DEBUG_STUBS:
303 avr_debug_stubs = TRUE;
306 case OPTION_DEBUG_RELAX:
307 avr_debug_relax = TRUE;
310 case OPTION_NO_STUBS:
314 case OPTION_NO_CALL_RET_REPLACEMENT:
316 /* This variable is defined in the bfd library. */
317 avr_replace_call_ret_sequences = FALSE;
323 # Put these extra avr-elf routines in ld_${EMULATION_NAME}_emulation
325 LDEMUL_BEFORE_PARSE=avr_elf_before_parse
326 LDEMUL_BEFORE_ALLOCATION=avr_elf_${EMULATION_NAME}_before_allocation
327 LDEMUL_AFTER_ALLOCATION=avr_elf_after_allocation
328 LDEMUL_CREATE_OUTPUT_SECTION_STATEMENTS=avr_elf_create_output_section_statements
329 LDEMUL_FINISH=avr_finish