| # This shell script emits a C file. -*- C -*- |
| # Copyright 2006, 2007, 2008 |
| # Free Software Foundation, Inc. |
| # |
| # This file is part of the GNU Binutils. |
| # |
| # This program is free software; you can redistribute it and/or modify |
| # it under the terms of the GNU General Public License as published by |
| # the Free Software Foundation; either version 3 of the License, or |
| # (at your option) any later version. |
| # |
| # This program is distributed in the hope that it will be useful, |
| # but WITHOUT ANY WARRANTY; without even the implied warranty of |
| # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| # GNU General Public License for more details. |
| # |
| # You should have received a copy of the GNU General Public License |
| # along with this program; if not, write to the Free Software |
| # Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, |
| # MA 02110-1301, USA. |
| |
| |
| # This file is sourced from elf32.em, and defines extra avr-elf specific |
| # routines. It is used to generate the trampolines for the avr6 family |
| # of devices where one needs to address the issue that it is not possible |
| # to reach the whole program memory by using 16 bit pointers. |
| |
| fragment <<EOF |
| |
| #include "elf32-avr.h" |
| #include "ldctor.h" |
| |
| /* The fake file and it's corresponding section meant to hold |
| the linker stubs if needed. */ |
| |
| static lang_input_statement_type *stub_file; |
| static asection *avr_stub_section; |
| |
| /* Variables set by the command-line parameters and transfered |
| to the bfd without use of global shared variables. */ |
| |
| static bfd_boolean avr_no_stubs = FALSE; |
| static bfd_boolean avr_debug_relax = FALSE; |
| static bfd_boolean avr_debug_stubs = FALSE; |
| static bfd_boolean avr_replace_call_ret_sequences = TRUE; |
| static bfd_vma avr_pc_wrap_around = 0x10000000; |
| |
| /* Transfers information to the bfd frontend. */ |
| |
| static void |
| avr_elf_set_global_bfd_parameters (void) |
| { |
| elf32_avr_setup_params (& link_info, |
| stub_file->the_bfd, |
| avr_stub_section, |
| avr_no_stubs, |
| avr_debug_stubs, |
| avr_debug_relax, |
| avr_pc_wrap_around, |
| avr_replace_call_ret_sequences); |
| } |
| |
| |
| /* Makes a conservative estimate of the trampoline section size that could |
| be corrected later on. */ |
| |
| static void |
| avr_elf_${EMULATION_NAME}_before_allocation (void) |
| { |
| int ret; |
| |
| gld${EMULATION_NAME}_before_allocation (); |
| |
| /* We only need stubs for the avr6 family. */ |
| if (strcmp ("${EMULATION_NAME}","avr6")) |
| avr_no_stubs = TRUE; |
| |
| avr_elf_set_global_bfd_parameters (); |
| |
| /* If generating a relocatable output file, then |
| we don't have to generate the trampolines. */ |
| if (link_info.relocatable) |
| avr_no_stubs = TRUE; |
| |
| if (avr_no_stubs) |
| return; |
| |
| ret = elf32_avr_setup_section_lists (link_info.output_bfd, &link_info); |
| |
| if (ret < 0) |
| einfo ("%X%P: can not setup the input section list: %E\n"); |
| |
| if (ret <= 0) |
| return; |
| |
| /* Call into the BFD backend to do the real "stub"-work. */ |
| if (! elf32_avr_size_stubs (link_info.output_bfd, &link_info, TRUE)) |
| einfo ("%X%P: can not size stub section: %E\n"); |
| } |
| |
| /* This is called before the input files are opened. We create a new |
| fake input file to hold the stub section and generate the section itself. */ |
| |
| static void |
| avr_elf_create_output_section_statements (void) |
| { |
| flagword flags; |
| |
| stub_file = lang_add_input_file ("linker stubs", |
| lang_input_file_is_fake_enum, |
| NULL); |
| |
| stub_file->the_bfd = bfd_create ("linker stubs", link_info.output_bfd); |
| if (stub_file->the_bfd == NULL |
| || !bfd_set_arch_mach (stub_file->the_bfd, |
| bfd_get_arch (link_info.output_bfd), |
| bfd_get_mach (link_info.output_bfd))) |
| { |
| einfo ("%X%P: can not create stub BFD %E\n"); |
| return; |
| } |
| |
| /* Now we add the stub section. */ |
| |
| flags = (SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE |
| | SEC_HAS_CONTENTS | SEC_RELOC | SEC_IN_MEMORY | SEC_KEEP); |
| avr_stub_section = bfd_make_section_anyway_with_flags (stub_file->the_bfd, |
| ".trampolines", |
| flags); |
| if (avr_stub_section == NULL) |
| goto err_ret; |
| |
| avr_stub_section->alignment_power = 1; |
| |
| ldlang_add_file (stub_file); |
| |
| return; |
| |
| err_ret: |
| einfo ("%X%P: can not make stub section: %E\n"); |
| return; |
| } |
| |
| /* Re-calculates the size of the stubs so that we won't waste space. */ |
| |
| static void |
| avr_elf_finish (void) |
| { |
| if (!avr_no_stubs) |
| { |
| /* Now build the linker stubs. */ |
| if (stub_file->the_bfd->sections != NULL) |
| { |
| /* Call again the trampoline analyzer to initialize the trampoline |
| stubs with the correct symbol addresses. Since there could have |
| been relaxation, the symbol addresses that were found during |
| first call may no longer be correct. */ |
| if (!elf32_avr_size_stubs (link_info.output_bfd, &link_info, FALSE)) |
| { |
| einfo ("%X%P: can not size stub section: %E\n"); |
| return; |
| } |
| |
| if (!elf32_avr_build_stubs (&link_info)) |
| einfo ("%X%P: can not build stubs: %E\n"); |
| } |
| } |
| |
| gld${EMULATION_NAME}_finish (); |
| } |
| |
| |
| EOF |
| |
| |
| PARSE_AND_LIST_PROLOGUE=' |
| |
| #define OPTION_NO_CALL_RET_REPLACEMENT 301 |
| #define OPTION_PMEM_WRAP_AROUND 302 |
| #define OPTION_NO_STUBS 303 |
| #define OPTION_DEBUG_STUBS 304 |
| #define OPTION_DEBUG_RELAX 305 |
| ' |
| |
| PARSE_AND_LIST_LONGOPTS=' |
| { "no-call-ret-replacement", no_argument, |
| NULL, OPTION_NO_CALL_RET_REPLACEMENT}, |
| { "pmem-wrap-around", required_argument, |
| NULL, OPTION_PMEM_WRAP_AROUND}, |
| { "no-stubs", no_argument, |
| NULL, OPTION_NO_STUBS}, |
| { "debug-stubs", no_argument, |
| NULL, OPTION_DEBUG_STUBS}, |
| { "debug-relax", no_argument, |
| NULL, OPTION_DEBUG_RELAX}, |
| ' |
| |
| PARSE_AND_LIST_OPTIONS=' |
| fprintf (file, _(" --pmem-wrap-around=<val> " |
| "Make the linker relaxation machine assume that a\n" |
| " " |
| " program counter wrap-around occures at address\n" |
| " " |
| " <val>. Supported values: 8k, 16k, 32k and 64k.\n")); |
| fprintf (file, _(" --no-call-ret-replacement " |
| "The relaxation machine normally will\n" |
| " " |
| " substitute two immediately following call/ret\n" |
| " " |
| " instructions by a single jump instruction.\n" |
| " " |
| " This option disables this optimization.\n")); |
| fprintf (file, _(" --no-stubs " |
| "If the linker detects to attempt to access\n" |
| " " |
| " an instruction beyond 128k by a reloc that\n" |
| " " |
| " is limited to 128k max, it inserts a jump\n" |
| " " |
| " stub. You can de-active this with this switch.\n")); |
| fprintf (file, _(" --debug-stubs " |
| "Used for debugging avr-ld.\n")); |
| fprintf (file, _(" --debug-relax " |
| "Used for debugging avr-ld.\n")); |
| ' |
| |
| PARSE_AND_LIST_ARGS_CASES=' |
| |
| case OPTION_PMEM_WRAP_AROUND: |
| { |
| /* This variable is defined in the bfd library. */ |
| if ((!strcmp (optarg,"32k")) || (!strcmp (optarg,"32K"))) |
| avr_pc_wrap_around = 32768; |
| else if ((!strcmp (optarg,"8k")) || (!strcmp (optarg,"8K"))) |
| avr_pc_wrap_around = 8192; |
| else if ((!strcmp (optarg,"16k")) || (!strcmp (optarg,"16K"))) |
| avr_pc_wrap_around = 16384; |
| else if ((!strcmp (optarg,"64k")) || (!strcmp (optarg,"64K"))) |
| avr_pc_wrap_around = 0x10000; |
| else |
| return FALSE; |
| } |
| break; |
| |
| case OPTION_DEBUG_STUBS: |
| avr_debug_stubs = TRUE; |
| break; |
| |
| case OPTION_DEBUG_RELAX: |
| avr_debug_relax = TRUE; |
| break; |
| |
| case OPTION_NO_STUBS: |
| avr_no_stubs = TRUE; |
| break; |
| |
| case OPTION_NO_CALL_RET_REPLACEMENT: |
| { |
| /* This variable is defined in the bfd library. */ |
| avr_replace_call_ret_sequences = FALSE; |
| } |
| break; |
| ' |
| |
| # |
| # Put these extra avr-elf routines in ld_${EMULATION_NAME}_emulation |
| # |
| LDEMUL_BEFORE_ALLOCATION=avr_elf_${EMULATION_NAME}_before_allocation |
| LDEMUL_FINISH=avr_elf_finish |
| LDEMUL_CREATE_OUTPUT_SECTION_STATEMENTS=avr_elf_create_output_section_statements |
