1# This shell script emits a C file. -*- C -*- 2# Copyright 2006, 2007, 2008, 2009 3# Free Software Foundation, Inc. 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 avr-elf specific 24# routines. It is used to generate the trampolines for the avr6 family 25# of devices where one needs to address the issue that it is not possible 26# to reach the whole program memory by using 16 bit pointers. 27 28fragment <<EOF 29 30#include "elf32-avr.h" 31#include "ldctor.h" 32 33/* The fake file and it's corresponding section meant to hold 34 the linker stubs if needed. */ 35 36static lang_input_statement_type *stub_file; 37static asection *avr_stub_section; 38 39/* Variables set by the command-line parameters and transfered 40 to the bfd without use of global shared variables. */ 41 42static bfd_boolean avr_no_stubs = FALSE; 43static bfd_boolean avr_debug_relax = FALSE; 44static bfd_boolean avr_debug_stubs = FALSE; 45static bfd_boolean avr_replace_call_ret_sequences = TRUE; 46static bfd_vma avr_pc_wrap_around = 0x10000000; 47 48/* Transfers information to the bfd frontend. */ 49 50static void 51avr_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 67static void 68avr_elf_${EMULATION_NAME}_before_allocation (void) 69{ 70 int ret; 71 72 gld${EMULATION_NAME}_before_allocation (); 73 74 /* We only need stubs for avr6, avrxmega6, and avrxmega7. */ 75 if (strcmp ("${EMULATION_NAME}","avr6") 76 && strcmp ("${EMULATION_NAME}","avrxmega6") 77 && strcmp ("${EMULATION_NAME}","avrxmega7") ) 78 avr_no_stubs = TRUE; 79 80 avr_elf_set_global_bfd_parameters (); 81 82 /* If generating a relocatable output file, then 83 we don't have to generate the trampolines. */ 84 if (link_info.relocatable) 85 avr_no_stubs = TRUE; 86 87 if (avr_no_stubs) 88 return; 89 90 ret = elf32_avr_setup_section_lists (link_info.output_bfd, &link_info); 91 92 if (ret < 0) 93 einfo ("%X%P: can not setup the input section list: %E\n"); 94 95 if (ret <= 0) 96 return; 97 98 /* Call into the BFD backend to do the real "stub"-work. */ 99 if (! elf32_avr_size_stubs (link_info.output_bfd, &link_info, TRUE)) 100 einfo ("%X%P: can not size stub section: %E\n"); 101} 102 103/* This is called before the input files are opened. We create a new 104 fake input file to hold the stub section and generate the section itself. */ 105 106static void 107avr_elf_create_output_section_statements (void) 108{ 109 flagword flags; 110 111 stub_file = lang_add_input_file ("linker stubs", 112 lang_input_file_is_fake_enum, 113 NULL); 114 115 stub_file->the_bfd = bfd_create ("linker stubs", link_info.output_bfd); 116 if (stub_file->the_bfd == NULL 117 || !bfd_set_arch_mach (stub_file->the_bfd, 118 bfd_get_arch (link_info.output_bfd), 119 bfd_get_mach (link_info.output_bfd))) 120 { 121 einfo ("%X%P: can not create stub BFD %E\n"); 122 return; 123 } 124 125 /* Now we add the stub section. */ 126 127 flags = (SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE 128 | SEC_HAS_CONTENTS | SEC_RELOC | SEC_IN_MEMORY | SEC_KEEP); 129 avr_stub_section = bfd_make_section_anyway_with_flags (stub_file->the_bfd, 130 ".trampolines", 131 flags); 132 if (avr_stub_section == NULL) 133 goto err_ret; 134 135 avr_stub_section->alignment_power = 1; 136 137 ldlang_add_file (stub_file); 138 139 return; 140 141 err_ret: 142 einfo ("%X%P: can not make stub section: %E\n"); 143 return; 144} 145 146/* Re-calculates the size of the stubs so that we won't waste space. */ 147 148static void 149avr_elf_after_allocation (void) 150{ 151 if (!avr_no_stubs && ! RELAXATION_ENABLED) 152 { 153 /* If relaxing, elf32_avr_size_stubs will be called from 154 elf32_avr_relax_section. */ 155 if (!elf32_avr_size_stubs (link_info.output_bfd, &link_info, TRUE)) 156 einfo ("%X%P: can not size stub section: %E\n"); 157 } 158 159 gld${EMULATION_NAME}_after_allocation (); 160 161 /* Now build the linker stubs. */ 162 if (!avr_no_stubs) 163 { 164 if (!elf32_avr_build_stubs (&link_info)) 165 einfo ("%X%P: can not build stubs: %E\n"); 166 } 167} 168 169 170EOF 171 172 173PARSE_AND_LIST_PROLOGUE=' 174 175#define OPTION_NO_CALL_RET_REPLACEMENT 301 176#define OPTION_PMEM_WRAP_AROUND 302 177#define OPTION_NO_STUBS 303 178#define OPTION_DEBUG_STUBS 304 179#define OPTION_DEBUG_RELAX 305 180' 181 182PARSE_AND_LIST_LONGOPTS=' 183 { "no-call-ret-replacement", no_argument, 184 NULL, OPTION_NO_CALL_RET_REPLACEMENT}, 185 { "pmem-wrap-around", required_argument, 186 NULL, OPTION_PMEM_WRAP_AROUND}, 187 { "no-stubs", no_argument, 188 NULL, OPTION_NO_STUBS}, 189 { "debug-stubs", no_argument, 190 NULL, OPTION_DEBUG_STUBS}, 191 { "debug-relax", no_argument, 192 NULL, OPTION_DEBUG_RELAX}, 193' 194 195PARSE_AND_LIST_OPTIONS=' 196 fprintf (file, _(" --pmem-wrap-around=<val> " 197 "Make the linker relaxation machine assume that a\n" 198 " " 199 " program counter wrap-around occures at address\n" 200 " " 201 " <val>. Supported values: 8k, 16k, 32k and 64k.\n")); 202 fprintf (file, _(" --no-call-ret-replacement " 203 "The relaxation machine normally will\n" 204 " " 205 " substitute two immediately following call/ret\n" 206 " " 207 " instructions by a single jump instruction.\n" 208 " " 209 " This option disables this optimization.\n")); 210 fprintf (file, _(" --no-stubs " 211 "If the linker detects to attempt to access\n" 212 " " 213 " an instruction beyond 128k by a reloc that\n" 214 " " 215 " is limited to 128k max, it inserts a jump\n" 216 " " 217 " stub. You can de-active this with this switch.\n")); 218 fprintf (file, _(" --debug-stubs " 219 "Used for debugging avr-ld.\n")); 220 fprintf (file, _(" --debug-relax " 221 "Used for debugging avr-ld.\n")); 222' 223 224PARSE_AND_LIST_ARGS_CASES=' 225 226 case OPTION_PMEM_WRAP_AROUND: 227 { 228 /* This variable is defined in the bfd library. */ 229 if ((!strcmp (optarg,"32k")) || (!strcmp (optarg,"32K"))) 230 avr_pc_wrap_around = 32768; 231 else if ((!strcmp (optarg,"8k")) || (!strcmp (optarg,"8K"))) 232 avr_pc_wrap_around = 8192; 233 else if ((!strcmp (optarg,"16k")) || (!strcmp (optarg,"16K"))) 234 avr_pc_wrap_around = 16384; 235 else if ((!strcmp (optarg,"64k")) || (!strcmp (optarg,"64K"))) 236 avr_pc_wrap_around = 0x10000; 237 else 238 return FALSE; 239 } 240 break; 241 242 case OPTION_DEBUG_STUBS: 243 avr_debug_stubs = TRUE; 244 break; 245 246 case OPTION_DEBUG_RELAX: 247 avr_debug_relax = TRUE; 248 break; 249 250 case OPTION_NO_STUBS: 251 avr_no_stubs = TRUE; 252 break; 253 254 case OPTION_NO_CALL_RET_REPLACEMENT: 255 { 256 /* This variable is defined in the bfd library. */ 257 avr_replace_call_ret_sequences = FALSE; 258 } 259 break; 260' 261 262# 263# Put these extra avr-elf routines in ld_${EMULATION_NAME}_emulation 264# 265LDEMUL_BEFORE_ALLOCATION=avr_elf_${EMULATION_NAME}_before_allocation 266LDEMUL_AFTER_ALLOCATION=avr_elf_after_allocation 267LDEMUL_CREATE_OUTPUT_SECTION_STATEMENTS=avr_elf_create_output_section_statements 268