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 the avr6 family. */ 75 if (strcmp ("${EMULATION_NAME}","avr6")) 76 avr_no_stubs = TRUE; 77 78 avr_elf_set_global_bfd_parameters (); 79 80 /* If generating a relocatable output file, then 81 we don't have to generate the trampolines. */ 82 if (link_info.relocatable) 83 avr_no_stubs = TRUE; 84 85 if (avr_no_stubs) 86 return; 87 88 ret = elf32_avr_setup_section_lists (link_info.output_bfd, &link_info); 89 90 if (ret < 0) 91 einfo ("%X%P: can not setup the input section list: %E\n"); 92 93 if (ret <= 0) 94 return; 95 96 /* Call into the BFD backend to do the real "stub"-work. */ 97 if (! elf32_avr_size_stubs (link_info.output_bfd, &link_info, TRUE)) 98 einfo ("%X%P: can not size stub section: %E\n"); 99} 100 101/* This is called before the input files are opened. We create a new 102 fake input file to hold the stub section and generate the section itself. */ 103 104static void 105avr_elf_create_output_section_statements (void) 106{ 107 flagword flags; 108 109 stub_file = lang_add_input_file ("linker stubs", 110 lang_input_file_is_fake_enum, 111 NULL); 112 113 stub_file->the_bfd = bfd_create ("linker stubs", link_info.output_bfd); 114 if (stub_file->the_bfd == NULL 115 || !bfd_set_arch_mach (stub_file->the_bfd, 116 bfd_get_arch (link_info.output_bfd), 117 bfd_get_mach (link_info.output_bfd))) 118 { 119 einfo ("%X%P: can not create stub BFD %E\n"); 120 return; 121 } 122 123 /* Now we add the stub section. */ 124 125 flags = (SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE 126 | SEC_HAS_CONTENTS | SEC_RELOC | SEC_IN_MEMORY | SEC_KEEP); 127 avr_stub_section = bfd_make_section_anyway_with_flags (stub_file->the_bfd, 128 ".trampolines", 129 flags); 130 if (avr_stub_section == NULL) 131 goto err_ret; 132 133 avr_stub_section->alignment_power = 1; 134 135 ldlang_add_file (stub_file); 136 137 return; 138 139 err_ret: 140 einfo ("%X%P: can not make stub section: %E\n"); 141 return; 142} 143 144/* Re-calculates the size of the stubs so that we won't waste space. */ 145 146static void 147avr_elf_after_allocation (void) 148{ 149 if (!avr_no_stubs && ! RELAXATION_ENABLED) 150 { 151 /* If relaxing, elf32_avr_size_stubs will be called from 152 elf32_avr_relax_section. */ 153 if (!elf32_avr_size_stubs (link_info.output_bfd, &link_info, FALSE)) 154 einfo ("%X%P: can not size stub section: %E\n"); 155 } 156 157 gld${EMULATION_NAME}_after_allocation (); 158 159 /* Now build the linker stubs. */ 160 if (!avr_no_stubs) 161 { 162 if (!elf32_avr_build_stubs (&link_info)) 163 einfo ("%X%P: can not build stubs: %E\n"); 164 } 165} 166 167 168EOF 169 170 171PARSE_AND_LIST_PROLOGUE=' 172 173#define OPTION_NO_CALL_RET_REPLACEMENT 301 174#define OPTION_PMEM_WRAP_AROUND 302 175#define OPTION_NO_STUBS 303 176#define OPTION_DEBUG_STUBS 304 177#define OPTION_DEBUG_RELAX 305 178' 179 180PARSE_AND_LIST_LONGOPTS=' 181 { "no-call-ret-replacement", no_argument, 182 NULL, OPTION_NO_CALL_RET_REPLACEMENT}, 183 { "pmem-wrap-around", required_argument, 184 NULL, OPTION_PMEM_WRAP_AROUND}, 185 { "no-stubs", no_argument, 186 NULL, OPTION_NO_STUBS}, 187 { "debug-stubs", no_argument, 188 NULL, OPTION_DEBUG_STUBS}, 189 { "debug-relax", no_argument, 190 NULL, OPTION_DEBUG_RELAX}, 191' 192 193PARSE_AND_LIST_OPTIONS=' 194 fprintf (file, _(" --pmem-wrap-around=<val> " 195 "Make the linker relaxation machine assume that a\n" 196 " " 197 " program counter wrap-around occures at address\n" 198 " " 199 " <val>. Supported values: 8k, 16k, 32k and 64k.\n")); 200 fprintf (file, _(" --no-call-ret-replacement " 201 "The relaxation machine normally will\n" 202 " " 203 " substitute two immediately following call/ret\n" 204 " " 205 " instructions by a single jump instruction.\n" 206 " " 207 " This option disables this optimization.\n")); 208 fprintf (file, _(" --no-stubs " 209 "If the linker detects to attempt to access\n" 210 " " 211 " an instruction beyond 128k by a reloc that\n" 212 " " 213 " is limited to 128k max, it inserts a jump\n" 214 " " 215 " stub. You can de-active this with this switch.\n")); 216 fprintf (file, _(" --debug-stubs " 217 "Used for debugging avr-ld.\n")); 218 fprintf (file, _(" --debug-relax " 219 "Used for debugging avr-ld.\n")); 220' 221 222PARSE_AND_LIST_ARGS_CASES=' 223 224 case OPTION_PMEM_WRAP_AROUND: 225 { 226 /* This variable is defined in the bfd library. */ 227 if ((!strcmp (optarg,"32k")) || (!strcmp (optarg,"32K"))) 228 avr_pc_wrap_around = 32768; 229 else if ((!strcmp (optarg,"8k")) || (!strcmp (optarg,"8K"))) 230 avr_pc_wrap_around = 8192; 231 else if ((!strcmp (optarg,"16k")) || (!strcmp (optarg,"16K"))) 232 avr_pc_wrap_around = 16384; 233 else if ((!strcmp (optarg,"64k")) || (!strcmp (optarg,"64K"))) 234 avr_pc_wrap_around = 0x10000; 235 else 236 return FALSE; 237 } 238 break; 239 240 case OPTION_DEBUG_STUBS: 241 avr_debug_stubs = TRUE; 242 break; 243 244 case OPTION_DEBUG_RELAX: 245 avr_debug_relax = TRUE; 246 break; 247 248 case OPTION_NO_STUBS: 249 avr_no_stubs = TRUE; 250 break; 251 252 case OPTION_NO_CALL_RET_REPLACEMENT: 253 { 254 /* This variable is defined in the bfd library. */ 255 avr_replace_call_ret_sequences = FALSE; 256 } 257 break; 258' 259 260# 261# Put these extra avr-elf routines in ld_${EMULATION_NAME}_emulation 262# 263LDEMUL_BEFORE_ALLOCATION=avr_elf_${EMULATION_NAME}_before_allocation 264LDEMUL_AFTER_ALLOCATION=avr_elf_after_allocation 265LDEMUL_CREATE_OUTPUT_SECTION_STATEMENTS=avr_elf_create_output_section_statements 266