1 # This shell script emits a C file. -*- C -*- 2 # Copyright (C) 2006-2014 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 32 /* The fake file and it's corresponding section meant to hold 33 the linker stubs if needed. */ 34 35 static lang_input_statement_type *stub_file; 36 static asection *avr_stub_section; 37 38 /* Variables set by the command-line parameters and transfered 39 to the bfd without use of global shared variables. */ 40 41 static bfd_boolean avr_no_stubs = FALSE; 42 static bfd_boolean avr_debug_relax = FALSE; 43 static bfd_boolean avr_debug_stubs = FALSE; 44 static bfd_boolean avr_replace_call_ret_sequences = TRUE; 45 static bfd_vma avr_pc_wrap_around = 0x10000000; 46 47 /* Transfers information to the bfd frontend. */ 48 49 static void 50 avr_elf_set_global_bfd_parameters (void) 51 { 52 elf32_avr_setup_params (& link_info, 53 stub_file->the_bfd, 54 avr_stub_section, 55 avr_no_stubs, 56 avr_debug_stubs, 57 avr_debug_relax, 58 avr_pc_wrap_around, 59 avr_replace_call_ret_sequences); 60 } 61 62 63 /* Makes a conservative estimate of the trampoline section size that could 64 be corrected later on. */ 65 66 static void 67 avr_elf_${EMULATION_NAME}_before_allocation (void) 68 { 69 int ret; 70 71 gld${EMULATION_NAME}_before_allocation (); 72 73 /* We only need stubs for avr6, avrxmega6, and avrxmega7. */ 74 if (strcmp ("${EMULATION_NAME}","avr6") 75 && strcmp ("${EMULATION_NAME}","avrxmega6") 76 && strcmp ("${EMULATION_NAME}","avrxmega7") ) 77 avr_no_stubs = TRUE; 78 79 avr_elf_set_global_bfd_parameters (); 80 81 /* If generating a relocatable output file, then 82 we don't have to generate the trampolines. */ 83 if (link_info.relocatable) 84 avr_no_stubs = TRUE; 85 86 if (avr_no_stubs) 87 return; 88 89 ret = elf32_avr_setup_section_lists (link_info.output_bfd, &link_info); 90 91 if (ret < 0) 92 einfo ("%X%P: can not setup the input section list: %E\n"); 93 94 if (ret <= 0) 95 return; 96 97 /* Call into the BFD backend to do the real "stub"-work. */ 98 if (! elf32_avr_size_stubs (link_info.output_bfd, &link_info, TRUE)) 99 einfo ("%X%P: can not size stub section: %E\n"); 100 } 101 102 /* This is called before the input files are opened. We create a new 103 fake input file to hold the stub section and generate the section itself. */ 104 105 static void 106 avr_elf_create_output_section_statements (void) 107 { 108 flagword flags; 109 110 stub_file = lang_add_input_file ("linker stubs", 111 lang_input_file_is_fake_enum, 112 NULL); 113 114 stub_file->the_bfd = bfd_create ("linker stubs", link_info.output_bfd); 115 if (stub_file->the_bfd == NULL 116 || !bfd_set_arch_mach (stub_file->the_bfd, 117 bfd_get_arch (link_info.output_bfd), 118 bfd_get_mach (link_info.output_bfd))) 119 { 120 einfo ("%X%P: can not create stub BFD %E\n"); 121 return; 122 } 123 124 /* Now we add the stub section. */ 125 126 flags = (SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE 127 | SEC_HAS_CONTENTS | SEC_RELOC | SEC_IN_MEMORY | SEC_KEEP); 128 avr_stub_section = bfd_make_section_anyway_with_flags (stub_file->the_bfd, 129 ".trampolines", 130 flags); 131 if (avr_stub_section == NULL) 132 goto err_ret; 133 134 avr_stub_section->alignment_power = 1; 135 136 ldlang_add_file (stub_file); 137 138 return; 139 140 err_ret: 141 einfo ("%X%P: can not make stub section: %E\n"); 142 return; 143 } 144 145 /* Re-calculates the size of the stubs so that we won't waste space. */ 146 147 static void 148 avr_elf_after_allocation (void) 149 { 150 if (!avr_no_stubs && ! RELAXATION_ENABLED) 151 { 152 /* If relaxing, elf32_avr_size_stubs will be called from 153 elf32_avr_relax_section. */ 154 if (!elf32_avr_size_stubs (link_info.output_bfd, &link_info, TRUE)) 155 einfo ("%X%P: can not size stub section: %E\n"); 156 } 157 158 gld${EMULATION_NAME}_after_allocation (); 159 160 /* Now build the linker stubs. */ 161 if (!avr_no_stubs) 162 { 163 if (!elf32_avr_build_stubs (&link_info)) 164 einfo ("%X%P: can not build stubs: %E\n"); 165 } 166 } 167 168 static void 169 avr_elf_before_parse (void) 170 { 171 /* Don't create a demand-paged executable, since this feature isn't 172 meaningful in AVR. */ 173 config.magic_demand_paged = FALSE; 174 175 gld${EMULATION_NAME}_before_parse (); 176 } 177 178 EOF 179 180 181 PARSE_AND_LIST_PROLOGUE=' 182 183 #define OPTION_NO_CALL_RET_REPLACEMENT 301 184 #define OPTION_PMEM_WRAP_AROUND 302 185 #define OPTION_NO_STUBS 303 186 #define OPTION_DEBUG_STUBS 304 187 #define OPTION_DEBUG_RELAX 305 188 ' 189 190 PARSE_AND_LIST_LONGOPTS=' 191 { "no-call-ret-replacement", no_argument, 192 NULL, OPTION_NO_CALL_RET_REPLACEMENT}, 193 { "pmem-wrap-around", required_argument, 194 NULL, OPTION_PMEM_WRAP_AROUND}, 195 { "no-stubs", no_argument, 196 NULL, OPTION_NO_STUBS}, 197 { "debug-stubs", no_argument, 198 NULL, OPTION_DEBUG_STUBS}, 199 { "debug-relax", no_argument, 200 NULL, OPTION_DEBUG_RELAX}, 201 ' 202 203 PARSE_AND_LIST_OPTIONS=' 204 fprintf (file, _(" --pmem-wrap-around=<val> " 205 "Make the linker relaxation machine assume that a\n" 206 " " 207 " program counter wrap-around occures at address\n" 208 " " 209 " <val>. Supported values: 8k, 16k, 32k and 64k.\n")); 210 fprintf (file, _(" --no-call-ret-replacement " 211 "The relaxation machine normally will\n" 212 " " 213 " substitute two immediately following call/ret\n" 214 " " 215 " instructions by a single jump instruction.\n" 216 " " 217 " This option disables this optimization.\n")); 218 fprintf (file, _(" --no-stubs " 219 "If the linker detects to attempt to access\n" 220 " " 221 " an instruction beyond 128k by a reloc that\n" 222 " " 223 " is limited to 128k max, it inserts a jump\n" 224 " " 225 " stub. You can de-active this with this switch.\n")); 226 fprintf (file, _(" --debug-stubs " 227 "Used for debugging avr-ld.\n")); 228 fprintf (file, _(" --debug-relax " 229 "Used for debugging avr-ld.\n")); 230 ' 231 232 PARSE_AND_LIST_ARGS_CASES=' 233 234 case OPTION_PMEM_WRAP_AROUND: 235 { 236 /* This variable is defined in the bfd library. */ 237 if ((!strcmp (optarg,"32k")) || (!strcmp (optarg,"32K"))) 238 avr_pc_wrap_around = 32768; 239 else if ((!strcmp (optarg,"8k")) || (!strcmp (optarg,"8K"))) 240 avr_pc_wrap_around = 8192; 241 else if ((!strcmp (optarg,"16k")) || (!strcmp (optarg,"16K"))) 242 avr_pc_wrap_around = 16384; 243 else if ((!strcmp (optarg,"64k")) || (!strcmp (optarg,"64K"))) 244 avr_pc_wrap_around = 0x10000; 245 else 246 return FALSE; 247 } 248 break; 249 250 case OPTION_DEBUG_STUBS: 251 avr_debug_stubs = TRUE; 252 break; 253 254 case OPTION_DEBUG_RELAX: 255 avr_debug_relax = TRUE; 256 break; 257 258 case OPTION_NO_STUBS: 259 avr_no_stubs = TRUE; 260 break; 261 262 case OPTION_NO_CALL_RET_REPLACEMENT: 263 { 264 /* This variable is defined in the bfd library. */ 265 avr_replace_call_ret_sequences = FALSE; 266 } 267 break; 268 ' 269 270 # 271 # Put these extra avr-elf routines in ld_${EMULATION_NAME}_emulation 272 # 273 LDEMUL_BEFORE_PARSE=avr_elf_before_parse 274 LDEMUL_BEFORE_ALLOCATION=avr_elf_${EMULATION_NAME}_before_allocation 275 LDEMUL_AFTER_ALLOCATION=avr_elf_after_allocation 276 LDEMUL_CREATE_OUTPUT_SECTION_STATEMENTS=avr_elf_create_output_section_statements 277
