1# This shell script emits a C file. -*- C -*- 2# Copyright (C) 2000-2024 Free Software Foundation, Inc. 3# Written by Michael Sokolov <msokolov@ivan.Harhan.ORG>, based on armelf.em 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 elf.em, and defines some extra routines for m68k 24# embedded systems using ELF and for some other systems using m68k ELF. While 25# it is sourced from elf.em for all m68k ELF configurations, here we include 26# only the features we want depending on the configuration. 27 28case ${target} in 29 m68*-*-elf) 30 echo "#define SUPPORT_EMBEDDED_RELOCS" >>e${EMULATION_NAME}.c 31 ;; 32esac 33 34case ${target} in 35 *-linux*) 36# Don't use multi-GOT by default due to glibc linker's assumption 37# that GOT pointer points to GOT[0]. 38# got_handling_target_default=GOT_HANDLING_MULTIGOT 39 got_handling_target_default=GOT_HANDLING_SINGLE 40 ;; 41 *) 42 got_handling_target_default=GOT_HANDLING_SINGLE 43 ;; 44esac 45 46fragment <<EOF 47 48#include "elf32-m68k.h" 49 50#define GOT_HANDLING_SINGLE (0) 51#define GOT_HANDLING_NEGATIVE (1) 52#define GOT_HANDLING_MULTIGOT (2) 53#define GOT_HANDLING_TARGET_DEFAULT ${got_handling_target_default} 54 55/* How to generate GOT. */ 56static int got_handling = GOT_HANDLING_DEFAULT; 57 58#ifdef SUPPORT_EMBEDDED_RELOCS 59static void check_sections (bfd *, asection *, void *); 60#endif 61 62/* This function is run after all the input files have been opened. */ 63 64static void 65m68k_elf_after_open (void) 66{ 67 /* Call the standard elf routine. */ 68 gld${EMULATION_NAME}_after_open (); 69 70#ifdef SUPPORT_EMBEDDED_RELOCS 71 if (command_line.embedded_relocs 72 && (!bfd_link_relocatable (&link_info))) 73 { 74 bfd *abfd; 75 76 /* In the embedded relocs mode we create a .emreloc section for each 77 input file with a nonzero .data section. The BFD backend will fill in 78 these sections with magic numbers which can be used to relocate the 79 data section at run time. */ 80 for (abfd = link_info.input_bfds; abfd != NULL; abfd = abfd->link.next) 81 { 82 asection *datasec; 83 84 if (bfd_get_flavour (abfd) != bfd_target_elf_flavour) 85 einfo (_("%F%P: %pB: all input objects must be ELF " 86 "for --embedded-relocs\n")); 87 88 datasec = bfd_get_section_by_name (abfd, ".data"); 89 90 /* Note that we assume that the reloc_count field has already 91 been set up. We could call bfd_get_reloc_upper_bound, but 92 that returns the size of a memory buffer rather than a reloc 93 count. We do not want to call bfd_canonicalize_reloc, 94 because although it would always work it would force us to 95 read in the relocs into BFD canonical form, which would waste 96 a significant amount of time and memory. */ 97 if (datasec != NULL && datasec->reloc_count > 0) 98 { 99 asection *relsec; 100 101 relsec = bfd_make_section_with_flags (abfd, ".emreloc", 102 (SEC_ALLOC 103 | SEC_LOAD 104 | SEC_HAS_CONTENTS 105 | SEC_IN_MEMORY)); 106 if (relsec == NULL 107 || !bfd_set_section_alignment (relsec, 2) 108 || !bfd_set_section_size (relsec, datasec->reloc_count * 12)) 109 einfo (_("%F%P: %pB: can not create .emreloc section: %E\n")); 110 } 111 112 /* Double check that all other data sections are empty, as is 113 required for embedded PIC code. */ 114 bfd_map_over_sections (abfd, check_sections, datasec); 115 } 116 } 117#endif /* SUPPORT_EMBEDDED_RELOCS */ 118} 119 120#ifdef SUPPORT_EMBEDDED_RELOCS 121/* Check that of the data sections, only the .data section has 122 relocs. This is called via bfd_map_over_sections. */ 123 124static void 125check_sections (bfd *abfd, asection *sec, void *datasec) 126{ 127 if ((bfd_section_flags (sec) & SEC_DATA) 128 && sec != datasec 129 && sec->reloc_count != 0) 130 einfo (_("%X%P: %pB: section %s has relocs; can not use --embedded-relocs\n"), 131 abfd, bfd_section_name (sec)); 132} 133 134#endif /* SUPPORT_EMBEDDED_RELOCS */ 135 136/* This function is called after the section sizes and offsets have 137 been set. */ 138 139static void 140m68k_elf_after_allocation (void) 141{ 142 /* Call the standard elf routine. */ 143 gld${EMULATION_NAME}_after_allocation (); 144 145#ifdef SUPPORT_EMBEDDED_RELOCS 146 if (command_line.embedded_relocs 147 && (!bfd_link_relocatable (&link_info))) 148 { 149 bfd *abfd; 150 151 /* If we are generating embedded relocs, call a special BFD backend 152 routine to do the work. */ 153 for (abfd = link_info.input_bfds; abfd != NULL; abfd = abfd->link.next) 154 { 155 asection *datasec, *relsec; 156 char *errmsg; 157 158 datasec = bfd_get_section_by_name (abfd, ".data"); 159 160 if (datasec == NULL || datasec->reloc_count == 0) 161 continue; 162 163 relsec = bfd_get_section_by_name (abfd, ".emreloc"); 164 ASSERT (relsec != NULL); 165 166 if (bfd_get_flavour (abfd) == bfd_target_elf_flavour) 167 { 168 if (! bfd_m68k_elf32_create_embedded_relocs (abfd, &link_info, 169 datasec, relsec, 170 &errmsg)) 171 { 172 if (errmsg == NULL) 173 einfo (_("%X%P: %pB: can not create " 174 "runtime reloc information: %E\n"), 175 abfd); 176 else 177 einfo (_("%X%P: %pB: can not create " 178 "runtime reloc information: %s\n"), 179 abfd, errmsg); 180 } 181 } 182 else 183 abort (); 184 } 185 } 186#endif /* SUPPORT_EMBEDDED_RELOCS */ 187} 188 189/* This is a convenient point to tell BFD about target specific flags. 190 After the output has been created, but before inputs are read. */ 191 192static void 193elf_m68k_create_output_section_statements (void) 194{ 195 bfd_elf_m68k_set_target_options (&link_info, got_handling); 196} 197 198EOF 199 200# Define some shell vars to insert bits of code into the standard elf 201# parse_args and list_options functions. 202# 203PARSE_AND_LIST_PROLOGUE=' 204#define OPTION_GOT 301 205' 206 207PARSE_AND_LIST_LONGOPTS=' 208 { "got", required_argument, NULL, OPTION_GOT}, 209' 210 211PARSE_AND_LIST_OPTIONS=' 212 fprintf (file, _(" --got=<type> Specify GOT handling scheme\n")); 213' 214 215PARSE_AND_LIST_ARGS_CASES=' 216 case OPTION_GOT: 217 if (strcmp (optarg, "target") == 0) 218 got_handling = GOT_HANDLING_TARGET_DEFAULT; 219 else if (strcmp (optarg, "single") == 0) 220 got_handling = 0; 221 else if (strcmp (optarg, "negative") == 0) 222 got_handling = 1; 223 else if (strcmp (optarg, "multigot") == 0) 224 got_handling = 2; 225 else 226 einfo (_("%P: unrecognized --got argument '\''%s'\''\n"), optarg); 227 break; 228' 229 230# We have our own after_open and after_allocation functions, but they call 231# the standard routines, so give them a different name. 232LDEMUL_AFTER_OPEN=m68k_elf_after_open 233LDEMUL_AFTER_ALLOCATION=m68k_elf_after_allocation 234LDEMUL_CREATE_OUTPUT_SECTION_STATEMENTS=elf_m68k_create_output_section_statements 235