1 /* BFD back-end for MS-DOS executables. 2 Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2001, 2002, 3 2003, 2004, 2005, 2006, 2007, 2009, 2011, 2012 4 Free Software Foundation, Inc. 5 Written by Bryan Ford of the University of Utah. 6 7 Contributed by the Center for Software Science at the 8 University of Utah (pa-gdb-bugs@cs.utah.edu). 9 10 This file is part of BFD, the Binary File Descriptor library. 11 12 This program is free software; you can redistribute it and/or modify 13 it under the terms of the GNU General Public License as published by 14 the Free Software Foundation; either version 3 of the License, or 15 (at your option) any later version. 16 17 This program is distributed in the hope that it will be useful, 18 but WITHOUT ANY WARRANTY; without even the implied warranty of 19 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 20 GNU General Public License for more details. 21 22 You should have received a copy of the GNU General Public License 23 along with this program; if not, write to the Free Software 24 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, 25 MA 02110-1301, USA. */ 26 27 28 #include "sysdep.h" 29 #include "bfd.h" 30 #include "libbfd.h" 31 #include "libaout.h" 32 33 #define EXE_MAGIC 0x5a4d 34 #define EXE_LOAD_HIGH 0x0000 35 #define EXE_LOAD_LOW 0xffff 36 #define EXE_PAGE_SIZE 512 37 38 static int 39 msdos_sizeof_headers (bfd *abfd ATTRIBUTE_UNUSED, 40 struct bfd_link_info *info ATTRIBUTE_UNUSED) 41 { 42 return 0; 43 } 44 45 static bfd_boolean 46 msdos_write_object_contents (bfd *abfd) 47 { 48 static char hdr[EXE_PAGE_SIZE]; 49 file_ptr outfile_size = sizeof(hdr); 50 bfd_vma high_vma = 0; 51 asection *sec; 52 53 /* Find the total size of the program on disk and in memory. */ 54 for (sec = abfd->sections; sec != (asection *) NULL; sec = sec->next) 55 { 56 if (sec->size == 0) 57 continue; 58 if (bfd_get_section_flags (abfd, sec) & SEC_ALLOC) 59 { 60 bfd_vma sec_vma = bfd_get_section_vma (abfd, sec) + sec->size; 61 if (sec_vma > high_vma) 62 high_vma = sec_vma; 63 } 64 if (bfd_get_section_flags (abfd, sec) & SEC_LOAD) 65 { 66 file_ptr sec_end = (sizeof (hdr) 67 + bfd_get_section_vma (abfd, sec) 68 + sec->size); 69 if (sec_end > outfile_size) 70 outfile_size = sec_end; 71 } 72 } 73 74 /* Make sure the program isn't too big. */ 75 if (high_vma > (bfd_vma)0xffff) 76 { 77 bfd_set_error(bfd_error_file_too_big); 78 return FALSE; 79 } 80 81 /* Constants. */ 82 H_PUT_16 (abfd, EXE_MAGIC, &hdr[0]); 83 H_PUT_16 (abfd, EXE_PAGE_SIZE / 16, &hdr[8]); 84 H_PUT_16 (abfd, EXE_LOAD_LOW, &hdr[12]); 85 H_PUT_16 (abfd, 0x3e, &hdr[24]); 86 H_PUT_16 (abfd, 0x0001, &hdr[28]); /* XXX??? */ 87 H_PUT_16 (abfd, 0x30fb, &hdr[30]); /* XXX??? */ 88 H_PUT_16 (abfd, 0x726a, &hdr[32]); /* XXX??? */ 89 90 /* Bytes in last page (0 = full page). */ 91 H_PUT_16 (abfd, outfile_size & (EXE_PAGE_SIZE - 1), &hdr[2]); 92 93 /* Number of pages. */ 94 H_PUT_16 (abfd, (outfile_size + EXE_PAGE_SIZE - 1) / EXE_PAGE_SIZE, &hdr[4]); 95 96 /* Set the initial stack pointer to the end of the bss. 97 The program's crt0 code must relocate it to a real stack. */ 98 H_PUT_16 (abfd, high_vma, &hdr[16]); 99 100 if (bfd_seek (abfd, (file_ptr) 0, SEEK_SET) != 0 101 || bfd_bwrite (hdr, (bfd_size_type) sizeof(hdr), abfd) != sizeof(hdr)) 102 return FALSE; 103 104 return TRUE; 105 } 106 107 static bfd_boolean 108 msdos_set_section_contents (bfd *abfd, 109 sec_ptr section, 110 const void *location, 111 file_ptr offset, 112 bfd_size_type count) 113 { 114 115 if (count == 0) 116 return TRUE; 117 118 section->filepos = EXE_PAGE_SIZE + bfd_get_section_vma (abfd, section); 119 120 if (bfd_get_section_flags (abfd, section) & SEC_LOAD) 121 { 122 if (bfd_seek (abfd, section->filepos + offset, SEEK_SET) != 0 123 || bfd_bwrite (location, count, abfd) != count) 124 return FALSE; 125 } 126 127 return TRUE; 128 } 129 130 131 132 #define msdos_mkobject aout_32_mkobject 133 #define msdos_make_empty_symbol aout_32_make_empty_symbol 134 #define msdos_bfd_reloc_type_lookup aout_32_reloc_type_lookup 135 #define msdos_bfd_reloc_name_lookup aout_32_reloc_name_lookup 136 137 #define msdos_close_and_cleanup _bfd_generic_close_and_cleanup 138 #define msdos_bfd_free_cached_info _bfd_generic_bfd_free_cached_info 139 #define msdos_new_section_hook _bfd_generic_new_section_hook 140 #define msdos_get_section_contents _bfd_generic_get_section_contents 141 #define msdos_get_section_contents_in_window \ 142 _bfd_generic_get_section_contents_in_window 143 #define msdos_bfd_get_relocated_section_contents \ 144 bfd_generic_get_relocated_section_contents 145 #define msdos_bfd_relax_section bfd_generic_relax_section 146 #define msdos_bfd_gc_sections bfd_generic_gc_sections 147 #define msdos_bfd_lookup_section_flags bfd_generic_lookup_section_flags 148 #define msdos_bfd_merge_sections bfd_generic_merge_sections 149 #define msdos_bfd_is_group_section bfd_generic_is_group_section 150 #define msdos_bfd_discard_group bfd_generic_discard_group 151 #define msdos_section_already_linked \ 152 _bfd_generic_section_already_linked 153 #define msdos_bfd_define_common_symbol bfd_generic_define_common_symbol 154 #define msdos_bfd_link_hash_table_create _bfd_generic_link_hash_table_create 155 #define msdos_bfd_link_hash_table_free _bfd_generic_link_hash_table_free 156 #define msdos_bfd_link_add_symbols _bfd_generic_link_add_symbols 157 #define msdos_bfd_link_just_syms _bfd_generic_link_just_syms 158 #define msdos_bfd_copy_link_hash_symbol_type \ 159 _bfd_generic_copy_link_hash_symbol_type 160 #define msdos_bfd_final_link _bfd_generic_final_link 161 #define msdos_bfd_link_split_section _bfd_generic_link_split_section 162 #define msdos_set_arch_mach _bfd_generic_set_arch_mach 163 164 #define msdos_get_symtab_upper_bound _bfd_nosymbols_get_symtab_upper_bound 165 #define msdos_canonicalize_symtab _bfd_nosymbols_canonicalize_symtab 166 #define msdos_print_symbol _bfd_nosymbols_print_symbol 167 #define msdos_get_symbol_info _bfd_nosymbols_get_symbol_info 168 #define msdos_find_nearest_line _bfd_nosymbols_find_nearest_line 169 #define msdos_find_inliner_info _bfd_nosymbols_find_inliner_info 170 #define msdos_get_lineno _bfd_nosymbols_get_lineno 171 #define msdos_bfd_is_target_special_symbol ((bfd_boolean (*) (bfd *, asymbol *)) bfd_false) 172 #define msdos_bfd_is_local_label_name _bfd_nosymbols_bfd_is_local_label_name 173 #define msdos_bfd_make_debug_symbol _bfd_nosymbols_bfd_make_debug_symbol 174 #define msdos_read_minisymbols _bfd_nosymbols_read_minisymbols 175 #define msdos_minisymbol_to_symbol _bfd_nosymbols_minisymbol_to_symbol 176 177 #define msdos_canonicalize_reloc _bfd_norelocs_canonicalize_reloc 178 #define msdos_get_reloc_upper_bound _bfd_norelocs_get_reloc_upper_bound 179 #define msdos_32_bfd_link_split_section _bfd_generic_link_split_section 180 181 const bfd_target i386msdos_vec = 182 { 183 "msdos", /* name */ 184 bfd_target_msdos_flavour, 185 BFD_ENDIAN_LITTLE, /* target byte order */ 186 BFD_ENDIAN_LITTLE, /* target headers byte order */ 187 (EXEC_P), /* object flags */ 188 (SEC_CODE | SEC_DATA | SEC_HAS_CONTENTS 189 | SEC_ALLOC | SEC_LOAD), /* section flags */ 190 0, /* leading underscore */ 191 ' ', /* ar_pad_char */ 192 16, /* ar_max_namelen */ 193 0, /* match priority. */ 194 bfd_getl64, bfd_getl_signed_64, bfd_putl64, 195 bfd_getl32, bfd_getl_signed_32, bfd_putl32, 196 bfd_getl16, bfd_getl_signed_16, bfd_putl16, /* data */ 197 bfd_getl64, bfd_getl_signed_64, bfd_putl64, 198 bfd_getl32, bfd_getl_signed_32, bfd_putl32, 199 bfd_getl16, bfd_getl_signed_16, bfd_putl16, /* hdrs */ 200 201 { 202 _bfd_dummy_target, 203 _bfd_dummy_target, /* bfd_check_format */ 204 _bfd_dummy_target, 205 _bfd_dummy_target, 206 }, 207 { 208 bfd_false, 209 msdos_mkobject, 210 _bfd_generic_mkarchive, 211 bfd_false, 212 }, 213 { /* bfd_write_contents */ 214 bfd_false, 215 msdos_write_object_contents, 216 _bfd_write_archive_contents, 217 bfd_false, 218 }, 219 220 BFD_JUMP_TABLE_GENERIC (msdos), 221 BFD_JUMP_TABLE_COPY (_bfd_generic), 222 BFD_JUMP_TABLE_CORE (_bfd_nocore), 223 BFD_JUMP_TABLE_ARCHIVE (_bfd_noarchive), 224 BFD_JUMP_TABLE_SYMBOLS (msdos), 225 BFD_JUMP_TABLE_RELOCS (msdos), 226 BFD_JUMP_TABLE_WRITE (msdos), 227 BFD_JUMP_TABLE_LINK (msdos), 228 BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic), 229 230 NULL, 231 232 NULL 233 }; 234 235 236