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