1 /* BFD back-end for MS-DOS executables. 2 Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2001, 2002, 3 2003 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 2 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ 24 25 26 #include "bfd.h" 27 #include "sysdep.h" 28 #include "libbfd.h" 29 #include "libaout.h" 30 31 #if 0 32 struct exe_header 33 { 34 unsigned short magic; 35 unsigned short bytes_in_last_page; 36 unsigned short npages; /* number of 512-byte "pages" including this header */ 37 unsigned short nrelocs; 38 unsigned short header_paras; /* number of 16-byte paragraphs in header */ 39 unsigned short reserved; 40 unsigned short load_switch; 41 unsigned short ss_ofs; 42 unsigned short sp; 43 unsigned short checksum; 44 unsigned short ip; 45 unsigned short cs_ofs; 46 unsigned short reloc_ofs; 47 unsigned short reserved2; 48 unsigned short something1; 49 unsigned short something2; 50 unsigned short something3; 51 }; 52 #endif 53 54 #define EXE_MAGIC 0x5a4d 55 #define EXE_LOAD_HIGH 0x0000 56 #define EXE_LOAD_LOW 0xffff 57 #define EXE_PAGE_SIZE 512 58 59 static int msdos_sizeof_headers 60 PARAMS ((bfd *, bfd_boolean)); 61 static bfd_boolean msdos_write_object_contents 62 PARAMS ((bfd *)); 63 static bfd_boolean msdos_set_section_contents 64 PARAMS ((bfd *, sec_ptr, const PTR, file_ptr, bfd_size_type)); 65 66 static int 67 msdos_sizeof_headers (abfd, exec) 68 bfd *abfd ATTRIBUTE_UNUSED; 69 bfd_boolean exec ATTRIBUTE_UNUSED; 70 { 71 return 0; 72 } 73 74 static bfd_boolean 75 msdos_write_object_contents (abfd) 76 bfd *abfd; 77 { 78 static char hdr[EXE_PAGE_SIZE]; 79 file_ptr outfile_size = sizeof(hdr); 80 bfd_vma high_vma = 0; 81 asection *sec; 82 83 /* Find the total size of the program on disk and in memory. */ 84 for (sec = abfd->sections; sec != (asection *) NULL; sec = sec->next) 85 { 86 if (bfd_get_section_size_before_reloc (sec) == 0) 87 continue; 88 if (bfd_get_section_flags (abfd, sec) & SEC_ALLOC) 89 { 90 bfd_vma sec_vma = bfd_get_section_vma (abfd, sec) 91 + bfd_get_section_size_before_reloc (sec); 92 if (sec_vma > high_vma) 93 high_vma = sec_vma; 94 } 95 if (bfd_get_section_flags (abfd, sec) & SEC_LOAD) 96 { 97 file_ptr sec_end = sizeof(hdr) 98 + bfd_get_section_vma (abfd, sec) 99 + bfd_get_section_size_before_reloc (sec); 100 if (sec_end > outfile_size) 101 outfile_size = sec_end; 102 } 103 } 104 105 /* Make sure the program isn't too big. */ 106 if (high_vma > (bfd_vma)0xffff) 107 { 108 bfd_set_error(bfd_error_file_too_big); 109 return FALSE; 110 } 111 112 /* Constants. */ 113 H_PUT_16 (abfd, EXE_MAGIC, &hdr[0]); 114 H_PUT_16 (abfd, EXE_PAGE_SIZE / 16, &hdr[8]); 115 H_PUT_16 (abfd, EXE_LOAD_LOW, &hdr[12]); 116 H_PUT_16 (abfd, 0x3e, &hdr[24]); 117 H_PUT_16 (abfd, 0x0001, &hdr[28]); /* XXX??? */ 118 H_PUT_16 (abfd, 0x30fb, &hdr[30]); /* XXX??? */ 119 H_PUT_16 (abfd, 0x726a, &hdr[32]); /* XXX??? */ 120 121 /* Bytes in last page (0 = full page). */ 122 H_PUT_16 (abfd, outfile_size & (EXE_PAGE_SIZE - 1), &hdr[2]); 123 124 /* Number of pages. */ 125 H_PUT_16 (abfd, (outfile_size + EXE_PAGE_SIZE - 1) / EXE_PAGE_SIZE, &hdr[4]); 126 127 /* Set the initial stack pointer to the end of the bss. 128 The program's crt0 code must relocate it to a real stack. */ 129 H_PUT_16 (abfd, high_vma, &hdr[16]); 130 131 if (bfd_seek (abfd, (file_ptr) 0, SEEK_SET) != 0 132 || bfd_bwrite (hdr, (bfd_size_type) sizeof(hdr), abfd) != sizeof(hdr)) 133 return FALSE; 134 135 return TRUE; 136 } 137 138 static bfd_boolean 139 msdos_set_section_contents (abfd, section, location, offset, count) 140 bfd *abfd; 141 sec_ptr section; 142 const PTR location; 143 file_ptr offset; 144 bfd_size_type count; 145 { 146 147 if (count == 0) 148 return TRUE; 149 150 section->filepos = EXE_PAGE_SIZE + bfd_get_section_vma (abfd, section); 151 152 if (bfd_get_section_flags (abfd, section) & SEC_LOAD) 153 { 154 if (bfd_seek (abfd, section->filepos + offset, SEEK_SET) != 0 155 || bfd_bwrite (location, count, abfd) != count) 156 return FALSE; 157 } 158 159 return TRUE; 160 } 161 162 163 164 #define msdos_mkobject aout_32_mkobject 165 #define msdos_make_empty_symbol aout_32_make_empty_symbol 166 #define msdos_bfd_reloc_type_lookup aout_32_reloc_type_lookup 167 168 #define msdos_close_and_cleanup _bfd_generic_close_and_cleanup 169 #define msdos_bfd_free_cached_info _bfd_generic_bfd_free_cached_info 170 #define msdos_new_section_hook _bfd_generic_new_section_hook 171 #define msdos_get_section_contents _bfd_generic_get_section_contents 172 #define msdos_get_section_contents_in_window \ 173 _bfd_generic_get_section_contents_in_window 174 #define msdos_bfd_get_relocated_section_contents \ 175 bfd_generic_get_relocated_section_contents 176 #define msdos_bfd_relax_section bfd_generic_relax_section 177 #define msdos_bfd_gc_sections bfd_generic_gc_sections 178 #define msdos_bfd_merge_sections bfd_generic_merge_sections 179 #define msdos_bfd_discard_group bfd_generic_discard_group 180 #define msdos_bfd_link_hash_table_create _bfd_generic_link_hash_table_create 181 #define msdos_bfd_link_hash_table_free _bfd_generic_link_hash_table_free 182 #define msdos_bfd_link_add_symbols _bfd_generic_link_add_symbols 183 #define msdos_bfd_link_just_syms _bfd_generic_link_just_syms 184 #define msdos_bfd_final_link _bfd_generic_final_link 185 #define msdos_bfd_link_split_section _bfd_generic_link_split_section 186 #define msdos_set_arch_mach _bfd_generic_set_arch_mach 187 188 #define msdos_get_symtab_upper_bound _bfd_nosymbols_get_symtab_upper_bound 189 #define msdos_canonicalize_symtab _bfd_nosymbols_canonicalize_symtab 190 #define msdos_print_symbol _bfd_nosymbols_print_symbol 191 #define msdos_get_symbol_info _bfd_nosymbols_get_symbol_info 192 #define msdos_find_nearest_line _bfd_nosymbols_find_nearest_line 193 #define msdos_get_lineno _bfd_nosymbols_get_lineno 194 #define msdos_bfd_is_local_label_name _bfd_nosymbols_bfd_is_local_label_name 195 #define msdos_bfd_make_debug_symbol _bfd_nosymbols_bfd_make_debug_symbol 196 #define msdos_read_minisymbols _bfd_nosymbols_read_minisymbols 197 #define msdos_minisymbol_to_symbol _bfd_nosymbols_minisymbol_to_symbol 198 199 #define msdos_canonicalize_reloc _bfd_norelocs_canonicalize_reloc 200 #define msdos_get_reloc_upper_bound _bfd_norelocs_get_reloc_upper_bound 201 #define msdos_32_bfd_link_split_section _bfd_generic_link_split_section 202 203 const bfd_target i386msdos_vec = 204 { 205 "msdos", /* name */ 206 bfd_target_msdos_flavour, 207 BFD_ENDIAN_LITTLE, /* target byte order */ 208 BFD_ENDIAN_LITTLE, /* target headers byte order */ 209 (EXEC_P), /* object flags */ 210 (SEC_CODE | SEC_DATA | SEC_HAS_CONTENTS 211 | SEC_ALLOC | SEC_LOAD), /* section flags */ 212 0, /* leading underscore */ 213 ' ', /* ar_pad_char */ 214 16, /* ar_max_namelen */ 215 bfd_getl64, bfd_getl_signed_64, bfd_putl64, 216 bfd_getl32, bfd_getl_signed_32, bfd_putl32, 217 bfd_getl16, bfd_getl_signed_16, bfd_putl16, /* data */ 218 bfd_getl64, bfd_getl_signed_64, bfd_putl64, 219 bfd_getl32, bfd_getl_signed_32, bfd_putl32, 220 bfd_getl16, bfd_getl_signed_16, bfd_putl16, /* hdrs */ 221 222 { 223 _bfd_dummy_target, 224 _bfd_dummy_target, /* bfd_check_format */ 225 _bfd_dummy_target, 226 _bfd_dummy_target, 227 }, 228 { 229 bfd_false, 230 msdos_mkobject, 231 _bfd_generic_mkarchive, 232 bfd_false, 233 }, 234 { /* bfd_write_contents */ 235 bfd_false, 236 msdos_write_object_contents, 237 _bfd_write_archive_contents, 238 bfd_false, 239 }, 240 241 BFD_JUMP_TABLE_GENERIC (msdos), 242 BFD_JUMP_TABLE_COPY (_bfd_generic), 243 BFD_JUMP_TABLE_CORE (_bfd_nocore), 244 BFD_JUMP_TABLE_ARCHIVE (_bfd_noarchive), 245 BFD_JUMP_TABLE_SYMBOLS (msdos), 246 BFD_JUMP_TABLE_RELOCS (msdos), 247 BFD_JUMP_TABLE_WRITE (msdos), 248 BFD_JUMP_TABLE_LINK (msdos), 249 BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic), 250 251 NULL, 252 253 (PTR) 0 254 }; 255 256 257