1/* BFD back-end for MS-DOS executables. 2 Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2001, 2002, 3 2003, 2004 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 32struct 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 59static int msdos_sizeof_headers 60 PARAMS ((bfd *, bfd_boolean)); 61static bfd_boolean msdos_write_object_contents 62 PARAMS ((bfd *)); 63static bfd_boolean msdos_set_section_contents 64 PARAMS ((bfd *, sec_ptr, const PTR, file_ptr, bfd_size_type)); 65 66static int 67msdos_sizeof_headers (abfd, exec) 68 bfd *abfd ATTRIBUTE_UNUSED; 69 bfd_boolean exec ATTRIBUTE_UNUSED; 70{ 71 return 0; 72} 73 74static bfd_boolean 75msdos_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 (sec->size == 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) + sec->size; 91 if (sec_vma > high_vma) 92 high_vma = sec_vma; 93 } 94 if (bfd_get_section_flags (abfd, sec) & SEC_LOAD) 95 { 96 file_ptr sec_end = (sizeof (hdr) 97 + bfd_get_section_vma (abfd, sec) 98 + sec->size); 99 if (sec_end > outfile_size) 100 outfile_size = sec_end; 101 } 102 } 103 104 /* Make sure the program isn't too big. */ 105 if (high_vma > (bfd_vma)0xffff) 106 { 107 bfd_set_error(bfd_error_file_too_big); 108 return FALSE; 109 } 110 111 /* Constants. */ 112 H_PUT_16 (abfd, EXE_MAGIC, &hdr[0]); 113 H_PUT_16 (abfd, EXE_PAGE_SIZE / 16, &hdr[8]); 114 H_PUT_16 (abfd, EXE_LOAD_LOW, &hdr[12]); 115 H_PUT_16 (abfd, 0x3e, &hdr[24]); 116 H_PUT_16 (abfd, 0x0001, &hdr[28]); /* XXX??? */ 117 H_PUT_16 (abfd, 0x30fb, &hdr[30]); /* XXX??? */ 118 H_PUT_16 (abfd, 0x726a, &hdr[32]); /* XXX??? */ 119 120 /* Bytes in last page (0 = full page). */ 121 H_PUT_16 (abfd, outfile_size & (EXE_PAGE_SIZE - 1), &hdr[2]); 122 123 /* Number of pages. */ 124 H_PUT_16 (abfd, (outfile_size + EXE_PAGE_SIZE - 1) / EXE_PAGE_SIZE, &hdr[4]); 125 126 /* Set the initial stack pointer to the end of the bss. 127 The program's crt0 code must relocate it to a real stack. */ 128 H_PUT_16 (abfd, high_vma, &hdr[16]); 129 130 if (bfd_seek (abfd, (file_ptr) 0, SEEK_SET) != 0 131 || bfd_bwrite (hdr, (bfd_size_type) sizeof(hdr), abfd) != sizeof(hdr)) 132 return FALSE; 133 134 return TRUE; 135} 136 137static bfd_boolean 138msdos_set_section_contents (abfd, section, location, offset, count) 139 bfd *abfd; 140 sec_ptr section; 141 const PTR location; 142 file_ptr offset; 143 bfd_size_type count; 144{ 145 146 if (count == 0) 147 return TRUE; 148 149 section->filepos = EXE_PAGE_SIZE + bfd_get_section_vma (abfd, section); 150 151 if (bfd_get_section_flags (abfd, section) & SEC_LOAD) 152 { 153 if (bfd_seek (abfd, section->filepos + offset, SEEK_SET) != 0 154 || bfd_bwrite (location, count, abfd) != count) 155 return FALSE; 156 } 157 158 return TRUE; 159} 160 161 162 163#define msdos_mkobject aout_32_mkobject 164#define msdos_make_empty_symbol aout_32_make_empty_symbol 165#define msdos_bfd_reloc_type_lookup aout_32_reloc_type_lookup 166 167#define msdos_close_and_cleanup _bfd_generic_close_and_cleanup 168#define msdos_bfd_free_cached_info _bfd_generic_bfd_free_cached_info 169#define msdos_new_section_hook _bfd_generic_new_section_hook 170#define msdos_get_section_contents _bfd_generic_get_section_contents 171#define msdos_get_section_contents_in_window \ 172 _bfd_generic_get_section_contents_in_window 173#define msdos_bfd_get_relocated_section_contents \ 174 bfd_generic_get_relocated_section_contents 175#define msdos_bfd_relax_section bfd_generic_relax_section 176#define msdos_bfd_gc_sections bfd_generic_gc_sections 177#define msdos_bfd_merge_sections bfd_generic_merge_sections 178#define msdos_bfd_is_group_section bfd_generic_is_group_section 179#define msdos_bfd_discard_group bfd_generic_discard_group 180#define msdos_section_already_linked \ 181 _bfd_generic_section_already_linked 182#define msdos_bfd_link_hash_table_create _bfd_generic_link_hash_table_create 183#define msdos_bfd_link_hash_table_free _bfd_generic_link_hash_table_free 184#define msdos_bfd_link_add_symbols _bfd_generic_link_add_symbols 185#define msdos_bfd_link_just_syms _bfd_generic_link_just_syms 186#define msdos_bfd_final_link _bfd_generic_final_link 187#define msdos_bfd_link_split_section _bfd_generic_link_split_section 188#define msdos_set_arch_mach _bfd_generic_set_arch_mach 189 190#define msdos_get_symtab_upper_bound _bfd_nosymbols_get_symtab_upper_bound 191#define msdos_canonicalize_symtab _bfd_nosymbols_canonicalize_symtab 192#define msdos_print_symbol _bfd_nosymbols_print_symbol 193#define msdos_get_symbol_info _bfd_nosymbols_get_symbol_info 194#define msdos_find_nearest_line _bfd_nosymbols_find_nearest_line 195#define msdos_get_lineno _bfd_nosymbols_get_lineno 196#define msdos_bfd_is_target_special_symbol ((bfd_boolean (*) (bfd *, asymbol *)) bfd_false) 197#define msdos_bfd_is_local_label_name _bfd_nosymbols_bfd_is_local_label_name 198#define msdos_bfd_make_debug_symbol _bfd_nosymbols_bfd_make_debug_symbol 199#define msdos_read_minisymbols _bfd_nosymbols_read_minisymbols 200#define msdos_minisymbol_to_symbol _bfd_nosymbols_minisymbol_to_symbol 201 202#define msdos_canonicalize_reloc _bfd_norelocs_canonicalize_reloc 203#define msdos_get_reloc_upper_bound _bfd_norelocs_get_reloc_upper_bound 204#define msdos_32_bfd_link_split_section _bfd_generic_link_split_section 205 206const bfd_target i386msdos_vec = 207 { 208 "msdos", /* name */ 209 bfd_target_msdos_flavour, 210 BFD_ENDIAN_LITTLE, /* target byte order */ 211 BFD_ENDIAN_LITTLE, /* target headers byte order */ 212 (EXEC_P), /* object flags */ 213 (SEC_CODE | SEC_DATA | SEC_HAS_CONTENTS 214 | SEC_ALLOC | SEC_LOAD), /* section flags */ 215 0, /* leading underscore */ 216 ' ', /* ar_pad_char */ 217 16, /* ar_max_namelen */ 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, /* data */ 221 bfd_getl64, bfd_getl_signed_64, bfd_putl64, 222 bfd_getl32, bfd_getl_signed_32, bfd_putl32, 223 bfd_getl16, bfd_getl_signed_16, bfd_putl16, /* hdrs */ 224 225 { 226 _bfd_dummy_target, 227 _bfd_dummy_target, /* bfd_check_format */ 228 _bfd_dummy_target, 229 _bfd_dummy_target, 230 }, 231 { 232 bfd_false, 233 msdos_mkobject, 234 _bfd_generic_mkarchive, 235 bfd_false, 236 }, 237 { /* bfd_write_contents */ 238 bfd_false, 239 msdos_write_object_contents, 240 _bfd_write_archive_contents, 241 bfd_false, 242 }, 243 244 BFD_JUMP_TABLE_GENERIC (msdos), 245 BFD_JUMP_TABLE_COPY (_bfd_generic), 246 BFD_JUMP_TABLE_CORE (_bfd_nocore), 247 BFD_JUMP_TABLE_ARCHIVE (_bfd_noarchive), 248 BFD_JUMP_TABLE_SYMBOLS (msdos), 249 BFD_JUMP_TABLE_RELOCS (msdos), 250 BFD_JUMP_TABLE_WRITE (msdos), 251 BFD_JUMP_TABLE_LINK (msdos), 252 BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic), 253 254 NULL, 255 256 (PTR) 0 257 }; 258 259 260