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 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., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. */ 24 25 26#include "bfd.h" 27#include "sysdep.h" 28#include "libbfd.h" 29#include "libaout.h" 30 31#define EXE_MAGIC 0x5a4d 32#define EXE_LOAD_HIGH 0x0000 33#define EXE_LOAD_LOW 0xffff 34#define EXE_PAGE_SIZE 512 35 36static int 37msdos_sizeof_headers (bfd *abfd ATTRIBUTE_UNUSED, 38 struct bfd_link_info *info ATTRIBUTE_UNUSED) 39{ 40 return 0; 41} 42 43static bfd_boolean 44msdos_write_object_contents (bfd *abfd) 45{ 46 static char hdr[EXE_PAGE_SIZE]; 47 file_ptr outfile_size = sizeof(hdr); 48 bfd_vma high_vma = 0; 49 asection *sec; 50 51 /* Find the total size of the program on disk and in memory. */ 52 for (sec = abfd->sections; sec != (asection *) NULL; sec = sec->next) 53 { 54 if (sec->size == 0) 55 continue; 56 if (bfd_get_section_flags (abfd, sec) & SEC_ALLOC) 57 { 58 bfd_vma sec_vma = bfd_get_section_vma (abfd, sec) + sec->size; 59 if (sec_vma > high_vma) 60 high_vma = sec_vma; 61 } 62 if (bfd_get_section_flags (abfd, sec) & SEC_LOAD) 63 { 64 file_ptr sec_end = (sizeof (hdr) 65 + bfd_get_section_vma (abfd, sec) 66 + sec->size); 67 if (sec_end > outfile_size) 68 outfile_size = sec_end; 69 } 70 } 71 72 /* Make sure the program isn't too big. */ 73 if (high_vma > (bfd_vma)0xffff) 74 { 75 bfd_set_error(bfd_error_file_too_big); 76 return FALSE; 77 } 78 79 /* Constants. */ 80 H_PUT_16 (abfd, EXE_MAGIC, &hdr[0]); 81 H_PUT_16 (abfd, EXE_PAGE_SIZE / 16, &hdr[8]); 82 H_PUT_16 (abfd, EXE_LOAD_LOW, &hdr[12]); 83 H_PUT_16 (abfd, 0x3e, &hdr[24]); 84 H_PUT_16 (abfd, 0x0001, &hdr[28]); /* XXX??? */ 85 H_PUT_16 (abfd, 0x30fb, &hdr[30]); /* XXX??? */ 86 H_PUT_16 (abfd, 0x726a, &hdr[32]); /* XXX??? */ 87 88 /* Bytes in last page (0 = full page). */ 89 H_PUT_16 (abfd, outfile_size & (EXE_PAGE_SIZE - 1), &hdr[2]); 90 91 /* Number of pages. */ 92 H_PUT_16 (abfd, (outfile_size + EXE_PAGE_SIZE - 1) / EXE_PAGE_SIZE, &hdr[4]); 93 94 /* Set the initial stack pointer to the end of the bss. 95 The program's crt0 code must relocate it to a real stack. */ 96 H_PUT_16 (abfd, high_vma, &hdr[16]); 97 98 if (bfd_seek (abfd, (file_ptr) 0, SEEK_SET) != 0 99 || bfd_bwrite (hdr, (bfd_size_type) sizeof(hdr), abfd) != sizeof(hdr)) 100 return FALSE; 101 102 return TRUE; 103} 104 105static bfd_boolean 106msdos_set_section_contents (bfd *abfd, 107 sec_ptr section, 108 const void *location, 109 file_ptr offset, 110 bfd_size_type count) 111{ 112 113 if (count == 0) 114 return TRUE; 115 116 section->filepos = EXE_PAGE_SIZE + bfd_get_section_vma (abfd, section); 117 118 if (bfd_get_section_flags (abfd, section) & SEC_LOAD) 119 { 120 if (bfd_seek (abfd, section->filepos + offset, SEEK_SET) != 0 121 || bfd_bwrite (location, count, abfd) != count) 122 return FALSE; 123 } 124 125 return TRUE; 126} 127 128 129 130#define msdos_mkobject aout_32_mkobject 131#define msdos_make_empty_symbol aout_32_make_empty_symbol 132#define msdos_bfd_reloc_type_lookup aout_32_reloc_type_lookup 133 134#define msdos_close_and_cleanup _bfd_generic_close_and_cleanup 135#define msdos_bfd_free_cached_info _bfd_generic_bfd_free_cached_info 136#define msdos_new_section_hook _bfd_generic_new_section_hook 137#define msdos_get_section_contents _bfd_generic_get_section_contents 138#define msdos_get_section_contents_in_window \ 139 _bfd_generic_get_section_contents_in_window 140#define msdos_bfd_get_relocated_section_contents \ 141 bfd_generic_get_relocated_section_contents 142#define msdos_bfd_relax_section bfd_generic_relax_section 143#define msdos_bfd_gc_sections bfd_generic_gc_sections 144#define msdos_bfd_merge_sections bfd_generic_merge_sections 145#define msdos_bfd_is_group_section bfd_generic_is_group_section 146#define msdos_bfd_discard_group bfd_generic_discard_group 147#define msdos_section_already_linked \ 148 _bfd_generic_section_already_linked 149#define msdos_bfd_link_hash_table_create _bfd_generic_link_hash_table_create 150#define msdos_bfd_link_hash_table_free _bfd_generic_link_hash_table_free 151#define msdos_bfd_link_add_symbols _bfd_generic_link_add_symbols 152#define msdos_bfd_link_just_syms _bfd_generic_link_just_syms 153#define msdos_bfd_final_link _bfd_generic_final_link 154#define msdos_bfd_link_split_section _bfd_generic_link_split_section 155#define msdos_set_arch_mach _bfd_generic_set_arch_mach 156 157#define msdos_get_symtab_upper_bound _bfd_nosymbols_get_symtab_upper_bound 158#define msdos_canonicalize_symtab _bfd_nosymbols_canonicalize_symtab 159#define msdos_print_symbol _bfd_nosymbols_print_symbol 160#define msdos_get_symbol_info _bfd_nosymbols_get_symbol_info 161#define msdos_find_nearest_line _bfd_nosymbols_find_nearest_line 162#define msdos_find_inliner_info _bfd_nosymbols_find_inliner_info 163#define msdos_get_lineno _bfd_nosymbols_get_lineno 164#define msdos_bfd_is_target_special_symbol ((bfd_boolean (*) (bfd *, asymbol *)) bfd_false) 165#define msdos_bfd_is_local_label_name _bfd_nosymbols_bfd_is_local_label_name 166#define msdos_bfd_make_debug_symbol _bfd_nosymbols_bfd_make_debug_symbol 167#define msdos_read_minisymbols _bfd_nosymbols_read_minisymbols 168#define msdos_minisymbol_to_symbol _bfd_nosymbols_minisymbol_to_symbol 169 170#define msdos_canonicalize_reloc _bfd_norelocs_canonicalize_reloc 171#define msdos_get_reloc_upper_bound _bfd_norelocs_get_reloc_upper_bound 172#define msdos_32_bfd_link_split_section _bfd_generic_link_split_section 173 174const bfd_target i386msdos_vec = 175 { 176 "msdos", /* name */ 177 bfd_target_msdos_flavour, 178 BFD_ENDIAN_LITTLE, /* target byte order */ 179 BFD_ENDIAN_LITTLE, /* target headers byte order */ 180 (EXEC_P), /* object flags */ 181 (SEC_CODE | SEC_DATA | SEC_HAS_CONTENTS 182 | SEC_ALLOC | SEC_LOAD), /* section flags */ 183 0, /* leading underscore */ 184 ' ', /* ar_pad_char */ 185 16, /* ar_max_namelen */ 186 bfd_getl64, bfd_getl_signed_64, bfd_putl64, 187 bfd_getl32, bfd_getl_signed_32, bfd_putl32, 188 bfd_getl16, bfd_getl_signed_16, bfd_putl16, /* data */ 189 bfd_getl64, bfd_getl_signed_64, bfd_putl64, 190 bfd_getl32, bfd_getl_signed_32, bfd_putl32, 191 bfd_getl16, bfd_getl_signed_16, bfd_putl16, /* hdrs */ 192 193 { 194 _bfd_dummy_target, 195 _bfd_dummy_target, /* bfd_check_format */ 196 _bfd_dummy_target, 197 _bfd_dummy_target, 198 }, 199 { 200 bfd_false, 201 msdos_mkobject, 202 _bfd_generic_mkarchive, 203 bfd_false, 204 }, 205 { /* bfd_write_contents */ 206 bfd_false, 207 msdos_write_object_contents, 208 _bfd_write_archive_contents, 209 bfd_false, 210 }, 211 212 BFD_JUMP_TABLE_GENERIC (msdos), 213 BFD_JUMP_TABLE_COPY (_bfd_generic), 214 BFD_JUMP_TABLE_CORE (_bfd_nocore), 215 BFD_JUMP_TABLE_ARCHIVE (_bfd_noarchive), 216 BFD_JUMP_TABLE_SYMBOLS (msdos), 217 BFD_JUMP_TABLE_RELOCS (msdos), 218 BFD_JUMP_TABLE_WRITE (msdos), 219 BFD_JUMP_TABLE_LINK (msdos), 220 BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic), 221 222 NULL, 223 224 (PTR) 0 225 }; 226 227 228