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
msdos_sizeof_headers(abfd,exec)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
msdos_write_object_contents(abfd)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
msdos_set_section_contents(abfd,section,location,offset,count)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