1 /* BFD back-end for Intel 386 COFF files (DJGPP variant with a stub).
2 Copyright 1997, 1998, 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
3 Written by Robert Hoehne.
4
5 This file is part of BFD, the Binary File Descriptor library.
6
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2 of the License, or
10 (at your option) any later version.
11
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
16
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software
19 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
20
21 /* This file handles now also stubbed coff images. The stub is a small
22 DOS executable program before the coff image to load it in memory
23 and execute it. This is needed, because DOS cannot run coff files.
24
25 All the functions below are called by the corresponding functions
26 from coffswap.h.
27 The only thing what they do is to adjust the information stored in
28 the COFF file which are offset into the file.
29 This is needed, because DJGPP uses a very special way to load and run
30 the coff image. It loads the image in memory and assumes then, that the
31 image had no stub by using the filepointers as pointers in the coff
32 image and NOT in the file.
33
34 To be compatible with any existing executables I have fixed this
35 here and NOT in the DJGPP startup code. */
36
37 #define TARGET_SYM go32stubbedcoff_vec
38 #define TARGET_NAME "coff-go32-exe"
39 #define TARGET_UNDERSCORE '_'
40 #define COFF_GO32_EXE
41 #define COFF_LONG_SECTION_NAMES
42 #define COFF_SUPPORT_GNU_LINKONCE
43 #define COFF_LONG_FILENAMES
44
45 #define COFF_SECTION_ALIGNMENT_ENTRIES \
46 { COFF_SECTION_NAME_EXACT_MATCH (".data"), \
47 COFF_ALIGNMENT_FIELD_EMPTY, COFF_ALIGNMENT_FIELD_EMPTY, 4 }, \
48 { COFF_SECTION_NAME_EXACT_MATCH (".text"), \
49 COFF_ALIGNMENT_FIELD_EMPTY, COFF_ALIGNMENT_FIELD_EMPTY, 4 }, \
50 { COFF_SECTION_NAME_PARTIAL_MATCH (".debug"), \
51 COFF_ALIGNMENT_FIELD_EMPTY, COFF_ALIGNMENT_FIELD_EMPTY, 0 }, \
52 { COFF_SECTION_NAME_PARTIAL_MATCH (".gnu.linkonce.wi"), \
53 COFF_ALIGNMENT_FIELD_EMPTY, COFF_ALIGNMENT_FIELD_EMPTY, 0 }
54
55 #include "bfd.h"
56
57 /* At first the prototypes. */
58
59 static void
60 adjust_filehdr_in_post PARAMS ((bfd *, PTR, PTR));
61 static void
62 adjust_filehdr_out_pre PARAMS ((bfd *, PTR, PTR));
63 static void
64 adjust_filehdr_out_post PARAMS ((bfd *, PTR, PTR));
65 static void
66 adjust_scnhdr_in_post PARAMS ((bfd *, PTR, PTR));
67 static void
68 adjust_scnhdr_out_pre PARAMS ((bfd *, PTR, PTR));
69 static void
70 adjust_scnhdr_out_post PARAMS ((bfd *, PTR, PTR));
71 static void
72 adjust_aux_in_post PARAMS ((bfd *, PTR, int, int, int, int, PTR));
73 static void
74 adjust_aux_out_pre PARAMS ((bfd *, PTR, int, int, int, int, PTR));
75 static void
76 adjust_aux_out_post PARAMS ((bfd *, PTR, int, int, int, int, PTR));
77 static void
78 create_go32_stub PARAMS ((bfd *));
79
80 /* All that ..._PRE and ...POST functions are called from the corresponding
81 coff_swap... functions. The ...PRE functions are called at the beginning
82 of the function and the ...POST functions at the end of the swap routines. */
83
84 #define COFF_ADJUST_FILEHDR_IN_POST adjust_filehdr_in_post
85 #define COFF_ADJUST_FILEHDR_OUT_PRE adjust_filehdr_out_pre
86 #define COFF_ADJUST_FILEHDR_OUT_POST adjust_filehdr_out_post
87
88 #define COFF_ADJUST_SCNHDR_IN_POST adjust_scnhdr_in_post
89 #define COFF_ADJUST_SCNHDR_OUT_PRE adjust_scnhdr_out_pre
90 #define COFF_ADJUST_SCNHDR_OUT_POST adjust_scnhdr_out_post
91
92 #define COFF_ADJUST_AUX_IN_POST adjust_aux_in_post
93 #define COFF_ADJUST_AUX_OUT_PRE adjust_aux_out_pre
94 #define COFF_ADJUST_AUX_OUT_POST adjust_aux_out_post
95
96 static bfd_boolean
97 go32_stubbed_coff_bfd_copy_private_bfd_data PARAMS ((bfd *, bfd *));
98
99 #define coff_bfd_copy_private_bfd_data go32_stubbed_coff_bfd_copy_private_bfd_data
100
101 #include "coff-i386.c"
102
103 /* I hold in the usrdata the stub. */
104 #define bfd_coff_go32stub bfd_usrdata
105
106 /* This macro is used, because I cannot assume the endianess of the
107 host system. */
108 #define _H(index) (H_GET_16 (abfd, (header+index*2)))
109
110 /* These bytes are a 2048-byte DOS executable, which loads the COFF
111 image into memory and then runs it. It is called 'stub'. */
112
113 static const unsigned char stub_bytes[STUBSIZE] =
114 {
115 #include "go32stub.h"
116 };
117
118 /*
119 I have not commented each swap function below, because the
120 technique is in any function the same. For the ...in function,
121 all the pointers are adjusted by adding STUBSIZE and for the
122 ...out function, it is subtracted first and after calling the
123 standard swap function it is reset to the old value. */
124
125 /* This macro is used for adjusting the filepointers, which
126 is done only, if the pointer is nonzero. */
127
128 #define ADJUST_VAL(val,diff) \
129 if (val != 0) val += diff
130
131 static void
adjust_filehdr_in_post(abfd,src,dst)132 adjust_filehdr_in_post (abfd, src, dst)
133 bfd *abfd;
134 PTR src;
135 PTR dst;
136 {
137 FILHDR *filehdr_src = (FILHDR *) src;
138 struct internal_filehdr *filehdr_dst = (struct internal_filehdr *) dst;
139
140 ADJUST_VAL (filehdr_dst->f_symptr, STUBSIZE);
141
142 /* Save now the stub to be used later. */
143 bfd_coff_go32stub (abfd) = (PTR) bfd_alloc (abfd, (bfd_size_type) STUBSIZE);
144
145 /* Since this function returns no status, I do not set here
146 any bfd_error_...
147 That means, before the use of bfd_coff_go32stub (), this value
148 should be checked if it is != NULL. */
149 if (bfd_coff_go32stub (abfd) == NULL)
150 return;
151 memcpy (bfd_coff_go32stub (abfd), filehdr_src->stub, STUBSIZE);
152 }
153
154 static void
adjust_filehdr_out_pre(abfd,in,out)155 adjust_filehdr_out_pre (abfd, in, out)
156 bfd *abfd;
157 PTR in;
158 PTR out;
159 {
160 struct internal_filehdr *filehdr_in = (struct internal_filehdr *) in;
161 FILHDR *filehdr_out = (FILHDR *) out;
162
163 /* Generate the stub. */
164 create_go32_stub (abfd);
165
166 /* Copy the stub to the file header. */
167 if (bfd_coff_go32stub (abfd) != NULL)
168 memcpy (filehdr_out->stub, bfd_coff_go32stub (abfd), STUBSIZE);
169 else
170 /* Use the default. */
171 memcpy (filehdr_out->stub, stub_bytes, STUBSIZE);
172
173 ADJUST_VAL (filehdr_in->f_symptr, -STUBSIZE);
174 }
175
176 static void
adjust_filehdr_out_post(abfd,in,out)177 adjust_filehdr_out_post (abfd, in, out)
178 bfd *abfd ATTRIBUTE_UNUSED;
179 PTR in;
180 PTR out ATTRIBUTE_UNUSED;
181 {
182 struct internal_filehdr *filehdr_in = (struct internal_filehdr *) in;
183 /* Undo the above change. */
184 ADJUST_VAL (filehdr_in->f_symptr, STUBSIZE);
185 }
186
187 static void
adjust_scnhdr_in_post(abfd,ext,in)188 adjust_scnhdr_in_post (abfd, ext, in)
189 bfd *abfd ATTRIBUTE_UNUSED;
190 PTR ext ATTRIBUTE_UNUSED;
191 PTR in;
192 {
193 struct internal_scnhdr *scnhdr_int = (struct internal_scnhdr *) in;
194
195 ADJUST_VAL (scnhdr_int->s_scnptr, STUBSIZE);
196 ADJUST_VAL (scnhdr_int->s_relptr, STUBSIZE);
197 ADJUST_VAL (scnhdr_int->s_lnnoptr, STUBSIZE);
198 }
199
200 static void
adjust_scnhdr_out_pre(abfd,in,out)201 adjust_scnhdr_out_pre (abfd, in, out)
202 bfd *abfd ATTRIBUTE_UNUSED;
203 PTR in;
204 PTR out ATTRIBUTE_UNUSED;
205 {
206 struct internal_scnhdr *scnhdr_int = (struct internal_scnhdr *) in;
207
208 ADJUST_VAL (scnhdr_int->s_scnptr, -STUBSIZE);
209 ADJUST_VAL (scnhdr_int->s_relptr, -STUBSIZE);
210 ADJUST_VAL (scnhdr_int->s_lnnoptr, -STUBSIZE);
211 }
212
213 static void
adjust_scnhdr_out_post(abfd,in,out)214 adjust_scnhdr_out_post (abfd, in, out)
215 bfd *abfd ATTRIBUTE_UNUSED;
216 PTR in;
217 PTR out ATTRIBUTE_UNUSED;
218 {
219 struct internal_scnhdr *scnhdr_int = (struct internal_scnhdr *) in;
220
221 ADJUST_VAL (scnhdr_int->s_scnptr, STUBSIZE);
222 ADJUST_VAL (scnhdr_int->s_relptr, STUBSIZE);
223 ADJUST_VAL (scnhdr_int->s_lnnoptr, STUBSIZE);
224 }
225
226 static void
adjust_aux_in_post(abfd,ext1,type,class,indx,numaux,in1)227 adjust_aux_in_post (abfd, ext1, type, class, indx, numaux, in1)
228 bfd *abfd ATTRIBUTE_UNUSED;
229 PTR ext1 ATTRIBUTE_UNUSED;
230 int type;
231 int class;
232 int indx ATTRIBUTE_UNUSED;
233 int numaux ATTRIBUTE_UNUSED;
234 PTR in1;
235 {
236 union internal_auxent *in = (union internal_auxent *) in1;
237
238 if (class == C_BLOCK || class == C_FCN || ISFCN (type) || ISTAG (class))
239 {
240 ADJUST_VAL (in->x_sym.x_fcnary.x_fcn.x_lnnoptr, STUBSIZE);
241 }
242 }
243
244 static void
adjust_aux_out_pre(abfd,inp,type,class,indx,numaux,extp)245 adjust_aux_out_pre (abfd, inp, type, class, indx, numaux, extp)
246 bfd *abfd ATTRIBUTE_UNUSED;
247 PTR inp;
248 int type;
249 int class;
250 int indx ATTRIBUTE_UNUSED;
251 int numaux ATTRIBUTE_UNUSED;
252 PTR extp ATTRIBUTE_UNUSED;
253 {
254 union internal_auxent *in = (union internal_auxent *) inp;
255
256 if (class == C_BLOCK || class == C_FCN || ISFCN (type) || ISTAG (class))
257 {
258 ADJUST_VAL (in->x_sym.x_fcnary.x_fcn.x_lnnoptr, -STUBSIZE);
259 }
260 }
261
262 static void
adjust_aux_out_post(abfd,inp,type,class,indx,numaux,extp)263 adjust_aux_out_post (abfd, inp, type, class, indx, numaux, extp)
264 bfd *abfd ATTRIBUTE_UNUSED;
265 PTR inp;
266 int type;
267 int class;
268 int indx ATTRIBUTE_UNUSED;
269 int numaux ATTRIBUTE_UNUSED;
270 PTR extp ATTRIBUTE_UNUSED;
271 {
272 union internal_auxent *in = (union internal_auxent *) inp;
273
274 if (class == C_BLOCK || class == C_FCN || ISFCN (type) || ISTAG (class))
275 {
276 ADJUST_VAL (in->x_sym.x_fcnary.x_fcn.x_lnnoptr, STUBSIZE);
277 }
278 }
279
280 /* That's the function, which creates the stub. There are
281 different cases from where the stub is taken.
282 At first the environment variable $(GO32STUB) is checked and then
283 $(STUB) if it was not set.
284 If it exists and points to a valid stub the stub is taken from
285 that file. This file can be also a whole executable file, because
286 the stub is computed from the exe information at the start of that
287 file.
288
289 If there was any error, the standard stub (compiled in this file)
290 is taken. */
291
292 static void
create_go32_stub(abfd)293 create_go32_stub (abfd)
294 bfd *abfd;
295 {
296 /* Do it only once. */
297 if (bfd_coff_go32stub (abfd) == NULL)
298 {
299 char *stub;
300 struct stat st;
301 int f;
302 unsigned char header[10];
303 char magic[8];
304 unsigned long coff_start;
305 long exe_start;
306
307 /* Check at first the environment variable $(GO32STUB). */
308 stub = getenv ("GO32STUB");
309 /* Now check the environment variable $(STUB). */
310 if (stub == NULL)
311 stub = getenv ("STUB");
312 if (stub == NULL)
313 goto stub_end;
314 if (stat (stub, &st) != 0)
315 goto stub_end;
316 #ifdef O_BINARY
317 f = open (stub, O_RDONLY | O_BINARY);
318 #else
319 f = open (stub, O_RDONLY);
320 #endif
321 if (f < 0)
322 goto stub_end;
323 if (read (f, &header, sizeof (header)) < 0)
324 {
325 close (f);
326 goto stub_end;
327 }
328 if (_H (0) != 0x5a4d) /* It is not an exe file. */
329 {
330 close (f);
331 goto stub_end;
332 }
333 /* Compute the size of the stub (it is every thing up
334 to the beginning of the coff image). */
335 coff_start = (long) _H (2) * 512L;
336 if (_H (1))
337 coff_start += (long) _H (1) - 512L;
338
339 /* Currently there is only a fixed stub size of 2048 bytes
340 supported. */
341 if (coff_start != 2048)
342 {
343 close (f);
344 goto stub_end;
345 }
346 exe_start = _H (4) * 16;
347 if ((long) lseek (f, exe_start, SEEK_SET) != exe_start)
348 {
349 close (f);
350 goto stub_end;
351 }
352 if (read (f, &magic, 8) != 8)
353 {
354 close (f);
355 goto stub_end;
356 }
357 if (memcmp (magic, "go32stub", 8) != 0)
358 {
359 close (f);
360 goto stub_end;
361 }
362 /* Now we found a correct stub (hopefully). */
363 bfd_coff_go32stub (abfd)
364 = (PTR) bfd_alloc (abfd, (bfd_size_type) coff_start);
365 if (bfd_coff_go32stub (abfd) == NULL)
366 {
367 close (f);
368 return;
369 }
370 lseek (f, 0L, SEEK_SET);
371 if ((unsigned long) read (f, bfd_coff_go32stub (abfd), coff_start)
372 != coff_start)
373 {
374 bfd_release (abfd, bfd_coff_go32stub (abfd));
375 bfd_coff_go32stub (abfd) = NULL;
376 }
377 close (f);
378 }
379 stub_end:
380 /* There was something wrong above, so use now the standard builtin
381 stub. */
382 if (bfd_coff_go32stub (abfd) == NULL)
383 {
384 bfd_coff_go32stub (abfd)
385 = (PTR) bfd_alloc (abfd, (bfd_size_type) STUBSIZE);
386 if (bfd_coff_go32stub (abfd) == NULL)
387 return;
388 memcpy (bfd_coff_go32stub (abfd), stub_bytes, STUBSIZE);
389 }
390 }
391
392 /* If ibfd was a stubbed coff image, copy the stub from that bfd
393 to the new obfd. */
394
395 static bfd_boolean
go32_stubbed_coff_bfd_copy_private_bfd_data(ibfd,obfd)396 go32_stubbed_coff_bfd_copy_private_bfd_data (ibfd, obfd)
397 bfd *ibfd;
398 bfd *obfd;
399 {
400 /* Check if both are the same targets. */
401 if (ibfd->xvec != obfd->xvec)
402 return TRUE;
403
404 /* Check if both have a valid stub. */
405 if (bfd_coff_go32stub (ibfd) == NULL
406 || bfd_coff_go32stub (obfd) == NULL)
407 return TRUE;
408
409 /* Now copy the stub. */
410 memcpy (bfd_coff_go32stub (obfd), bfd_coff_go32stub (ibfd), STUBSIZE);
411
412 return TRUE;
413 }
414