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[binutils.git] / bfd / coff-stgo32.c
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1 /* BFD back-end for Intel 386 COFF files (DJGPP variant with a stub).
2 Copyright 1997, 1998, 1999, 2000, 2001, 2002, 2005, 2006, 2007, 2009
3 Free Software Foundation, Inc.
4 Written by Robert Hoehne.
6 This file is part of BFD, the Binary File Descriptor library.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21 MA 02110-1301, USA. */
23 /* This file handles now also stubbed coff images. The stub is a small
24 DOS executable program before the coff image to load it in memory
25 and execute it. This is needed, because DOS cannot run coff files.
27 All the functions below are called by the corresponding functions
28 from coffswap.h.
29 The only thing what they do is to adjust the information stored in
30 the COFF file which are offset into the file.
31 This is needed, because DJGPP uses a very special way to load and run
32 the coff image. It loads the image in memory and assumes then, that the
33 image had no stub by using the filepointers as pointers in the coff
34 image and NOT in the file.
36 To be compatible with any existing executables I have fixed this
37 here and NOT in the DJGPP startup code. */
39 #define TARGET_SYM go32stubbedcoff_vec
40 #define TARGET_NAME "coff-go32-exe"
41 #define TARGET_UNDERSCORE '_'
42 #define COFF_GO32_EXE
43 #define COFF_LONG_SECTION_NAMES
44 #define COFF_SUPPORT_GNU_LINKONCE
45 #define COFF_LONG_FILENAMES
47 #define COFF_SECTION_ALIGNMENT_ENTRIES \
48 { COFF_SECTION_NAME_EXACT_MATCH (".data"), \
49 COFF_ALIGNMENT_FIELD_EMPTY, COFF_ALIGNMENT_FIELD_EMPTY, 4 }, \
50 { COFF_SECTION_NAME_EXACT_MATCH (".text"), \
51 COFF_ALIGNMENT_FIELD_EMPTY, COFF_ALIGNMENT_FIELD_EMPTY, 4 }, \
52 { COFF_SECTION_NAME_PARTIAL_MATCH (".debug"), \
53 COFF_ALIGNMENT_FIELD_EMPTY, COFF_ALIGNMENT_FIELD_EMPTY, 0 }, \
54 { COFF_SECTION_NAME_PARTIAL_MATCH (".gnu.linkonce.wi"), \
55 COFF_ALIGNMENT_FIELD_EMPTY, COFF_ALIGNMENT_FIELD_EMPTY, 0 }
57 #include "bfd.h"
59 /* At first the prototypes. */
61 static void
62 adjust_filehdr_in_post PARAMS ((bfd *, PTR, PTR));
63 static void
64 adjust_filehdr_out_pre PARAMS ((bfd *, PTR, PTR));
65 static void
66 adjust_filehdr_out_post PARAMS ((bfd *, PTR, PTR));
67 static void
68 adjust_scnhdr_in_post PARAMS ((bfd *, PTR, PTR));
69 static void
70 adjust_scnhdr_out_pre PARAMS ((bfd *, PTR, PTR));
71 static void
72 adjust_scnhdr_out_post PARAMS ((bfd *, PTR, PTR));
73 static void
74 adjust_aux_in_post PARAMS ((bfd *, PTR, int, int, int, int, PTR));
75 static void
76 adjust_aux_out_pre PARAMS ((bfd *, PTR, int, int, int, int, PTR));
77 static void
78 adjust_aux_out_post PARAMS ((bfd *, PTR, int, int, int, int, PTR));
79 static void
80 create_go32_stub PARAMS ((bfd *));
82 /* All that ..._PRE and ...POST functions are called from the corresponding
83 coff_swap... functions. The ...PRE functions are called at the beginning
84 of the function and the ...POST functions at the end of the swap routines. */
86 #define COFF_ADJUST_FILEHDR_IN_POST adjust_filehdr_in_post
87 #define COFF_ADJUST_FILEHDR_OUT_PRE adjust_filehdr_out_pre
88 #define COFF_ADJUST_FILEHDR_OUT_POST adjust_filehdr_out_post
90 #define COFF_ADJUST_SCNHDR_IN_POST adjust_scnhdr_in_post
91 #define COFF_ADJUST_SCNHDR_OUT_PRE adjust_scnhdr_out_pre
92 #define COFF_ADJUST_SCNHDR_OUT_POST adjust_scnhdr_out_post
94 #define COFF_ADJUST_AUX_IN_POST adjust_aux_in_post
95 #define COFF_ADJUST_AUX_OUT_PRE adjust_aux_out_pre
96 #define COFF_ADJUST_AUX_OUT_POST adjust_aux_out_post
98 static bfd_boolean
99 go32_stubbed_coff_bfd_copy_private_bfd_data PARAMS ((bfd *, bfd *));
101 #define coff_bfd_copy_private_bfd_data go32_stubbed_coff_bfd_copy_private_bfd_data
103 #include "coff-i386.c"
105 /* This macro is used, because I cannot assume the endianess of the
106 host system. */
107 #define _H(index) (H_GET_16 (abfd, (header+index*2)))
109 /* These bytes are a 2048-byte DOS executable, which loads the COFF
110 image into memory and then runs it. It is called 'stub'. */
112 static const unsigned char stub_bytes[GO32_STUBSIZE] =
114 #include "go32stub.h"
118 I have not commented each swap function below, because the
119 technique is in any function the same. For the ...in function,
120 all the pointers are adjusted by adding GO32_STUBSIZE and for the
121 ...out function, it is subtracted first and after calling the
122 standard swap function it is reset to the old value. */
124 /* This macro is used for adjusting the filepointers, which
125 is done only, if the pointer is nonzero. */
127 #define ADJUST_VAL(val,diff) \
128 if (val != 0) val += diff
130 static void
131 adjust_filehdr_in_post (abfd, src, dst)
132 bfd *abfd ATTRIBUTE_UNUSED;
133 PTR src;
134 PTR dst;
136 FILHDR *filehdr_src = (FILHDR *) src;
137 struct internal_filehdr *filehdr_dst = (struct internal_filehdr *) dst;
139 ADJUST_VAL (filehdr_dst->f_symptr, GO32_STUBSIZE);
141 /* Save now the stub to be used later. Put the stub data to FILEHDR_DST
142 first as coff_data (abfd) still does not exist. It may not even be ever
143 created as we are just checking the file format of ABFD. */
144 memcpy (filehdr_dst->go32stub, filehdr_src->stub, GO32_STUBSIZE);
145 filehdr_dst->f_flags |= F_GO32STUB;
148 static void
149 adjust_filehdr_out_pre (abfd, in, out)
150 bfd *abfd;
151 PTR in;
152 PTR out;
154 struct internal_filehdr *filehdr_in = (struct internal_filehdr *) in;
155 FILHDR *filehdr_out = (FILHDR *) out;
157 /* Generate the stub. */
158 create_go32_stub (abfd);
160 /* Copy the stub to the file header. */
161 if (coff_data (abfd)->go32stub != NULL)
162 memcpy (filehdr_out->stub, coff_data (abfd)->go32stub, GO32_STUBSIZE);
163 else
164 /* Use the default. */
165 memcpy (filehdr_out->stub, stub_bytes, GO32_STUBSIZE);
167 ADJUST_VAL (filehdr_in->f_symptr, -GO32_STUBSIZE);
170 static void
171 adjust_filehdr_out_post (abfd, in, out)
172 bfd *abfd ATTRIBUTE_UNUSED;
173 PTR in;
174 PTR out ATTRIBUTE_UNUSED;
176 struct internal_filehdr *filehdr_in = (struct internal_filehdr *) in;
177 /* Undo the above change. */
178 ADJUST_VAL (filehdr_in->f_symptr, GO32_STUBSIZE);
181 static void
182 adjust_scnhdr_in_post (abfd, ext, in)
183 bfd *abfd ATTRIBUTE_UNUSED;
184 PTR ext ATTRIBUTE_UNUSED;
185 PTR in;
187 struct internal_scnhdr *scnhdr_int = (struct internal_scnhdr *) in;
189 ADJUST_VAL (scnhdr_int->s_scnptr, GO32_STUBSIZE);
190 ADJUST_VAL (scnhdr_int->s_relptr, GO32_STUBSIZE);
191 ADJUST_VAL (scnhdr_int->s_lnnoptr, GO32_STUBSIZE);
194 static void
195 adjust_scnhdr_out_pre (abfd, in, out)
196 bfd *abfd ATTRIBUTE_UNUSED;
197 PTR in;
198 PTR out ATTRIBUTE_UNUSED;
200 struct internal_scnhdr *scnhdr_int = (struct internal_scnhdr *) in;
202 ADJUST_VAL (scnhdr_int->s_scnptr, -GO32_STUBSIZE);
203 ADJUST_VAL (scnhdr_int->s_relptr, -GO32_STUBSIZE);
204 ADJUST_VAL (scnhdr_int->s_lnnoptr, -GO32_STUBSIZE);
207 static void
208 adjust_scnhdr_out_post (abfd, in, out)
209 bfd *abfd ATTRIBUTE_UNUSED;
210 PTR in;
211 PTR out ATTRIBUTE_UNUSED;
213 struct internal_scnhdr *scnhdr_int = (struct internal_scnhdr *) in;
215 ADJUST_VAL (scnhdr_int->s_scnptr, GO32_STUBSIZE);
216 ADJUST_VAL (scnhdr_int->s_relptr, GO32_STUBSIZE);
217 ADJUST_VAL (scnhdr_int->s_lnnoptr, GO32_STUBSIZE);
220 static void
221 adjust_aux_in_post (abfd, ext1, type, in_class, indx, numaux, in1)
222 bfd *abfd ATTRIBUTE_UNUSED;
223 PTR ext1 ATTRIBUTE_UNUSED;
224 int type;
225 int in_class;
226 int indx ATTRIBUTE_UNUSED;
227 int numaux ATTRIBUTE_UNUSED;
228 PTR in1;
230 union internal_auxent *in = (union internal_auxent *) in1;
232 if (in_class == C_BLOCK || in_class == C_FCN || ISFCN (type)
233 || ISTAG (in_class))
235 ADJUST_VAL (in->x_sym.x_fcnary.x_fcn.x_lnnoptr, GO32_STUBSIZE);
239 static void
240 adjust_aux_out_pre (abfd, inp, type, in_class, indx, numaux, extp)
241 bfd *abfd ATTRIBUTE_UNUSED;
242 PTR inp;
243 int type;
244 int in_class;
245 int indx ATTRIBUTE_UNUSED;
246 int numaux ATTRIBUTE_UNUSED;
247 PTR extp ATTRIBUTE_UNUSED;
249 union internal_auxent *in = (union internal_auxent *) inp;
251 if (in_class == C_BLOCK || in_class == C_FCN || ISFCN (type)
252 || ISTAG (in_class))
254 ADJUST_VAL (in->x_sym.x_fcnary.x_fcn.x_lnnoptr, -GO32_STUBSIZE);
258 static void
259 adjust_aux_out_post (abfd, inp, type, in_class, indx, numaux, extp)
260 bfd *abfd ATTRIBUTE_UNUSED;
261 PTR inp;
262 int type;
263 int in_class;
264 int indx ATTRIBUTE_UNUSED;
265 int numaux ATTRIBUTE_UNUSED;
266 PTR extp ATTRIBUTE_UNUSED;
268 union internal_auxent *in = (union internal_auxent *) inp;
270 if (in_class == C_BLOCK || in_class == C_FCN || ISFCN (type)
271 || ISTAG (in_class))
273 ADJUST_VAL (in->x_sym.x_fcnary.x_fcn.x_lnnoptr, GO32_STUBSIZE);
277 /* That's the function, which creates the stub. There are
278 different cases from where the stub is taken.
279 At first the environment variable $(GO32STUB) is checked and then
280 $(STUB) if it was not set.
281 If it exists and points to a valid stub the stub is taken from
282 that file. This file can be also a whole executable file, because
283 the stub is computed from the exe information at the start of that
284 file.
286 If there was any error, the standard stub (compiled in this file)
287 is taken. */
289 static void
290 create_go32_stub (abfd)
291 bfd *abfd;
293 /* Do it only once. */
294 if (coff_data (abfd)->go32stub == NULL)
296 char *stub;
297 struct stat st;
298 int f;
299 unsigned char header[10];
300 char magic[8];
301 unsigned long coff_start;
302 long exe_start;
304 /* Check at first the environment variable $(GO32STUB). */
305 stub = getenv ("GO32STUB");
306 /* Now check the environment variable $(STUB). */
307 if (stub == NULL)
308 stub = getenv ("STUB");
309 if (stub == NULL)
310 goto stub_end;
311 if (stat (stub, &st) != 0)
312 goto stub_end;
313 #ifdef O_BINARY
314 f = open (stub, O_RDONLY | O_BINARY);
315 #else
316 f = open (stub, O_RDONLY);
317 #endif
318 if (f < 0)
319 goto stub_end;
320 if (read (f, &header, sizeof (header)) < 0)
322 close (f);
323 goto stub_end;
325 if (_H (0) != 0x5a4d) /* It is not an exe file. */
327 close (f);
328 goto stub_end;
330 /* Compute the size of the stub (it is every thing up
331 to the beginning of the coff image). */
332 coff_start = (long) _H (2) * 512L;
333 if (_H (1))
334 coff_start += (long) _H (1) - 512L;
336 /* Currently there is only a fixed stub size of 2048 bytes
337 supported. */
338 if (coff_start != 2048)
340 close (f);
341 goto stub_end;
343 exe_start = _H (4) * 16;
344 if ((long) lseek (f, exe_start, SEEK_SET) != exe_start)
346 close (f);
347 goto stub_end;
349 if (read (f, &magic, 8) != 8)
351 close (f);
352 goto stub_end;
354 if (! CONST_STRNEQ (magic, "go32stub"))
356 close (f);
357 goto stub_end;
359 /* Now we found a correct stub (hopefully). */
360 coff_data (abfd)->go32stub = bfd_alloc (abfd, (bfd_size_type) coff_start);
361 if (coff_data (abfd)->go32stub == NULL)
363 close (f);
364 return;
366 lseek (f, 0L, SEEK_SET);
367 if ((unsigned long) read (f, coff_data (abfd)->go32stub, coff_start)
368 != coff_start)
370 bfd_release (abfd, coff_data (abfd)->go32stub);
371 coff_data (abfd)->go32stub = NULL;
373 close (f);
375 stub_end:
376 /* There was something wrong above, so use now the standard builtin
377 stub. */
378 if (coff_data (abfd)->go32stub == NULL)
380 coff_data (abfd)->go32stub
381 = bfd_alloc (abfd, (bfd_size_type) GO32_STUBSIZE);
382 if (coff_data (abfd)->go32stub == NULL)
383 return;
384 memcpy (coff_data (abfd)->go32stub, stub_bytes, GO32_STUBSIZE);
388 /* If ibfd was a stubbed coff image, copy the stub from that bfd
389 to the new obfd. */
391 static bfd_boolean
392 go32_stubbed_coff_bfd_copy_private_bfd_data (ibfd, obfd)
393 bfd *ibfd;
394 bfd *obfd;
396 /* Check if both are the same targets. */
397 if (ibfd->xvec != obfd->xvec)
398 return TRUE;
400 /* Check if we have a source stub. */
401 if (coff_data (ibfd)->go32stub == NULL)
402 return TRUE;
404 /* As adjust_filehdr_out_pre may get called only after this function,
405 optionally allocate the output stub. */
406 if (coff_data (obfd)->go32stub == NULL)
407 coff_data (obfd)->go32stub = bfd_alloc (obfd,
408 (bfd_size_type) GO32_STUBSIZE);
410 /* Now copy the stub. */
411 if (coff_data (obfd)->go32stub != NULL)
412 memcpy (coff_data (obfd)->go32stub, coff_data (ibfd)->go32stub,
413 GO32_STUBSIZE);
415 return TRUE;