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[binutils.git] / bfd / coff-stgo32.c
blobb8928befa689baf15d99290a05f935196cc0caae
1 /* BFD back-end for Intel 386 COFF files (DJGPP variant with a stub).
2 Copyright 1997, 1998, 1999, 2000, 2001, 2002, 2006, 2007
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 /* I hold in the usrdata the stub. */
106 #define bfd_coff_go32stub bfd_usrdata
108 /* This macro is used, because I cannot assume the endianess of the
109 host system. */
110 #define _H(index) (H_GET_16 (abfd, (header+index*2)))
112 /* These bytes are a 2048-byte DOS executable, which loads the COFF
113 image into memory and then runs it. It is called 'stub'. */
115 static const unsigned char stub_bytes[STUBSIZE] =
117 #include "go32stub.h"
121 I have not commented each swap function below, because the
122 technique is in any function the same. For the ...in function,
123 all the pointers are adjusted by adding STUBSIZE and for the
124 ...out function, it is subtracted first and after calling the
125 standard swap function it is reset to the old value. */
127 /* This macro is used for adjusting the filepointers, which
128 is done only, if the pointer is nonzero. */
130 #define ADJUST_VAL(val,diff) \
131 if (val != 0) val += diff
133 static void
134 adjust_filehdr_in_post (abfd, src, dst)
135 bfd *abfd;
136 PTR src;
137 PTR dst;
139 FILHDR *filehdr_src = (FILHDR *) src;
140 struct internal_filehdr *filehdr_dst = (struct internal_filehdr *) dst;
142 ADJUST_VAL (filehdr_dst->f_symptr, STUBSIZE);
144 /* Save now the stub to be used later. */
145 bfd_coff_go32stub (abfd) = (PTR) bfd_alloc (abfd, (bfd_size_type) STUBSIZE);
147 /* Since this function returns no status, I do not set here
148 any bfd_error_...
149 That means, before the use of bfd_coff_go32stub (), this value
150 should be checked if it is != NULL. */
151 if (bfd_coff_go32stub (abfd) == NULL)
152 return;
153 memcpy (bfd_coff_go32stub (abfd), filehdr_src->stub, STUBSIZE);
156 static void
157 adjust_filehdr_out_pre (abfd, in, out)
158 bfd *abfd;
159 PTR in;
160 PTR out;
162 struct internal_filehdr *filehdr_in = (struct internal_filehdr *) in;
163 FILHDR *filehdr_out = (FILHDR *) out;
165 /* Generate the stub. */
166 create_go32_stub (abfd);
168 /* Copy the stub to the file header. */
169 if (bfd_coff_go32stub (abfd) != NULL)
170 memcpy (filehdr_out->stub, bfd_coff_go32stub (abfd), STUBSIZE);
171 else
172 /* Use the default. */
173 memcpy (filehdr_out->stub, stub_bytes, STUBSIZE);
175 ADJUST_VAL (filehdr_in->f_symptr, -STUBSIZE);
178 static void
179 adjust_filehdr_out_post (abfd, in, out)
180 bfd *abfd ATTRIBUTE_UNUSED;
181 PTR in;
182 PTR out ATTRIBUTE_UNUSED;
184 struct internal_filehdr *filehdr_in = (struct internal_filehdr *) in;
185 /* Undo the above change. */
186 ADJUST_VAL (filehdr_in->f_symptr, STUBSIZE);
189 static void
190 adjust_scnhdr_in_post (abfd, ext, in)
191 bfd *abfd ATTRIBUTE_UNUSED;
192 PTR ext ATTRIBUTE_UNUSED;
193 PTR in;
195 struct internal_scnhdr *scnhdr_int = (struct internal_scnhdr *) in;
197 ADJUST_VAL (scnhdr_int->s_scnptr, STUBSIZE);
198 ADJUST_VAL (scnhdr_int->s_relptr, STUBSIZE);
199 ADJUST_VAL (scnhdr_int->s_lnnoptr, STUBSIZE);
202 static void
203 adjust_scnhdr_out_pre (abfd, in, out)
204 bfd *abfd ATTRIBUTE_UNUSED;
205 PTR in;
206 PTR out ATTRIBUTE_UNUSED;
208 struct internal_scnhdr *scnhdr_int = (struct internal_scnhdr *) in;
210 ADJUST_VAL (scnhdr_int->s_scnptr, -STUBSIZE);
211 ADJUST_VAL (scnhdr_int->s_relptr, -STUBSIZE);
212 ADJUST_VAL (scnhdr_int->s_lnnoptr, -STUBSIZE);
215 static void
216 adjust_scnhdr_out_post (abfd, in, out)
217 bfd *abfd ATTRIBUTE_UNUSED;
218 PTR in;
219 PTR out ATTRIBUTE_UNUSED;
221 struct internal_scnhdr *scnhdr_int = (struct internal_scnhdr *) in;
223 ADJUST_VAL (scnhdr_int->s_scnptr, STUBSIZE);
224 ADJUST_VAL (scnhdr_int->s_relptr, STUBSIZE);
225 ADJUST_VAL (scnhdr_int->s_lnnoptr, STUBSIZE);
228 static void
229 adjust_aux_in_post (abfd, ext1, type, class, indx, numaux, in1)
230 bfd *abfd ATTRIBUTE_UNUSED;
231 PTR ext1 ATTRIBUTE_UNUSED;
232 int type;
233 int class;
234 int indx ATTRIBUTE_UNUSED;
235 int numaux ATTRIBUTE_UNUSED;
236 PTR in1;
238 union internal_auxent *in = (union internal_auxent *) in1;
240 if (class == C_BLOCK || class == C_FCN || ISFCN (type) || ISTAG (class))
242 ADJUST_VAL (in->x_sym.x_fcnary.x_fcn.x_lnnoptr, STUBSIZE);
246 static void
247 adjust_aux_out_pre (abfd, inp, type, class, indx, numaux, extp)
248 bfd *abfd ATTRIBUTE_UNUSED;
249 PTR inp;
250 int type;
251 int class;
252 int indx ATTRIBUTE_UNUSED;
253 int numaux ATTRIBUTE_UNUSED;
254 PTR extp ATTRIBUTE_UNUSED;
256 union internal_auxent *in = (union internal_auxent *) inp;
258 if (class == C_BLOCK || class == C_FCN || ISFCN (type) || ISTAG (class))
260 ADJUST_VAL (in->x_sym.x_fcnary.x_fcn.x_lnnoptr, -STUBSIZE);
264 static void
265 adjust_aux_out_post (abfd, inp, type, class, indx, numaux, extp)
266 bfd *abfd ATTRIBUTE_UNUSED;
267 PTR inp;
268 int type;
269 int class;
270 int indx ATTRIBUTE_UNUSED;
271 int numaux ATTRIBUTE_UNUSED;
272 PTR extp ATTRIBUTE_UNUSED;
274 union internal_auxent *in = (union internal_auxent *) inp;
276 if (class == C_BLOCK || class == C_FCN || ISFCN (type) || ISTAG (class))
278 ADJUST_VAL (in->x_sym.x_fcnary.x_fcn.x_lnnoptr, STUBSIZE);
282 /* That's the function, which creates the stub. There are
283 different cases from where the stub is taken.
284 At first the environment variable $(GO32STUB) is checked and then
285 $(STUB) if it was not set.
286 If it exists and points to a valid stub the stub is taken from
287 that file. This file can be also a whole executable file, because
288 the stub is computed from the exe information at the start of that
289 file.
291 If there was any error, the standard stub (compiled in this file)
292 is taken. */
294 static void
295 create_go32_stub (abfd)
296 bfd *abfd;
298 /* Do it only once. */
299 if (bfd_coff_go32stub (abfd) == NULL)
301 char *stub;
302 struct stat st;
303 int f;
304 unsigned char header[10];
305 char magic[8];
306 unsigned long coff_start;
307 long exe_start;
309 /* Check at first the environment variable $(GO32STUB). */
310 stub = getenv ("GO32STUB");
311 /* Now check the environment variable $(STUB). */
312 if (stub == NULL)
313 stub = getenv ("STUB");
314 if (stub == NULL)
315 goto stub_end;
316 if (stat (stub, &st) != 0)
317 goto stub_end;
318 #ifdef O_BINARY
319 f = open (stub, O_RDONLY | O_BINARY);
320 #else
321 f = open (stub, O_RDONLY);
322 #endif
323 if (f < 0)
324 goto stub_end;
325 if (read (f, &header, sizeof (header)) < 0)
327 close (f);
328 goto stub_end;
330 if (_H (0) != 0x5a4d) /* It is not an exe file. */
332 close (f);
333 goto stub_end;
335 /* Compute the size of the stub (it is every thing up
336 to the beginning of the coff image). */
337 coff_start = (long) _H (2) * 512L;
338 if (_H (1))
339 coff_start += (long) _H (1) - 512L;
341 /* Currently there is only a fixed stub size of 2048 bytes
342 supported. */
343 if (coff_start != 2048)
345 close (f);
346 goto stub_end;
348 exe_start = _H (4) * 16;
349 if ((long) lseek (f, exe_start, SEEK_SET) != exe_start)
351 close (f);
352 goto stub_end;
354 if (read (f, &magic, 8) != 8)
356 close (f);
357 goto stub_end;
359 if (! CONST_STRNEQ (magic, "go32stub"))
361 close (f);
362 goto stub_end;
364 /* Now we found a correct stub (hopefully). */
365 bfd_coff_go32stub (abfd)
366 = (PTR) bfd_alloc (abfd, (bfd_size_type) coff_start);
367 if (bfd_coff_go32stub (abfd) == NULL)
369 close (f);
370 return;
372 lseek (f, 0L, SEEK_SET);
373 if ((unsigned long) read (f, bfd_coff_go32stub (abfd), coff_start)
374 != coff_start)
376 bfd_release (abfd, bfd_coff_go32stub (abfd));
377 bfd_coff_go32stub (abfd) = NULL;
379 close (f);
381 stub_end:
382 /* There was something wrong above, so use now the standard builtin
383 stub. */
384 if (bfd_coff_go32stub (abfd) == NULL)
386 bfd_coff_go32stub (abfd)
387 = (PTR) bfd_alloc (abfd, (bfd_size_type) STUBSIZE);
388 if (bfd_coff_go32stub (abfd) == NULL)
389 return;
390 memcpy (bfd_coff_go32stub (abfd), stub_bytes, STUBSIZE);
394 /* If ibfd was a stubbed coff image, copy the stub from that bfd
395 to the new obfd. */
397 static bfd_boolean
398 go32_stubbed_coff_bfd_copy_private_bfd_data (ibfd, obfd)
399 bfd *ibfd;
400 bfd *obfd;
402 /* Check if both are the same targets. */
403 if (ibfd->xvec != obfd->xvec)
404 return TRUE;
406 /* Check if both have a valid stub. */
407 if (bfd_coff_go32stub (ibfd) == NULL
408 || bfd_coff_go32stub (obfd) == NULL)
409 return TRUE;
411 /* Now copy the stub. */
412 memcpy (bfd_coff_go32stub (obfd), bfd_coff_go32stub (ibfd), STUBSIZE);
414 return TRUE;