1 /* BFD back-end for Intel 386 COFF files (go32 variant with a stub).
2 Copyright 1997, 1998, 1999 Free Software Foundation, Inc.
3 Written by Robert Hoehne.
5 This file is part of BFD, the Binary File Descriptor library.
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.
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.
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. */
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.
25 All the functions below are called by the corresponding functions
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.
34 To be compatible with any existing executables I have fixed this
35 here and NOT in the DJGPP startup code.
38 #define TARGET_SYM go32stubbedcoff_vec
39 #define TARGET_NAME "coff-go32-exe"
40 #define TARGET_UNDERSCORE '_'
42 #define COFF_LONG_SECTION_NAMES
43 #define COFF_SUPPORT_GNU_LINKONCE
47 /* At first the prototypes */
50 adjust_filehdr_in_post
PARAMS ((bfd
* abfd
, PTR src
, PTR dst
));
52 adjust_filehdr_out_pre
PARAMS ((bfd
* abfd
, PTR in
, PTR out
));
54 adjust_filehdr_out_post
PARAMS ((bfd
* abfd
, PTR in
, PTR out
));
57 adjust_scnhdr_in_post
PARAMS ((bfd
* abfd
, PTR ext
, PTR in
));
59 adjust_scnhdr_out_pre
PARAMS ((bfd
* abfd
, PTR in
, PTR out
));
61 adjust_scnhdr_out_post
PARAMS ((bfd
* abfd
, PTR in
, PTR out
));
64 adjust_aux_in_post
PARAMS ((bfd
* abfd
, PTR ext1
, int type
, int class, int indx
,
65 int numaux
, PTR in1
));
67 adjust_aux_out_pre
PARAMS ((bfd
* abfd
, PTR inp
, int type
, int class, int indx
,
68 int numaux
, PTR extp
));
70 adjust_aux_out_post
PARAMS ((bfd
* abfd
, PTR inp
, int type
, int class, int indx
,
71 int numaux
, PTR extp
));
74 create_go32_stub
PARAMS ((bfd
* abfd
));
77 All that ..._PRE and ...POST functions are called from the corresponding
78 coff_swap... functions. The ...PRE functions are called at the beginning
79 of the function and the ...POST functions at the end of the swap routines.
82 #define COFF_ADJUST_FILEHDR_IN_POST adjust_filehdr_in_post
83 #define COFF_ADJUST_FILEHDR_OUT_PRE adjust_filehdr_out_pre
84 #define COFF_ADJUST_FILEHDR_OUT_POST adjust_filehdr_out_post
86 #define COFF_ADJUST_SCNHDR_IN_POST adjust_scnhdr_in_post
87 #define COFF_ADJUST_SCNHDR_OUT_PRE adjust_scnhdr_out_pre
88 #define COFF_ADJUST_SCNHDR_OUT_POST adjust_scnhdr_out_post
90 #define COFF_ADJUST_AUX_IN_POST adjust_aux_in_post
91 #define COFF_ADJUST_AUX_OUT_PRE adjust_aux_out_pre
92 #define COFF_ADJUST_AUX_OUT_POST adjust_aux_out_post
95 go32_stubbed_coff_bfd_copy_private_bfd_data
PARAMS ((bfd
* ibfd
, bfd
* obfd
));
97 #define coff_bfd_copy_private_bfd_data go32_stubbed_coff_bfd_copy_private_bfd_data
99 #include "coff-i386.c"
101 /* I hold in the usrdata the stub */
102 #define bfd_coff_go32stub bfd_usrdata
104 /* This macro is used, because I cannot assume the endianess of the
106 #define _H(index) (bfd_h_get_16(abfd, (bfd_byte *)(header+index*2)))
108 /* This function checks if the bfd is a stubbed coff image */
109 static const bfd_target
*
110 go32_stubbed_coff_object_p (abfd
)
113 unsigned char header
[10];
115 unsigned long coff_start
, exe_start
;
117 if (bfd_read (&header
, 1, sizeof (header
), abfd
) != sizeof (header
))
119 if (bfd_get_error () != bfd_error_system_call
)
120 bfd_set_error (bfd_error_wrong_format
);
123 if (_H (0) != 0x5a4d) /* it is not an exe file. maybe a coff-image */
125 if (bfd_get_error () != bfd_error_system_call
)
126 bfd_set_error (bfd_error_wrong_format
);
129 coff_start
= (long) _H (2) * 512L;
131 coff_start
+= (long) _H (1) - 512L;
133 /* We can handle only a stub with a length of STUBSIZE */
134 if (coff_start
!= STUBSIZE
)
136 bfd_set_error (bfd_error_wrong_format
);
139 exe_start
= _H (4) * 16;
140 if (bfd_seek (abfd
, exe_start
, SEEK_SET
) != 0)
142 if (bfd_read (&magic
, 1, 8, abfd
) != 8)
144 if (bfd_get_error () != bfd_error_system_call
)
145 bfd_set_error (bfd_error_wrong_format
);
148 if (memcmp (magic
, "go32stub", 8) != 0)
150 bfd_set_error (bfd_error_wrong_format
);
153 if (bfd_seek (abfd
, 0, SEEK_SET
) != 0)
156 /* Call the normal COFF detection routine */
157 return coff_object_p (abfd
);
160 /* These bytes are a 2048-byte DOS executable, which loads the COFF
161 image into memory and then runs it. It is called 'stub' */
163 static unsigned char stub_bytes
[STUBSIZE
] =
165 #include "go32stub.h"
169 I have not commented each swap function below, because the
170 technique is in any function the same. For the ...in function,
171 all the pointers are adjusted by adding STUBSIZE and for the
172 ...out function, it is subtracted first and after calling the
173 standard swap function it is reset to the old value */
175 /* This macro is used for adjusting the filepointers, which
176 is done only, if the pointer is nonzero */
178 #define ADJUST_VAL(val,diff) \
179 if (val != 0) val += diff
182 adjust_filehdr_in_post (abfd
, src
, dst
)
187 FILHDR
*filehdr_src
= (FILHDR
*) src
;
188 struct internal_filehdr
*filehdr_dst
= (struct internal_filehdr
*) dst
;
190 ADJUST_VAL (filehdr_dst
->f_symptr
, STUBSIZE
);
192 /* Save now the stub to be used later */
193 bfd_coff_go32stub (abfd
) = (PTR
) bfd_alloc (abfd
, STUBSIZE
);
195 /* Since this function returns no status, I do not set here
197 That means, before the use of bfd_coff_go32stub (), this value
198 should be checked if it is != NULL */
199 if (bfd_coff_go32stub (abfd
) == NULL
)
201 memcpy (bfd_coff_go32stub (abfd
), filehdr_src
->stub
, STUBSIZE
);
205 adjust_filehdr_out_pre (abfd
, in
, out
)
210 struct internal_filehdr
*filehdr_in
= (struct internal_filehdr
*) in
;
211 FILHDR
*filehdr_out
= (FILHDR
*) out
;
213 /* Generate the stub */
214 create_go32_stub (abfd
);
216 /* Copy the stub to the file header */
217 if (bfd_coff_go32stub (abfd
) != NULL
)
218 memcpy (filehdr_out
->stub
, bfd_coff_go32stub (abfd
), STUBSIZE
);
220 /* use the default */
221 memcpy (filehdr_out
->stub
, stub_bytes
, STUBSIZE
);
223 ADJUST_VAL (filehdr_in
->f_symptr
, -STUBSIZE
);
227 adjust_filehdr_out_post (abfd
, in
, out
)
228 bfd
*abfd ATTRIBUTE_UNUSED
;
230 PTR out ATTRIBUTE_UNUSED
;
232 struct internal_filehdr
*filehdr_in
= (struct internal_filehdr
*) in
;
233 /* undo the above change */
234 ADJUST_VAL (filehdr_in
->f_symptr
, STUBSIZE
);
238 adjust_scnhdr_in_post (abfd
, ext
, in
)
239 bfd
*abfd ATTRIBUTE_UNUSED
;
240 PTR ext ATTRIBUTE_UNUSED
;
243 struct internal_scnhdr
*scnhdr_int
= (struct internal_scnhdr
*) in
;
245 ADJUST_VAL (scnhdr_int
->s_scnptr
, STUBSIZE
);
246 ADJUST_VAL (scnhdr_int
->s_relptr
, STUBSIZE
);
247 ADJUST_VAL (scnhdr_int
->s_lnnoptr
, STUBSIZE
);
251 adjust_scnhdr_out_pre (abfd
, in
, out
)
252 bfd
*abfd ATTRIBUTE_UNUSED
;
254 PTR out ATTRIBUTE_UNUSED
;
256 struct internal_scnhdr
*scnhdr_int
= (struct internal_scnhdr
*) in
;
258 ADJUST_VAL (scnhdr_int
->s_scnptr
, -STUBSIZE
);
259 ADJUST_VAL (scnhdr_int
->s_relptr
, -STUBSIZE
);
260 ADJUST_VAL (scnhdr_int
->s_lnnoptr
, -STUBSIZE
);
264 adjust_scnhdr_out_post (abfd
, in
, out
)
265 bfd
*abfd ATTRIBUTE_UNUSED
;
267 PTR out ATTRIBUTE_UNUSED
;
269 struct internal_scnhdr
*scnhdr_int
= (struct internal_scnhdr
*) in
;
271 ADJUST_VAL (scnhdr_int
->s_scnptr
, STUBSIZE
);
272 ADJUST_VAL (scnhdr_int
->s_relptr
, STUBSIZE
);
273 ADJUST_VAL (scnhdr_int
->s_lnnoptr
, STUBSIZE
);
277 adjust_aux_in_post (abfd
, ext1
, type
, class, indx
, numaux
, in1
)
278 bfd
*abfd ATTRIBUTE_UNUSED
;
279 PTR ext1 ATTRIBUTE_UNUSED
;
282 int indx ATTRIBUTE_UNUSED
;
283 int numaux ATTRIBUTE_UNUSED
;
286 union internal_auxent
*in
= (union internal_auxent
*) in1
;
288 if (class == C_BLOCK
|| class == C_FCN
|| ISFCN (type
) || ISTAG (class))
290 ADJUST_VAL (in
->x_sym
.x_fcnary
.x_fcn
.x_lnnoptr
, STUBSIZE
);
295 adjust_aux_out_pre (abfd
, inp
, type
, class, indx
, numaux
, extp
)
296 bfd
*abfd ATTRIBUTE_UNUSED
;
300 int indx ATTRIBUTE_UNUSED
;
301 int numaux ATTRIBUTE_UNUSED
;
302 PTR extp ATTRIBUTE_UNUSED
;
304 union internal_auxent
*in
= (union internal_auxent
*) inp
;
306 if (class == C_BLOCK
|| class == C_FCN
|| ISFCN (type
) || ISTAG (class))
308 ADJUST_VAL (in
->x_sym
.x_fcnary
.x_fcn
.x_lnnoptr
, -STUBSIZE
);
313 adjust_aux_out_post (abfd
, inp
, type
, class, indx
, numaux
, extp
)
314 bfd
*abfd ATTRIBUTE_UNUSED
;
318 int indx ATTRIBUTE_UNUSED
;
319 int numaux ATTRIBUTE_UNUSED
;
320 PTR extp ATTRIBUTE_UNUSED
;
322 union internal_auxent
*in
= (union internal_auxent
*) inp
;
324 if (class == C_BLOCK
|| class == C_FCN
|| ISFCN (type
) || ISTAG (class))
326 ADJUST_VAL (in
->x_sym
.x_fcnary
.x_fcn
.x_lnnoptr
, STUBSIZE
);
331 That's the function, which creates the stub. There are
332 different cases from where the stub is taken.
333 At first the environment variable $(GO32STUB) is checked and then
334 $(STUB) if it was not set.
335 If it exists and points to a valid stub the stub is taken from
336 that file. This file can be also a whole executable file, because
337 the stub is computed from the exe information at the start of that
340 If there was any error, the standard stub (compiled in this file)
345 create_go32_stub (abfd
)
348 /* Do it only once */
349 if (bfd_coff_go32stub (abfd
) == NULL
)
354 unsigned char header
[10];
356 unsigned long coff_start
, exe_start
;
358 /* Check at first the environment variable $(GO32STUB) */
359 stub
= getenv ("GO32STUB");
360 /* Now check the environment variable $(STUB) */
362 stub
= getenv ("STUB");
365 if (stat (stub
, &st
) != 0)
368 f
= open (stub
, O_RDONLY
| O_BINARY
);
370 f
= open (stub
, O_RDONLY
);
374 if (read (f
, &header
, sizeof (header
)) < 0)
379 if (_H (0) != 0x5a4d) /* it is not an exe file */
384 /* Compute the size of the stub (it is every thing up
385 to the beginning of the coff image) */
386 coff_start
= (long) _H (2) * 512L;
388 coff_start
+= (long) _H (1) - 512L;
390 /* Currently there is only a fixed stub size of 2048 bytes
392 if (coff_start
!= 2048)
397 exe_start
= _H (4) * 16;
398 if ((unsigned long) lseek (f
, exe_start
, SEEK_SET
) != exe_start
)
403 if (read (f
, &magic
, 8) != 8)
408 if (memcmp (magic
, "go32stub", 8) != 0)
413 /* Now we found a correct stub (hopefully) */
414 bfd_coff_go32stub (abfd
) = (PTR
) bfd_alloc (abfd
, coff_start
);
415 if (bfd_coff_go32stub (abfd
) == NULL
)
420 lseek (f
, 0L, SEEK_SET
);
421 if ((unsigned long) read (f
, bfd_coff_go32stub (abfd
), coff_start
)
424 bfd_release (abfd
, bfd_coff_go32stub (abfd
));
425 bfd_coff_go32stub (abfd
) = NULL
;
430 /* There was something wrong above, so use now the standard builtin
432 if (bfd_coff_go32stub (abfd
) == NULL
)
434 bfd_coff_go32stub (abfd
) = (PTR
) bfd_alloc (abfd
, STUBSIZE
);
435 if (bfd_coff_go32stub (abfd
) == NULL
)
440 memcpy (bfd_coff_go32stub (abfd
), stub_bytes
, STUBSIZE
);
444 /* If ibfd was a stubbed coff image, copy the stub from that bfd
449 go32_stubbed_coff_bfd_copy_private_bfd_data (ibfd
, obfd
)
453 /* check if both are the same targets */
454 if (ibfd
->xvec
!= obfd
->xvec
)
457 /* check if both have a valid stub */
458 if (bfd_coff_go32stub (ibfd
) == NULL
459 || bfd_coff_go32stub (obfd
) == NULL
)
462 /* Now copy the stub */
463 memcpy (bfd_coff_go32stub (obfd
), bfd_coff_go32stub (ibfd
), STUBSIZE
);