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 2011, 2012 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
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 '_'
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 }
60 /* All that ..._PRE and ...POST functions are called from the corresponding
61 coff_swap... functions. The ...PRE functions are called at the beginning
62 of the function and the ...POST functions at the end of the swap routines. */
65 adjust_filehdr_in_post (bfd
*, void *, void *);
67 adjust_filehdr_out_pre (bfd
*, void *, void *);
69 adjust_filehdr_out_post (bfd
*, void *, void *);
71 adjust_scnhdr_in_post (bfd
*, void *, void *);
73 adjust_scnhdr_out_pre (bfd
*, void *, void *);
75 adjust_scnhdr_out_post (bfd
*, void *, void *);
77 adjust_aux_in_post (bfd
*, void *, int, int, int, int, void *);
79 adjust_aux_out_pre (bfd
*, void *, int, int, int, int, void *);
81 adjust_aux_out_post (bfd
*, void *, int, int, int, int, void *);
83 create_go32_stub (bfd
*);
85 #define COFF_ADJUST_FILEHDR_IN_POST adjust_filehdr_in_post
86 #define COFF_ADJUST_FILEHDR_OUT_PRE adjust_filehdr_out_pre
87 #define COFF_ADJUST_FILEHDR_OUT_POST adjust_filehdr_out_post
89 #define COFF_ADJUST_SCNHDR_IN_POST adjust_scnhdr_in_post
90 #define COFF_ADJUST_SCNHDR_OUT_PRE adjust_scnhdr_out_pre
91 #define COFF_ADJUST_SCNHDR_OUT_POST adjust_scnhdr_out_post
93 #define COFF_ADJUST_AUX_IN_POST adjust_aux_in_post
94 #define COFF_ADJUST_AUX_OUT_PRE adjust_aux_out_pre
95 #define COFF_ADJUST_AUX_OUT_POST adjust_aux_out_post
97 static const bfd_target
*go32_check_format (bfd
*);
99 #define COFF_CHECK_FORMAT go32_check_format
102 go32_stubbed_coff_bfd_copy_private_bfd_data (bfd
*, bfd
*);
104 #define coff_bfd_copy_private_bfd_data go32_stubbed_coff_bfd_copy_private_bfd_data
106 #include "coff-i386.c"
108 /* This macro is used, because I cannot assume the endianness of the
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
[GO32_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 GO32_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
134 adjust_filehdr_in_post (bfd
* abfd ATTRIBUTE_UNUSED
,
138 FILHDR
*filehdr_src
= (FILHDR
*) src
;
139 struct internal_filehdr
*filehdr_dst
= (struct internal_filehdr
*) dst
;
141 ADJUST_VAL (filehdr_dst
->f_symptr
, GO32_STUBSIZE
);
143 /* Save now the stub to be used later. Put the stub data to FILEHDR_DST
144 first as coff_data (abfd) still does not exist. It may not even be ever
145 created as we are just checking the file format of ABFD. */
146 memcpy (filehdr_dst
->go32stub
, filehdr_src
->stub
, GO32_STUBSIZE
);
147 filehdr_dst
->f_flags
|= F_GO32STUB
;
151 adjust_filehdr_out_pre (bfd
* abfd
, void * in
, void * out
)
153 struct internal_filehdr
*filehdr_in
= (struct internal_filehdr
*) in
;
154 FILHDR
*filehdr_out
= (FILHDR
*) out
;
156 /* Generate the stub. */
157 create_go32_stub (abfd
);
159 /* Copy the stub to the file header. */
160 if (coff_data (abfd
)->go32stub
!= NULL
)
161 memcpy (filehdr_out
->stub
, coff_data (abfd
)->go32stub
, GO32_STUBSIZE
);
163 /* Use the default. */
164 memcpy (filehdr_out
->stub
, stub_bytes
, GO32_STUBSIZE
);
166 ADJUST_VAL (filehdr_in
->f_symptr
, -GO32_STUBSIZE
);
170 adjust_filehdr_out_post (bfd
* abfd ATTRIBUTE_UNUSED
,
172 void * out ATTRIBUTE_UNUSED
)
174 struct internal_filehdr
*filehdr_in
= (struct internal_filehdr
*) in
;
175 /* Undo the above change. */
176 ADJUST_VAL (filehdr_in
->f_symptr
, GO32_STUBSIZE
);
180 adjust_scnhdr_in_post (bfd
* abfd ATTRIBUTE_UNUSED
,
181 void * ext ATTRIBUTE_UNUSED
,
184 struct internal_scnhdr
*scnhdr_int
= (struct internal_scnhdr
*) in
;
186 ADJUST_VAL (scnhdr_int
->s_scnptr
, GO32_STUBSIZE
);
187 ADJUST_VAL (scnhdr_int
->s_relptr
, GO32_STUBSIZE
);
188 ADJUST_VAL (scnhdr_int
->s_lnnoptr
, GO32_STUBSIZE
);
192 adjust_scnhdr_out_pre (bfd
* abfd ATTRIBUTE_UNUSED
,
194 void * out ATTRIBUTE_UNUSED
)
196 struct internal_scnhdr
*scnhdr_int
= (struct internal_scnhdr
*) in
;
198 ADJUST_VAL (scnhdr_int
->s_scnptr
, -GO32_STUBSIZE
);
199 ADJUST_VAL (scnhdr_int
->s_relptr
, -GO32_STUBSIZE
);
200 ADJUST_VAL (scnhdr_int
->s_lnnoptr
, -GO32_STUBSIZE
);
204 adjust_scnhdr_out_post (bfd
* abfd ATTRIBUTE_UNUSED
,
206 void * out ATTRIBUTE_UNUSED
)
208 struct internal_scnhdr
*scnhdr_int
= (struct internal_scnhdr
*) in
;
210 ADJUST_VAL (scnhdr_int
->s_scnptr
, GO32_STUBSIZE
);
211 ADJUST_VAL (scnhdr_int
->s_relptr
, GO32_STUBSIZE
);
212 ADJUST_VAL (scnhdr_int
->s_lnnoptr
, GO32_STUBSIZE
);
216 adjust_aux_in_post (bfd
* abfd ATTRIBUTE_UNUSED
,
217 void * ext1 ATTRIBUTE_UNUSED
,
220 int indx ATTRIBUTE_UNUSED
,
221 int numaux ATTRIBUTE_UNUSED
,
224 union internal_auxent
*in
= (union internal_auxent
*) in1
;
226 if (in_class
== C_BLOCK
|| in_class
== C_FCN
|| ISFCN (type
)
229 ADJUST_VAL (in
->x_sym
.x_fcnary
.x_fcn
.x_lnnoptr
, GO32_STUBSIZE
);
234 adjust_aux_out_pre (bfd
*abfd ATTRIBUTE_UNUSED
,
238 int indx ATTRIBUTE_UNUSED
,
239 int numaux ATTRIBUTE_UNUSED
,
240 void * extp ATTRIBUTE_UNUSED
)
242 union internal_auxent
*in
= (union internal_auxent
*) inp
;
244 if (in_class
== C_BLOCK
|| in_class
== C_FCN
|| ISFCN (type
)
247 ADJUST_VAL (in
->x_sym
.x_fcnary
.x_fcn
.x_lnnoptr
, -GO32_STUBSIZE
);
252 adjust_aux_out_post (bfd
*abfd ATTRIBUTE_UNUSED
,
256 int indx ATTRIBUTE_UNUSED
,
257 int numaux ATTRIBUTE_UNUSED
,
258 void * extp ATTRIBUTE_UNUSED
)
260 union internal_auxent
*in
= (union internal_auxent
*) inp
;
262 if (in_class
== C_BLOCK
|| in_class
== C_FCN
|| ISFCN (type
)
265 ADJUST_VAL (in
->x_sym
.x_fcnary
.x_fcn
.x_lnnoptr
, GO32_STUBSIZE
);
269 /* That's the function, which creates the stub. There are
270 different cases from where the stub is taken.
271 At first the environment variable $(GO32STUB) is checked and then
272 $(STUB) if it was not set.
273 If it exists and points to a valid stub the stub is taken from
274 that file. This file can be also a whole executable file, because
275 the stub is computed from the exe information at the start of that
278 If there was any error, the standard stub (compiled in this file)
282 create_go32_stub (bfd
*abfd
)
284 /* Do it only once. */
285 if (coff_data (abfd
)->go32stub
== NULL
)
290 unsigned char header
[10];
292 unsigned long coff_start
;
295 /* Check at first the environment variable $(GO32STUB). */
296 stub
= getenv ("GO32STUB");
297 /* Now check the environment variable $(STUB). */
299 stub
= getenv ("STUB");
302 if (stat (stub
, &st
) != 0)
305 f
= open (stub
, O_RDONLY
| O_BINARY
);
307 f
= open (stub
, O_RDONLY
);
311 if (read (f
, &header
, sizeof (header
)) < 0)
316 if (_H (0) != 0x5a4d) /* It is not an exe file. */
321 /* Compute the size of the stub (it is every thing up
322 to the beginning of the coff image). */
323 coff_start
= (long) _H (2) * 512L;
325 coff_start
+= (long) _H (1) - 512L;
327 /* Currently there is only a fixed stub size of 2048 bytes
329 if (coff_start
!= 2048)
334 exe_start
= _H (4) * 16;
335 if ((long) lseek (f
, exe_start
, SEEK_SET
) != exe_start
)
340 if (read (f
, &magic
, 8) != 8)
345 if (! CONST_STRNEQ (magic
, "go32stub"))
350 /* Now we found a correct stub (hopefully). */
351 coff_data (abfd
)->go32stub
= bfd_alloc (abfd
, (bfd_size_type
) coff_start
);
352 if (coff_data (abfd
)->go32stub
== NULL
)
357 lseek (f
, 0L, SEEK_SET
);
358 if ((unsigned long) read (f
, coff_data (abfd
)->go32stub
, coff_start
)
361 bfd_release (abfd
, coff_data (abfd
)->go32stub
);
362 coff_data (abfd
)->go32stub
= NULL
;
367 /* There was something wrong above, so use now the standard builtin
369 if (coff_data (abfd
)->go32stub
== NULL
)
371 coff_data (abfd
)->go32stub
372 = bfd_alloc (abfd
, (bfd_size_type
) GO32_STUBSIZE
);
373 if (coff_data (abfd
)->go32stub
== NULL
)
375 memcpy (coff_data (abfd
)->go32stub
, stub_bytes
, GO32_STUBSIZE
);
379 /* If ibfd was a stubbed coff image, copy the stub from that bfd
383 go32_stubbed_coff_bfd_copy_private_bfd_data (bfd
*ibfd
, bfd
*obfd
)
385 /* Check if both are the same targets. */
386 if (ibfd
->xvec
!= obfd
->xvec
)
389 /* Check if we have a source stub. */
390 if (coff_data (ibfd
)->go32stub
== NULL
)
393 /* As adjust_filehdr_out_pre may get called only after this function,
394 optionally allocate the output stub. */
395 if (coff_data (obfd
)->go32stub
== NULL
)
396 coff_data (obfd
)->go32stub
= bfd_alloc (obfd
,
397 (bfd_size_type
) GO32_STUBSIZE
);
399 /* Now copy the stub. */
400 if (coff_data (obfd
)->go32stub
!= NULL
)
401 memcpy (coff_data (obfd
)->go32stub
, coff_data (ibfd
)->go32stub
,
407 /* coff_object_p only checks 2 bytes F_MAGIC at GO32_STUBSIZE inside the file
408 which is too fragile. */
410 static const bfd_target
*
411 go32_check_format (bfd
*abfd
)
415 if (bfd_bread (mz
, 2, abfd
) != 2 || mz
[0] != 'M' || mz
[1] != 'Z')
417 bfd_set_error (bfd_error_wrong_format
);
421 if (bfd_seek (abfd
, 0, SEEK_SET
) != 0)
424 return coff_object_p (abfd
);
This page took 0.043525 seconds and 4 git commands to generate.