| 1 | /* BFD back-end for Intel 386 COFF files (go32 variant with a stub). |
| 2 | Copyright 1997, 1998 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 | |
| 38 | #define TARGET_SYM go32stubbedcoff_vec |
| 39 | #define TARGET_NAME "coff-go32-exe" |
| 40 | #define TARGET_UNDERSCORE '_' |
| 41 | #define COFF_GO32_EXE |
| 42 | |
| 43 | #include "bfd.h" |
| 44 | |
| 45 | /* At first the prototypes */ |
| 46 | |
| 47 | static void |
| 48 | adjust_filehdr_in_post PARAMS ((bfd * abfd, PTR src, PTR dst)); |
| 49 | static void |
| 50 | adjust_filehdr_out_pre PARAMS ((bfd * abfd, PTR in, PTR out)); |
| 51 | static void |
| 52 | adjust_filehdr_out_post PARAMS ((bfd * abfd, PTR in, PTR out)); |
| 53 | |
| 54 | static void |
| 55 | adjust_scnhdr_in_post PARAMS ((bfd * abfd, PTR ext, PTR in)); |
| 56 | static void |
| 57 | adjust_scnhdr_out_pre PARAMS ((bfd * abfd, PTR in, PTR out)); |
| 58 | static void |
| 59 | adjust_scnhdr_out_post PARAMS ((bfd * abfd, PTR in, PTR out)); |
| 60 | |
| 61 | static void |
| 62 | adjust_aux_in_post PARAMS ((bfd * abfd, PTR ext1, int type, int class, int indx, |
| 63 | int numaux, PTR in1)); |
| 64 | static void |
| 65 | adjust_aux_out_pre PARAMS ((bfd * abfd, PTR inp, int type, int class, int indx, |
| 66 | int numaux, PTR extp)); |
| 67 | static void |
| 68 | adjust_aux_out_post PARAMS ((bfd * abfd, PTR inp, int type, int class, int indx, |
| 69 | int numaux, PTR extp)); |
| 70 | |
| 71 | static void |
| 72 | create_go32_stub PARAMS ((bfd * abfd)); |
| 73 | |
| 74 | /* |
| 75 | All that ..._PRE and ...POST functions are called from the corresponding |
| 76 | coff_swap... functions. The ...PRE functions are called at the beginning |
| 77 | of the function and the ...POST functions at the end of the swap routines. |
| 78 | */ |
| 79 | |
| 80 | #define COFF_ADJUST_FILEHDR_IN_POST adjust_filehdr_in_post |
| 81 | #define COFF_ADJUST_FILEHDR_OUT_PRE adjust_filehdr_out_pre |
| 82 | #define COFF_ADJUST_FILEHDR_OUT_POST adjust_filehdr_out_post |
| 83 | |
| 84 | #define COFF_ADJUST_SCNHDR_IN_POST adjust_scnhdr_in_post |
| 85 | #define COFF_ADJUST_SCNHDR_OUT_PRE adjust_scnhdr_out_pre |
| 86 | #define COFF_ADJUST_SCNHDR_OUT_POST adjust_scnhdr_out_post |
| 87 | |
| 88 | #define COFF_ADJUST_AUX_IN_POST adjust_aux_in_post |
| 89 | #define COFF_ADJUST_AUX_OUT_PRE adjust_aux_out_pre |
| 90 | #define COFF_ADJUST_AUX_OUT_POST adjust_aux_out_post |
| 91 | |
| 92 | static boolean |
| 93 | go32_stubbed_coff_bfd_copy_private_bfd_data PARAMS ((bfd * ibfd, bfd * obfd)); |
| 94 | |
| 95 | #define coff_bfd_copy_private_bfd_data go32_stubbed_coff_bfd_copy_private_bfd_data |
| 96 | |
| 97 | #include "coff-i386.c" |
| 98 | |
| 99 | /* I hold in the usrdata the stub */ |
| 100 | #define bfd_coff_go32stub bfd_usrdata |
| 101 | |
| 102 | /* This macro is used, because I cannot assume the endianess of the |
| 103 | host system */ |
| 104 | #define _H(index) (bfd_h_get_16(abfd, (bfd_byte *)(header+index*2))) |
| 105 | |
| 106 | /* This function checks if the bfd is a stubbed coff image */ |
| 107 | static const bfd_target * |
| 108 | go32_stubbed_coff_object_p (abfd) |
| 109 | bfd *abfd; |
| 110 | { |
| 111 | unsigned char header[10]; |
| 112 | char magic[8]; |
| 113 | unsigned long coff_start, exe_start; |
| 114 | |
| 115 | if (bfd_read (&header, 1, sizeof (header), abfd) != sizeof (header)) |
| 116 | { |
| 117 | if (bfd_get_error () != bfd_error_system_call) |
| 118 | bfd_set_error (bfd_error_wrong_format); |
| 119 | return 0; |
| 120 | } |
| 121 | if (_H (0) != 0x5a4d) /* it is not an exe file. maybe a coff-image */ |
| 122 | { |
| 123 | if (bfd_get_error () != bfd_error_system_call) |
| 124 | bfd_set_error (bfd_error_wrong_format); |
| 125 | return 0; |
| 126 | } |
| 127 | coff_start = (long) _H (2) * 512L; |
| 128 | if (_H (1)) |
| 129 | coff_start += (long) _H (1) - 512L; |
| 130 | |
| 131 | /* We can handle only a stub with a length of STUBSIZE */ |
| 132 | if (coff_start != STUBSIZE) |
| 133 | { |
| 134 | bfd_set_error (bfd_error_wrong_format); |
| 135 | return 0; |
| 136 | } |
| 137 | exe_start = _H (4) * 16; |
| 138 | if (bfd_seek (abfd, exe_start, SEEK_SET) != 0) |
| 139 | return 0; |
| 140 | if (bfd_read (&magic, 1, 8, abfd) != 8) |
| 141 | { |
| 142 | if (bfd_get_error () != bfd_error_system_call) |
| 143 | bfd_set_error (bfd_error_wrong_format); |
| 144 | return 0; |
| 145 | } |
| 146 | if (memcmp (magic, "go32stub", 8) != 0) |
| 147 | { |
| 148 | bfd_set_error (bfd_error_wrong_format); |
| 149 | return 0; |
| 150 | } |
| 151 | if (bfd_seek (abfd, 0, SEEK_SET) != 0) |
| 152 | return 0; |
| 153 | |
| 154 | /* Call the normal COFF detection routine */ |
| 155 | return coff_object_p (abfd); |
| 156 | } |
| 157 | |
| 158 | /* These bytes are a 2048-byte DOS executable, which loads the COFF |
| 159 | image into memory and then runs it. It is called 'stub' */ |
| 160 | |
| 161 | static unsigned char stub_bytes[STUBSIZE] = |
| 162 | { |
| 163 | #include "go32stub.h" |
| 164 | }; |
| 165 | |
| 166 | /* |
| 167 | I have not commented each swap function below, because the |
| 168 | technique is in any function the same. For the ...in function, |
| 169 | all the pointers are adjusted by adding STUBSIZE and for the |
| 170 | ...out function, it is subtracted first and after calling the |
| 171 | standard swap function it is reset to the old value */ |
| 172 | |
| 173 | /* This macro is used for adjusting the filepointers, which |
| 174 | is done only, if the pointer is nonzero */ |
| 175 | |
| 176 | #define ADJUST_VAL(val,diff) \ |
| 177 | if (val != 0) val += diff |
| 178 | |
| 179 | static void |
| 180 | adjust_filehdr_in_post (abfd, src, dst) |
| 181 | bfd *abfd; |
| 182 | PTR src; |
| 183 | PTR dst; |
| 184 | { |
| 185 | FILHDR *filehdr_src = (FILHDR *) src; |
| 186 | struct internal_filehdr *filehdr_dst = (struct internal_filehdr *) dst; |
| 187 | |
| 188 | ADJUST_VAL (filehdr_dst->f_symptr, STUBSIZE); |
| 189 | |
| 190 | /* Save now the stub to be used later */ |
| 191 | bfd_coff_go32stub (abfd) = (PTR) bfd_alloc (abfd, STUBSIZE); |
| 192 | |
| 193 | /* Since this function returns no status, I do not set here |
| 194 | any bfd_error_... |
| 195 | That means, before the use of bfd_coff_go32stub (), this value |
| 196 | should be checked if it is != NULL */ |
| 197 | if (bfd_coff_go32stub (abfd) == NULL) |
| 198 | return; |
| 199 | memcpy (bfd_coff_go32stub (abfd), filehdr_src->stub, STUBSIZE); |
| 200 | } |
| 201 | |
| 202 | static void |
| 203 | adjust_filehdr_out_pre (abfd, in, out) |
| 204 | bfd *abfd; |
| 205 | PTR in; |
| 206 | PTR out; |
| 207 | { |
| 208 | struct internal_filehdr *filehdr_in = (struct internal_filehdr *) in; |
| 209 | FILHDR *filehdr_out = (FILHDR *) out; |
| 210 | |
| 211 | /* Generate the stub */ |
| 212 | create_go32_stub (abfd); |
| 213 | |
| 214 | /* Copy the stub to the file header */ |
| 215 | if (bfd_coff_go32stub (abfd) != NULL) |
| 216 | memcpy (filehdr_out->stub, bfd_coff_go32stub (abfd), STUBSIZE); |
| 217 | else |
| 218 | /* use the default */ |
| 219 | memcpy (filehdr_out->stub, stub_bytes, STUBSIZE); |
| 220 | |
| 221 | ADJUST_VAL (filehdr_in->f_symptr, -STUBSIZE); |
| 222 | } |
| 223 | |
| 224 | static void |
| 225 | adjust_filehdr_out_post (abfd, in, out) |
| 226 | bfd *abfd; |
| 227 | PTR in; |
| 228 | PTR out; |
| 229 | { |
| 230 | struct internal_filehdr *filehdr_in = (struct internal_filehdr *) in; |
| 231 | /* undo the above change */ |
| 232 | ADJUST_VAL (filehdr_in->f_symptr, STUBSIZE); |
| 233 | } |
| 234 | |
| 235 | static void |
| 236 | adjust_scnhdr_in_post (abfd, ext, in) |
| 237 | bfd *abfd; |
| 238 | PTR ext; |
| 239 | PTR in; |
| 240 | { |
| 241 | struct internal_scnhdr *scnhdr_int = (struct internal_scnhdr *) in; |
| 242 | |
| 243 | ADJUST_VAL (scnhdr_int->s_scnptr, STUBSIZE); |
| 244 | ADJUST_VAL (scnhdr_int->s_relptr, STUBSIZE); |
| 245 | ADJUST_VAL (scnhdr_int->s_lnnoptr, STUBSIZE); |
| 246 | } |
| 247 | |
| 248 | static void |
| 249 | adjust_scnhdr_out_pre (abfd, in, out) |
| 250 | bfd *abfd; |
| 251 | PTR in; |
| 252 | PTR out; |
| 253 | { |
| 254 | struct internal_scnhdr *scnhdr_int = (struct internal_scnhdr *) in; |
| 255 | |
| 256 | ADJUST_VAL (scnhdr_int->s_scnptr, -STUBSIZE); |
| 257 | ADJUST_VAL (scnhdr_int->s_relptr, -STUBSIZE); |
| 258 | ADJUST_VAL (scnhdr_int->s_lnnoptr, -STUBSIZE); |
| 259 | } |
| 260 | |
| 261 | static void |
| 262 | adjust_scnhdr_out_post (abfd, in, out) |
| 263 | bfd *abfd; |
| 264 | PTR in; |
| 265 | PTR out; |
| 266 | { |
| 267 | struct internal_scnhdr *scnhdr_int = (struct internal_scnhdr *) in; |
| 268 | |
| 269 | ADJUST_VAL (scnhdr_int->s_scnptr, STUBSIZE); |
| 270 | ADJUST_VAL (scnhdr_int->s_relptr, STUBSIZE); |
| 271 | ADJUST_VAL (scnhdr_int->s_lnnoptr, STUBSIZE); |
| 272 | } |
| 273 | |
| 274 | static void |
| 275 | adjust_aux_in_post (abfd, ext1, type, class, indx, numaux, in1) |
| 276 | bfd *abfd; |
| 277 | PTR ext1; |
| 278 | int type; |
| 279 | int class; |
| 280 | int indx; |
| 281 | int numaux; |
| 282 | PTR in1; |
| 283 | { |
| 284 | union internal_auxent *in = (union internal_auxent *) in1; |
| 285 | |
| 286 | if (class == C_BLOCK || class == C_FCN || ISFCN (type) || ISTAG (class)) |
| 287 | { |
| 288 | ADJUST_VAL (in->x_sym.x_fcnary.x_fcn.x_lnnoptr, STUBSIZE); |
| 289 | } |
| 290 | } |
| 291 | |
| 292 | static void |
| 293 | adjust_aux_out_pre (abfd, inp, type, class, indx, numaux, extp) |
| 294 | bfd *abfd; |
| 295 | PTR inp; |
| 296 | int type; |
| 297 | int class; |
| 298 | int indx; |
| 299 | int numaux; |
| 300 | PTR extp; |
| 301 | { |
| 302 | union internal_auxent *in = (union internal_auxent *) inp; |
| 303 | |
| 304 | if (class == C_BLOCK || class == C_FCN || ISFCN (type) || ISTAG (class)) |
| 305 | { |
| 306 | ADJUST_VAL (in->x_sym.x_fcnary.x_fcn.x_lnnoptr, -STUBSIZE); |
| 307 | } |
| 308 | } |
| 309 | |
| 310 | static void |
| 311 | adjust_aux_out_post (abfd, inp, type, class, indx, numaux, extp) |
| 312 | bfd *abfd; |
| 313 | PTR inp; |
| 314 | int type; |
| 315 | int class; |
| 316 | int indx; |
| 317 | int numaux; |
| 318 | PTR extp; |
| 319 | { |
| 320 | union internal_auxent *in = (union internal_auxent *) inp; |
| 321 | |
| 322 | if (class == C_BLOCK || class == C_FCN || ISFCN (type) || ISTAG (class)) |
| 323 | { |
| 324 | ADJUST_VAL (in->x_sym.x_fcnary.x_fcn.x_lnnoptr, STUBSIZE); |
| 325 | } |
| 326 | } |
| 327 | |
| 328 | /* |
| 329 | That's the function, which creates the stub. There are |
| 330 | different cases from where the stub is taken. |
| 331 | At first the environment variable $(GO32STUB) is checked and then |
| 332 | $(STUB) if it was not set. |
| 333 | If it exists and points to a valid stub the stub is taken from |
| 334 | that file. This file can be also a whole executable file, because |
| 335 | the stub is computed from the exe information at the start of that |
| 336 | file. |
| 337 | |
| 338 | If there was any error, the standard stub (compiled in this file) |
| 339 | is taken. |
| 340 | */ |
| 341 | |
| 342 | static void |
| 343 | create_go32_stub (abfd) |
| 344 | bfd *abfd; |
| 345 | { |
| 346 | /* Do it only once */ |
| 347 | if (bfd_coff_go32stub (abfd) == NULL) |
| 348 | { |
| 349 | char *stub; |
| 350 | struct stat st; |
| 351 | int f; |
| 352 | unsigned char header[10]; |
| 353 | char magic[8]; |
| 354 | unsigned long coff_start, exe_start; |
| 355 | |
| 356 | /* Check at first the environment variable $(GO32STUB) */ |
| 357 | stub = getenv ("GO32STUB"); |
| 358 | /* Now check the environment variable $(STUB) */ |
| 359 | if (stub == NULL) |
| 360 | stub = getenv ("STUB"); |
| 361 | if (stub == NULL) |
| 362 | goto stub_end; |
| 363 | if (stat (stub, &st) != 0) |
| 364 | goto stub_end; |
| 365 | #ifdef O_BINARY |
| 366 | f = open (stub, O_RDONLY | O_BINARY); |
| 367 | #else |
| 368 | f = open (stub, O_RDONLY); |
| 369 | #endif |
| 370 | if (f < 0) |
| 371 | goto stub_end; |
| 372 | if (read (f, &header, sizeof (header)) < 0) |
| 373 | { |
| 374 | close (f); |
| 375 | goto stub_end; |
| 376 | } |
| 377 | if (_H (0) != 0x5a4d) /* it is not an exe file */ |
| 378 | { |
| 379 | close (f); |
| 380 | goto stub_end; |
| 381 | } |
| 382 | /* Compute the size of the stub (it is every thing up |
| 383 | to the beginning of the coff image) */ |
| 384 | coff_start = (long) _H (2) * 512L; |
| 385 | if (_H (1)) |
| 386 | coff_start += (long) _H (1) - 512L; |
| 387 | |
| 388 | /* Currently there is only a fixed stub size of 2048 bytes |
| 389 | supported */ |
| 390 | if (coff_start != 2048) |
| 391 | { |
| 392 | close (f); |
| 393 | goto stub_end; |
| 394 | } |
| 395 | exe_start = _H (4) * 16; |
| 396 | if ((unsigned long) lseek (f, exe_start, SEEK_SET) != exe_start) |
| 397 | { |
| 398 | close (f); |
| 399 | goto stub_end; |
| 400 | } |
| 401 | if (read (f, &magic, 8) != 8) |
| 402 | { |
| 403 | close (f); |
| 404 | goto stub_end; |
| 405 | } |
| 406 | if (memcmp (magic, "go32stub", 8) != 0) |
| 407 | { |
| 408 | close (f); |
| 409 | goto stub_end; |
| 410 | } |
| 411 | /* Now we found a correct stub (hopefully) */ |
| 412 | bfd_coff_go32stub (abfd) = (PTR) bfd_alloc (abfd, coff_start); |
| 413 | if (bfd_coff_go32stub (abfd) == NULL) |
| 414 | { |
| 415 | close (f); |
| 416 | return; |
| 417 | } |
| 418 | lseek (f, 0L, SEEK_SET); |
| 419 | if ((unsigned long) read (f, bfd_coff_go32stub (abfd), coff_start) |
| 420 | != coff_start) |
| 421 | { |
| 422 | bfd_release (abfd, bfd_coff_go32stub (abfd)); |
| 423 | bfd_coff_go32stub (abfd) = NULL; |
| 424 | } |
| 425 | close (f); |
| 426 | } |
| 427 | stub_end: |
| 428 | /* There was something wrong above, so use now the standard builtin |
| 429 | stub */ |
| 430 | if (bfd_coff_go32stub (abfd) == NULL) |
| 431 | { |
| 432 | bfd_coff_go32stub (abfd) = (PTR) bfd_alloc (abfd, STUBSIZE); |
| 433 | if (bfd_coff_go32stub (abfd) == NULL) |
| 434 | { |
| 435 | return; |
| 436 | } |
| 437 | |
| 438 | memcpy (bfd_coff_go32stub (abfd), stub_bytes, STUBSIZE); |
| 439 | } |
| 440 | } |
| 441 | |
| 442 | /* If ibfd was a stubbed coff image, copy the stub from that bfd |
| 443 | to the new obfd. |
| 444 | */ |
| 445 | |
| 446 | static boolean |
| 447 | go32_stubbed_coff_bfd_copy_private_bfd_data (ibfd, obfd) |
| 448 | bfd *ibfd; |
| 449 | bfd *obfd; |
| 450 | { |
| 451 | /* check if both are the same targets */ |
| 452 | if (ibfd->xvec != obfd->xvec) |
| 453 | return true; |
| 454 | |
| 455 | /* check if both have a valid stub */ |
| 456 | if (bfd_coff_go32stub (ibfd) == NULL |
| 457 | || bfd_coff_go32stub (obfd) == NULL) |
| 458 | return true; |
| 459 | |
| 460 | /* Now copy the stub */ |
| 461 | memcpy (bfd_coff_go32stub (obfd), bfd_coff_go32stub (ibfd), STUBSIZE); |
| 462 | |
| 463 | return true; |
| 464 | } |