1 /* 2 * Copyright (c) 1995 3 * Ted Lemon (hereinafter referred to as the author) 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. The name of the author may not be used to endorse or promote products 14 * derived from this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 /* elf2ecoff.c 30 31 This program converts an elf executable to an ECOFF executable. 32 No symbol table is retained. This is useful primarily in building 33 net-bootable kernels for machines (e.g., DECstation and Alpha) which 34 only support the ECOFF object file format. */ 35 36 #include <stdio.h> 37 #include <string.h> 38 #include <errno.h> 39 #include <sys/types.h> 40 #include <fcntl.h> 41 #include <unistd.h> 42 #include <elf.h> 43 #include <limits.h> 44 #include <netinet/in.h> 45 #include <stdlib.h> 46 47 #include "ecoff.h" 48 49 /* 50 * Some extra ELF definitions 51 */ 52 #define PT_MIPS_REGINFO 0x70000000 /* Register usage information */ 53 54 /* -------------------------------------------------------------------- */ 55 56 struct sect { 57 unsigned long vaddr; 58 unsigned long len; 59 }; 60 61 int *symTypeTable; 62 int must_convert_endian; 63 int format_bigendian; 64 65 static void copy(int out, int in, off_t offset, off_t size) 66 { 67 char ibuf[4096]; 68 int remaining, cur, count; 69 70 /* Go to the start of the ELF symbol table... */ 71 if (lseek(in, offset, SEEK_SET) < 0) { 72 perror("copy: lseek"); 73 exit(1); 74 } 75 76 remaining = size; 77 while (remaining) { 78 cur = remaining; 79 if (cur > sizeof ibuf) 80 cur = sizeof ibuf; 81 remaining -= cur; 82 if ((count = read(in, ibuf, cur)) != cur) { 83 fprintf(stderr, "copy: read: %s\n", 84 count ? strerror(errno) : 85 "premature end of file"); 86 exit(1); 87 } 88 if ((count = write(out, ibuf, cur)) != cur) { 89 perror("copy: write"); 90 exit(1); 91 } 92 } 93 } 94 95 /* 96 * Combine two segments, which must be contiguous. If pad is true, it's 97 * okay for there to be padding between. 98 */ 99 static void combine(struct sect *base, struct sect *new, int pad) 100 { 101 if (!base->len) 102 *base = *new; 103 else if (new->len) { 104 if (base->vaddr + base->len != new->vaddr) { 105 if (pad) 106 base->len = new->vaddr - base->vaddr; 107 else { 108 fprintf(stderr, 109 "Non-contiguous data can't be converted.\n"); 110 exit(1); 111 } 112 } 113 base->len += new->len; 114 } 115 } 116 117 static int phcmp(const void *v1, const void *v2) 118 { 119 const Elf32_Phdr *h1 = v1; 120 const Elf32_Phdr *h2 = v2; 121 122 if (h1->p_vaddr > h2->p_vaddr) 123 return 1; 124 else if (h1->p_vaddr < h2->p_vaddr) 125 return -1; 126 else 127 return 0; 128 } 129 130 static char *saveRead(int file, off_t offset, off_t len, char *name) 131 { 132 char *tmp; 133 int count; 134 off_t off; 135 if ((off = lseek(file, offset, SEEK_SET)) < 0) { 136 fprintf(stderr, "%s: fseek: %s\n", name, strerror(errno)); 137 exit(1); 138 } 139 if (!(tmp = (char *) malloc(len))) { 140 fprintf(stderr, "%s: Can't allocate %ld bytes.\n", name, 141 len); 142 exit(1); 143 } 144 count = read(file, tmp, len); 145 if (count != len) { 146 fprintf(stderr, "%s: read: %s.\n", 147 name, 148 count ? strerror(errno) : "End of file reached"); 149 exit(1); 150 } 151 return tmp; 152 } 153 154 #define swab16(x) \ 155 ((unsigned short)( \ 156 (((unsigned short)(x) & (unsigned short)0x00ffU) << 8) | \ 157 (((unsigned short)(x) & (unsigned short)0xff00U) >> 8) )) 158 159 #define swab32(x) \ 160 ((unsigned int)( \ 161 (((unsigned int)(x) & (unsigned int)0x000000ffUL) << 24) | \ 162 (((unsigned int)(x) & (unsigned int)0x0000ff00UL) << 8) | \ 163 (((unsigned int)(x) & (unsigned int)0x00ff0000UL) >> 8) | \ 164 (((unsigned int)(x) & (unsigned int)0xff000000UL) >> 24) )) 165 166 static void convert_elf_hdr(Elf32_Ehdr * e) 167 { 168 e->e_type = swab16(e->e_type); 169 e->e_machine = swab16(e->e_machine); 170 e->e_version = swab32(e->e_version); 171 e->e_entry = swab32(e->e_entry); 172 e->e_phoff = swab32(e->e_phoff); 173 e->e_shoff = swab32(e->e_shoff); 174 e->e_flags = swab32(e->e_flags); 175 e->e_ehsize = swab16(e->e_ehsize); 176 e->e_phentsize = swab16(e->e_phentsize); 177 e->e_phnum = swab16(e->e_phnum); 178 e->e_shentsize = swab16(e->e_shentsize); 179 e->e_shnum = swab16(e->e_shnum); 180 e->e_shstrndx = swab16(e->e_shstrndx); 181 } 182 183 static void convert_elf_phdrs(Elf32_Phdr * p, int num) 184 { 185 int i; 186 187 for (i = 0; i < num; i++, p++) { 188 p->p_type = swab32(p->p_type); 189 p->p_offset = swab32(p->p_offset); 190 p->p_vaddr = swab32(p->p_vaddr); 191 p->p_paddr = swab32(p->p_paddr); 192 p->p_filesz = swab32(p->p_filesz); 193 p->p_memsz = swab32(p->p_memsz); 194 p->p_flags = swab32(p->p_flags); 195 p->p_align = swab32(p->p_align); 196 } 197 198 } 199 200 static void convert_elf_shdrs(Elf32_Shdr * s, int num) 201 { 202 int i; 203 204 for (i = 0; i < num; i++, s++) { 205 s->sh_name = swab32(s->sh_name); 206 s->sh_type = swab32(s->sh_type); 207 s->sh_flags = swab32(s->sh_flags); 208 s->sh_addr = swab32(s->sh_addr); 209 s->sh_offset = swab32(s->sh_offset); 210 s->sh_size = swab32(s->sh_size); 211 s->sh_link = swab32(s->sh_link); 212 s->sh_info = swab32(s->sh_info); 213 s->sh_addralign = swab32(s->sh_addralign); 214 s->sh_entsize = swab32(s->sh_entsize); 215 } 216 } 217 218 static void convert_ecoff_filehdr(struct filehdr *f) 219 { 220 f->f_magic = swab16(f->f_magic); 221 f->f_nscns = swab16(f->f_nscns); 222 f->f_timdat = swab32(f->f_timdat); 223 f->f_symptr = swab32(f->f_symptr); 224 f->f_nsyms = swab32(f->f_nsyms); 225 f->f_opthdr = swab16(f->f_opthdr); 226 f->f_flags = swab16(f->f_flags); 227 } 228 229 static void convert_ecoff_aouthdr(struct aouthdr *a) 230 { 231 a->magic = swab16(a->magic); 232 a->vstamp = swab16(a->vstamp); 233 a->tsize = swab32(a->tsize); 234 a->dsize = swab32(a->dsize); 235 a->bsize = swab32(a->bsize); 236 a->entry = swab32(a->entry); 237 a->text_start = swab32(a->text_start); 238 a->data_start = swab32(a->data_start); 239 a->bss_start = swab32(a->bss_start); 240 a->gprmask = swab32(a->gprmask); 241 a->cprmask[0] = swab32(a->cprmask[0]); 242 a->cprmask[1] = swab32(a->cprmask[1]); 243 a->cprmask[2] = swab32(a->cprmask[2]); 244 a->cprmask[3] = swab32(a->cprmask[3]); 245 a->gp_value = swab32(a->gp_value); 246 } 247 248 static void convert_ecoff_esecs(struct scnhdr *s, int num) 249 { 250 int i; 251 252 for (i = 0; i < num; i++, s++) { 253 s->s_paddr = swab32(s->s_paddr); 254 s->s_vaddr = swab32(s->s_vaddr); 255 s->s_size = swab32(s->s_size); 256 s->s_scnptr = swab32(s->s_scnptr); 257 s->s_relptr = swab32(s->s_relptr); 258 s->s_lnnoptr = swab32(s->s_lnnoptr); 259 s->s_nreloc = swab16(s->s_nreloc); 260 s->s_nlnno = swab16(s->s_nlnno); 261 s->s_flags = swab32(s->s_flags); 262 } 263 } 264 265 int main(int argc, char *argv[]) 266 { 267 Elf32_Ehdr ex; 268 Elf32_Phdr *ph; 269 Elf32_Shdr *sh; 270 char *shstrtab; 271 int i, pad; 272 struct sect text, data, bss; 273 struct filehdr efh; 274 struct aouthdr eah; 275 struct scnhdr esecs[6]; 276 int infile, outfile; 277 unsigned long cur_vma = ULONG_MAX; 278 int addflag = 0; 279 int nosecs; 280 281 text.len = data.len = bss.len = 0; 282 text.vaddr = data.vaddr = bss.vaddr = 0; 283 284 /* Check args... */ 285 if (argc < 3 || argc > 4) { 286 usage: 287 fprintf(stderr, 288 "usage: elf2ecoff <elf executable> <ecoff executable> [-a]\n"); 289 exit(1); 290 } 291 if (argc == 4) { 292 if (strcmp(argv[3], "-a")) 293 goto usage; 294 addflag = 1; 295 } 296 297 /* Try the input file... */ 298 if ((infile = open(argv[1], O_RDONLY)) < 0) { 299 fprintf(stderr, "Can't open %s for read: %s\n", 300 argv[1], strerror(errno)); 301 exit(1); 302 } 303 304 /* Read the header, which is at the beginning of the file... */ 305 i = read(infile, &ex, sizeof ex); 306 if (i != sizeof ex) { 307 fprintf(stderr, "ex: %s: %s.\n", 308 argv[1], 309 i ? strerror(errno) : "End of file reached"); 310 exit(1); 311 } 312 313 if (ex.e_ident[EI_DATA] == ELFDATA2MSB) 314 format_bigendian = 1; 315 316 if (ntohs(0xaa55) == 0xaa55) { 317 if (!format_bigendian) 318 must_convert_endian = 1; 319 } else { 320 if (format_bigendian) 321 must_convert_endian = 1; 322 } 323 if (must_convert_endian) 324 convert_elf_hdr(&ex); 325 326 /* Read the program headers... */ 327 ph = (Elf32_Phdr *) saveRead(infile, ex.e_phoff, 328 ex.e_phnum * sizeof(Elf32_Phdr), 329 "ph"); 330 if (must_convert_endian) 331 convert_elf_phdrs(ph, ex.e_phnum); 332 /* Read the section headers... */ 333 sh = (Elf32_Shdr *) saveRead(infile, ex.e_shoff, 334 ex.e_shnum * sizeof(Elf32_Shdr), 335 "sh"); 336 if (must_convert_endian) 337 convert_elf_shdrs(sh, ex.e_shnum); 338 /* Read in the section string table. */ 339 shstrtab = saveRead(infile, sh[ex.e_shstrndx].sh_offset, 340 sh[ex.e_shstrndx].sh_size, "shstrtab"); 341 342 /* Figure out if we can cram the program header into an ECOFF 343 header... Basically, we can't handle anything but loadable 344 segments, but we can ignore some kinds of segments. We can't 345 handle holes in the address space. Segments may be out of order, 346 so we sort them first. */ 347 348 qsort(ph, ex.e_phnum, sizeof(Elf32_Phdr), phcmp); 349 350 for (i = 0; i < ex.e_phnum; i++) { 351 /* Section types we can ignore... */ 352 if (ph[i].p_type == PT_NULL || ph[i].p_type == PT_NOTE || 353 ph[i].p_type == PT_PHDR 354 || ph[i].p_type == PT_MIPS_REGINFO) 355 continue; 356 /* Section types we can't handle... */ 357 else if (ph[i].p_type != PT_LOAD) { 358 fprintf(stderr, 359 "Program header %d type %d can't be converted.\n", 360 ex.e_phnum, ph[i].p_type); 361 exit(1); 362 } 363 /* Writable (data) segment? */ 364 if (ph[i].p_flags & PF_W) { 365 struct sect ndata, nbss; 366 367 ndata.vaddr = ph[i].p_vaddr; 368 ndata.len = ph[i].p_filesz; 369 nbss.vaddr = ph[i].p_vaddr + ph[i].p_filesz; 370 nbss.len = ph[i].p_memsz - ph[i].p_filesz; 371 372 combine(&data, &ndata, 0); 373 combine(&bss, &nbss, 1); 374 } else { 375 struct sect ntxt; 376 377 ntxt.vaddr = ph[i].p_vaddr; 378 ntxt.len = ph[i].p_filesz; 379 380 combine(&text, &ntxt, 0); 381 } 382 /* Remember the lowest segment start address. */ 383 if (ph[i].p_vaddr < cur_vma) 384 cur_vma = ph[i].p_vaddr; 385 } 386 387 /* Sections must be in order to be converted... */ 388 if (text.vaddr > data.vaddr || data.vaddr > bss.vaddr || 389 text.vaddr + text.len > data.vaddr 390 || data.vaddr + data.len > bss.vaddr) { 391 fprintf(stderr, 392 "Sections ordering prevents a.out conversion.\n"); 393 exit(1); 394 } 395 396 /* If there's a data section but no text section, then the loader 397 combined everything into one section. That needs to be the 398 text section, so just make the data section zero length following 399 text. */ 400 if (data.len && !text.len) { 401 text = data; 402 data.vaddr = text.vaddr + text.len; 403 data.len = 0; 404 } 405 406 /* If there is a gap between text and data, we'll fill it when we copy 407 the data, so update the length of the text segment as represented in 408 a.out to reflect that, since a.out doesn't allow gaps in the program 409 address space. */ 410 if (text.vaddr + text.len < data.vaddr) 411 text.len = data.vaddr - text.vaddr; 412 413 /* We now have enough information to cons up an a.out header... */ 414 eah.magic = OMAGIC; 415 eah.vstamp = 200; 416 eah.tsize = text.len; 417 eah.dsize = data.len; 418 eah.bsize = bss.len; 419 eah.entry = ex.e_entry; 420 eah.text_start = text.vaddr; 421 eah.data_start = data.vaddr; 422 eah.bss_start = bss.vaddr; 423 eah.gprmask = 0xf3fffffe; 424 memset(&eah.cprmask, '\0', sizeof eah.cprmask); 425 eah.gp_value = 0; /* unused. */ 426 427 if (format_bigendian) 428 efh.f_magic = MIPSEBMAGIC; 429 else 430 efh.f_magic = MIPSELMAGIC; 431 if (addflag) 432 nosecs = 6; 433 else 434 nosecs = 3; 435 efh.f_nscns = nosecs; 436 efh.f_timdat = 0; /* bogus */ 437 efh.f_symptr = 0; 438 efh.f_nsyms = 0; 439 efh.f_opthdr = sizeof eah; 440 efh.f_flags = 0x100f; /* Stripped, not sharable. */ 441 442 memset(esecs, 0, sizeof esecs); 443 strcpy(esecs[0].s_name, ".text"); 444 strcpy(esecs[1].s_name, ".data"); 445 strcpy(esecs[2].s_name, ".bss"); 446 if (addflag) { 447 strcpy(esecs[3].s_name, ".rdata"); 448 strcpy(esecs[4].s_name, ".sdata"); 449 strcpy(esecs[5].s_name, ".sbss"); 450 } 451 esecs[0].s_paddr = esecs[0].s_vaddr = eah.text_start; 452 esecs[1].s_paddr = esecs[1].s_vaddr = eah.data_start; 453 esecs[2].s_paddr = esecs[2].s_vaddr = eah.bss_start; 454 if (addflag) { 455 esecs[3].s_paddr = esecs[3].s_vaddr = 0; 456 esecs[4].s_paddr = esecs[4].s_vaddr = 0; 457 esecs[5].s_paddr = esecs[5].s_vaddr = 0; 458 } 459 esecs[0].s_size = eah.tsize; 460 esecs[1].s_size = eah.dsize; 461 esecs[2].s_size = eah.bsize; 462 if (addflag) { 463 esecs[3].s_size = 0; 464 esecs[4].s_size = 0; 465 esecs[5].s_size = 0; 466 } 467 esecs[0].s_scnptr = N_TXTOFF(efh, eah); 468 esecs[1].s_scnptr = N_DATOFF(efh, eah); 469 #define ECOFF_SEGMENT_ALIGNMENT(a) 0x10 470 #define ECOFF_ROUND(s, a) (((s)+(a)-1)&~((a)-1)) 471 esecs[2].s_scnptr = esecs[1].s_scnptr + 472 ECOFF_ROUND(esecs[1].s_size, ECOFF_SEGMENT_ALIGNMENT(&eah)); 473 if (addflag) { 474 esecs[3].s_scnptr = 0; 475 esecs[4].s_scnptr = 0; 476 esecs[5].s_scnptr = 0; 477 } 478 esecs[0].s_relptr = esecs[1].s_relptr = esecs[2].s_relptr = 0; 479 esecs[0].s_lnnoptr = esecs[1].s_lnnoptr = esecs[2].s_lnnoptr = 0; 480 esecs[0].s_nreloc = esecs[1].s_nreloc = esecs[2].s_nreloc = 0; 481 esecs[0].s_nlnno = esecs[1].s_nlnno = esecs[2].s_nlnno = 0; 482 if (addflag) { 483 esecs[3].s_relptr = esecs[4].s_relptr 484 = esecs[5].s_relptr = 0; 485 esecs[3].s_lnnoptr = esecs[4].s_lnnoptr 486 = esecs[5].s_lnnoptr = 0; 487 esecs[3].s_nreloc = esecs[4].s_nreloc = esecs[5].s_nreloc = 488 0; 489 esecs[3].s_nlnno = esecs[4].s_nlnno = esecs[5].s_nlnno = 0; 490 } 491 esecs[0].s_flags = 0x20; 492 esecs[1].s_flags = 0x40; 493 esecs[2].s_flags = 0x82; 494 if (addflag) { 495 esecs[3].s_flags = 0x100; 496 esecs[4].s_flags = 0x200; 497 esecs[5].s_flags = 0x400; 498 } 499 500 /* Make the output file... */ 501 if ((outfile = open(argv[2], O_WRONLY | O_CREAT, 0777)) < 0) { 502 fprintf(stderr, "Unable to create %s: %s\n", argv[2], 503 strerror(errno)); 504 exit(1); 505 } 506 507 if (must_convert_endian) 508 convert_ecoff_filehdr(&efh); 509 /* Write the headers... */ 510 i = write(outfile, &efh, sizeof efh); 511 if (i != sizeof efh) { 512 perror("efh: write"); 513 exit(1); 514 515 for (i = 0; i < nosecs; i++) { 516 printf 517 ("Section %d: %s phys %lx size %lx file offset %lx\n", 518 i, esecs[i].s_name, esecs[i].s_paddr, 519 esecs[i].s_size, esecs[i].s_scnptr); 520 } 521 } 522 fprintf(stderr, "wrote %d byte file header.\n", i); 523 524 if (must_convert_endian) 525 convert_ecoff_aouthdr(&eah); 526 i = write(outfile, &eah, sizeof eah); 527 if (i != sizeof eah) { 528 perror("eah: write"); 529 exit(1); 530 } 531 fprintf(stderr, "wrote %d byte a.out header.\n", i); 532 533 if (must_convert_endian) 534 convert_ecoff_esecs(&esecs[0], nosecs); 535 i = write(outfile, &esecs, nosecs * sizeof(struct scnhdr)); 536 if (i != nosecs * sizeof(struct scnhdr)) { 537 perror("esecs: write"); 538 exit(1); 539 } 540 fprintf(stderr, "wrote %d bytes of section headers.\n", i); 541 542 pad = (sizeof(efh) + sizeof(eah) + nosecs * sizeof(struct scnhdr)) & 15; 543 if (pad) { 544 pad = 16 - pad; 545 i = write(outfile, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0", pad); 546 if (i < 0) { 547 perror("ipad: write"); 548 exit(1); 549 } 550 fprintf(stderr, "wrote %d byte pad.\n", i); 551 } 552 553 /* 554 * Copy the loadable sections. Zero-fill any gaps less than 64k; 555 * complain about any zero-filling, and die if we're asked to zero-fill 556 * more than 64k. 557 */ 558 for (i = 0; i < ex.e_phnum; i++) { 559 /* Unprocessable sections were handled above, so just verify that 560 the section can be loaded before copying. */ 561 if (ph[i].p_type == PT_LOAD && ph[i].p_filesz) { 562 if (cur_vma != ph[i].p_vaddr) { 563 unsigned long gap = 564 ph[i].p_vaddr - cur_vma; 565 char obuf[1024]; 566 if (gap > 65536) { 567 fprintf(stderr, 568 "Intersegment gap (%ld bytes) too large.\n", 569 gap); 570 exit(1); 571 } 572 fprintf(stderr, 573 "Warning: %ld byte intersegment gap.\n", 574 gap); 575 memset(obuf, 0, sizeof obuf); 576 while (gap) { 577 int count = 578 write(outfile, obuf, 579 (gap > 580 sizeof obuf ? sizeof 581 obuf : gap)); 582 if (count < 0) { 583 fprintf(stderr, 584 "Error writing gap: %s\n", 585 strerror(errno)); 586 exit(1); 587 } 588 gap -= count; 589 } 590 } 591 fprintf(stderr, "writing %d bytes...\n", 592 ph[i].p_filesz); 593 copy(outfile, infile, ph[i].p_offset, 594 ph[i].p_filesz); 595 cur_vma = ph[i].p_vaddr + ph[i].p_filesz; 596 } 597 } 598 599 /* 600 * Write a page of padding for boot PROMS that read entire pages. 601 * Without this, they may attempt to read past the end of the 602 * data section, incur an error, and refuse to boot. 603 */ 604 { 605 char obuf[4096]; 606 memset(obuf, 0, sizeof obuf); 607 if (write(outfile, obuf, sizeof(obuf)) != sizeof(obuf)) { 608 fprintf(stderr, "Error writing PROM padding: %s\n", 609 strerror(errno)); 610 exit(1); 611 } 612 } 613 614 /* Looks like we won... */ 615 exit(0); 616 } 617