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 #define PT_MIPS_ABIFLAGS 0x70000003 /* Records ABI related flags */ 54 55 /* -------------------------------------------------------------------- */ 56 57 struct sect { 58 unsigned long vaddr; 59 unsigned long len; 60 }; 61 62 int *symTypeTable; 63 int must_convert_endian; 64 int format_bigendian; 65 66 static void copy(int out, int in, off_t offset, off_t size) 67 { 68 char ibuf[4096]; 69 int remaining, cur, count; 70 71 /* Go to the start of the ELF symbol table... */ 72 if (lseek(in, offset, SEEK_SET) < 0) { 73 perror("copy: lseek"); 74 exit(1); 75 } 76 77 remaining = size; 78 while (remaining) { 79 cur = remaining; 80 if (cur > sizeof ibuf) 81 cur = sizeof ibuf; 82 remaining -= cur; 83 if ((count = read(in, ibuf, cur)) != cur) { 84 fprintf(stderr, "copy: read: %s\n", 85 count ? strerror(errno) : 86 "premature end of file"); 87 exit(1); 88 } 89 if ((count = write(out, ibuf, cur)) != cur) { 90 perror("copy: write"); 91 exit(1); 92 } 93 } 94 } 95 96 /* 97 * Combine two segments, which must be contiguous. If pad is true, it's 98 * okay for there to be padding between. 99 */ 100 static void combine(struct sect *base, struct sect *new, int pad) 101 { 102 if (!base->len) 103 *base = *new; 104 else if (new->len) { 105 if (base->vaddr + base->len != new->vaddr) { 106 if (pad) 107 base->len = new->vaddr - base->vaddr; 108 else { 109 fprintf(stderr, 110 "Non-contiguous data can't be converted.\n"); 111 exit(1); 112 } 113 } 114 base->len += new->len; 115 } 116 } 117 118 static int phcmp(const void *v1, const void *v2) 119 { 120 const Elf32_Phdr *h1 = v1; 121 const Elf32_Phdr *h2 = v2; 122 123 if (h1->p_vaddr > h2->p_vaddr) 124 return 1; 125 else if (h1->p_vaddr < h2->p_vaddr) 126 return -1; 127 else 128 return 0; 129 } 130 131 static char *saveRead(int file, off_t offset, off_t len, char *name) 132 { 133 char *tmp; 134 int count; 135 off_t off; 136 if ((off = lseek(file, offset, SEEK_SET)) < 0) { 137 fprintf(stderr, "%s: fseek: %s\n", name, strerror(errno)); 138 exit(1); 139 } 140 if (!(tmp = (char *) malloc(len))) { 141 fprintf(stderr, "%s: Can't allocate %ld bytes.\n", name, 142 len); 143 exit(1); 144 } 145 count = read(file, tmp, len); 146 if (count != len) { 147 fprintf(stderr, "%s: read: %s.\n", 148 name, 149 count ? strerror(errno) : "End of file reached"); 150 exit(1); 151 } 152 return tmp; 153 } 154 155 #define swab16(x) \ 156 ((unsigned short)( \ 157 (((unsigned short)(x) & (unsigned short)0x00ffU) << 8) | \ 158 (((unsigned short)(x) & (unsigned short)0xff00U) >> 8) )) 159 160 #define swab32(x) \ 161 ((unsigned int)( \ 162 (((unsigned int)(x) & (unsigned int)0x000000ffUL) << 24) | \ 163 (((unsigned int)(x) & (unsigned int)0x0000ff00UL) << 8) | \ 164 (((unsigned int)(x) & (unsigned int)0x00ff0000UL) >> 8) | \ 165 (((unsigned int)(x) & (unsigned int)0xff000000UL) >> 24) )) 166 167 static void convert_elf_hdr(Elf32_Ehdr * e) 168 { 169 e->e_type = swab16(e->e_type); 170 e->e_machine = swab16(e->e_machine); 171 e->e_version = swab32(e->e_version); 172 e->e_entry = swab32(e->e_entry); 173 e->e_phoff = swab32(e->e_phoff); 174 e->e_shoff = swab32(e->e_shoff); 175 e->e_flags = swab32(e->e_flags); 176 e->e_ehsize = swab16(e->e_ehsize); 177 e->e_phentsize = swab16(e->e_phentsize); 178 e->e_phnum = swab16(e->e_phnum); 179 e->e_shentsize = swab16(e->e_shentsize); 180 e->e_shnum = swab16(e->e_shnum); 181 e->e_shstrndx = swab16(e->e_shstrndx); 182 } 183 184 static void convert_elf_phdrs(Elf32_Phdr * p, int num) 185 { 186 int i; 187 188 for (i = 0; i < num; i++, p++) { 189 p->p_type = swab32(p->p_type); 190 p->p_offset = swab32(p->p_offset); 191 p->p_vaddr = swab32(p->p_vaddr); 192 p->p_paddr = swab32(p->p_paddr); 193 p->p_filesz = swab32(p->p_filesz); 194 p->p_memsz = swab32(p->p_memsz); 195 p->p_flags = swab32(p->p_flags); 196 p->p_align = swab32(p->p_align); 197 } 198 199 } 200 201 static void convert_elf_shdrs(Elf32_Shdr * s, int num) 202 { 203 int i; 204 205 for (i = 0; i < num; i++, s++) { 206 s->sh_name = swab32(s->sh_name); 207 s->sh_type = swab32(s->sh_type); 208 s->sh_flags = swab32(s->sh_flags); 209 s->sh_addr = swab32(s->sh_addr); 210 s->sh_offset = swab32(s->sh_offset); 211 s->sh_size = swab32(s->sh_size); 212 s->sh_link = swab32(s->sh_link); 213 s->sh_info = swab32(s->sh_info); 214 s->sh_addralign = swab32(s->sh_addralign); 215 s->sh_entsize = swab32(s->sh_entsize); 216 } 217 } 218 219 static void convert_ecoff_filehdr(struct filehdr *f) 220 { 221 f->f_magic = swab16(f->f_magic); 222 f->f_nscns = swab16(f->f_nscns); 223 f->f_timdat = swab32(f->f_timdat); 224 f->f_symptr = swab32(f->f_symptr); 225 f->f_nsyms = swab32(f->f_nsyms); 226 f->f_opthdr = swab16(f->f_opthdr); 227 f->f_flags = swab16(f->f_flags); 228 } 229 230 static void convert_ecoff_aouthdr(struct aouthdr *a) 231 { 232 a->magic = swab16(a->magic); 233 a->vstamp = swab16(a->vstamp); 234 a->tsize = swab32(a->tsize); 235 a->dsize = swab32(a->dsize); 236 a->bsize = swab32(a->bsize); 237 a->entry = swab32(a->entry); 238 a->text_start = swab32(a->text_start); 239 a->data_start = swab32(a->data_start); 240 a->bss_start = swab32(a->bss_start); 241 a->gprmask = swab32(a->gprmask); 242 a->cprmask[0] = swab32(a->cprmask[0]); 243 a->cprmask[1] = swab32(a->cprmask[1]); 244 a->cprmask[2] = swab32(a->cprmask[2]); 245 a->cprmask[3] = swab32(a->cprmask[3]); 246 a->gp_value = swab32(a->gp_value); 247 } 248 249 static void convert_ecoff_esecs(struct scnhdr *s, int num) 250 { 251 int i; 252 253 for (i = 0; i < num; i++, s++) { 254 s->s_paddr = swab32(s->s_paddr); 255 s->s_vaddr = swab32(s->s_vaddr); 256 s->s_size = swab32(s->s_size); 257 s->s_scnptr = swab32(s->s_scnptr); 258 s->s_relptr = swab32(s->s_relptr); 259 s->s_lnnoptr = swab32(s->s_lnnoptr); 260 s->s_nreloc = swab16(s->s_nreloc); 261 s->s_nlnno = swab16(s->s_nlnno); 262 s->s_flags = swab32(s->s_flags); 263 } 264 } 265 266 int main(int argc, char *argv[]) 267 { 268 Elf32_Ehdr ex; 269 Elf32_Phdr *ph; 270 Elf32_Shdr *sh; 271 char *shstrtab; 272 int i, pad; 273 struct sect text, data, bss; 274 struct filehdr efh; 275 struct aouthdr eah; 276 struct scnhdr esecs[6]; 277 int infile, outfile; 278 unsigned long cur_vma = ULONG_MAX; 279 int addflag = 0; 280 int nosecs; 281 282 text.len = data.len = bss.len = 0; 283 text.vaddr = data.vaddr = bss.vaddr = 0; 284 285 /* Check args... */ 286 if (argc < 3 || argc > 4) { 287 usage: 288 fprintf(stderr, 289 "usage: elf2ecoff <elf executable> <ecoff executable> [-a]\n"); 290 exit(1); 291 } 292 if (argc == 4) { 293 if (strcmp(argv[3], "-a")) 294 goto usage; 295 addflag = 1; 296 } 297 298 /* Try the input file... */ 299 if ((infile = open(argv[1], O_RDONLY)) < 0) { 300 fprintf(stderr, "Can't open %s for read: %s\n", 301 argv[1], strerror(errno)); 302 exit(1); 303 } 304 305 /* Read the header, which is at the beginning of the file... */ 306 i = read(infile, &ex, sizeof ex); 307 if (i != sizeof ex) { 308 fprintf(stderr, "ex: %s: %s.\n", 309 argv[1], 310 i ? strerror(errno) : "End of file reached"); 311 exit(1); 312 } 313 314 if (ex.e_ident[EI_DATA] == ELFDATA2MSB) 315 format_bigendian = 1; 316 317 if (ntohs(0xaa55) == 0xaa55) { 318 if (!format_bigendian) 319 must_convert_endian = 1; 320 } else { 321 if (format_bigendian) 322 must_convert_endian = 1; 323 } 324 if (must_convert_endian) 325 convert_elf_hdr(&ex); 326 327 /* Read the program headers... */ 328 ph = (Elf32_Phdr *) saveRead(infile, ex.e_phoff, 329 ex.e_phnum * sizeof(Elf32_Phdr), 330 "ph"); 331 if (must_convert_endian) 332 convert_elf_phdrs(ph, ex.e_phnum); 333 /* Read the section headers... */ 334 sh = (Elf32_Shdr *) saveRead(infile, ex.e_shoff, 335 ex.e_shnum * sizeof(Elf32_Shdr), 336 "sh"); 337 if (must_convert_endian) 338 convert_elf_shdrs(sh, ex.e_shnum); 339 /* Read in the section string table. */ 340 shstrtab = saveRead(infile, sh[ex.e_shstrndx].sh_offset, 341 sh[ex.e_shstrndx].sh_size, "shstrtab"); 342 343 /* Figure out if we can cram the program header into an ECOFF 344 header... Basically, we can't handle anything but loadable 345 segments, but we can ignore some kinds of segments. We can't 346 handle holes in the address space. Segments may be out of order, 347 so we sort them first. */ 348 349 qsort(ph, ex.e_phnum, sizeof(Elf32_Phdr), phcmp); 350 351 for (i = 0; i < ex.e_phnum; i++) { 352 /* Section types we can ignore... */ 353 switch (ph[i].p_type) { 354 case PT_NULL: 355 case PT_NOTE: 356 case PT_PHDR: 357 case PT_MIPS_REGINFO: 358 case PT_MIPS_ABIFLAGS: 359 continue; 360 361 case PT_LOAD: 362 /* Writable (data) segment? */ 363 if (ph[i].p_flags & PF_W) { 364 struct sect ndata, nbss; 365 366 ndata.vaddr = ph[i].p_vaddr; 367 ndata.len = ph[i].p_filesz; 368 nbss.vaddr = ph[i].p_vaddr + ph[i].p_filesz; 369 nbss.len = ph[i].p_memsz - ph[i].p_filesz; 370 371 combine(&data, &ndata, 0); 372 combine(&bss, &nbss, 1); 373 } else { 374 struct sect ntxt; 375 376 ntxt.vaddr = ph[i].p_vaddr; 377 ntxt.len = ph[i].p_filesz; 378 379 combine(&text, &ntxt, 0); 380 } 381 /* Remember the lowest segment start address. */ 382 if (ph[i].p_vaddr < cur_vma) 383 cur_vma = ph[i].p_vaddr; 384 break; 385 386 default: 387 /* Section types we can't handle... */ 388 fprintf(stderr, 389 "Program header %d type %d can't be converted.\n", 390 ex.e_phnum, ph[i].p_type); 391 exit(1); 392 } 393 } 394 395 /* Sections must be in order to be converted... */ 396 if (text.vaddr > data.vaddr || data.vaddr > bss.vaddr || 397 text.vaddr + text.len > data.vaddr 398 || data.vaddr + data.len > bss.vaddr) { 399 fprintf(stderr, 400 "Sections ordering prevents a.out conversion.\n"); 401 exit(1); 402 } 403 404 /* If there's a data section but no text section, then the loader 405 combined everything into one section. That needs to be the 406 text section, so just make the data section zero length following 407 text. */ 408 if (data.len && !text.len) { 409 text = data; 410 data.vaddr = text.vaddr + text.len; 411 data.len = 0; 412 } 413 414 /* If there is a gap between text and data, we'll fill it when we copy 415 the data, so update the length of the text segment as represented in 416 a.out to reflect that, since a.out doesn't allow gaps in the program 417 address space. */ 418 if (text.vaddr + text.len < data.vaddr) 419 text.len = data.vaddr - text.vaddr; 420 421 /* We now have enough information to cons up an a.out header... */ 422 eah.magic = OMAGIC; 423 eah.vstamp = 200; 424 eah.tsize = text.len; 425 eah.dsize = data.len; 426 eah.bsize = bss.len; 427 eah.entry = ex.e_entry; 428 eah.text_start = text.vaddr; 429 eah.data_start = data.vaddr; 430 eah.bss_start = bss.vaddr; 431 eah.gprmask = 0xf3fffffe; 432 memset(&eah.cprmask, '\0', sizeof eah.cprmask); 433 eah.gp_value = 0; /* unused. */ 434 435 if (format_bigendian) 436 efh.f_magic = MIPSEBMAGIC; 437 else 438 efh.f_magic = MIPSELMAGIC; 439 if (addflag) 440 nosecs = 6; 441 else 442 nosecs = 3; 443 efh.f_nscns = nosecs; 444 efh.f_timdat = 0; /* bogus */ 445 efh.f_symptr = 0; 446 efh.f_nsyms = 0; 447 efh.f_opthdr = sizeof eah; 448 efh.f_flags = 0x100f; /* Stripped, not sharable. */ 449 450 memset(esecs, 0, sizeof esecs); 451 strcpy(esecs[0].s_name, ".text"); 452 strcpy(esecs[1].s_name, ".data"); 453 strcpy(esecs[2].s_name, ".bss"); 454 if (addflag) { 455 strcpy(esecs[3].s_name, ".rdata"); 456 strcpy(esecs[4].s_name, ".sdata"); 457 strcpy(esecs[5].s_name, ".sbss"); 458 } 459 esecs[0].s_paddr = esecs[0].s_vaddr = eah.text_start; 460 esecs[1].s_paddr = esecs[1].s_vaddr = eah.data_start; 461 esecs[2].s_paddr = esecs[2].s_vaddr = eah.bss_start; 462 if (addflag) { 463 esecs[3].s_paddr = esecs[3].s_vaddr = 0; 464 esecs[4].s_paddr = esecs[4].s_vaddr = 0; 465 esecs[5].s_paddr = esecs[5].s_vaddr = 0; 466 } 467 esecs[0].s_size = eah.tsize; 468 esecs[1].s_size = eah.dsize; 469 esecs[2].s_size = eah.bsize; 470 if (addflag) { 471 esecs[3].s_size = 0; 472 esecs[4].s_size = 0; 473 esecs[5].s_size = 0; 474 } 475 esecs[0].s_scnptr = N_TXTOFF(efh, eah); 476 esecs[1].s_scnptr = N_DATOFF(efh, eah); 477 #define ECOFF_SEGMENT_ALIGNMENT(a) 0x10 478 #define ECOFF_ROUND(s, a) (((s)+(a)-1)&~((a)-1)) 479 esecs[2].s_scnptr = esecs[1].s_scnptr + 480 ECOFF_ROUND(esecs[1].s_size, ECOFF_SEGMENT_ALIGNMENT(&eah)); 481 if (addflag) { 482 esecs[3].s_scnptr = 0; 483 esecs[4].s_scnptr = 0; 484 esecs[5].s_scnptr = 0; 485 } 486 esecs[0].s_relptr = esecs[1].s_relptr = esecs[2].s_relptr = 0; 487 esecs[0].s_lnnoptr = esecs[1].s_lnnoptr = esecs[2].s_lnnoptr = 0; 488 esecs[0].s_nreloc = esecs[1].s_nreloc = esecs[2].s_nreloc = 0; 489 esecs[0].s_nlnno = esecs[1].s_nlnno = esecs[2].s_nlnno = 0; 490 if (addflag) { 491 esecs[3].s_relptr = esecs[4].s_relptr 492 = esecs[5].s_relptr = 0; 493 esecs[3].s_lnnoptr = esecs[4].s_lnnoptr 494 = esecs[5].s_lnnoptr = 0; 495 esecs[3].s_nreloc = esecs[4].s_nreloc = esecs[5].s_nreloc = 496 0; 497 esecs[3].s_nlnno = esecs[4].s_nlnno = esecs[5].s_nlnno = 0; 498 } 499 esecs[0].s_flags = 0x20; 500 esecs[1].s_flags = 0x40; 501 esecs[2].s_flags = 0x82; 502 if (addflag) { 503 esecs[3].s_flags = 0x100; 504 esecs[4].s_flags = 0x200; 505 esecs[5].s_flags = 0x400; 506 } 507 508 /* Make the output file... */ 509 if ((outfile = open(argv[2], O_WRONLY | O_CREAT, 0777)) < 0) { 510 fprintf(stderr, "Unable to create %s: %s\n", argv[2], 511 strerror(errno)); 512 exit(1); 513 } 514 515 if (must_convert_endian) 516 convert_ecoff_filehdr(&efh); 517 /* Write the headers... */ 518 i = write(outfile, &efh, sizeof efh); 519 if (i != sizeof efh) { 520 perror("efh: write"); 521 exit(1); 522 523 for (i = 0; i < nosecs; i++) { 524 printf 525 ("Section %d: %s phys %lx size %lx file offset %lx\n", 526 i, esecs[i].s_name, esecs[i].s_paddr, 527 esecs[i].s_size, esecs[i].s_scnptr); 528 } 529 } 530 fprintf(stderr, "wrote %d byte file header.\n", i); 531 532 if (must_convert_endian) 533 convert_ecoff_aouthdr(&eah); 534 i = write(outfile, &eah, sizeof eah); 535 if (i != sizeof eah) { 536 perror("eah: write"); 537 exit(1); 538 } 539 fprintf(stderr, "wrote %d byte a.out header.\n", i); 540 541 if (must_convert_endian) 542 convert_ecoff_esecs(&esecs[0], nosecs); 543 i = write(outfile, &esecs, nosecs * sizeof(struct scnhdr)); 544 if (i != nosecs * sizeof(struct scnhdr)) { 545 perror("esecs: write"); 546 exit(1); 547 } 548 fprintf(stderr, "wrote %d bytes of section headers.\n", i); 549 550 pad = (sizeof(efh) + sizeof(eah) + nosecs * sizeof(struct scnhdr)) & 15; 551 if (pad) { 552 pad = 16 - pad; 553 i = write(outfile, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0", pad); 554 if (i < 0) { 555 perror("ipad: write"); 556 exit(1); 557 } 558 fprintf(stderr, "wrote %d byte pad.\n", i); 559 } 560 561 /* 562 * Copy the loadable sections. Zero-fill any gaps less than 64k; 563 * complain about any zero-filling, and die if we're asked to zero-fill 564 * more than 64k. 565 */ 566 for (i = 0; i < ex.e_phnum; i++) { 567 /* Unprocessable sections were handled above, so just verify that 568 the section can be loaded before copying. */ 569 if (ph[i].p_type == PT_LOAD && ph[i].p_filesz) { 570 if (cur_vma != ph[i].p_vaddr) { 571 unsigned long gap = 572 ph[i].p_vaddr - cur_vma; 573 char obuf[1024]; 574 if (gap > 65536) { 575 fprintf(stderr, 576 "Intersegment gap (%ld bytes) too large.\n", 577 gap); 578 exit(1); 579 } 580 fprintf(stderr, 581 "Warning: %ld byte intersegment gap.\n", 582 gap); 583 memset(obuf, 0, sizeof obuf); 584 while (gap) { 585 int count = 586 write(outfile, obuf, 587 (gap > 588 sizeof obuf ? sizeof 589 obuf : gap)); 590 if (count < 0) { 591 fprintf(stderr, 592 "Error writing gap: %s\n", 593 strerror(errno)); 594 exit(1); 595 } 596 gap -= count; 597 } 598 } 599 fprintf(stderr, "writing %d bytes...\n", 600 ph[i].p_filesz); 601 copy(outfile, infile, ph[i].p_offset, 602 ph[i].p_filesz); 603 cur_vma = ph[i].p_vaddr + ph[i].p_filesz; 604 } 605 } 606 607 /* 608 * Write a page of padding for boot PROMS that read entire pages. 609 * Without this, they may attempt to read past the end of the 610 * data section, incur an error, and refuse to boot. 611 */ 612 { 613 char obuf[4096]; 614 memset(obuf, 0, sizeof obuf); 615 if (write(outfile, obuf, sizeof(obuf)) != sizeof(obuf)) { 616 fprintf(stderr, "Error writing PROM padding: %s\n", 617 strerror(errno)); 618 exit(1); 619 } 620 } 621 622 /* Looks like we won... */ 623 exit(0); 624 } 625