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 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); 338 339 /* Figure out if we can cram the program header into an ECOFF 340 header... Basically, we can't handle anything but loadable 341 segments, but we can ignore some kinds of segments. We can't 342 handle holes in the address space. Segments may be out of order, 343 so we sort them first. */ 344 345 qsort(ph, ex.e_phnum, sizeof(Elf32_Phdr), phcmp); 346 347 for (i = 0; i < ex.e_phnum; i++) { 348 /* Section types we can ignore... */ 349 switch (ph[i].p_type) { 350 case PT_NULL: 351 case PT_NOTE: 352 case PT_PHDR: 353 case PT_MIPS_REGINFO: 354 case PT_MIPS_ABIFLAGS: 355 continue; 356 357 case PT_LOAD: 358 /* Writable (data) segment? */ 359 if (ph[i].p_flags & PF_W) { 360 struct sect ndata, nbss; 361 362 ndata.vaddr = ph[i].p_vaddr; 363 ndata.len = ph[i].p_filesz; 364 nbss.vaddr = ph[i].p_vaddr + ph[i].p_filesz; 365 nbss.len = ph[i].p_memsz - ph[i].p_filesz; 366 367 combine(&data, &ndata, 0); 368 combine(&bss, &nbss, 1); 369 } else { 370 struct sect ntxt; 371 372 ntxt.vaddr = ph[i].p_vaddr; 373 ntxt.len = ph[i].p_filesz; 374 375 combine(&text, &ntxt, 0); 376 } 377 /* Remember the lowest segment start address. */ 378 if (ph[i].p_vaddr < cur_vma) 379 cur_vma = ph[i].p_vaddr; 380 break; 381 382 default: 383 /* Section types we can't handle... */ 384 fprintf(stderr, 385 "Program header %d type %d can't be converted.\n", 386 ex.e_phnum, ph[i].p_type); 387 exit(1); 388 } 389 } 390 391 /* Sections must be in order to be converted... */ 392 if (text.vaddr > data.vaddr || data.vaddr > bss.vaddr || 393 text.vaddr + text.len > data.vaddr 394 || data.vaddr + data.len > bss.vaddr) { 395 fprintf(stderr, 396 "Sections ordering prevents a.out conversion.\n"); 397 exit(1); 398 } 399 400 /* If there's a data section but no text section, then the loader 401 combined everything into one section. That needs to be the 402 text section, so just make the data section zero length following 403 text. */ 404 if (data.len && !text.len) { 405 text = data; 406 data.vaddr = text.vaddr + text.len; 407 data.len = 0; 408 } 409 410 /* If there is a gap between text and data, we'll fill it when we copy 411 the data, so update the length of the text segment as represented in 412 a.out to reflect that, since a.out doesn't allow gaps in the program 413 address space. */ 414 if (text.vaddr + text.len < data.vaddr) 415 text.len = data.vaddr - text.vaddr; 416 417 /* We now have enough information to cons up an a.out header... */ 418 eah.magic = OMAGIC; 419 eah.vstamp = 200; 420 eah.tsize = text.len; 421 eah.dsize = data.len; 422 eah.bsize = bss.len; 423 eah.entry = ex.e_entry; 424 eah.text_start = text.vaddr; 425 eah.data_start = data.vaddr; 426 eah.bss_start = bss.vaddr; 427 eah.gprmask = 0xf3fffffe; 428 memset(&eah.cprmask, '\0', sizeof eah.cprmask); 429 eah.gp_value = 0; /* unused. */ 430 431 if (format_bigendian) 432 efh.f_magic = MIPSEBMAGIC; 433 else 434 efh.f_magic = MIPSELMAGIC; 435 if (addflag) 436 nosecs = 6; 437 else 438 nosecs = 3; 439 efh.f_nscns = nosecs; 440 efh.f_timdat = 0; /* bogus */ 441 efh.f_symptr = 0; 442 efh.f_nsyms = 0; 443 efh.f_opthdr = sizeof eah; 444 efh.f_flags = 0x100f; /* Stripped, not sharable. */ 445 446 memset(esecs, 0, sizeof esecs); 447 strcpy(esecs[0].s_name, ".text"); 448 strcpy(esecs[1].s_name, ".data"); 449 strcpy(esecs[2].s_name, ".bss"); 450 if (addflag) { 451 strcpy(esecs[3].s_name, ".rdata"); 452 strcpy(esecs[4].s_name, ".sdata"); 453 strcpy(esecs[5].s_name, ".sbss"); 454 } 455 esecs[0].s_paddr = esecs[0].s_vaddr = eah.text_start; 456 esecs[1].s_paddr = esecs[1].s_vaddr = eah.data_start; 457 esecs[2].s_paddr = esecs[2].s_vaddr = eah.bss_start; 458 if (addflag) { 459 esecs[3].s_paddr = esecs[3].s_vaddr = 0; 460 esecs[4].s_paddr = esecs[4].s_vaddr = 0; 461 esecs[5].s_paddr = esecs[5].s_vaddr = 0; 462 } 463 esecs[0].s_size = eah.tsize; 464 esecs[1].s_size = eah.dsize; 465 esecs[2].s_size = eah.bsize; 466 if (addflag) { 467 esecs[3].s_size = 0; 468 esecs[4].s_size = 0; 469 esecs[5].s_size = 0; 470 } 471 esecs[0].s_scnptr = N_TXTOFF(efh, eah); 472 esecs[1].s_scnptr = N_DATOFF(efh, eah); 473 #define ECOFF_SEGMENT_ALIGNMENT(a) 0x10 474 #define ECOFF_ROUND(s, a) (((s)+(a)-1)&~((a)-1)) 475 esecs[2].s_scnptr = esecs[1].s_scnptr + 476 ECOFF_ROUND(esecs[1].s_size, ECOFF_SEGMENT_ALIGNMENT(&eah)); 477 if (addflag) { 478 esecs[3].s_scnptr = 0; 479 esecs[4].s_scnptr = 0; 480 esecs[5].s_scnptr = 0; 481 } 482 esecs[0].s_relptr = esecs[1].s_relptr = esecs[2].s_relptr = 0; 483 esecs[0].s_lnnoptr = esecs[1].s_lnnoptr = esecs[2].s_lnnoptr = 0; 484 esecs[0].s_nreloc = esecs[1].s_nreloc = esecs[2].s_nreloc = 0; 485 esecs[0].s_nlnno = esecs[1].s_nlnno = esecs[2].s_nlnno = 0; 486 if (addflag) { 487 esecs[3].s_relptr = esecs[4].s_relptr 488 = esecs[5].s_relptr = 0; 489 esecs[3].s_lnnoptr = esecs[4].s_lnnoptr 490 = esecs[5].s_lnnoptr = 0; 491 esecs[3].s_nreloc = esecs[4].s_nreloc = esecs[5].s_nreloc = 492 0; 493 esecs[3].s_nlnno = esecs[4].s_nlnno = esecs[5].s_nlnno = 0; 494 } 495 esecs[0].s_flags = 0x20; 496 esecs[1].s_flags = 0x40; 497 esecs[2].s_flags = 0x82; 498 if (addflag) { 499 esecs[3].s_flags = 0x100; 500 esecs[4].s_flags = 0x200; 501 esecs[5].s_flags = 0x400; 502 } 503 504 /* Make the output file... */ 505 if ((outfile = open(argv[2], O_WRONLY | O_CREAT, 0777)) < 0) { 506 fprintf(stderr, "Unable to create %s: %s\n", argv[2], 507 strerror(errno)); 508 exit(1); 509 } 510 511 if (must_convert_endian) 512 convert_ecoff_filehdr(&efh); 513 /* Write the headers... */ 514 i = write(outfile, &efh, sizeof efh); 515 if (i != sizeof efh) { 516 perror("efh: write"); 517 exit(1); 518 519 for (i = 0; i < nosecs; i++) { 520 printf 521 ("Section %d: %s phys %lx size %lx file offset %lx\n", 522 i, esecs[i].s_name, esecs[i].s_paddr, 523 esecs[i].s_size, esecs[i].s_scnptr); 524 } 525 } 526 fprintf(stderr, "wrote %d byte file header.\n", i); 527 528 if (must_convert_endian) 529 convert_ecoff_aouthdr(&eah); 530 i = write(outfile, &eah, sizeof eah); 531 if (i != sizeof eah) { 532 perror("eah: write"); 533 exit(1); 534 } 535 fprintf(stderr, "wrote %d byte a.out header.\n", i); 536 537 if (must_convert_endian) 538 convert_ecoff_esecs(&esecs[0], nosecs); 539 i = write(outfile, &esecs, nosecs * sizeof(struct scnhdr)); 540 if (i != nosecs * sizeof(struct scnhdr)) { 541 perror("esecs: write"); 542 exit(1); 543 } 544 fprintf(stderr, "wrote %d bytes of section headers.\n", i); 545 546 pad = (sizeof(efh) + sizeof(eah) + nosecs * sizeof(struct scnhdr)) & 15; 547 if (pad) { 548 pad = 16 - pad; 549 i = write(outfile, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0", pad); 550 if (i < 0) { 551 perror("ipad: write"); 552 exit(1); 553 } 554 fprintf(stderr, "wrote %d byte pad.\n", i); 555 } 556 557 /* 558 * Copy the loadable sections. Zero-fill any gaps less than 64k; 559 * complain about any zero-filling, and die if we're asked to zero-fill 560 * more than 64k. 561 */ 562 for (i = 0; i < ex.e_phnum; i++) { 563 /* Unprocessable sections were handled above, so just verify that 564 the section can be loaded before copying. */ 565 if (ph[i].p_type == PT_LOAD && ph[i].p_filesz) { 566 if (cur_vma != ph[i].p_vaddr) { 567 unsigned long gap = 568 ph[i].p_vaddr - cur_vma; 569 char obuf[1024]; 570 if (gap > 65536) { 571 fprintf(stderr, 572 "Intersegment gap (%ld bytes) too large.\n", 573 gap); 574 exit(1); 575 } 576 fprintf(stderr, 577 "Warning: %ld byte intersegment gap.\n", 578 gap); 579 memset(obuf, 0, sizeof obuf); 580 while (gap) { 581 int count = 582 write(outfile, obuf, 583 (gap > 584 sizeof obuf ? sizeof 585 obuf : gap)); 586 if (count < 0) { 587 fprintf(stderr, 588 "Error writing gap: %s\n", 589 strerror(errno)); 590 exit(1); 591 } 592 gap -= count; 593 } 594 } 595 fprintf(stderr, "writing %d bytes...\n", 596 ph[i].p_filesz); 597 copy(outfile, infile, ph[i].p_offset, 598 ph[i].p_filesz); 599 cur_vma = ph[i].p_vaddr + ph[i].p_filesz; 600 } 601 } 602 603 /* 604 * Write a page of padding for boot PROMS that read entire pages. 605 * Without this, they may attempt to read past the end of the 606 * data section, incur an error, and refuse to boot. 607 */ 608 { 609 char obuf[4096]; 610 memset(obuf, 0, sizeof obuf); 611 if (write(outfile, obuf, sizeof(obuf)) != sizeof(obuf)) { 612 fprintf(stderr, "Error writing PROM padding: %s\n", 613 strerror(errno)); 614 exit(1); 615 } 616 } 617 618 /* Looks like we won... */ 619 exit(0); 620 } 621