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 56struct sect { 57 unsigned long vaddr; 58 unsigned long len; 59}; 60 61int *symTypeTable; 62int must_convert_endian = 0; 63int format_bigendian = 0; 64 65static 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 */ 99static 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 117static 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 130static 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 166static 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 183static 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 200static 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 218static 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 229static 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 248static 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 265int 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", argv[1], 308 i ? strerror(errno) : "End of file reached"); 309 exit(1); 310 } 311 312 if (ex.e_ident[EI_DATA] == ELFDATA2MSB) 313 format_bigendian = 1; 314 315 if (ntohs(0xaa55) == 0xaa55) { 316 if (!format_bigendian) 317 must_convert_endian = 1; 318 } else { 319 if (format_bigendian) 320 must_convert_endian = 1; 321 } 322 if (must_convert_endian) 323 convert_elf_hdr(&ex); 324 325 /* Read the program headers... */ 326 ph = (Elf32_Phdr *) saveRead(infile, ex.e_phoff, 327 ex.e_phnum * sizeof(Elf32_Phdr), "ph"); 328 if (must_convert_endian) 329 convert_elf_phdrs(ph, ex.e_phnum); 330 /* Read the section headers... */ 331 sh = (Elf32_Shdr *) saveRead(infile, ex.e_shoff, 332 ex.e_shnum * sizeof(Elf32_Shdr), 333 "sh"); 334 if (must_convert_endian) 335 convert_elf_shdrs(sh, ex.e_shnum); 336 /* Read in the section string table. */ 337 shstrtab = saveRead(infile, sh[ex.e_shstrndx].sh_offset, 338 sh[ex.e_shstrndx].sh_size, "shstrtab"); 339 340 /* Figure out if we can cram the program header into an ECOFF 341 header... Basically, we can't handle anything but loadable 342 segments, but we can ignore some kinds of segments. We can't 343 handle holes in the address space. Segments may be out of order, 344 so we sort them first. */ 345 346 qsort(ph, ex.e_phnum, sizeof(Elf32_Phdr), phcmp); 347 348 for (i = 0; i < ex.e_phnum; i++) { 349 /* Section types we can ignore... */ 350 if (ph[i].p_type == PT_NULL || ph[i].p_type == PT_NOTE || 351 ph[i].p_type == PT_PHDR 352 || ph[i].p_type == PT_MIPS_REGINFO) 353 continue; 354 /* Section types we can't handle... */ 355 else if (ph[i].p_type != PT_LOAD) { 356 fprintf(stderr, 357 "Program header %d type %d can't be converted.\n", 358 ex.e_phnum, ph[i].p_type); 359 exit(1); 360 } 361 /* Writable (data) segment? */ 362 if (ph[i].p_flags & PF_W) { 363 struct sect ndata, nbss; 364 365 ndata.vaddr = ph[i].p_vaddr; 366 ndata.len = ph[i].p_filesz; 367 nbss.vaddr = ph[i].p_vaddr + ph[i].p_filesz; 368 nbss.len = ph[i].p_memsz - ph[i].p_filesz; 369 370 combine(&data, &ndata, 0); 371 combine(&bss, &nbss, 1); 372 } else { 373 struct sect ntxt; 374 375 ntxt.vaddr = ph[i].p_vaddr; 376 ntxt.len = ph[i].p_filesz; 377 378 combine(&text, &ntxt, 0); 379 } 380 /* Remember the lowest segment start address. */ 381 if (ph[i].p_vaddr < cur_vma) 382 cur_vma = ph[i].p_vaddr; 383 } 384 385 /* Sections must be in order to be converted... */ 386 if (text.vaddr > data.vaddr || data.vaddr > bss.vaddr || 387 text.vaddr + text.len > data.vaddr 388 || data.vaddr + data.len > bss.vaddr) { 389 fprintf(stderr, 390 "Sections ordering prevents a.out conversion.\n"); 391 exit(1); 392 } 393 394 /* 395 * If there's a data section but no text section, then the loader 396 * combined everything into one section. That needs to be the text 397 * section, so just make the data section zero length following text. 398 */ 399 if (data.len && !text.len) { 400 text = data; 401 data.vaddr = text.vaddr + text.len; 402 data.len = 0; 403 } 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 */ 411 if (text.vaddr + text.len < data.vaddr) 412 text.len = data.vaddr - text.vaddr; 413 414 /* We now have enough information to cons up an a.out header... */ 415 eah.magic = OMAGIC; 416 eah.vstamp = 200; 417 eah.tsize = text.len; 418 eah.dsize = data.len; 419 eah.bsize = bss.len; 420 eah.entry = ex.e_entry; 421 eah.text_start = text.vaddr; 422 eah.data_start = data.vaddr; 423 eah.bss_start = bss.vaddr; 424 eah.gprmask = 0xf3fffffe; 425 memset(&eah.cprmask, '\0', sizeof(eah.cprmask)); 426 eah.gp_value = 0; /* unused. */ 427 428 if (format_bigendian) 429 efh.f_magic = MIPSEBMAGIC; 430 else 431 efh.f_magic = MIPSELMAGIC; 432 if (addflag) 433 nosecs = 6; 434 else 435 nosecs = 3; 436 efh.f_nscns = nosecs; 437 efh.f_timdat = 0; /* bogus */ 438 efh.f_symptr = 0; 439 efh.f_nsyms = 0; 440 efh.f_opthdr = sizeof(eah); 441 efh.f_flags = 0x100f; /* Stripped, not sharable. */ 442 443 memset(esecs, 0, sizeof(esecs)); 444 strcpy(esecs[0].s_name, ".text"); 445 strcpy(esecs[1].s_name, ".data"); 446 strcpy(esecs[2].s_name, ".bss"); 447 if (addflag) { 448 strcpy(esecs[3].s_name, ".rdata"); 449 strcpy(esecs[4].s_name, ".sdata"); 450 strcpy(esecs[5].s_name, ".sbss"); 451 } 452 esecs[0].s_paddr = esecs[0].s_vaddr = eah.text_start; 453 esecs[1].s_paddr = esecs[1].s_vaddr = eah.data_start; 454 esecs[2].s_paddr = esecs[2].s_vaddr = eah.bss_start; 455 if (addflag) { 456 esecs[3].s_paddr = esecs[3].s_vaddr = 0; 457 esecs[4].s_paddr = esecs[4].s_vaddr = 0; 458 esecs[5].s_paddr = esecs[5].s_vaddr = 0; 459 } 460 esecs[0].s_size = eah.tsize; 461 esecs[1].s_size = eah.dsize; 462 esecs[2].s_size = eah.bsize; 463 if (addflag) { 464 esecs[3].s_size = 0; 465 esecs[4].s_size = 0; 466 esecs[5].s_size = 0; 467 } 468 esecs[0].s_scnptr = N_TXTOFF(efh, eah); 469 esecs[1].s_scnptr = N_DATOFF(efh, eah); 470#define ECOFF_SEGMENT_ALIGNMENT(a) 0x10 471#define ECOFF_ROUND(s,a) (((s)+(a)-1)&~((a)-1)) 472 esecs[2].s_scnptr = esecs[1].s_scnptr + 473 ECOFF_ROUND(esecs[1].s_size, ECOFF_SEGMENT_ALIGNMENT(&eah)); 474 if (addflag) { 475 esecs[3].s_scnptr = 0; 476 esecs[4].s_scnptr = 0; 477 esecs[5].s_scnptr = 0; 478 } 479 esecs[0].s_relptr = esecs[1].s_relptr = esecs[2].s_relptr = 0; 480 esecs[0].s_lnnoptr = esecs[1].s_lnnoptr = esecs[2].s_lnnoptr = 0; 481 esecs[0].s_nreloc = esecs[1].s_nreloc = esecs[2].s_nreloc = 0; 482 esecs[0].s_nlnno = esecs[1].s_nlnno = esecs[2].s_nlnno = 0; 483 if (addflag) { 484 esecs[3].s_relptr = esecs[4].s_relptr 485 = esecs[5].s_relptr = 0; 486 esecs[3].s_lnnoptr = esecs[4].s_lnnoptr 487 = esecs[5].s_lnnoptr = 0; 488 esecs[3].s_nreloc = esecs[4].s_nreloc = esecs[5].s_nreloc = 489 0; 490 esecs[3].s_nlnno = esecs[4].s_nlnno = esecs[5].s_nlnno = 0; 491 } 492 esecs[0].s_flags = 0x20; 493 esecs[1].s_flags = 0x40; 494 esecs[2].s_flags = 0x82; 495 if (addflag) { 496 esecs[3].s_flags = 0x100; 497 esecs[4].s_flags = 0x200; 498 esecs[5].s_flags = 0x400; 499 } 500 501 /* Make the output file... */ 502 if ((outfile = open(argv[2], O_WRONLY | O_CREAT, 0777)) < 0) { 503 fprintf(stderr, "Unable to create %s: %s\n", argv[2], 504 strerror(errno)); 505 exit(1); 506 } 507 508 if (must_convert_endian) 509 convert_ecoff_filehdr(&efh); 510 /* Write the headers... */ 511 i = write(outfile, &efh, sizeof(efh)); 512 if (i != sizeof efh) { 513 perror("efh: write"); 514 exit(1); 515 } 516 517 for (i = 0; i < nosecs; i++) { 518 printf("Section %d: %s phys %lx size %lx file offset %lx\n", 519 i, esecs[i].s_name, esecs[i].s_paddr, 520 esecs[i].s_size, esecs[i].s_scnptr); 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 /* 560 * Unprocessable sections were handled above, so just verify 561 * that the section can be loaded before copying. 562 */ 563 if (ph[i].p_type != PT_LOAD || ph[i].p_filesz == 0) 564 continue; 565 566 if (cur_vma != ph[i].p_vaddr) { 567 unsigned long gap = ph[i].p_vaddr - cur_vma; 568 char obuf[1024]; 569 570 if (gap > 65536) { 571 fprintf(stderr, "Intersegment gap (%ld " 572 "bytes) too large.\n", gap); 573 exit(1); 574 } 575 fprintf(stderr, "Warning: %ld byte intersegment gap.\n", 576 gap); 577 memset(obuf, 0, sizeof(obuf)); 578 while (gap) { 579 int count = write(outfile, obuf, 580 gap > sizeof(obuf) ? sizeof(obuf) : gap); 581 if (count < 0) { 582 fprintf(stderr, 583 "Error writing gap: %s\n", 584 strerror(errno)); 585 exit(1); 586 } 587 gap -= count; 588 } 589 } 590 fprintf(stderr, "writing %d bytes...\n", ph[i].p_filesz); 591 copy(outfile, infile, ph[i].p_offset, ph[i].p_filesz); 592 cur_vma = ph[i].p_vaddr + ph[i].p_filesz; 593 } 594 595 /* 596 * Write a page of padding for boot PROMS that read entire pages. 597 * Without this, they may attempt to read past the end of the 598 * data section, incur an error, and refuse to boot. 599 */ 600 { 601 char obuf[4096]; 602 memset(obuf, 0, sizeof(obuf)); 603 if (write(outfile, obuf, sizeof(obuf)) != sizeof(obuf)) { 604 fprintf(stderr, "Error writing PROM padding: %s\n", 605 strerror(errno)); 606 exit(1); 607 } 608 } 609 610 /* Looks like we won... */ 611 exit(0); 612} 613