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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;
63int format_bigendian;
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",
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}
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
57struct sect {
58 unsigned long vaddr;
59 unsigned long len;
60};
61
62int *symTypeTable;
63int must_convert_endian;
64int format_bigendian;
65
66static 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 */
100static 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
118static 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
131static 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
167static 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
184static 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
201static 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
219static 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
230static 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
249static 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
266int 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}