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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#include <stdint.h>
47#include <inttypes.h>
48
49#include "ecoff.h"
50
51/*
52 * Some extra ELF definitions
53 */
54#define PT_MIPS_REGINFO 0x70000000 /* Register usage information */
55#define PT_MIPS_ABIFLAGS 0x70000003 /* Records ABI related flags */
56
57/* -------------------------------------------------------------------- */
58
59struct sect {
60 uint32_t vaddr;
61 uint32_t len;
62};
63
64int *symTypeTable;
65int must_convert_endian;
66int format_bigendian;
67
68static void copy(int out, int in, off_t offset, off_t size)
69{
70 char ibuf[4096];
71 int remaining, cur, count;
72
73 /* Go to the start of the ELF symbol table... */
74 if (lseek(in, offset, SEEK_SET) < 0) {
75 perror("copy: lseek");
76 exit(1);
77 }
78
79 remaining = size;
80 while (remaining) {
81 cur = remaining;
82 if (cur > sizeof ibuf)
83 cur = sizeof ibuf;
84 remaining -= cur;
85 if ((count = read(in, ibuf, cur)) != cur) {
86 fprintf(stderr, "copy: read: %s\n",
87 count ? strerror(errno) :
88 "premature end of file");
89 exit(1);
90 }
91 if ((count = write(out, ibuf, cur)) != cur) {
92 perror("copy: write");
93 exit(1);
94 }
95 }
96}
97
98/*
99 * Combine two segments, which must be contiguous. If pad is true, it's
100 * okay for there to be padding between.
101 */
102static void combine(struct sect *base, struct sect *new, int pad)
103{
104 if (!base->len)
105 *base = *new;
106 else if (new->len) {
107 if (base->vaddr + base->len != new->vaddr) {
108 if (pad)
109 base->len = new->vaddr - base->vaddr;
110 else {
111 fprintf(stderr,
112 "Non-contiguous data can't be converted.\n");
113 exit(1);
114 }
115 }
116 base->len += new->len;
117 }
118}
119
120static int phcmp(const void *v1, const void *v2)
121{
122 const Elf32_Phdr *h1 = v1;
123 const Elf32_Phdr *h2 = v2;
124
125 if (h1->p_vaddr > h2->p_vaddr)
126 return 1;
127 else if (h1->p_vaddr < h2->p_vaddr)
128 return -1;
129 else
130 return 0;
131}
132
133static char *saveRead(int file, off_t offset, off_t len, char *name)
134{
135 char *tmp;
136 int count;
137 off_t off;
138 if ((off = lseek(file, offset, SEEK_SET)) < 0) {
139 fprintf(stderr, "%s: fseek: %s\n", name, strerror(errno));
140 exit(1);
141 }
142 if (!(tmp = (char *) malloc(len))) {
143 fprintf(stderr, "%s: Can't allocate %ld bytes.\n", name,
144 len);
145 exit(1);
146 }
147 count = read(file, tmp, len);
148 if (count != len) {
149 fprintf(stderr, "%s: read: %s.\n",
150 name,
151 count ? strerror(errno) : "End of file reached");
152 exit(1);
153 }
154 return tmp;
155}
156
157#define swab16(x) \
158 ((uint16_t)( \
159 (((uint16_t)(x) & (uint16_t)0x00ffU) << 8) | \
160 (((uint16_t)(x) & (uint16_t)0xff00U) >> 8) ))
161
162#define swab32(x) \
163 ((unsigned int)( \
164 (((uint32_t)(x) & (uint32_t)0x000000ffUL) << 24) | \
165 (((uint32_t)(x) & (uint32_t)0x0000ff00UL) << 8) | \
166 (((uint32_t)(x) & (uint32_t)0x00ff0000UL) >> 8) | \
167 (((uint32_t)(x) & (uint32_t)0xff000000UL) >> 24) ))
168
169static void convert_elf_hdr(Elf32_Ehdr * e)
170{
171 e->e_type = swab16(e->e_type);
172 e->e_machine = swab16(e->e_machine);
173 e->e_version = swab32(e->e_version);
174 e->e_entry = swab32(e->e_entry);
175 e->e_phoff = swab32(e->e_phoff);
176 e->e_shoff = swab32(e->e_shoff);
177 e->e_flags = swab32(e->e_flags);
178 e->e_ehsize = swab16(e->e_ehsize);
179 e->e_phentsize = swab16(e->e_phentsize);
180 e->e_phnum = swab16(e->e_phnum);
181 e->e_shentsize = swab16(e->e_shentsize);
182 e->e_shnum = swab16(e->e_shnum);
183 e->e_shstrndx = swab16(e->e_shstrndx);
184}
185
186static void convert_elf_phdrs(Elf32_Phdr * p, int num)
187{
188 int i;
189
190 for (i = 0; i < num; i++, p++) {
191 p->p_type = swab32(p->p_type);
192 p->p_offset = swab32(p->p_offset);
193 p->p_vaddr = swab32(p->p_vaddr);
194 p->p_paddr = swab32(p->p_paddr);
195 p->p_filesz = swab32(p->p_filesz);
196 p->p_memsz = swab32(p->p_memsz);
197 p->p_flags = swab32(p->p_flags);
198 p->p_align = swab32(p->p_align);
199 }
200
201}
202
203static void convert_elf_shdrs(Elf32_Shdr * s, int num)
204{
205 int i;
206
207 for (i = 0; i < num; i++, s++) {
208 s->sh_name = swab32(s->sh_name);
209 s->sh_type = swab32(s->sh_type);
210 s->sh_flags = swab32(s->sh_flags);
211 s->sh_addr = swab32(s->sh_addr);
212 s->sh_offset = swab32(s->sh_offset);
213 s->sh_size = swab32(s->sh_size);
214 s->sh_link = swab32(s->sh_link);
215 s->sh_info = swab32(s->sh_info);
216 s->sh_addralign = swab32(s->sh_addralign);
217 s->sh_entsize = swab32(s->sh_entsize);
218 }
219}
220
221static void convert_ecoff_filehdr(struct filehdr *f)
222{
223 f->f_magic = swab16(f->f_magic);
224 f->f_nscns = swab16(f->f_nscns);
225 f->f_timdat = swab32(f->f_timdat);
226 f->f_symptr = swab32(f->f_symptr);
227 f->f_nsyms = swab32(f->f_nsyms);
228 f->f_opthdr = swab16(f->f_opthdr);
229 f->f_flags = swab16(f->f_flags);
230}
231
232static void convert_ecoff_aouthdr(struct aouthdr *a)
233{
234 a->magic = swab16(a->magic);
235 a->vstamp = swab16(a->vstamp);
236 a->tsize = swab32(a->tsize);
237 a->dsize = swab32(a->dsize);
238 a->bsize = swab32(a->bsize);
239 a->entry = swab32(a->entry);
240 a->text_start = swab32(a->text_start);
241 a->data_start = swab32(a->data_start);
242 a->bss_start = swab32(a->bss_start);
243 a->gprmask = swab32(a->gprmask);
244 a->cprmask[0] = swab32(a->cprmask[0]);
245 a->cprmask[1] = swab32(a->cprmask[1]);
246 a->cprmask[2] = swab32(a->cprmask[2]);
247 a->cprmask[3] = swab32(a->cprmask[3]);
248 a->gp_value = swab32(a->gp_value);
249}
250
251static void convert_ecoff_esecs(struct scnhdr *s, int num)
252{
253 int i;
254
255 for (i = 0; i < num; i++, s++) {
256 s->s_paddr = swab32(s->s_paddr);
257 s->s_vaddr = swab32(s->s_vaddr);
258 s->s_size = swab32(s->s_size);
259 s->s_scnptr = swab32(s->s_scnptr);
260 s->s_relptr = swab32(s->s_relptr);
261 s->s_lnnoptr = swab32(s->s_lnnoptr);
262 s->s_nreloc = swab16(s->s_nreloc);
263 s->s_nlnno = swab16(s->s_nlnno);
264 s->s_flags = swab32(s->s_flags);
265 }
266}
267
268int main(int argc, char *argv[])
269{
270 Elf32_Ehdr ex;
271 Elf32_Phdr *ph;
272 Elf32_Shdr *sh;
273 int i, pad;
274 struct sect text, data, bss;
275 struct filehdr efh;
276 struct aouthdr eah;
277 struct scnhdr esecs[6];
278 int infile, outfile;
279 uint32_t cur_vma = UINT32_MAX;
280 int addflag = 0;
281 int nosecs;
282
283 text.len = data.len = bss.len = 0;
284 text.vaddr = data.vaddr = bss.vaddr = 0;
285
286 /* Check args... */
287 if (argc < 3 || argc > 4) {
288 usage:
289 fprintf(stderr,
290 "usage: elf2ecoff <elf executable> <ecoff executable> [-a]\n");
291 exit(1);
292 }
293 if (argc == 4) {
294 if (strcmp(argv[3], "-a"))
295 goto usage;
296 addflag = 1;
297 }
298
299 /* Try the input file... */
300 if ((infile = open(argv[1], O_RDONLY)) < 0) {
301 fprintf(stderr, "Can't open %s for read: %s\n",
302 argv[1], strerror(errno));
303 exit(1);
304 }
305
306 /* Read the header, which is at the beginning of the file... */
307 i = read(infile, &ex, sizeof ex);
308 if (i != sizeof ex) {
309 fprintf(stderr, "ex: %s: %s.\n",
310 argv[1],
311 i ? strerror(errno) : "End of file reached");
312 exit(1);
313 }
314
315 if (ex.e_ident[EI_DATA] == ELFDATA2MSB)
316 format_bigendian = 1;
317
318 if (ntohs(0xaa55) == 0xaa55) {
319 if (!format_bigendian)
320 must_convert_endian = 1;
321 } else {
322 if (format_bigendian)
323 must_convert_endian = 1;
324 }
325 if (must_convert_endian)
326 convert_elf_hdr(&ex);
327
328 /* Read the program headers... */
329 ph = (Elf32_Phdr *) saveRead(infile, ex.e_phoff,
330 ex.e_phnum * sizeof(Elf32_Phdr),
331 "ph");
332 if (must_convert_endian)
333 convert_elf_phdrs(ph, ex.e_phnum);
334 /* Read the section headers... */
335 sh = (Elf32_Shdr *) saveRead(infile, ex.e_shoff,
336 ex.e_shnum * sizeof(Elf32_Shdr),
337 "sh");
338 if (must_convert_endian)
339 convert_elf_shdrs(sh, ex.e_shnum);
340
341 /* Figure out if we can cram the program header into an ECOFF
342 header... Basically, we can't handle anything but loadable
343 segments, but we can ignore some kinds of segments. We can't
344 handle holes in the address space. Segments may be out of order,
345 so we sort them first. */
346
347 qsort(ph, ex.e_phnum, sizeof(Elf32_Phdr), phcmp);
348
349 for (i = 0; i < ex.e_phnum; i++) {
350 /* Section types we can ignore... */
351 switch (ph[i].p_type) {
352 case PT_NULL:
353 case PT_NOTE:
354 case PT_PHDR:
355 case PT_MIPS_REGINFO:
356 case PT_MIPS_ABIFLAGS:
357 continue;
358
359 case PT_LOAD:
360 /* Writable (data) segment? */
361 if (ph[i].p_flags & PF_W) {
362 struct sect ndata, nbss;
363
364 ndata.vaddr = ph[i].p_vaddr;
365 ndata.len = ph[i].p_filesz;
366 nbss.vaddr = ph[i].p_vaddr + ph[i].p_filesz;
367 nbss.len = ph[i].p_memsz - ph[i].p_filesz;
368
369 combine(&data, &ndata, 0);
370 combine(&bss, &nbss, 1);
371 } else {
372 struct sect ntxt;
373
374 ntxt.vaddr = ph[i].p_vaddr;
375 ntxt.len = ph[i].p_filesz;
376
377 combine(&text, &ntxt, 0);
378 }
379 /* Remember the lowest segment start address. */
380 if (ph[i].p_vaddr < cur_vma)
381 cur_vma = ph[i].p_vaddr;
382 break;
383
384 default:
385 /* Section types we can't handle... */
386 fprintf(stderr,
387 "Program header %d type %d can't be converted.\n",
388 ex.e_phnum, ph[i].p_type);
389 exit(1);
390 }
391 }
392
393 /* Sections must be in order to be converted... */
394 if (text.vaddr > data.vaddr || data.vaddr > bss.vaddr ||
395 text.vaddr + text.len > data.vaddr
396 || data.vaddr + data.len > bss.vaddr) {
397 fprintf(stderr,
398 "Sections ordering prevents a.out conversion.\n");
399 exit(1);
400 }
401
402 /* If there's a data section but no text section, then the loader
403 combined everything into one section. That needs to be the
404 text section, so just make the data section zero length following
405 text. */
406 if (data.len && !text.len) {
407 text = data;
408 data.vaddr = text.vaddr + text.len;
409 data.len = 0;
410 }
411
412 /* If there is a gap between text and data, we'll fill it when we copy
413 the data, so update the length of the text segment as represented in
414 a.out to reflect that, since a.out doesn't allow gaps in the program
415 address space. */
416 if (text.vaddr + text.len < data.vaddr)
417 text.len = data.vaddr - text.vaddr;
418
419 /* We now have enough information to cons up an a.out header... */
420 eah.magic = OMAGIC;
421 eah.vstamp = 200;
422 eah.tsize = text.len;
423 eah.dsize = data.len;
424 eah.bsize = bss.len;
425 eah.entry = ex.e_entry;
426 eah.text_start = text.vaddr;
427 eah.data_start = data.vaddr;
428 eah.bss_start = bss.vaddr;
429 eah.gprmask = 0xf3fffffe;
430 memset(&eah.cprmask, '\0', sizeof eah.cprmask);
431 eah.gp_value = 0; /* unused. */
432
433 if (format_bigendian)
434 efh.f_magic = MIPSEBMAGIC;
435 else
436 efh.f_magic = MIPSELMAGIC;
437 if (addflag)
438 nosecs = 6;
439 else
440 nosecs = 3;
441 efh.f_nscns = nosecs;
442 efh.f_timdat = 0; /* bogus */
443 efh.f_symptr = 0;
444 efh.f_nsyms = 0;
445 efh.f_opthdr = sizeof eah;
446 efh.f_flags = 0x100f; /* Stripped, not shareable. */
447
448 memset(esecs, 0, sizeof esecs);
449 strcpy(esecs[0].s_name, ".text");
450 strcpy(esecs[1].s_name, ".data");
451 strcpy(esecs[2].s_name, ".bss");
452 if (addflag) {
453 strcpy(esecs[3].s_name, ".rdata");
454 strcpy(esecs[4].s_name, ".sdata");
455 strcpy(esecs[5].s_name, ".sbss");
456 }
457 esecs[0].s_paddr = esecs[0].s_vaddr = eah.text_start;
458 esecs[1].s_paddr = esecs[1].s_vaddr = eah.data_start;
459 esecs[2].s_paddr = esecs[2].s_vaddr = eah.bss_start;
460 if (addflag) {
461 esecs[3].s_paddr = esecs[3].s_vaddr = 0;
462 esecs[4].s_paddr = esecs[4].s_vaddr = 0;
463 esecs[5].s_paddr = esecs[5].s_vaddr = 0;
464 }
465 esecs[0].s_size = eah.tsize;
466 esecs[1].s_size = eah.dsize;
467 esecs[2].s_size = eah.bsize;
468 if (addflag) {
469 esecs[3].s_size = 0;
470 esecs[4].s_size = 0;
471 esecs[5].s_size = 0;
472 }
473 esecs[0].s_scnptr = N_TXTOFF(efh, eah);
474 esecs[1].s_scnptr = N_DATOFF(efh, eah);
475#define ECOFF_SEGMENT_ALIGNMENT(a) 0x10
476#define ECOFF_ROUND(s, a) (((s)+(a)-1)&~((a)-1))
477 esecs[2].s_scnptr = esecs[1].s_scnptr +
478 ECOFF_ROUND(esecs[1].s_size, ECOFF_SEGMENT_ALIGNMENT(&eah));
479 if (addflag) {
480 esecs[3].s_scnptr = 0;
481 esecs[4].s_scnptr = 0;
482 esecs[5].s_scnptr = 0;
483 }
484 esecs[0].s_relptr = esecs[1].s_relptr = esecs[2].s_relptr = 0;
485 esecs[0].s_lnnoptr = esecs[1].s_lnnoptr = esecs[2].s_lnnoptr = 0;
486 esecs[0].s_nreloc = esecs[1].s_nreloc = esecs[2].s_nreloc = 0;
487 esecs[0].s_nlnno = esecs[1].s_nlnno = esecs[2].s_nlnno = 0;
488 if (addflag) {
489 esecs[3].s_relptr = esecs[4].s_relptr
490 = esecs[5].s_relptr = 0;
491 esecs[3].s_lnnoptr = esecs[4].s_lnnoptr
492 = esecs[5].s_lnnoptr = 0;
493 esecs[3].s_nreloc = esecs[4].s_nreloc = esecs[5].s_nreloc =
494 0;
495 esecs[3].s_nlnno = esecs[4].s_nlnno = esecs[5].s_nlnno = 0;
496 }
497 esecs[0].s_flags = 0x20;
498 esecs[1].s_flags = 0x40;
499 esecs[2].s_flags = 0x82;
500 if (addflag) {
501 esecs[3].s_flags = 0x100;
502 esecs[4].s_flags = 0x200;
503 esecs[5].s_flags = 0x400;
504 }
505
506 /* Make the output file... */
507 if ((outfile = open(argv[2], O_WRONLY | O_CREAT, 0777)) < 0) {
508 fprintf(stderr, "Unable to create %s: %s\n", argv[2],
509 strerror(errno));
510 exit(1);
511 }
512
513 if (must_convert_endian)
514 convert_ecoff_filehdr(&efh);
515 /* Write the headers... */
516 i = write(outfile, &efh, sizeof efh);
517 if (i != sizeof efh) {
518 perror("efh: write");
519 exit(1);
520
521 for (i = 0; i < nosecs; i++) {
522 printf
523 ("Section %d: %s phys %"PRIx32" size %"PRIx32"\t file offset %"PRIx32"\n",
524 i, esecs[i].s_name, esecs[i].s_paddr,
525 esecs[i].s_size, esecs[i].s_scnptr);
526 }
527 }
528 fprintf(stderr, "wrote %d byte file header.\n", i);
529
530 if (must_convert_endian)
531 convert_ecoff_aouthdr(&eah);
532 i = write(outfile, &eah, sizeof eah);
533 if (i != sizeof eah) {
534 perror("eah: write");
535 exit(1);
536 }
537 fprintf(stderr, "wrote %d byte a.out header.\n", i);
538
539 if (must_convert_endian)
540 convert_ecoff_esecs(&esecs[0], nosecs);
541 i = write(outfile, &esecs, nosecs * sizeof(struct scnhdr));
542 if (i != nosecs * sizeof(struct scnhdr)) {
543 perror("esecs: write");
544 exit(1);
545 }
546 fprintf(stderr, "wrote %d bytes of section headers.\n", i);
547
548 pad = (sizeof(efh) + sizeof(eah) + nosecs * sizeof(struct scnhdr)) & 15;
549 if (pad) {
550 pad = 16 - pad;
551 i = write(outfile, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0", pad);
552 if (i < 0) {
553 perror("ipad: write");
554 exit(1);
555 }
556 fprintf(stderr, "wrote %d byte pad.\n", i);
557 }
558
559 /*
560 * Copy the loadable sections. Zero-fill any gaps less than 64k;
561 * complain about any zero-filling, and die if we're asked to zero-fill
562 * more than 64k.
563 */
564 for (i = 0; i < ex.e_phnum; i++) {
565 /* Unprocessable sections were handled above, so just verify that
566 the section can be loaded before copying. */
567 if (ph[i].p_type == PT_LOAD && ph[i].p_filesz) {
568 if (cur_vma != ph[i].p_vaddr) {
569 uint32_t gap = ph[i].p_vaddr - cur_vma;
570 char obuf[1024];
571 if (gap > 65536) {
572 fprintf(stderr,
573 "Intersegment gap (%"PRId32" bytes) too large.\n",
574 gap);
575 exit(1);
576 }
577 fprintf(stderr,
578 "Warning: %d byte intersegment gap.\n",
579 gap);
580 memset(obuf, 0, sizeof obuf);
581 while (gap) {
582 int count =
583 write(outfile, obuf,
584 (gap >
585 sizeof obuf ? sizeof
586 obuf : gap));
587 if (count < 0) {
588 fprintf(stderr,
589 "Error writing gap: %s\n",
590 strerror(errno));
591 exit(1);
592 }
593 gap -= count;
594 }
595 }
596 fprintf(stderr, "writing %d bytes...\n",
597 ph[i].p_filesz);
598 copy(outfile, infile, ph[i].p_offset,
599 ph[i].p_filesz);
600 cur_vma = ph[i].p_vaddr + ph[i].p_filesz;
601 }
602 }
603
604 /*
605 * Write a page of padding for boot PROMS that read entire pages.
606 * Without this, they may attempt to read past the end of the
607 * data section, incur an error, and refuse to boot.
608 */
609 {
610 char obuf[4096];
611 memset(obuf, 0, sizeof obuf);
612 if (write(outfile, obuf, sizeof(obuf)) != sizeof(obuf)) {
613 fprintf(stderr, "Error writing PROM padding: %s\n",
614 strerror(errno));
615 exit(1);
616 }
617 }
618
619 /* Looks like we won... */
620 exit(0);
621}