xref: /freebsd/contrib/elftoolchain/elfcopy/ascii.c (revision dd41de95a84d979615a2ef11df6850622bf6184e)
1 /*-
2  * Copyright (c) 2010,2011 Kai Wang
3  * All rights reserved.
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  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/param.h>
28 #include <ctype.h>
29 #include <err.h>
30 #include <gelf.h>
31 #include <stdint.h>
32 #include <stdio.h>
33 #include <stdlib.h>
34 #include <string.h>
35 #include <unistd.h>
36 
37 #include "elfcopy.h"
38 
39 ELFTC_VCSID("$Id: ascii.c 3757 2019-06-28 01:15:28Z emaste $");
40 
41 static void append_data(struct section *s, const void *buf, size_t sz);
42 static char hex_digit(uint8_t n);
43 static int hex_value(int x);
44 static void finalize_data_section(struct section *s);
45 static int ishexdigit(int x);
46 static int ihex_read(const char *line, char *type, uint64_t *addr,
47     uint64_t *num, uint8_t *data, size_t *sz);
48 static void ihex_write(int ofd, int type, uint64_t addr, uint64_t num,
49     const void *buf, size_t sz);
50 static void ihex_write_00(int ofd, uint64_t addr, const void *buf, size_t sz);
51 static void ihex_write_01(int ofd);
52 static void ihex_write_04(int ofd, uint16_t addr);
53 static void ihex_write_05(int ofd, uint64_t e_entry);
54 static struct section *new_data_section(struct elfcopy *ecp, int sec_index,
55     uint64_t off, uint64_t addr);
56 static int read_num(const char *line, int *len, uint64_t *num, size_t sz,
57     int *checksum);
58 static int srec_read(const char *line, char *type, uint64_t *addr,
59     uint8_t *data, size_t *sz);
60 static void srec_write(int ofd, char type, uint64_t addr, const void *buf,
61     size_t sz);
62 static void srec_write_symtab(int ofd, const char *ofn, Elf *e, Elf_Scn *scn,
63     GElf_Shdr *sh);
64 static void srec_write_S0(int ofd, const char *ofn);
65 static void srec_write_Sd(int ofd, char dr, uint64_t addr, const void *buf,
66     size_t sz, size_t rlen);
67 static void srec_write_Se(int ofd, uint64_t e_entry, int forceS3);
68 static void write_num(char *line, int *len, uint64_t num, size_t sz,
69     int *checksum);
70 
71 #define	_LINE_BUFSZ	1024
72 #define	_DATA_BUFSZ	256
73 
74 /*
75  * Convert ELF object to S-Record.
76  */
77 void
78 create_srec(struct elfcopy *ecp, int ifd, int ofd, const char *ofn)
79 {
80 	Elf *e;
81 	Elf_Scn *scn;
82 	Elf_Data *d;
83 	GElf_Ehdr eh;
84 	GElf_Shdr sh;
85 	uint64_t max_addr;
86 	size_t rlen;
87 	int elferr, addr_sz;
88 	char dr;
89 
90 	if ((e = elf_begin(ifd, ELF_C_READ, NULL)) == NULL)
91 		errx(EXIT_FAILURE, "elf_begin() failed: %s",
92 		    elf_errmsg(-1));
93 
94 	/* Output a symbol table for `symbolsrec' target. */
95 	if (!strncmp(ecp->otgt, "symbolsrec", strlen("symbolsrec"))) {
96 		scn = NULL;
97 		while ((scn = elf_nextscn(e, scn)) != NULL) {
98 			if (gelf_getshdr(scn, &sh) == NULL) {
99 				warnx("gelf_getshdr failed: %s",
100 				    elf_errmsg(-1));
101 				(void) elf_errno();
102 				continue;
103 			}
104 			if (sh.sh_type != SHT_SYMTAB)
105 				continue;
106 			srec_write_symtab(ofd, ofn, e, scn, &sh);
107 			break;
108 		}
109 	}
110 
111 	if (ecp->flags & SREC_FORCE_S3)
112 		dr = '3';
113 	else {
114 		/*
115 		 * Find maximum address size in the first iteration.
116 		 */
117 		max_addr = 0;
118 		scn = NULL;
119 		while ((scn = elf_nextscn(e, scn)) != NULL) {
120 			if (gelf_getshdr(scn, &sh) == NULL) {
121 				warnx("gelf_getshdr failed: %s",
122 				    elf_errmsg(-1));
123 				(void) elf_errno();
124 				continue;
125 			}
126 			if ((sh.sh_flags & SHF_ALLOC) == 0 ||
127 			    sh.sh_type == SHT_NOBITS ||
128 			    sh.sh_size == 0)
129 				continue;
130 			if ((uint64_t) sh.sh_addr > max_addr)
131 				max_addr = sh.sh_addr;
132 		}
133 		elferr = elf_errno();
134 		if (elferr != 0)
135 			warnx("elf_nextscn failed: %s", elf_errmsg(elferr));
136 
137 		if (max_addr <= 0xFFFF)
138 			dr = '1';
139 		else if (max_addr <= 0xFFFFFF)
140 			dr = '2';
141 		else
142 			dr = '3';
143 	}
144 
145 	if (ecp->flags & SREC_FORCE_LEN) {
146 		addr_sz = dr - '0' + 1;
147 		if (ecp->srec_len < 1)
148 			rlen = 1;
149 		else if (ecp->srec_len + addr_sz + 1 > 255)
150 			rlen = 255 - (addr_sz + 1);
151 		else
152 			rlen = ecp->srec_len;
153 	} else
154 		rlen = 16;
155 
156 	/* Generate S0 record which contains the output filename. */
157 	srec_write_S0(ofd, ofn);
158 
159 	/* Generate S{1,2,3} data records for section data. */
160 	scn = NULL;
161 	while ((scn = elf_nextscn(e, scn)) != NULL) {
162 		if (gelf_getshdr(scn, &sh) == NULL) {
163 			warnx("gelf_getshdr failed: %s", elf_errmsg(-1));
164 			(void) elf_errno();
165 			continue;
166 		}
167 		if ((sh.sh_flags & SHF_ALLOC) == 0 ||
168 		    sh.sh_type == SHT_NOBITS ||
169 		    sh.sh_size == 0)
170 			continue;
171 		if (sh.sh_addr > 0xFFFFFFFF) {
172 			warnx("address space too big for S-Record file");
173 			continue;
174 		}
175 		(void) elf_errno();
176 		if ((d = elf_getdata(scn, NULL)) == NULL) {
177 			elferr = elf_errno();
178 			if (elferr != 0)
179 				warnx("elf_getdata failed: %s", elf_errmsg(-1));
180 			continue;
181 		}
182 		if (d->d_buf == NULL || d->d_size == 0)
183 			continue;
184 		srec_write_Sd(ofd, dr, sh.sh_addr, d->d_buf, d->d_size, rlen);
185 	}
186 	elferr = elf_errno();
187 	if (elferr != 0)
188 		warnx("elf_nextscn failed: %s", elf_errmsg(elferr));
189 
190 	/* Generate S{7,8,9} end of block record. */
191 	if (gelf_getehdr(e, &eh) == NULL)
192 		errx(EXIT_FAILURE, "gelf_getehdr() failed: %s",
193 		    elf_errmsg(-1));
194 	srec_write_Se(ofd, eh.e_entry, ecp->flags & SREC_FORCE_S3);
195 }
196 
197 void
198 create_elf_from_srec(struct elfcopy *ecp, int ifd)
199 {
200 	char line[_LINE_BUFSZ], name[_LINE_BUFSZ];
201 	uint8_t data[_DATA_BUFSZ];
202 	GElf_Ehdr oeh;
203 	struct section *s, *shtab;
204 	FILE *ifp;
205 	uint64_t addr, entry, off, sec_addr;
206 	uintmax_t st_value;
207 	size_t sz;
208 	int _ifd, first, sec_index, in_symtab, symtab_created;
209 	char *rlt;
210 	char type;
211 
212 	if ((_ifd = dup(ifd)) < 0)
213 		err(EXIT_FAILURE, "dup failed");
214 	if ((ifp = fdopen(_ifd, "r")) == NULL)
215 		err(EXIT_FAILURE, "fdopen failed");
216 
217 	/* Create EHDR for output .o file. */
218 	if (gelf_newehdr(ecp->eout, ecp->oec) == NULL)
219 		errx(EXIT_FAILURE, "gelf_newehdr failed: %s",
220 		    elf_errmsg(-1));
221 	if (gelf_getehdr(ecp->eout, &oeh) == NULL)
222 		errx(EXIT_FAILURE, "gelf_getehdr() failed: %s",
223 		    elf_errmsg(-1));
224 
225 	/* Initialise e_ident fields. */
226 	oeh.e_ident[EI_CLASS] = ecp->oec;
227 	oeh.e_ident[EI_DATA] = ecp->oed;
228 	/*
229 	 * TODO: Set OSABI according to the OS platform where elfcopy(1)
230 	 * was build. (probably)
231 	 */
232 	oeh.e_ident[EI_OSABI] = ELFOSABI_NONE;
233 	oeh.e_machine = ecp->oem;
234 	oeh.e_type = ET_REL;
235 	oeh.e_entry = 0;
236 
237 	ecp->flags |= RELOCATABLE;
238 
239 	/* Create .shstrtab section */
240 	init_shstrtab(ecp);
241 	ecp->shstrtab->off = 0;
242 
243 	/* Data sections are inserted after EHDR. */
244 	off = gelf_fsize(ecp->eout, ELF_T_EHDR, 1, EV_CURRENT);
245 	if (off == 0)
246 		errx(EXIT_FAILURE, "gelf_fsize() failed: %s", elf_errmsg(-1));
247 
248 	/* Create data sections. */
249 	s = NULL;
250 	first = 1;
251 	sec_index = 1;
252 	sec_addr = entry = 0;
253 	while (fgets(line, _LINE_BUFSZ, ifp) != NULL) {
254 		sz = 0;
255 		if (line[0] == '\r' || line[0] == '\n')
256 			continue;
257 		if (line[0] == '$' && line[1] == '$') {
258 			ecp->flags |= SYMTAB_EXIST;
259 			while ((rlt = fgets(line, _LINE_BUFSZ, ifp)) != NULL) {
260 				if (line[0] == '$' && line[1] == '$')
261 					break;
262 			}
263 			if (rlt == NULL)
264 				break;
265 			continue;
266 		}
267 		if (line[0] != 'S' || line[1] < '0' || line[1] > '9') {
268 			warnx("Invalid srec record");
269 			continue;
270 		}
271 		if (srec_read(line, &type, &addr, data, &sz) < 0) {
272 			warnx("Invalid srec record or mismatched checksum");
273 			continue;
274 		}
275 		switch (type) {
276 		case '1':
277 		case '2':
278 		case '3':
279 			if (sz == 0)
280 				break;
281 			if (first || sec_addr != addr) {
282 				if (s != NULL)
283 					finalize_data_section(s);
284 				s = new_data_section(ecp, sec_index, off,
285 				    addr);
286 				if (s == NULL) {
287 					warnx("new_data_section failed");
288 					break;
289 				}
290 				sec_index++;
291 				sec_addr = addr;
292 				first = 0;
293 			}
294 			append_data(s, data, sz);
295 			off += sz;
296 			sec_addr += sz;
297 			break;
298 		case '7':
299 		case '8':
300 		case '9':
301 			entry = addr;
302 			break;
303 		default:
304 			break;
305 		}
306 	}
307 	if (s != NULL)
308 		finalize_data_section(s);
309 	if (ferror(ifp))
310 		warn("fgets failed");
311 
312 	/* Insert .shstrtab after data sections. */
313 	if ((ecp->shstrtab->os = elf_newscn(ecp->eout)) == NULL)
314 		errx(EXIT_FAILURE, "elf_newscn failed: %s",
315 		    elf_errmsg(-1));
316 	insert_to_sec_list(ecp, ecp->shstrtab, 1);
317 
318 	/* Insert section header table here. */
319 	shtab = insert_shtab(ecp, 1);
320 
321 	/*
322 	 * Rescan and create symbol table if we found '$$' section in
323 	 * the first scan.
324 	 */
325 	symtab_created = 0;
326 	in_symtab = 0;
327 	if (ecp->flags & SYMTAB_EXIST) {
328 		if (fseek(ifp, 0, SEEK_SET) < 0) {
329 			warn("fseek failed");
330 			ecp->flags &= ~SYMTAB_EXIST;
331 			goto done;
332 		}
333 		while (fgets(line, _LINE_BUFSZ, ifp) != NULL) {
334 			if (in_symtab) {
335 				if (line[0] == '$' && line[1] == '$') {
336 					in_symtab = 0;
337 					continue;
338 				}
339 				if (sscanf(line, "%s $%jx", name,
340 				    &st_value) != 2) {
341 					warnx("Invalid symbolsrec record");
342 					continue;
343 				}
344 				if (!symtab_created) {
345 					create_external_symtab(ecp);
346 					symtab_created = 1;
347 				}
348 				add_to_symtab(ecp, name, st_value, 0, SHN_ABS,
349 				    ELF32_ST_INFO(STB_GLOBAL, STT_NOTYPE), 0, 1);
350 			}
351 			if (line[0] == '$' && line[1] == '$') {
352 				in_symtab = 1;
353 				continue;
354 			}
355 		}
356 	}
357 	if (ferror(ifp))
358 		warn("fgets failed");
359 	if (symtab_created) {
360 		finalize_external_symtab(ecp);
361 		create_symtab_data(ecp);
362 		/* Count in .symtab and .strtab section headers.  */
363 		shtab->sz += gelf_fsize(ecp->eout, ELF_T_SHDR, 2, EV_CURRENT);
364 	} else
365 		ecp->flags &= ~SYMTAB_EXIST;
366 
367 done:
368 	fclose(ifp);
369 
370 	/* Set entry point. */
371 	oeh.e_entry = entry;
372 
373 	/*
374 	 * Write the underlying ehdr. Note that it should be called
375 	 * before elf_setshstrndx() since it will overwrite e->e_shstrndx.
376 	 */
377 	if (gelf_update_ehdr(ecp->eout, &oeh) == 0)
378 		errx(EXIT_FAILURE, "gelf_update_ehdr() failed: %s",
379 		    elf_errmsg(-1));
380 
381 	/* Update sh_name pointer for each section header entry. */
382 	update_shdr(ecp, 0);
383 
384 	/* Renew oeh to get the updated e_shstrndx. */
385 	if (gelf_getehdr(ecp->eout, &oeh) == NULL)
386 		errx(EXIT_FAILURE, "gelf_getehdr() failed: %s",
387 		    elf_errmsg(-1));
388 
389 	/* Resync section offsets. */
390 	resync_sections(ecp);
391 
392 	/* Store SHDR offset in EHDR. */
393 	oeh.e_shoff = shtab->off;
394 
395 	/* Update ehdr since we modified e_shoff. */
396 	if (gelf_update_ehdr(ecp->eout, &oeh) == 0)
397 		errx(EXIT_FAILURE, "gelf_update_ehdr() failed: %s",
398 		    elf_errmsg(-1));
399 
400 	/* Write out the output elf object. */
401 	if (elf_update(ecp->eout, ELF_C_WRITE) < 0)
402 		errx(EXIT_FAILURE, "elf_update() failed: %s",
403 		    elf_errmsg(-1));
404 
405 	/* Release allocated resource. */
406 	free_elf(ecp);
407 }
408 
409 void
410 create_ihex(int ifd, int ofd)
411 {
412 	Elf *e;
413 	Elf_Scn *scn;
414 	Elf_Data *d;
415 	GElf_Ehdr eh;
416 	GElf_Shdr sh;
417 	int elferr;
418 	uint16_t addr_hi, old_addr_hi;
419 
420 	if ((e = elf_begin(ifd, ELF_C_READ, NULL)) == NULL)
421 		errx(EXIT_FAILURE, "elf_begin() failed: %s",
422 		    elf_errmsg(-1));
423 
424 	old_addr_hi = 0;
425 	scn = NULL;
426 	while ((scn = elf_nextscn(e, scn)) != NULL) {
427 		if (gelf_getshdr(scn, &sh) == NULL) {
428 			warnx("gelf_getshdr failed: %s", elf_errmsg(-1));
429 			(void) elf_errno();
430 			continue;
431 		}
432 		if ((sh.sh_flags & SHF_ALLOC) == 0 ||
433 		    sh.sh_type == SHT_NOBITS ||
434 		    sh.sh_size == 0)
435 			continue;
436 		if (sh.sh_addr > 0xFFFFFFFF) {
437 			warnx("address space too big for Intel Hex file");
438 			continue;
439 		}
440 		(void) elf_errno();
441 		if ((d = elf_getdata(scn, NULL)) == NULL) {
442 			elferr = elf_errno();
443 			if (elferr != 0)
444 				warnx("elf_getdata failed: %s", elf_errmsg(-1));
445 			continue;
446 		}
447 		if (d->d_buf == NULL || d->d_size == 0)
448 			continue;
449 		addr_hi = (sh.sh_addr >> 16) & 0xFFFF;
450 		if (addr_hi > 0 && addr_hi != old_addr_hi) {
451 			/* Write 04 record if addr_hi is new. */
452 			old_addr_hi = addr_hi;
453 			ihex_write_04(ofd, addr_hi);
454 		}
455 		ihex_write_00(ofd, sh.sh_addr, d->d_buf, d->d_size);
456 	}
457 	elferr = elf_errno();
458 	if (elferr != 0)
459 		warnx("elf_nextscn failed: %s", elf_errmsg(elferr));
460 
461 	if (gelf_getehdr(e, &eh) == NULL)
462 		errx(EXIT_FAILURE, "gelf_getehdr() failed: %s",
463 		    elf_errmsg(-1));
464 	ihex_write_05(ofd, eh.e_entry);
465 	ihex_write_01(ofd);
466 }
467 
468 void
469 create_elf_from_ihex(struct elfcopy *ecp, int ifd)
470 {
471 	char line[_LINE_BUFSZ];
472 	uint8_t data[_DATA_BUFSZ];
473 	GElf_Ehdr oeh;
474 	struct section *s, *shtab;
475 	FILE *ifp;
476 	uint64_t addr, addr_base, entry, num, off, rec_addr, sec_addr;
477 	size_t sz;
478 	int _ifd, first, sec_index;
479 	char type;
480 
481 	if ((_ifd = dup(ifd)) < 0)
482 		err(EXIT_FAILURE, "dup failed");
483 	if ((ifp = fdopen(_ifd, "r")) == NULL)
484 		err(EXIT_FAILURE, "fdopen failed");
485 
486 	/* Create EHDR for output .o file. */
487 	if (gelf_newehdr(ecp->eout, ecp->oec) == NULL)
488 		errx(EXIT_FAILURE, "gelf_newehdr failed: %s",
489 		    elf_errmsg(-1));
490 	if (gelf_getehdr(ecp->eout, &oeh) == NULL)
491 		errx(EXIT_FAILURE, "gelf_getehdr() failed: %s",
492 		    elf_errmsg(-1));
493 
494 	/* Initialise e_ident fields. */
495 	oeh.e_ident[EI_CLASS] = ecp->oec;
496 	oeh.e_ident[EI_DATA] = ecp->oed;
497 	/*
498 	 * TODO: Set OSABI according to the OS platform where elfcopy(1)
499 	 * was build. (probably)
500 	 */
501 	oeh.e_ident[EI_OSABI] = ELFOSABI_NONE;
502 	oeh.e_machine = ecp->oem;
503 	oeh.e_type = ET_REL;
504 	oeh.e_entry = 0;
505 
506 	ecp->flags |= RELOCATABLE;
507 
508 	/* Create .shstrtab section */
509 	init_shstrtab(ecp);
510 	ecp->shstrtab->off = 0;
511 
512 	/* Data sections are inserted after EHDR. */
513 	off = gelf_fsize(ecp->eout, ELF_T_EHDR, 1, EV_CURRENT);
514 	if (off == 0)
515 		errx(EXIT_FAILURE, "gelf_fsize() failed: %s", elf_errmsg(-1));
516 
517 	/* Create data sections. */
518 	s = NULL;
519 	first = 1;
520 	sec_index = 1;
521 	addr_base = rec_addr = sec_addr = entry = 0;
522 	while (fgets(line, _LINE_BUFSZ, ifp) != NULL) {
523 		if (line[0] == '\r' || line[0] == '\n')
524 			continue;
525 		if (line[0] != ':') {
526 			warnx("Invalid ihex record");
527 			continue;
528 		}
529 		if (ihex_read(line, &type, &addr, &num, data, &sz) < 0) {
530 			warnx("Invalid ihex record or mismatched checksum");
531 			continue;
532 		}
533 		switch (type) {
534 		case '0':
535 			/* Data record. */
536 			if (sz == 0)
537 				break;
538 			rec_addr = addr_base + addr;
539 			if (first || sec_addr != rec_addr) {
540 				if (s != NULL)
541 					finalize_data_section(s);
542 				s = new_data_section(ecp, sec_index, off,
543 				    rec_addr);
544 				if (s == NULL) {
545 					warnx("new_data_section failed");
546 					break;
547 				}
548 				sec_index++;
549 				sec_addr = rec_addr;
550 				first = 0;
551 			}
552 			append_data(s, data, sz);
553 			off += sz;
554 			sec_addr += sz;
555 			break;
556 		case '1':
557 			/* End of file record. */
558 			goto done;
559 		case '2':
560 			/* Extended segment address record. */
561 			addr_base = addr << 4;
562 			break;
563 		case '3':
564 			/* Start segment address record (CS:IP). Ignored. */
565 			break;
566 		case '4':
567 			/* Extended linear address record. */
568 			addr_base = num << 16;
569 			break;
570 		case '5':
571 			/* Start linear address record. */
572 			entry = num;
573 			break;
574 		default:
575 			break;
576 		}
577 	}
578 done:
579 	if (s != NULL)
580 		finalize_data_section(s);
581 	if (ferror(ifp))
582 		warn("fgets failed");
583 	fclose(ifp);
584 
585 	/* Insert .shstrtab after data sections. */
586 	if ((ecp->shstrtab->os = elf_newscn(ecp->eout)) == NULL)
587 		errx(EXIT_FAILURE, "elf_newscn failed: %s",
588 		    elf_errmsg(-1));
589 	insert_to_sec_list(ecp, ecp->shstrtab, 1);
590 
591 	/* Insert section header table here. */
592 	shtab = insert_shtab(ecp, 1);
593 
594 	/* Set entry point. */
595 	oeh.e_entry = entry;
596 
597 	/*
598 	 * Write the underlying ehdr. Note that it should be called
599 	 * before elf_setshstrndx() since it will overwrite e->e_shstrndx.
600 	 */
601 	if (gelf_update_ehdr(ecp->eout, &oeh) == 0)
602 		errx(EXIT_FAILURE, "gelf_update_ehdr() failed: %s",
603 		    elf_errmsg(-1));
604 
605 	/* Update sh_name pointer for each section header entry. */
606 	update_shdr(ecp, 0);
607 
608 	/* Renew oeh to get the updated e_shstrndx. */
609 	if (gelf_getehdr(ecp->eout, &oeh) == NULL)
610 		errx(EXIT_FAILURE, "gelf_getehdr() failed: %s",
611 		    elf_errmsg(-1));
612 
613 	/* Resync section offsets. */
614 	resync_sections(ecp);
615 
616 	/* Store SHDR offset in EHDR. */
617 	oeh.e_shoff = shtab->off;
618 
619 	/* Update ehdr since we modified e_shoff. */
620 	if (gelf_update_ehdr(ecp->eout, &oeh) == 0)
621 		errx(EXIT_FAILURE, "gelf_update_ehdr() failed: %s",
622 		    elf_errmsg(-1));
623 
624 	/* Write out the output elf object. */
625 	if (elf_update(ecp->eout, ELF_C_WRITE) < 0)
626 		errx(EXIT_FAILURE, "elf_update() failed: %s",
627 		    elf_errmsg(-1));
628 
629 	/* Release allocated resource. */
630 	free_elf(ecp);
631 }
632 
633 #define	_SEC_NAMESZ	64
634 #define	_SEC_INIT_CAP	1024
635 
636 static struct section *
637 new_data_section(struct elfcopy *ecp, int sec_index, uint64_t off,
638     uint64_t addr)
639 {
640 	char *name;
641 
642 	if ((name = malloc(_SEC_NAMESZ)) == NULL)
643 		errx(EXIT_FAILURE, "malloc failed");
644 	snprintf(name, _SEC_NAMESZ, ".sec%d", sec_index);
645 
646 	return (create_external_section(ecp, name, name, NULL, 0, off,
647 		SHT_PROGBITS, ELF_T_BYTE, SHF_ALLOC | SHF_WRITE, 1, addr, 0));
648 }
649 
650 static void
651 finalize_data_section(struct section *s)
652 {
653 	Elf_Data *od;
654 
655 	if ((od = elf_newdata(s->os)) == NULL)
656 		errx(EXIT_FAILURE, "elf_newdata() failed: %s",
657 		    elf_errmsg(-1));
658 	od->d_align = s->align;
659 	od->d_off = 0;
660 	od->d_buf = s->buf;
661 	od->d_size = s->sz;
662 	od->d_version = EV_CURRENT;
663 }
664 
665 static void
666 append_data(struct section *s, const void *buf, size_t sz)
667 {
668 	uint8_t *p;
669 
670 	if (s->buf == NULL) {
671 		s->sz = 0;
672 		s->cap = _SEC_INIT_CAP;
673 		if ((s->buf = malloc(s->cap)) == NULL)
674 			err(EXIT_FAILURE, "malloc failed");
675 	}
676 
677 	while (sz + s->sz > s->cap) {
678 		s->cap *= 2;
679 		if ((s->buf = realloc(s->buf, s->cap)) == NULL)
680 			err(EXIT_FAILURE, "realloc failed");
681 	}
682 
683 	p = s->buf;
684 	memcpy(&p[s->sz], buf, sz);
685 	s->sz += sz;
686 }
687 
688 static int
689 srec_read(const char *line, char *type, uint64_t *addr, uint8_t *data,
690     size_t *sz)
691 {
692 	uint64_t count, _checksum, num;
693 	size_t addr_sz;
694 	int checksum, i, len;
695 
696 	checksum = 0;
697 	len = 2;
698 	if (read_num(line, &len, &count, 1, &checksum) < 0)
699 		return (-1);
700 	*type = line[1];
701 	switch (*type) {
702 	case '0':
703 	case '1':
704 	case '5':
705 	case '9':
706 		addr_sz = 2;
707 		break;
708 	case '2':
709 	case '8':
710 		addr_sz = 3;
711 		break;
712 	case '3':
713 	case '7':
714 		addr_sz = 4;
715 		break;
716 	default:
717 		return (-1);
718 	}
719 
720 	if (read_num(line, &len, addr, addr_sz, &checksum) < 0)
721 		return (-1);
722 
723 	count -= addr_sz + 1;
724 	if (*type >= '0' && *type <= '3') {
725 		for (i = 0; (uint64_t) i < count; i++) {
726 			if (read_num(line, &len, &num, 1, &checksum) < 0)
727 				return -1;
728 			data[i] = (uint8_t) num;
729 		}
730 		*sz = count;
731 	} else
732 		*sz = 0;
733 
734 	if (read_num(line, &len, &_checksum, 1, NULL) < 0)
735 		return (-1);
736 
737 	if ((int) _checksum != (~checksum & 0xFF))
738 		return (-1);
739 
740 	return (0);
741 }
742 
743 static void
744 srec_write_symtab(int ofd, const char *ofn, Elf *e, Elf_Scn *scn, GElf_Shdr *sh)
745 {
746 	char line[_LINE_BUFSZ];
747 	GElf_Sym sym;
748 	Elf_Data *d;
749 	const char *name;
750 	size_t sc;
751 	int elferr, i;
752 
753 #define _WRITE_LINE do {						\
754 	if (write(ofd, line, strlen(line)) != (ssize_t) strlen(line)) 	\
755 		errx(EXIT_FAILURE, "write failed");				\
756 	} while (0)
757 
758 
759 	(void) elf_errno();
760 	if ((d = elf_getdata(scn, NULL)) == NULL) {
761 		elferr = elf_errno();
762 		if (elferr != 0)
763 			warnx("elf_getdata failed: %s",
764 			    elf_errmsg(-1));
765 		return;
766 	}
767 	if (d->d_buf == NULL || d->d_size == 0)
768 		return;
769 
770 	snprintf(line, sizeof(line), "$$ %s\r\n", ofn);
771 	_WRITE_LINE;
772 	sc = d->d_size / sh->sh_entsize;
773 	for (i = 1; (size_t) i < sc; i++) {
774 		if (gelf_getsym(d, i, &sym) != &sym) {
775 			warnx("gelf_getsym failed: %s", elf_errmsg(-1));
776 			continue;
777 		}
778 		if (GELF_ST_TYPE(sym.st_info) == STT_SECTION ||
779 		    GELF_ST_TYPE(sym.st_info) == STT_FILE)
780 			continue;
781 		if ((name = elf_strptr(e, sh->sh_link, sym.st_name)) == NULL) {
782 			warnx("elf_strptr failed: %s", elf_errmsg(-1));
783 			continue;
784 		}
785 		snprintf(line, sizeof(line), "  %s $%jx\r\n", name,
786 		    (uintmax_t) sym.st_value);
787 		_WRITE_LINE;
788 	}
789 	snprintf(line, sizeof(line), "$$ \r\n");
790 	_WRITE_LINE;
791 
792 #undef	_WRITE_LINE
793 }
794 
795 static void
796 srec_write_S0(int ofd, const char *ofn)
797 {
798 
799 	srec_write(ofd, '0', 0, ofn, strlen(ofn));
800 }
801 
802 static void
803 srec_write_Sd(int ofd, char dr, uint64_t addr, const void *buf, size_t sz,
804     size_t rlen)
805 {
806 	const uint8_t *p, *pe;
807 
808 	p = buf;
809 	pe = p + sz;
810 	while (pe - p >= (int) rlen) {
811 		srec_write(ofd, dr, addr, p, rlen);
812 		addr += rlen;
813 		p += rlen;
814 	}
815 	if (pe - p > 0)
816 		srec_write(ofd, dr, addr, p, pe - p);
817 }
818 
819 static void
820 srec_write_Se(int ofd, uint64_t e_entry, int forceS3)
821 {
822 	char er;
823 
824 	if (e_entry > 0xFFFFFFFF) {
825 		warnx("address space too big for S-Record file");
826 		return;
827 	}
828 
829 	if (forceS3)
830 		er = '7';
831 	else {
832 		if (e_entry <= 0xFFFF)
833 			er = '9';
834 		else if (e_entry <= 0xFFFFFF)
835 			er = '8';
836 		else
837 			er = '7';
838 	}
839 
840 	srec_write(ofd, er, e_entry, NULL, 0);
841 }
842 
843 static void
844 srec_write(int ofd, char type, uint64_t addr, const void *buf, size_t sz)
845 {
846 	char line[_LINE_BUFSZ];
847 	const uint8_t *p, *pe;
848 	int len, addr_sz, checksum;
849 
850 	if (type == '0' || type == '1' || type == '5' || type == '9')
851 		addr_sz = 2;
852 	else if (type == '2' || type == '8')
853 		addr_sz = 3;
854 	else
855 		addr_sz = 4;
856 
857 	checksum = 0;
858 	line[0] = 'S';
859 	line[1] = type;
860 	len = 2;
861 	write_num(line, &len, addr_sz + sz + 1, 1, &checksum);
862 	write_num(line, &len, addr, addr_sz, &checksum);
863 	for (p = buf, pe = p + sz; p < pe; p++)
864 		write_num(line, &len, *p, 1, &checksum);
865 	write_num(line, &len, ~checksum & 0xFF, 1, NULL);
866 	line[len++] = '\r';
867 	line[len++] = '\n';
868 	if (write(ofd, line, len) != (ssize_t) len)
869 		err(EXIT_FAILURE, "write failed");
870 }
871 
872 static void
873 ihex_write_00(int ofd, uint64_t addr, const void *buf, size_t sz)
874 {
875 	uint16_t addr_hi, old_addr_hi;
876 	const uint8_t *p, *pe;
877 
878 	old_addr_hi = (addr >> 16) & 0xFFFF;
879 	p = buf;
880 	pe = p + sz;
881 	while (pe - p >= 16) {
882 		ihex_write(ofd, 0, addr, 0, p, 16);
883 		addr += 16;
884 		p += 16;
885 		addr_hi = (addr >> 16) & 0xFFFF;
886 		if (addr_hi != old_addr_hi) {
887 			old_addr_hi = addr_hi;
888 			ihex_write_04(ofd, addr_hi);
889 		}
890 	}
891 	if (pe - p > 0)
892 		ihex_write(ofd, 0, addr, 0, p, pe - p);
893 }
894 
895 static int
896 ihex_read(const char *line, char *type, uint64_t *addr, uint64_t *num,
897     uint8_t *data, size_t *sz)
898 {
899 	uint64_t count, _checksum;
900 	int checksum, i, len;
901 
902 	*sz = 0;
903 	checksum = 0;
904 	len = 1;
905 	if (read_num(line, &len, &count, 1, &checksum) < 0)
906 		return (-1);
907 	if (read_num(line, &len, addr, 2, &checksum) < 0)
908 		return (-1);
909 	if (line[len++] != '0')
910 		return (-1);
911 	*type = line[len++];
912 	checksum += *type - '0';
913 	switch (*type) {
914 	case '0':
915 		for (i = 0; (uint64_t) i < count; i++) {
916 			if (read_num(line, &len, num, 1, &checksum) < 0)
917 				return (-1);
918 			data[i] = (uint8_t) *num;
919 		}
920 		*sz = count;
921 		break;
922 	case '1':
923 		if (count != 0)
924 			return (-1);
925 		break;
926 	case '2':
927 	case '4':
928 		if (count != 2)
929 			return (-1);
930 		if (read_num(line, &len, num, 2, &checksum) < 0)
931 			return (-1);
932 		break;
933 	case '3':
934 	case '5':
935 		if (count != 4)
936 			return (-1);
937 		if (read_num(line, &len, num, 4, &checksum) < 0)
938 			return (-1);
939 		break;
940 	default:
941 		return (-1);
942 	}
943 
944 	if (read_num(line, &len, &_checksum, 1, &checksum) < 0)
945 		return (-1);
946 
947 	if ((checksum & 0xFF) != 0) {
948 		return (-1);
949 	}
950 
951 	return (0);
952 }
953 
954 static void
955 ihex_write_01(int ofd)
956 {
957 
958 	ihex_write(ofd, 1, 0, 0, NULL, 0);
959 }
960 
961 static void
962 ihex_write_04(int ofd, uint16_t addr)
963 {
964 
965 	ihex_write(ofd, 4, 0, addr, NULL, 2);
966 }
967 
968 static void
969 ihex_write_05(int ofd, uint64_t e_entry)
970 {
971 
972 	if (e_entry > 0xFFFFFFFF) {
973 		warnx("address space too big for Intel Hex file");
974 		return;
975 	}
976 
977 	ihex_write(ofd, 5, 0, e_entry, NULL, 4);
978 }
979 
980 static void
981 ihex_write(int ofd, int type, uint64_t addr, uint64_t num, const void *buf,
982     size_t sz)
983 {
984 	char line[_LINE_BUFSZ];
985 	const uint8_t *p, *pe;
986 	int len, checksum;
987 
988 	if (sz > 16)
989 		errx(EXIT_FAILURE, "Internal: ihex_write() sz too big");
990 	checksum = 0;
991 	line[0] = ':';
992 	len = 1;
993 	write_num(line, &len, sz, 1, &checksum);
994 	write_num(line, &len, addr, 2, &checksum);
995 	write_num(line, &len, type, 1, &checksum);
996 	if (sz > 0) {
997 		if (buf != NULL) {
998 			for (p = buf, pe = p + sz; p < pe; p++)
999 				write_num(line, &len, *p, 1, &checksum);
1000 		} else
1001 			write_num(line, &len, num, sz, &checksum);
1002 	}
1003 	write_num(line, &len, (~checksum + 1) & 0xFF, 1, NULL);
1004 	line[len++] = '\r';
1005 	line[len++] = '\n';
1006 	if (write(ofd, line, len) != (ssize_t) len)
1007 		err(EXIT_FAILURE, "write failed");
1008 }
1009 
1010 static int
1011 read_num(const char *line, int *len, uint64_t *num, size_t sz, int *checksum)
1012 {
1013 	uint8_t b;
1014 
1015 	*num = 0;
1016 	for (; sz > 0; sz--) {
1017 		if (!ishexdigit(line[*len]) || !ishexdigit(line[*len + 1]))
1018 			return (-1);
1019 		b = (hex_value(line[*len]) << 4) | hex_value(line[*len + 1]);
1020 		*num = (*num << 8) | b;
1021 		*len += 2;
1022 		if (checksum != NULL)
1023 			*checksum = (*checksum + b) & 0xFF;
1024 	}
1025 
1026 	return (0);
1027 }
1028 
1029 static void
1030 write_num(char *line, int *len, uint64_t num, size_t sz, int *checksum)
1031 {
1032 	uint8_t b;
1033 
1034 	for (; sz > 0; sz--) {
1035 		b = (num >> ((sz - 1) * 8)) & 0xFF;
1036 		line[*len] = hex_digit((b >> 4) & 0xF);
1037 		line[*len + 1] = hex_digit(b & 0xF);
1038 		*len += 2;
1039 		if (checksum != NULL)
1040 			*checksum = (*checksum + b) & 0xFF;
1041 	}
1042 }
1043 
1044 static char
1045 hex_digit(uint8_t n)
1046 {
1047 
1048 	return ((n < 10) ? '0' + n : 'A' + (n - 10));
1049 }
1050 
1051 static int
1052 hex_value(int x)
1053 {
1054 
1055 	if (isdigit(x))
1056 		return (x - '0');
1057 	else if (x >= 'a' && x <= 'f')
1058 		return (x - 'a' + 10);
1059 	else
1060 		return (x - 'A' + 10);
1061 }
1062 
1063 static int
1064 ishexdigit(int x)
1065 {
1066 
1067 	if (isdigit(x))
1068 		return (1);
1069 	if ((x >= 'a' && x <= 'f') || (x >= 'A' && x <= 'F'))
1070 		return (1);
1071 
1072 	return (0);
1073 }
1074