xref: /linux/scripts/dtc/flattree.c (revision ddc4097b77bbb227851a44287acb2fb8a9896cc1)
1 /*
2  * (C) Copyright David Gibson <dwg@au1.ibm.com>, IBM Corporation.  2005.
3  *
4  *
5  * This program is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU General Public License as
7  * published by the Free Software Foundation; either version 2 of the
8  * License, or (at your option) any later version.
9  *
10  *  This program is distributed in the hope that it will be useful,
11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13  *  General Public License for more details.
14  *
15  *  You should have received a copy of the GNU General Public License
16  *  along with this program; if not, write to the Free Software
17  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
18  *                                                                   USA
19  */
20 
21 #include "dtc.h"
22 #include "srcpos.h"
23 
24 #define FTF_FULLPATH	0x1
25 #define FTF_VARALIGN	0x2
26 #define FTF_NAMEPROPS	0x4
27 #define FTF_BOOTCPUID	0x8
28 #define FTF_STRTABSIZE	0x10
29 #define FTF_STRUCTSIZE	0x20
30 #define FTF_NOPS	0x40
31 
32 static struct version_info {
33 	int version;
34 	int last_comp_version;
35 	int hdr_size;
36 	int flags;
37 } version_table[] = {
38 	{1, 1, FDT_V1_SIZE,
39 	 FTF_FULLPATH|FTF_VARALIGN|FTF_NAMEPROPS},
40 	{2, 1, FDT_V2_SIZE,
41 	 FTF_FULLPATH|FTF_VARALIGN|FTF_NAMEPROPS|FTF_BOOTCPUID},
42 	{3, 1, FDT_V3_SIZE,
43 	 FTF_FULLPATH|FTF_VARALIGN|FTF_NAMEPROPS|FTF_BOOTCPUID|FTF_STRTABSIZE},
44 	{16, 16, FDT_V3_SIZE,
45 	 FTF_BOOTCPUID|FTF_STRTABSIZE|FTF_NOPS},
46 	{17, 16, FDT_V17_SIZE,
47 	 FTF_BOOTCPUID|FTF_STRTABSIZE|FTF_STRUCTSIZE|FTF_NOPS},
48 };
49 
50 struct emitter {
51 	void (*cell)(void *, cell_t);
52 	void (*string)(void *, char *, int);
53 	void (*align)(void *, int);
54 	void (*data)(void *, struct data);
55 	void (*beginnode)(void *, const char *);
56 	void (*endnode)(void *, const char *);
57 	void (*property)(void *, const char *);
58 };
59 
60 static void bin_emit_cell(void *e, cell_t val)
61 {
62 	struct data *dtbuf = e;
63 
64 	*dtbuf = data_append_cell(*dtbuf, val);
65 }
66 
67 static void bin_emit_string(void *e, char *str, int len)
68 {
69 	struct data *dtbuf = e;
70 
71 	if (len == 0)
72 		len = strlen(str);
73 
74 	*dtbuf = data_append_data(*dtbuf, str, len);
75 	*dtbuf = data_append_byte(*dtbuf, '\0');
76 }
77 
78 static void bin_emit_align(void *e, int a)
79 {
80 	struct data *dtbuf = e;
81 
82 	*dtbuf = data_append_align(*dtbuf, a);
83 }
84 
85 static void bin_emit_data(void *e, struct data d)
86 {
87 	struct data *dtbuf = e;
88 
89 	*dtbuf = data_append_data(*dtbuf, d.val, d.len);
90 }
91 
92 static void bin_emit_beginnode(void *e, const char *label)
93 {
94 	bin_emit_cell(e, FDT_BEGIN_NODE);
95 }
96 
97 static void bin_emit_endnode(void *e, const char *label)
98 {
99 	bin_emit_cell(e, FDT_END_NODE);
100 }
101 
102 static void bin_emit_property(void *e, const char *label)
103 {
104 	bin_emit_cell(e, FDT_PROP);
105 }
106 
107 static struct emitter bin_emitter = {
108 	.cell = bin_emit_cell,
109 	.string = bin_emit_string,
110 	.align = bin_emit_align,
111 	.data = bin_emit_data,
112 	.beginnode = bin_emit_beginnode,
113 	.endnode = bin_emit_endnode,
114 	.property = bin_emit_property,
115 };
116 
117 static void emit_label(FILE *f, const char *prefix, const char *label)
118 {
119 	fprintf(f, "\t.globl\t%s_%s\n", prefix, label);
120 	fprintf(f, "%s_%s:\n", prefix, label);
121 	fprintf(f, "_%s_%s:\n", prefix, label);
122 }
123 
124 static void emit_offset_label(FILE *f, const char *label, int offset)
125 {
126 	fprintf(f, "\t.globl\t%s\n", label);
127 	fprintf(f, "%s\t= . + %d\n", label, offset);
128 }
129 
130 static void asm_emit_cell(void *e, cell_t val)
131 {
132 	FILE *f = e;
133 
134 	fprintf(f, "\t.long\t0x%x\n", val);
135 }
136 
137 static void asm_emit_string(void *e, char *str, int len)
138 {
139 	FILE *f = e;
140 	char c = 0;
141 
142 	if (len != 0) {
143 		/* XXX: ewww */
144 		c = str[len];
145 		str[len] = '\0';
146 	}
147 
148 	fprintf(f, "\t.string\t\"%s\"\n", str);
149 
150 	if (len != 0) {
151 		str[len] = c;
152 	}
153 }
154 
155 static void asm_emit_align(void *e, int a)
156 {
157 	FILE *f = e;
158 
159 	fprintf(f, "\t.balign\t%d\n", a);
160 }
161 
162 static void asm_emit_data(void *e, struct data d)
163 {
164 	FILE *f = e;
165 	int off = 0;
166 	struct marker *m = d.markers;
167 
168 	for_each_marker_of_type(m, LABEL)
169 		emit_offset_label(f, m->ref, m->offset);
170 
171 	while ((d.len - off) >= sizeof(uint32_t)) {
172 		fprintf(f, "\t.long\t0x%x\n",
173 			fdt32_to_cpu(*((uint32_t *)(d.val+off))));
174 		off += sizeof(uint32_t);
175 	}
176 
177 	while ((d.len - off) >= 1) {
178 		fprintf(f, "\t.byte\t0x%hhx\n", d.val[off]);
179 		off += 1;
180 	}
181 
182 	assert(off == d.len);
183 }
184 
185 static void asm_emit_beginnode(void *e, const char *label)
186 {
187 	FILE *f = e;
188 
189 	if (label) {
190 		fprintf(f, "\t.globl\t%s\n", label);
191 		fprintf(f, "%s:\n", label);
192 	}
193 	fprintf(f, "\t.long\tFDT_BEGIN_NODE\n");
194 }
195 
196 static void asm_emit_endnode(void *e, const char *label)
197 {
198 	FILE *f = e;
199 
200 	fprintf(f, "\t.long\tFDT_END_NODE\n");
201 	if (label) {
202 		fprintf(f, "\t.globl\t%s_end\n", label);
203 		fprintf(f, "%s_end:\n", label);
204 	}
205 }
206 
207 static void asm_emit_property(void *e, const char *label)
208 {
209 	FILE *f = e;
210 
211 	if (label) {
212 		fprintf(f, "\t.globl\t%s\n", label);
213 		fprintf(f, "%s:\n", label);
214 	}
215 	fprintf(f, "\t.long\tFDT_PROP\n");
216 }
217 
218 static struct emitter asm_emitter = {
219 	.cell = asm_emit_cell,
220 	.string = asm_emit_string,
221 	.align = asm_emit_align,
222 	.data = asm_emit_data,
223 	.beginnode = asm_emit_beginnode,
224 	.endnode = asm_emit_endnode,
225 	.property = asm_emit_property,
226 };
227 
228 static int stringtable_insert(struct data *d, const char *str)
229 {
230 	int i;
231 
232 	/* FIXME: do this more efficiently? */
233 
234 	for (i = 0; i < d->len; i++) {
235 		if (streq(str, d->val + i))
236 			return i;
237 	}
238 
239 	*d = data_append_data(*d, str, strlen(str)+1);
240 	return i;
241 }
242 
243 static void flatten_tree(struct node *tree, struct emitter *emit,
244 			 void *etarget, struct data *strbuf,
245 			 struct version_info *vi)
246 {
247 	struct property *prop;
248 	struct node *child;
249 	int seen_name_prop = 0;
250 
251 	emit->beginnode(etarget, tree->label);
252 
253 	if (vi->flags & FTF_FULLPATH)
254 		emit->string(etarget, tree->fullpath, 0);
255 	else
256 		emit->string(etarget, tree->name, 0);
257 
258 	emit->align(etarget, sizeof(cell_t));
259 
260 	for_each_property(tree, prop) {
261 		int nameoff;
262 
263 		if (streq(prop->name, "name"))
264 			seen_name_prop = 1;
265 
266 		nameoff = stringtable_insert(strbuf, prop->name);
267 
268 		emit->property(etarget, prop->label);
269 		emit->cell(etarget, prop->val.len);
270 		emit->cell(etarget, nameoff);
271 
272 		if ((vi->flags & FTF_VARALIGN) && (prop->val.len >= 8))
273 			emit->align(etarget, 8);
274 
275 		emit->data(etarget, prop->val);
276 		emit->align(etarget, sizeof(cell_t));
277 	}
278 
279 	if ((vi->flags & FTF_NAMEPROPS) && !seen_name_prop) {
280 		emit->property(etarget, NULL);
281 		emit->cell(etarget, tree->basenamelen+1);
282 		emit->cell(etarget, stringtable_insert(strbuf, "name"));
283 
284 		if ((vi->flags & FTF_VARALIGN) && ((tree->basenamelen+1) >= 8))
285 			emit->align(etarget, 8);
286 
287 		emit->string(etarget, tree->name, tree->basenamelen);
288 		emit->align(etarget, sizeof(cell_t));
289 	}
290 
291 	for_each_child(tree, child) {
292 		flatten_tree(child, emit, etarget, strbuf, vi);
293 	}
294 
295 	emit->endnode(etarget, tree->label);
296 }
297 
298 static struct data flatten_reserve_list(struct reserve_info *reservelist,
299 				 struct version_info *vi)
300 {
301 	struct reserve_info *re;
302 	struct data d = empty_data;
303 	static struct fdt_reserve_entry null_re = {0,0};
304 	int    j;
305 
306 	for (re = reservelist; re; re = re->next) {
307 		d = data_append_re(d, &re->re);
308 	}
309 	/*
310 	 * Add additional reserved slots if the user asked for them.
311 	 */
312 	for (j = 0; j < reservenum; j++) {
313 		d = data_append_re(d, &null_re);
314 	}
315 
316 	return d;
317 }
318 
319 static void make_fdt_header(struct fdt_header *fdt,
320 			    struct version_info *vi,
321 			    int reservesize, int dtsize, int strsize,
322 			    int boot_cpuid_phys)
323 {
324 	int reserve_off;
325 
326 	reservesize += sizeof(struct fdt_reserve_entry);
327 
328 	memset(fdt, 0xff, sizeof(*fdt));
329 
330 	fdt->magic = cpu_to_fdt32(FDT_MAGIC);
331 	fdt->version = cpu_to_fdt32(vi->version);
332 	fdt->last_comp_version = cpu_to_fdt32(vi->last_comp_version);
333 
334 	/* Reserve map should be doubleword aligned */
335 	reserve_off = ALIGN(vi->hdr_size, 8);
336 
337 	fdt->off_mem_rsvmap = cpu_to_fdt32(reserve_off);
338 	fdt->off_dt_struct = cpu_to_fdt32(reserve_off + reservesize);
339 	fdt->off_dt_strings = cpu_to_fdt32(reserve_off + reservesize
340 					  + dtsize);
341 	fdt->totalsize = cpu_to_fdt32(reserve_off + reservesize + dtsize + strsize);
342 
343 	if (vi->flags & FTF_BOOTCPUID)
344 		fdt->boot_cpuid_phys = cpu_to_fdt32(boot_cpuid_phys);
345 	if (vi->flags & FTF_STRTABSIZE)
346 		fdt->size_dt_strings = cpu_to_fdt32(strsize);
347 	if (vi->flags & FTF_STRUCTSIZE)
348 		fdt->size_dt_struct = cpu_to_fdt32(dtsize);
349 }
350 
351 void dt_to_blob(FILE *f, struct boot_info *bi, int version)
352 {
353 	struct version_info *vi = NULL;
354 	int i;
355 	struct data blob       = empty_data;
356 	struct data reservebuf = empty_data;
357 	struct data dtbuf      = empty_data;
358 	struct data strbuf     = empty_data;
359 	struct fdt_header fdt;
360 	int padlen = 0;
361 
362 	for (i = 0; i < ARRAY_SIZE(version_table); i++) {
363 		if (version_table[i].version == version)
364 			vi = &version_table[i];
365 	}
366 	if (!vi)
367 		die("Unknown device tree blob version %d\n", version);
368 
369 	flatten_tree(bi->dt, &bin_emitter, &dtbuf, &strbuf, vi);
370 	bin_emit_cell(&dtbuf, FDT_END);
371 
372 	reservebuf = flatten_reserve_list(bi->reservelist, vi);
373 
374 	/* Make header */
375 	make_fdt_header(&fdt, vi, reservebuf.len, dtbuf.len, strbuf.len,
376 			bi->boot_cpuid_phys);
377 
378 	/*
379 	 * If the user asked for more space than is used, adjust the totalsize.
380 	 */
381 	if (minsize > 0) {
382 		padlen = minsize - fdt32_to_cpu(fdt.totalsize);
383 		if ((padlen < 0) && (quiet < 1))
384 			fprintf(stderr,
385 				"Warning: blob size %d >= minimum size %d\n",
386 				fdt32_to_cpu(fdt.totalsize), minsize);
387 	}
388 
389 	if (padsize > 0)
390 		padlen = padsize;
391 
392 	if (padlen > 0) {
393 		int tsize = fdt32_to_cpu(fdt.totalsize);
394 		tsize += padlen;
395 		fdt.totalsize = cpu_to_fdt32(tsize);
396 	}
397 
398 	/*
399 	 * Assemble the blob: start with the header, add with alignment
400 	 * the reserve buffer, add the reserve map terminating zeroes,
401 	 * the device tree itself, and finally the strings.
402 	 */
403 	blob = data_append_data(blob, &fdt, vi->hdr_size);
404 	blob = data_append_align(blob, 8);
405 	blob = data_merge(blob, reservebuf);
406 	blob = data_append_zeroes(blob, sizeof(struct fdt_reserve_entry));
407 	blob = data_merge(blob, dtbuf);
408 	blob = data_merge(blob, strbuf);
409 
410 	/*
411 	 * If the user asked for more space than is used, pad out the blob.
412 	 */
413 	if (padlen > 0)
414 		blob = data_append_zeroes(blob, padlen);
415 
416 	fwrite(blob.val, blob.len, 1, f);
417 
418 	if (ferror(f))
419 		die("Error writing device tree blob: %s\n", strerror(errno));
420 
421 	/*
422 	 * data_merge() frees the right-hand element so only the blob
423 	 * remains to be freed.
424 	 */
425 	data_free(blob);
426 }
427 
428 static void dump_stringtable_asm(FILE *f, struct data strbuf)
429 {
430 	const char *p;
431 	int len;
432 
433 	p = strbuf.val;
434 
435 	while (p < (strbuf.val + strbuf.len)) {
436 		len = strlen(p);
437 		fprintf(f, "\t.string \"%s\"\n", p);
438 		p += len+1;
439 	}
440 }
441 
442 void dt_to_asm(FILE *f, struct boot_info *bi, int version)
443 {
444 	struct version_info *vi = NULL;
445 	int i;
446 	struct data strbuf = empty_data;
447 	struct reserve_info *re;
448 	const char *symprefix = "dt";
449 
450 	for (i = 0; i < ARRAY_SIZE(version_table); i++) {
451 		if (version_table[i].version == version)
452 			vi = &version_table[i];
453 	}
454 	if (!vi)
455 		die("Unknown device tree blob version %d\n", version);
456 
457 	fprintf(f, "/* autogenerated by dtc, do not edit */\n\n");
458 	fprintf(f, "#define FDT_MAGIC 0x%x\n", FDT_MAGIC);
459 	fprintf(f, "#define FDT_BEGIN_NODE 0x%x\n", FDT_BEGIN_NODE);
460 	fprintf(f, "#define FDT_END_NODE 0x%x\n", FDT_END_NODE);
461 	fprintf(f, "#define FDT_PROP 0x%x\n", FDT_PROP);
462 	fprintf(f, "#define FDT_END 0x%x\n", FDT_END);
463 	fprintf(f, "\n");
464 
465 	emit_label(f, symprefix, "blob_start");
466 	emit_label(f, symprefix, "header");
467 	fprintf(f, "\t.long\tFDT_MAGIC\t\t\t\t/* magic */\n");
468 	fprintf(f, "\t.long\t_%s_blob_abs_end - _%s_blob_start\t/* totalsize */\n",
469 		symprefix, symprefix);
470 	fprintf(f, "\t.long\t_%s_struct_start - _%s_blob_start\t/* off_dt_struct */\n",
471 		symprefix, symprefix);
472 	fprintf(f, "\t.long\t_%s_strings_start - _%s_blob_start\t/* off_dt_strings */\n",
473 		symprefix, symprefix);
474 	fprintf(f, "\t.long\t_%s_reserve_map - _%s_blob_start\t/* off_dt_strings */\n",
475 		symprefix, symprefix);
476 	fprintf(f, "\t.long\t%d\t\t\t\t\t/* version */\n", vi->version);
477 	fprintf(f, "\t.long\t%d\t\t\t\t\t/* last_comp_version */\n",
478 		vi->last_comp_version);
479 
480 	if (vi->flags & FTF_BOOTCPUID)
481 		fprintf(f, "\t.long\t%i\t\t\t\t\t/* boot_cpuid_phys */\n",
482 			bi->boot_cpuid_phys);
483 
484 	if (vi->flags & FTF_STRTABSIZE)
485 		fprintf(f, "\t.long\t_%s_strings_end - _%s_strings_start\t/* size_dt_strings */\n",
486 			symprefix, symprefix);
487 
488 	if (vi->flags & FTF_STRUCTSIZE)
489 		fprintf(f, "\t.long\t_%s_struct_end - _%s_struct_start\t/* size_dt_struct */\n",
490 			symprefix, symprefix);
491 
492 	/*
493 	 * Reserve map entries.
494 	 * Align the reserve map to a doubleword boundary.
495 	 * Each entry is an (address, size) pair of u64 values.
496 	 * Always supply a zero-sized temination entry.
497 	 */
498 	asm_emit_align(f, 8);
499 	emit_label(f, symprefix, "reserve_map");
500 
501 	fprintf(f, "/* Memory reserve map from source file */\n");
502 
503 	/*
504 	 * Use .long on high and low halfs of u64s to avoid .quad
505 	 * as it appears .quad isn't available in some assemblers.
506 	 */
507 	for (re = bi->reservelist; re; re = re->next) {
508 		if (re->label) {
509 			fprintf(f, "\t.globl\t%s\n", re->label);
510 			fprintf(f, "%s:\n", re->label);
511 		}
512 		fprintf(f, "\t.long\t0x%08x, 0x%08x\n",
513 			(unsigned int)(re->re.address >> 32),
514 			(unsigned int)(re->re.address & 0xffffffff));
515 		fprintf(f, "\t.long\t0x%08x, 0x%08x\n",
516 			(unsigned int)(re->re.size >> 32),
517 			(unsigned int)(re->re.size & 0xffffffff));
518 	}
519 	for (i = 0; i < reservenum; i++) {
520 		fprintf(f, "\t.long\t0, 0\n\t.long\t0, 0\n");
521 	}
522 
523 	fprintf(f, "\t.long\t0, 0\n\t.long\t0, 0\n");
524 
525 	emit_label(f, symprefix, "struct_start");
526 	flatten_tree(bi->dt, &asm_emitter, f, &strbuf, vi);
527 	fprintf(f, "\t.long\tFDT_END\n");
528 	emit_label(f, symprefix, "struct_end");
529 
530 	emit_label(f, symprefix, "strings_start");
531 	dump_stringtable_asm(f, strbuf);
532 	emit_label(f, symprefix, "strings_end");
533 
534 	emit_label(f, symprefix, "blob_end");
535 
536 	/*
537 	 * If the user asked for more space than is used, pad it out.
538 	 */
539 	if (minsize > 0) {
540 		fprintf(f, "\t.space\t%d - (_%s_blob_end - _%s_blob_start), 0\n",
541 			minsize, symprefix, symprefix);
542 	}
543 	if (padsize > 0) {
544 		fprintf(f, "\t.space\t%d, 0\n", padsize);
545 	}
546 	emit_label(f, symprefix, "blob_abs_end");
547 
548 	data_free(strbuf);
549 }
550 
551 struct inbuf {
552 	char *base, *limit, *ptr;
553 };
554 
555 static void inbuf_init(struct inbuf *inb, void *base, void *limit)
556 {
557 	inb->base = base;
558 	inb->limit = limit;
559 	inb->ptr = inb->base;
560 }
561 
562 static void flat_read_chunk(struct inbuf *inb, void *p, int len)
563 {
564 	if ((inb->ptr + len) > inb->limit)
565 		die("Premature end of data parsing flat device tree\n");
566 
567 	memcpy(p, inb->ptr, len);
568 
569 	inb->ptr += len;
570 }
571 
572 static uint32_t flat_read_word(struct inbuf *inb)
573 {
574 	uint32_t val;
575 
576 	assert(((inb->ptr - inb->base) % sizeof(val)) == 0);
577 
578 	flat_read_chunk(inb, &val, sizeof(val));
579 
580 	return fdt32_to_cpu(val);
581 }
582 
583 static void flat_realign(struct inbuf *inb, int align)
584 {
585 	int off = inb->ptr - inb->base;
586 
587 	inb->ptr = inb->base + ALIGN(off, align);
588 	if (inb->ptr > inb->limit)
589 		die("Premature end of data parsing flat device tree\n");
590 }
591 
592 static char *flat_read_string(struct inbuf *inb)
593 {
594 	int len = 0;
595 	const char *p = inb->ptr;
596 	char *str;
597 
598 	do {
599 		if (p >= inb->limit)
600 			die("Premature end of data parsing flat device tree\n");
601 		len++;
602 	} while ((*p++) != '\0');
603 
604 	str = strdup(inb->ptr);
605 
606 	inb->ptr += len;
607 
608 	flat_realign(inb, sizeof(uint32_t));
609 
610 	return str;
611 }
612 
613 static struct data flat_read_data(struct inbuf *inb, int len)
614 {
615 	struct data d = empty_data;
616 
617 	if (len == 0)
618 		return empty_data;
619 
620 	d = data_grow_for(d, len);
621 	d.len = len;
622 
623 	flat_read_chunk(inb, d.val, len);
624 
625 	flat_realign(inb, sizeof(uint32_t));
626 
627 	return d;
628 }
629 
630 static char *flat_read_stringtable(struct inbuf *inb, int offset)
631 {
632 	const char *p;
633 
634 	p = inb->base + offset;
635 	while (1) {
636 		if (p >= inb->limit || p < inb->base)
637 			die("String offset %d overruns string table\n",
638 			    offset);
639 
640 		if (*p == '\0')
641 			break;
642 
643 		p++;
644 	}
645 
646 	return strdup(inb->base + offset);
647 }
648 
649 static struct property *flat_read_property(struct inbuf *dtbuf,
650 					   struct inbuf *strbuf, int flags)
651 {
652 	uint32_t proplen, stroff;
653 	char *name;
654 	struct data val;
655 
656 	proplen = flat_read_word(dtbuf);
657 	stroff = flat_read_word(dtbuf);
658 
659 	name = flat_read_stringtable(strbuf, stroff);
660 
661 	if ((flags & FTF_VARALIGN) && (proplen >= 8))
662 		flat_realign(dtbuf, 8);
663 
664 	val = flat_read_data(dtbuf, proplen);
665 
666 	return build_property(name, val, NULL);
667 }
668 
669 
670 static struct reserve_info *flat_read_mem_reserve(struct inbuf *inb)
671 {
672 	struct reserve_info *reservelist = NULL;
673 	struct reserve_info *new;
674 	const char *p;
675 	struct fdt_reserve_entry re;
676 
677 	/*
678 	 * Each entry is a pair of u64 (addr, size) values for 4 cell_t's.
679 	 * List terminates at an entry with size equal to zero.
680 	 *
681 	 * First pass, count entries.
682 	 */
683 	p = inb->ptr;
684 	while (1) {
685 		flat_read_chunk(inb, &re, sizeof(re));
686 		re.address  = fdt64_to_cpu(re.address);
687 		re.size = fdt64_to_cpu(re.size);
688 		if (re.size == 0)
689 			break;
690 
691 		new = build_reserve_entry(re.address, re.size, NULL);
692 		reservelist = add_reserve_entry(reservelist, new);
693 	}
694 
695 	return reservelist;
696 }
697 
698 
699 static char *nodename_from_path(const char *ppath, const char *cpath)
700 {
701 	int plen;
702 
703 	plen = strlen(ppath);
704 
705 	if (!strneq(ppath, cpath, plen))
706 		die("Path \"%s\" is not valid as a child of \"%s\"\n",
707 		    cpath, ppath);
708 
709 	/* root node is a special case */
710 	if (!streq(ppath, "/"))
711 		plen++;
712 
713 	return strdup(cpath + plen);
714 }
715 
716 static struct node *unflatten_tree(struct inbuf *dtbuf,
717 				   struct inbuf *strbuf,
718 				   const char *parent_flatname, int flags)
719 {
720 	struct node *node;
721 	char *flatname;
722 	uint32_t val;
723 
724 	node = build_node(NULL, NULL);
725 
726 	flatname = flat_read_string(dtbuf);
727 
728 	if (flags & FTF_FULLPATH)
729 		node->name = nodename_from_path(parent_flatname, flatname);
730 	else
731 		node->name = flatname;
732 
733 	do {
734 		struct property *prop;
735 		struct node *child;
736 
737 		val = flat_read_word(dtbuf);
738 		switch (val) {
739 		case FDT_PROP:
740 			if (node->children)
741 				fprintf(stderr, "Warning: Flat tree input has "
742 					"subnodes preceding a property.\n");
743 			prop = flat_read_property(dtbuf, strbuf, flags);
744 			add_property(node, prop);
745 			break;
746 
747 		case FDT_BEGIN_NODE:
748 			child = unflatten_tree(dtbuf,strbuf, flatname, flags);
749 			add_child(node, child);
750 			break;
751 
752 		case FDT_END_NODE:
753 			break;
754 
755 		case FDT_END:
756 			die("Premature FDT_END in device tree blob\n");
757 			break;
758 
759 		case FDT_NOP:
760 			if (!(flags & FTF_NOPS))
761 				fprintf(stderr, "Warning: NOP tag found in flat tree"
762 					" version <16\n");
763 
764 			/* Ignore */
765 			break;
766 
767 		default:
768 			die("Invalid opcode word %08x in device tree blob\n",
769 			    val);
770 		}
771 	} while (val != FDT_END_NODE);
772 
773 	return node;
774 }
775 
776 
777 struct boot_info *dt_from_blob(const char *fname)
778 {
779 	struct dtc_file *dtcf;
780 	uint32_t magic, totalsize, version, size_dt, boot_cpuid_phys;
781 	uint32_t off_dt, off_str, off_mem_rsvmap;
782 	int rc;
783 	char *blob;
784 	struct fdt_header *fdt;
785 	char *p;
786 	struct inbuf dtbuf, strbuf;
787 	struct inbuf memresvbuf;
788 	int sizeleft;
789 	struct reserve_info *reservelist;
790 	struct node *tree;
791 	uint32_t val;
792 	int flags = 0;
793 
794 	dtcf = dtc_open_file(fname, NULL);
795 
796 	rc = fread(&magic, sizeof(magic), 1, dtcf->file);
797 	if (ferror(dtcf->file))
798 		die("Error reading DT blob magic number: %s\n",
799 		    strerror(errno));
800 	if (rc < 1) {
801 		if (feof(dtcf->file))
802 			die("EOF reading DT blob magic number\n");
803 		else
804 			die("Mysterious short read reading magic number\n");
805 	}
806 
807 	magic = fdt32_to_cpu(magic);
808 	if (magic != FDT_MAGIC)
809 		die("Blob has incorrect magic number\n");
810 
811 	rc = fread(&totalsize, sizeof(totalsize), 1, dtcf->file);
812 	if (ferror(dtcf->file))
813 		die("Error reading DT blob size: %s\n", strerror(errno));
814 	if (rc < 1) {
815 		if (feof(dtcf->file))
816 			die("EOF reading DT blob size\n");
817 		else
818 			die("Mysterious short read reading blob size\n");
819 	}
820 
821 	totalsize = fdt32_to_cpu(totalsize);
822 	if (totalsize < FDT_V1_SIZE)
823 		die("DT blob size (%d) is too small\n", totalsize);
824 
825 	blob = xmalloc(totalsize);
826 
827 	fdt = (struct fdt_header *)blob;
828 	fdt->magic = cpu_to_fdt32(magic);
829 	fdt->totalsize = cpu_to_fdt32(totalsize);
830 
831 	sizeleft = totalsize - sizeof(magic) - sizeof(totalsize);
832 	p = blob + sizeof(magic)  + sizeof(totalsize);
833 
834 	while (sizeleft) {
835 		if (feof(dtcf->file))
836 			die("EOF before reading %d bytes of DT blob\n",
837 			    totalsize);
838 
839 		rc = fread(p, 1, sizeleft, dtcf->file);
840 		if (ferror(dtcf->file))
841 			die("Error reading DT blob: %s\n",
842 			    strerror(errno));
843 
844 		sizeleft -= rc;
845 		p += rc;
846 	}
847 
848 	off_dt = fdt32_to_cpu(fdt->off_dt_struct);
849 	off_str = fdt32_to_cpu(fdt->off_dt_strings);
850 	off_mem_rsvmap = fdt32_to_cpu(fdt->off_mem_rsvmap);
851 	version = fdt32_to_cpu(fdt->version);
852 	boot_cpuid_phys = fdt32_to_cpu(fdt->boot_cpuid_phys);
853 
854 	if (off_mem_rsvmap >= totalsize)
855 		die("Mem Reserve structure offset exceeds total size\n");
856 
857 	if (off_dt >= totalsize)
858 		die("DT structure offset exceeds total size\n");
859 
860 	if (off_str > totalsize)
861 		die("String table offset exceeds total size\n");
862 
863 	if (version >= 3) {
864 		uint32_t size_str = fdt32_to_cpu(fdt->size_dt_strings);
865 		if (off_str+size_str > totalsize)
866 			die("String table extends past total size\n");
867 		inbuf_init(&strbuf, blob + off_str, blob + off_str + size_str);
868 	} else {
869 		inbuf_init(&strbuf, blob + off_str, blob + totalsize);
870 	}
871 
872 	if (version >= 17) {
873 		size_dt = fdt32_to_cpu(fdt->size_dt_struct);
874 		if (off_dt+size_dt > totalsize)
875 			die("Structure block extends past total size\n");
876 	}
877 
878 	if (version < 16) {
879 		flags |= FTF_FULLPATH | FTF_NAMEPROPS | FTF_VARALIGN;
880 	} else {
881 		flags |= FTF_NOPS;
882 	}
883 
884 	inbuf_init(&memresvbuf,
885 		   blob + off_mem_rsvmap, blob + totalsize);
886 	inbuf_init(&dtbuf, blob + off_dt, blob + totalsize);
887 
888 	reservelist = flat_read_mem_reserve(&memresvbuf);
889 
890 	val = flat_read_word(&dtbuf);
891 
892 	if (val != FDT_BEGIN_NODE)
893 		die("Device tree blob doesn't begin with FDT_BEGIN_NODE (begins with 0x%08x)\n", val);
894 
895 	tree = unflatten_tree(&dtbuf, &strbuf, "", flags);
896 
897 	val = flat_read_word(&dtbuf);
898 	if (val != FDT_END)
899 		die("Device tree blob doesn't end with FDT_END\n");
900 
901 	free(blob);
902 
903 	dtc_close_file(dtcf);
904 
905 	return build_boot_info(reservelist, tree, boot_cpuid_phys);
906 }
907