xref: /openbmc/linux/scripts/dtc/flattree.c (revision b9b77222)
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 *, const char *, int);
53 	void (*align)(void *, int);
54 	void (*data)(void *, struct data);
55 	void (*beginnode)(void *, struct label *labels);
56 	void (*endnode)(void *, struct label *labels);
57 	void (*property)(void *, struct label *labels);
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, const 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, struct label *labels)
93 {
94 	bin_emit_cell(e, FDT_BEGIN_NODE);
95 }
96 
97 static void bin_emit_endnode(void *e, struct label *labels)
98 {
99 	bin_emit_cell(e, FDT_END_NODE);
100 }
101 
102 static void bin_emit_property(void *e, struct label *labels)
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 #define ASM_EMIT_BELONG(f, fmt, ...) \
131 	{ \
132 		fprintf((f), "\t.byte\t((" fmt ") >> 24) & 0xff\n", __VA_ARGS__); \
133 		fprintf((f), "\t.byte\t((" fmt ") >> 16) & 0xff\n", __VA_ARGS__); \
134 		fprintf((f), "\t.byte\t((" fmt ") >> 8) & 0xff\n", __VA_ARGS__); \
135 		fprintf((f), "\t.byte\t(" fmt ") & 0xff\n", __VA_ARGS__); \
136 	}
137 
138 static void asm_emit_cell(void *e, cell_t val)
139 {
140 	FILE *f = e;
141 
142 	fprintf(f, "\t.byte 0x%02x; .byte 0x%02x; .byte 0x%02x; .byte 0x%02x\n",
143 		(val >> 24) & 0xff, (val >> 16) & 0xff,
144 		(val >> 8) & 0xff, val & 0xff);
145 }
146 
147 static void asm_emit_string(void *e, const char *str, int len)
148 {
149 	FILE *f = e;
150 
151 	if (len != 0)
152 		fprintf(f, "\t.string\t\"%.*s\"\n", len, str);
153 	else
154 		fprintf(f, "\t.string\t\"%s\"\n", str);
155 }
156 
157 static void asm_emit_align(void *e, int a)
158 {
159 	FILE *f = e;
160 
161 	fprintf(f, "\t.balign\t%d, 0\n", a);
162 }
163 
164 static void asm_emit_data(void *e, struct data d)
165 {
166 	FILE *f = e;
167 	int off = 0;
168 	struct marker *m = d.markers;
169 
170 	for_each_marker_of_type(m, LABEL)
171 		emit_offset_label(f, m->ref, m->offset);
172 
173 	while ((d.len - off) >= sizeof(uint32_t)) {
174 		asm_emit_cell(e, fdt32_to_cpu(*((fdt32_t *)(d.val+off))));
175 		off += sizeof(uint32_t);
176 	}
177 
178 	while ((d.len - off) >= 1) {
179 		fprintf(f, "\t.byte\t0x%hhx\n", d.val[off]);
180 		off += 1;
181 	}
182 
183 	assert(off == d.len);
184 }
185 
186 static void asm_emit_beginnode(void *e, struct label *labels)
187 {
188 	FILE *f = e;
189 	struct label *l;
190 
191 	for_each_label(labels, l) {
192 		fprintf(f, "\t.globl\t%s\n", l->label);
193 		fprintf(f, "%s:\n", l->label);
194 	}
195 	fprintf(f, "\t/* FDT_BEGIN_NODE */\n");
196 	asm_emit_cell(e, FDT_BEGIN_NODE);
197 }
198 
199 static void asm_emit_endnode(void *e, struct label *labels)
200 {
201 	FILE *f = e;
202 	struct label *l;
203 
204 	fprintf(f, "\t/* FDT_END_NODE */\n");
205 	asm_emit_cell(e, FDT_END_NODE);
206 	for_each_label(labels, l) {
207 		fprintf(f, "\t.globl\t%s_end\n", l->label);
208 		fprintf(f, "%s_end:\n", l->label);
209 	}
210 }
211 
212 static void asm_emit_property(void *e, struct label *labels)
213 {
214 	FILE *f = e;
215 	struct label *l;
216 
217 	for_each_label(labels, l) {
218 		fprintf(f, "\t.globl\t%s\n", l->label);
219 		fprintf(f, "%s:\n", l->label);
220 	}
221 	fprintf(f, "\t/* FDT_PROP */\n");
222 	asm_emit_cell(e, FDT_PROP);
223 }
224 
225 static struct emitter asm_emitter = {
226 	.cell = asm_emit_cell,
227 	.string = asm_emit_string,
228 	.align = asm_emit_align,
229 	.data = asm_emit_data,
230 	.beginnode = asm_emit_beginnode,
231 	.endnode = asm_emit_endnode,
232 	.property = asm_emit_property,
233 };
234 
235 static int stringtable_insert(struct data *d, const char *str)
236 {
237 	int i;
238 
239 	/* FIXME: do this more efficiently? */
240 
241 	for (i = 0; i < d->len; i++) {
242 		if (streq(str, d->val + i))
243 			return i;
244 	}
245 
246 	*d = data_append_data(*d, str, strlen(str)+1);
247 	return i;
248 }
249 
250 static void flatten_tree(struct node *tree, struct emitter *emit,
251 			 void *etarget, struct data *strbuf,
252 			 struct version_info *vi)
253 {
254 	struct property *prop;
255 	struct node *child;
256 	bool seen_name_prop = false;
257 
258 	if (tree->deleted)
259 		return;
260 
261 	emit->beginnode(etarget, tree->labels);
262 
263 	if (vi->flags & FTF_FULLPATH)
264 		emit->string(etarget, tree->fullpath, 0);
265 	else
266 		emit->string(etarget, tree->name, 0);
267 
268 	emit->align(etarget, sizeof(cell_t));
269 
270 	for_each_property(tree, prop) {
271 		int nameoff;
272 
273 		if (streq(prop->name, "name"))
274 			seen_name_prop = true;
275 
276 		nameoff = stringtable_insert(strbuf, prop->name);
277 
278 		emit->property(etarget, prop->labels);
279 		emit->cell(etarget, prop->val.len);
280 		emit->cell(etarget, nameoff);
281 
282 		if ((vi->flags & FTF_VARALIGN) && (prop->val.len >= 8))
283 			emit->align(etarget, 8);
284 
285 		emit->data(etarget, prop->val);
286 		emit->align(etarget, sizeof(cell_t));
287 	}
288 
289 	if ((vi->flags & FTF_NAMEPROPS) && !seen_name_prop) {
290 		emit->property(etarget, NULL);
291 		emit->cell(etarget, tree->basenamelen+1);
292 		emit->cell(etarget, stringtable_insert(strbuf, "name"));
293 
294 		if ((vi->flags & FTF_VARALIGN) && ((tree->basenamelen+1) >= 8))
295 			emit->align(etarget, 8);
296 
297 		emit->string(etarget, tree->name, tree->basenamelen);
298 		emit->align(etarget, sizeof(cell_t));
299 	}
300 
301 	for_each_child(tree, child) {
302 		flatten_tree(child, emit, etarget, strbuf, vi);
303 	}
304 
305 	emit->endnode(etarget, tree->labels);
306 }
307 
308 static struct data flatten_reserve_list(struct reserve_info *reservelist,
309 				 struct version_info *vi)
310 {
311 	struct reserve_info *re;
312 	struct data d = empty_data;
313 	int    j;
314 
315 	for (re = reservelist; re; re = re->next) {
316 		d = data_append_re(d, re->address, re->size);
317 	}
318 	/*
319 	 * Add additional reserved slots if the user asked for them.
320 	 */
321 	for (j = 0; j < reservenum; j++) {
322 		d = data_append_re(d, 0, 0);
323 	}
324 
325 	return d;
326 }
327 
328 static void make_fdt_header(struct fdt_header *fdt,
329 			    struct version_info *vi,
330 			    int reservesize, int dtsize, int strsize,
331 			    int boot_cpuid_phys)
332 {
333 	int reserve_off;
334 
335 	reservesize += sizeof(struct fdt_reserve_entry);
336 
337 	memset(fdt, 0xff, sizeof(*fdt));
338 
339 	fdt->magic = cpu_to_fdt32(FDT_MAGIC);
340 	fdt->version = cpu_to_fdt32(vi->version);
341 	fdt->last_comp_version = cpu_to_fdt32(vi->last_comp_version);
342 
343 	/* Reserve map should be doubleword aligned */
344 	reserve_off = ALIGN(vi->hdr_size, 8);
345 
346 	fdt->off_mem_rsvmap = cpu_to_fdt32(reserve_off);
347 	fdt->off_dt_struct = cpu_to_fdt32(reserve_off + reservesize);
348 	fdt->off_dt_strings = cpu_to_fdt32(reserve_off + reservesize
349 					  + dtsize);
350 	fdt->totalsize = cpu_to_fdt32(reserve_off + reservesize + dtsize + strsize);
351 
352 	if (vi->flags & FTF_BOOTCPUID)
353 		fdt->boot_cpuid_phys = cpu_to_fdt32(boot_cpuid_phys);
354 	if (vi->flags & FTF_STRTABSIZE)
355 		fdt->size_dt_strings = cpu_to_fdt32(strsize);
356 	if (vi->flags & FTF_STRUCTSIZE)
357 		fdt->size_dt_struct = cpu_to_fdt32(dtsize);
358 }
359 
360 void dt_to_blob(FILE *f, struct dt_info *dti, int version)
361 {
362 	struct version_info *vi = NULL;
363 	int i;
364 	struct data blob       = empty_data;
365 	struct data reservebuf = empty_data;
366 	struct data dtbuf      = empty_data;
367 	struct data strbuf     = empty_data;
368 	struct fdt_header fdt;
369 	int padlen = 0;
370 
371 	for (i = 0; i < ARRAY_SIZE(version_table); i++) {
372 		if (version_table[i].version == version)
373 			vi = &version_table[i];
374 	}
375 	if (!vi)
376 		die("Unknown device tree blob version %d\n", version);
377 
378 	flatten_tree(dti->dt, &bin_emitter, &dtbuf, &strbuf, vi);
379 	bin_emit_cell(&dtbuf, FDT_END);
380 
381 	reservebuf = flatten_reserve_list(dti->reservelist, vi);
382 
383 	/* Make header */
384 	make_fdt_header(&fdt, vi, reservebuf.len, dtbuf.len, strbuf.len,
385 			dti->boot_cpuid_phys);
386 
387 	/*
388 	 * If the user asked for more space than is used, adjust the totalsize.
389 	 */
390 	if (minsize > 0) {
391 		padlen = minsize - fdt32_to_cpu(fdt.totalsize);
392 		if (padlen < 0) {
393 			padlen = 0;
394 			if (quiet < 1)
395 				fprintf(stderr,
396 					"Warning: blob size %d >= minimum size %d\n",
397 					fdt32_to_cpu(fdt.totalsize), minsize);
398 		}
399 	}
400 
401 	if (padsize > 0)
402 		padlen = padsize;
403 
404 	if (alignsize > 0)
405 		padlen = ALIGN(fdt32_to_cpu(fdt.totalsize) + padlen, alignsize)
406 			- fdt32_to_cpu(fdt.totalsize);
407 
408 	if (padlen > 0) {
409 		int tsize = fdt32_to_cpu(fdt.totalsize);
410 		tsize += padlen;
411 		fdt.totalsize = cpu_to_fdt32(tsize);
412 	}
413 
414 	/*
415 	 * Assemble the blob: start with the header, add with alignment
416 	 * the reserve buffer, add the reserve map terminating zeroes,
417 	 * the device tree itself, and finally the strings.
418 	 */
419 	blob = data_append_data(blob, &fdt, vi->hdr_size);
420 	blob = data_append_align(blob, 8);
421 	blob = data_merge(blob, reservebuf);
422 	blob = data_append_zeroes(blob, sizeof(struct fdt_reserve_entry));
423 	blob = data_merge(blob, dtbuf);
424 	blob = data_merge(blob, strbuf);
425 
426 	/*
427 	 * If the user asked for more space than is used, pad out the blob.
428 	 */
429 	if (padlen > 0)
430 		blob = data_append_zeroes(blob, padlen);
431 
432 	if (fwrite(blob.val, blob.len, 1, f) != 1) {
433 		if (ferror(f))
434 			die("Error writing device tree blob: %s\n",
435 			    strerror(errno));
436 		else
437 			die("Short write on device tree blob\n");
438 	}
439 
440 	/*
441 	 * data_merge() frees the right-hand element so only the blob
442 	 * remains to be freed.
443 	 */
444 	data_free(blob);
445 }
446 
447 static void dump_stringtable_asm(FILE *f, struct data strbuf)
448 {
449 	const char *p;
450 	int len;
451 
452 	p = strbuf.val;
453 
454 	while (p < (strbuf.val + strbuf.len)) {
455 		len = strlen(p);
456 		fprintf(f, "\t.string \"%s\"\n", p);
457 		p += len+1;
458 	}
459 }
460 
461 void dt_to_asm(FILE *f, struct dt_info *dti, int version)
462 {
463 	struct version_info *vi = NULL;
464 	int i;
465 	struct data strbuf = empty_data;
466 	struct reserve_info *re;
467 	const char *symprefix = "dt";
468 
469 	for (i = 0; i < ARRAY_SIZE(version_table); i++) {
470 		if (version_table[i].version == version)
471 			vi = &version_table[i];
472 	}
473 	if (!vi)
474 		die("Unknown device tree blob version %d\n", version);
475 
476 	fprintf(f, "/* autogenerated by dtc, do not edit */\n\n");
477 
478 	emit_label(f, symprefix, "blob_start");
479 	emit_label(f, symprefix, "header");
480 	fprintf(f, "\t/* magic */\n");
481 	asm_emit_cell(f, FDT_MAGIC);
482 	fprintf(f, "\t/* totalsize */\n");
483 	ASM_EMIT_BELONG(f, "_%s_blob_abs_end - _%s_blob_start",
484 			symprefix, symprefix);
485 	fprintf(f, "\t/* off_dt_struct */\n");
486 	ASM_EMIT_BELONG(f, "_%s_struct_start - _%s_blob_start",
487 		symprefix, symprefix);
488 	fprintf(f, "\t/* off_dt_strings */\n");
489 	ASM_EMIT_BELONG(f, "_%s_strings_start - _%s_blob_start",
490 		symprefix, symprefix);
491 	fprintf(f, "\t/* off_mem_rsvmap */\n");
492 	ASM_EMIT_BELONG(f, "_%s_reserve_map - _%s_blob_start",
493 		symprefix, symprefix);
494 	fprintf(f, "\t/* version */\n");
495 	asm_emit_cell(f, vi->version);
496 	fprintf(f, "\t/* last_comp_version */\n");
497 	asm_emit_cell(f, vi->last_comp_version);
498 
499 	if (vi->flags & FTF_BOOTCPUID) {
500 		fprintf(f, "\t/* boot_cpuid_phys */\n");
501 		asm_emit_cell(f, dti->boot_cpuid_phys);
502 	}
503 
504 	if (vi->flags & FTF_STRTABSIZE) {
505 		fprintf(f, "\t/* size_dt_strings */\n");
506 		ASM_EMIT_BELONG(f, "_%s_strings_end - _%s_strings_start",
507 				symprefix, symprefix);
508 	}
509 
510 	if (vi->flags & FTF_STRUCTSIZE) {
511 		fprintf(f, "\t/* size_dt_struct */\n");
512 		ASM_EMIT_BELONG(f, "_%s_struct_end - _%s_struct_start",
513 			symprefix, symprefix);
514 	}
515 
516 	/*
517 	 * Reserve map entries.
518 	 * Align the reserve map to a doubleword boundary.
519 	 * Each entry is an (address, size) pair of u64 values.
520 	 * Always supply a zero-sized temination entry.
521 	 */
522 	asm_emit_align(f, 8);
523 	emit_label(f, symprefix, "reserve_map");
524 
525 	fprintf(f, "/* Memory reserve map from source file */\n");
526 
527 	/*
528 	 * Use .long on high and low halfs of u64s to avoid .quad
529 	 * as it appears .quad isn't available in some assemblers.
530 	 */
531 	for (re = dti->reservelist; re; re = re->next) {
532 		struct label *l;
533 
534 		for_each_label(re->labels, l) {
535 			fprintf(f, "\t.globl\t%s\n", l->label);
536 			fprintf(f, "%s:\n", l->label);
537 		}
538 		ASM_EMIT_BELONG(f, "0x%08x", (unsigned int)(re->address >> 32));
539 		ASM_EMIT_BELONG(f, "0x%08x",
540 				(unsigned int)(re->address & 0xffffffff));
541 		ASM_EMIT_BELONG(f, "0x%08x", (unsigned int)(re->size >> 32));
542 		ASM_EMIT_BELONG(f, "0x%08x", (unsigned int)(re->size & 0xffffffff));
543 	}
544 	for (i = 0; i < reservenum; i++) {
545 		fprintf(f, "\t.long\t0, 0\n\t.long\t0, 0\n");
546 	}
547 
548 	fprintf(f, "\t.long\t0, 0\n\t.long\t0, 0\n");
549 
550 	emit_label(f, symprefix, "struct_start");
551 	flatten_tree(dti->dt, &asm_emitter, f, &strbuf, vi);
552 
553 	fprintf(f, "\t/* FDT_END */\n");
554 	asm_emit_cell(f, FDT_END);
555 	emit_label(f, symprefix, "struct_end");
556 
557 	emit_label(f, symprefix, "strings_start");
558 	dump_stringtable_asm(f, strbuf);
559 	emit_label(f, symprefix, "strings_end");
560 
561 	emit_label(f, symprefix, "blob_end");
562 
563 	/*
564 	 * If the user asked for more space than is used, pad it out.
565 	 */
566 	if (minsize > 0) {
567 		fprintf(f, "\t.space\t%d - (_%s_blob_end - _%s_blob_start), 0\n",
568 			minsize, symprefix, symprefix);
569 	}
570 	if (padsize > 0) {
571 		fprintf(f, "\t.space\t%d, 0\n", padsize);
572 	}
573 	if (alignsize > 0)
574 		asm_emit_align(f, alignsize);
575 	emit_label(f, symprefix, "blob_abs_end");
576 
577 	data_free(strbuf);
578 }
579 
580 struct inbuf {
581 	char *base, *limit, *ptr;
582 };
583 
584 static void inbuf_init(struct inbuf *inb, void *base, void *limit)
585 {
586 	inb->base = base;
587 	inb->limit = limit;
588 	inb->ptr = inb->base;
589 }
590 
591 static void flat_read_chunk(struct inbuf *inb, void *p, int len)
592 {
593 	if ((inb->ptr + len) > inb->limit)
594 		die("Premature end of data parsing flat device tree\n");
595 
596 	memcpy(p, inb->ptr, len);
597 
598 	inb->ptr += len;
599 }
600 
601 static uint32_t flat_read_word(struct inbuf *inb)
602 {
603 	fdt32_t val;
604 
605 	assert(((inb->ptr - inb->base) % sizeof(val)) == 0);
606 
607 	flat_read_chunk(inb, &val, sizeof(val));
608 
609 	return fdt32_to_cpu(val);
610 }
611 
612 static void flat_realign(struct inbuf *inb, int align)
613 {
614 	int off = inb->ptr - inb->base;
615 
616 	inb->ptr = inb->base + ALIGN(off, align);
617 	if (inb->ptr > inb->limit)
618 		die("Premature end of data parsing flat device tree\n");
619 }
620 
621 static char *flat_read_string(struct inbuf *inb)
622 {
623 	int len = 0;
624 	const char *p = inb->ptr;
625 	char *str;
626 
627 	do {
628 		if (p >= inb->limit)
629 			die("Premature end of data parsing flat device tree\n");
630 		len++;
631 	} while ((*p++) != '\0');
632 
633 	str = xstrdup(inb->ptr);
634 
635 	inb->ptr += len;
636 
637 	flat_realign(inb, sizeof(uint32_t));
638 
639 	return str;
640 }
641 
642 static struct data flat_read_data(struct inbuf *inb, int len)
643 {
644 	struct data d = empty_data;
645 
646 	if (len == 0)
647 		return empty_data;
648 
649 	d = data_grow_for(d, len);
650 	d.len = len;
651 
652 	flat_read_chunk(inb, d.val, len);
653 
654 	flat_realign(inb, sizeof(uint32_t));
655 
656 	return d;
657 }
658 
659 static char *flat_read_stringtable(struct inbuf *inb, int offset)
660 {
661 	const char *p;
662 
663 	p = inb->base + offset;
664 	while (1) {
665 		if (p >= inb->limit || p < inb->base)
666 			die("String offset %d overruns string table\n",
667 			    offset);
668 
669 		if (*p == '\0')
670 			break;
671 
672 		p++;
673 	}
674 
675 	return xstrdup(inb->base + offset);
676 }
677 
678 static struct property *flat_read_property(struct inbuf *dtbuf,
679 					   struct inbuf *strbuf, int flags)
680 {
681 	uint32_t proplen, stroff;
682 	char *name;
683 	struct data val;
684 
685 	proplen = flat_read_word(dtbuf);
686 	stroff = flat_read_word(dtbuf);
687 
688 	name = flat_read_stringtable(strbuf, stroff);
689 
690 	if ((flags & FTF_VARALIGN) && (proplen >= 8))
691 		flat_realign(dtbuf, 8);
692 
693 	val = flat_read_data(dtbuf, proplen);
694 
695 	return build_property(name, val);
696 }
697 
698 
699 static struct reserve_info *flat_read_mem_reserve(struct inbuf *inb)
700 {
701 	struct reserve_info *reservelist = NULL;
702 	struct reserve_info *new;
703 	struct fdt_reserve_entry re;
704 
705 	/*
706 	 * Each entry is a pair of u64 (addr, size) values for 4 cell_t's.
707 	 * List terminates at an entry with size equal to zero.
708 	 *
709 	 * First pass, count entries.
710 	 */
711 	while (1) {
712 		uint64_t address, size;
713 
714 		flat_read_chunk(inb, &re, sizeof(re));
715 		address  = fdt64_to_cpu(re.address);
716 		size = fdt64_to_cpu(re.size);
717 		if (size == 0)
718 			break;
719 
720 		new = build_reserve_entry(address, size);
721 		reservelist = add_reserve_entry(reservelist, new);
722 	}
723 
724 	return reservelist;
725 }
726 
727 
728 static char *nodename_from_path(const char *ppath, const char *cpath)
729 {
730 	int plen;
731 
732 	plen = strlen(ppath);
733 
734 	if (!strstarts(cpath, ppath))
735 		die("Path \"%s\" is not valid as a child of \"%s\"\n",
736 		    cpath, ppath);
737 
738 	/* root node is a special case */
739 	if (!streq(ppath, "/"))
740 		plen++;
741 
742 	return xstrdup(cpath + plen);
743 }
744 
745 static struct node *unflatten_tree(struct inbuf *dtbuf,
746 				   struct inbuf *strbuf,
747 				   const char *parent_flatname, int flags)
748 {
749 	struct node *node;
750 	char *flatname;
751 	uint32_t val;
752 
753 	node = build_node(NULL, NULL);
754 
755 	flatname = flat_read_string(dtbuf);
756 
757 	if (flags & FTF_FULLPATH)
758 		node->name = nodename_from_path(parent_flatname, flatname);
759 	else
760 		node->name = flatname;
761 
762 	do {
763 		struct property *prop;
764 		struct node *child;
765 
766 		val = flat_read_word(dtbuf);
767 		switch (val) {
768 		case FDT_PROP:
769 			if (node->children)
770 				fprintf(stderr, "Warning: Flat tree input has "
771 					"subnodes preceding a property.\n");
772 			prop = flat_read_property(dtbuf, strbuf, flags);
773 			add_property(node, prop);
774 			break;
775 
776 		case FDT_BEGIN_NODE:
777 			child = unflatten_tree(dtbuf,strbuf, flatname, flags);
778 			add_child(node, child);
779 			break;
780 
781 		case FDT_END_NODE:
782 			break;
783 
784 		case FDT_END:
785 			die("Premature FDT_END in device tree blob\n");
786 			break;
787 
788 		case FDT_NOP:
789 			if (!(flags & FTF_NOPS))
790 				fprintf(stderr, "Warning: NOP tag found in flat tree"
791 					" version <16\n");
792 
793 			/* Ignore */
794 			break;
795 
796 		default:
797 			die("Invalid opcode word %08x in device tree blob\n",
798 			    val);
799 		}
800 	} while (val != FDT_END_NODE);
801 
802 	if (node->name != flatname) {
803 		free(flatname);
804 	}
805 
806 	return node;
807 }
808 
809 
810 struct dt_info *dt_from_blob(const char *fname)
811 {
812 	FILE *f;
813 	fdt32_t magic_buf, totalsize_buf;
814 	uint32_t magic, totalsize, version, size_dt, boot_cpuid_phys;
815 	uint32_t off_dt, off_str, off_mem_rsvmap;
816 	int rc;
817 	char *blob;
818 	struct fdt_header *fdt;
819 	char *p;
820 	struct inbuf dtbuf, strbuf;
821 	struct inbuf memresvbuf;
822 	int sizeleft;
823 	struct reserve_info *reservelist;
824 	struct node *tree;
825 	uint32_t val;
826 	int flags = 0;
827 
828 	f = srcfile_relative_open(fname, NULL);
829 
830 	rc = fread(&magic_buf, sizeof(magic_buf), 1, f);
831 	if (ferror(f))
832 		die("Error reading DT blob magic number: %s\n",
833 		    strerror(errno));
834 	if (rc < 1) {
835 		if (feof(f))
836 			die("EOF reading DT blob magic number\n");
837 		else
838 			die("Mysterious short read reading magic number\n");
839 	}
840 
841 	magic = fdt32_to_cpu(magic_buf);
842 	if (magic != FDT_MAGIC)
843 		die("Blob has incorrect magic number\n");
844 
845 	rc = fread(&totalsize_buf, sizeof(totalsize_buf), 1, f);
846 	if (ferror(f))
847 		die("Error reading DT blob size: %s\n", strerror(errno));
848 	if (rc < 1) {
849 		if (feof(f))
850 			die("EOF reading DT blob size\n");
851 		else
852 			die("Mysterious short read reading blob size\n");
853 	}
854 
855 	totalsize = fdt32_to_cpu(totalsize_buf);
856 	if (totalsize < FDT_V1_SIZE)
857 		die("DT blob size (%d) is too small\n", totalsize);
858 
859 	blob = xmalloc(totalsize);
860 
861 	fdt = (struct fdt_header *)blob;
862 	fdt->magic = cpu_to_fdt32(magic);
863 	fdt->totalsize = cpu_to_fdt32(totalsize);
864 
865 	sizeleft = totalsize - sizeof(magic) - sizeof(totalsize);
866 	p = blob + sizeof(magic)  + sizeof(totalsize);
867 
868 	while (sizeleft) {
869 		if (feof(f))
870 			die("EOF before reading %d bytes of DT blob\n",
871 			    totalsize);
872 
873 		rc = fread(p, 1, sizeleft, f);
874 		if (ferror(f))
875 			die("Error reading DT blob: %s\n",
876 			    strerror(errno));
877 
878 		sizeleft -= rc;
879 		p += rc;
880 	}
881 
882 	off_dt = fdt32_to_cpu(fdt->off_dt_struct);
883 	off_str = fdt32_to_cpu(fdt->off_dt_strings);
884 	off_mem_rsvmap = fdt32_to_cpu(fdt->off_mem_rsvmap);
885 	version = fdt32_to_cpu(fdt->version);
886 	boot_cpuid_phys = fdt32_to_cpu(fdt->boot_cpuid_phys);
887 
888 	if (off_mem_rsvmap >= totalsize)
889 		die("Mem Reserve structure offset exceeds total size\n");
890 
891 	if (off_dt >= totalsize)
892 		die("DT structure offset exceeds total size\n");
893 
894 	if (off_str > totalsize)
895 		die("String table offset exceeds total size\n");
896 
897 	if (version >= 3) {
898 		uint32_t size_str = fdt32_to_cpu(fdt->size_dt_strings);
899 		if ((off_str+size_str < off_str) || (off_str+size_str > totalsize))
900 			die("String table extends past total size\n");
901 		inbuf_init(&strbuf, blob + off_str, blob + off_str + size_str);
902 	} else {
903 		inbuf_init(&strbuf, blob + off_str, blob + totalsize);
904 	}
905 
906 	if (version >= 17) {
907 		size_dt = fdt32_to_cpu(fdt->size_dt_struct);
908 		if ((off_dt+size_dt < off_dt) || (off_dt+size_dt > totalsize))
909 			die("Structure block extends past total size\n");
910 	}
911 
912 	if (version < 16) {
913 		flags |= FTF_FULLPATH | FTF_NAMEPROPS | FTF_VARALIGN;
914 	} else {
915 		flags |= FTF_NOPS;
916 	}
917 
918 	inbuf_init(&memresvbuf,
919 		   blob + off_mem_rsvmap, blob + totalsize);
920 	inbuf_init(&dtbuf, blob + off_dt, blob + totalsize);
921 
922 	reservelist = flat_read_mem_reserve(&memresvbuf);
923 
924 	val = flat_read_word(&dtbuf);
925 
926 	if (val != FDT_BEGIN_NODE)
927 		die("Device tree blob doesn't begin with FDT_BEGIN_NODE (begins with 0x%08x)\n", val);
928 
929 	tree = unflatten_tree(&dtbuf, &strbuf, "", flags);
930 
931 	val = flat_read_word(&dtbuf);
932 	if (val != FDT_END)
933 		die("Device tree blob doesn't end with FDT_END\n");
934 
935 	free(blob);
936 
937 	fclose(f);
938 
939 	return build_dt_info(DTSF_V1, reservelist, tree, boot_cpuid_phys);
940 }
941