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1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * (C) Copyright David Gibson <dwg@au1.ibm.com>, IBM Corporation.  2005.
4  */
5 
6 #include "dtc.h"
7 #include "srcpos.h"
8 
9 #define FTF_FULLPATH	0x1
10 #define FTF_VARALIGN	0x2
11 #define FTF_NAMEPROPS	0x4
12 #define FTF_BOOTCPUID	0x8
13 #define FTF_STRTABSIZE	0x10
14 #define FTF_STRUCTSIZE	0x20
15 #define FTF_NOPS	0x40
16 
17 static struct version_info {
18 	int version;
19 	int last_comp_version;
20 	int hdr_size;
21 	int flags;
22 } version_table[] = {
23 	{1, 1, FDT_V1_SIZE,
24 	 FTF_FULLPATH|FTF_VARALIGN|FTF_NAMEPROPS},
25 	{2, 1, FDT_V2_SIZE,
26 	 FTF_FULLPATH|FTF_VARALIGN|FTF_NAMEPROPS|FTF_BOOTCPUID},
27 	{3, 1, FDT_V3_SIZE,
28 	 FTF_FULLPATH|FTF_VARALIGN|FTF_NAMEPROPS|FTF_BOOTCPUID|FTF_STRTABSIZE},
29 	{16, 16, FDT_V3_SIZE,
30 	 FTF_BOOTCPUID|FTF_STRTABSIZE|FTF_NOPS},
31 	{17, 16, FDT_V17_SIZE,
32 	 FTF_BOOTCPUID|FTF_STRTABSIZE|FTF_STRUCTSIZE|FTF_NOPS},
33 };
34 
35 struct emitter {
36 	void (*cell)(void *, cell_t);
37 	void (*string)(void *, const char *, int);
38 	void (*align)(void *, int);
39 	void (*data)(void *, struct data);
40 	void (*beginnode)(void *, struct label *labels);
41 	void (*endnode)(void *, struct label *labels);
42 	void (*property)(void *, struct label *labels);
43 };
44 
bin_emit_cell(void * e,cell_t val)45 static void bin_emit_cell(void *e, cell_t val)
46 {
47 	struct data *dtbuf = e;
48 
49 	*dtbuf = data_append_cell(*dtbuf, val);
50 }
51 
bin_emit_string(void * e,const char * str,int len)52 static void bin_emit_string(void *e, const char *str, int len)
53 {
54 	struct data *dtbuf = e;
55 
56 	if (len == 0)
57 		len = strlen(str);
58 
59 	*dtbuf = data_append_data(*dtbuf, str, len);
60 	*dtbuf = data_append_byte(*dtbuf, '\0');
61 }
62 
bin_emit_align(void * e,int a)63 static void bin_emit_align(void *e, int a)
64 {
65 	struct data *dtbuf = e;
66 
67 	*dtbuf = data_append_align(*dtbuf, a);
68 }
69 
bin_emit_data(void * e,struct data d)70 static void bin_emit_data(void *e, struct data d)
71 {
72 	struct data *dtbuf = e;
73 
74 	*dtbuf = data_append_data(*dtbuf, d.val, d.len);
75 }
76 
bin_emit_beginnode(void * e,struct label * labels)77 static void bin_emit_beginnode(void *e, struct label *labels)
78 {
79 	bin_emit_cell(e, FDT_BEGIN_NODE);
80 }
81 
bin_emit_endnode(void * e,struct label * labels)82 static void bin_emit_endnode(void *e, struct label *labels)
83 {
84 	bin_emit_cell(e, FDT_END_NODE);
85 }
86 
bin_emit_property(void * e,struct label * labels)87 static void bin_emit_property(void *e, struct label *labels)
88 {
89 	bin_emit_cell(e, FDT_PROP);
90 }
91 
92 static struct emitter bin_emitter = {
93 	.cell = bin_emit_cell,
94 	.string = bin_emit_string,
95 	.align = bin_emit_align,
96 	.data = bin_emit_data,
97 	.beginnode = bin_emit_beginnode,
98 	.endnode = bin_emit_endnode,
99 	.property = bin_emit_property,
100 };
101 
emit_label(FILE * f,const char * prefix,const char * label)102 static void emit_label(FILE *f, const char *prefix, const char *label)
103 {
104 	fprintf(f, "\t.globl\t%s_%s\n", prefix, label);
105 	fprintf(f, "%s_%s:\n", prefix, label);
106 	fprintf(f, "_%s_%s:\n", prefix, label);
107 }
108 
emit_offset_label(FILE * f,const char * label,int offset)109 static void emit_offset_label(FILE *f, const char *label, int offset)
110 {
111 	fprintf(f, "\t.globl\t%s\n", label);
112 	fprintf(f, "%s\t= . + %d\n", label, offset);
113 }
114 
115 #define ASM_EMIT_BELONG(f, fmt, ...) \
116 	{ \
117 		fprintf((f), "\t.byte\t((" fmt ") >> 24) & 0xff\n", __VA_ARGS__); \
118 		fprintf((f), "\t.byte\t((" fmt ") >> 16) & 0xff\n", __VA_ARGS__); \
119 		fprintf((f), "\t.byte\t((" fmt ") >> 8) & 0xff\n", __VA_ARGS__); \
120 		fprintf((f), "\t.byte\t(" fmt ") & 0xff\n", __VA_ARGS__); \
121 	}
122 
asm_emit_cell(void * e,cell_t val)123 static void asm_emit_cell(void *e, cell_t val)
124 {
125 	FILE *f = e;
126 
127 	fprintf(f, "\t.byte 0x%02x; .byte 0x%02x; .byte 0x%02x; .byte 0x%02x\n",
128 		(val >> 24) & 0xff, (val >> 16) & 0xff,
129 		(val >> 8) & 0xff, val & 0xff);
130 }
131 
asm_emit_string(void * e,const char * str,int len)132 static void asm_emit_string(void *e, const char *str, int len)
133 {
134 	FILE *f = e;
135 
136 	if (len != 0)
137 		fprintf(f, "\t.string\t\"%.*s\"\n", len, str);
138 	else
139 		fprintf(f, "\t.string\t\"%s\"\n", str);
140 }
141 
asm_emit_align(void * e,int a)142 static void asm_emit_align(void *e, int a)
143 {
144 	FILE *f = e;
145 
146 	fprintf(f, "\t.balign\t%d, 0\n", a);
147 }
148 
asm_emit_data(void * e,struct data d)149 static void asm_emit_data(void *e, struct data d)
150 {
151 	FILE *f = e;
152 	int off = 0;
153 	struct marker *m = d.markers;
154 
155 	for_each_marker_of_type(m, LABEL)
156 		emit_offset_label(f, m->ref, m->offset);
157 
158 	while ((d.len - off) >= sizeof(uint32_t)) {
159 		asm_emit_cell(e, fdt32_to_cpu(*((fdt32_t *)(d.val+off))));
160 		off += sizeof(uint32_t);
161 	}
162 
163 	while ((d.len - off) >= 1) {
164 		fprintf(f, "\t.byte\t0x%hhx\n", d.val[off]);
165 		off += 1;
166 	}
167 
168 	assert(off == d.len);
169 }
170 
asm_emit_beginnode(void * e,struct label * labels)171 static void asm_emit_beginnode(void *e, struct label *labels)
172 {
173 	FILE *f = e;
174 	struct label *l;
175 
176 	for_each_label(labels, l) {
177 		fprintf(f, "\t.globl\t%s\n", l->label);
178 		fprintf(f, "%s:\n", l->label);
179 	}
180 	fprintf(f, "\t/* FDT_BEGIN_NODE */\n");
181 	asm_emit_cell(e, FDT_BEGIN_NODE);
182 }
183 
asm_emit_endnode(void * e,struct label * labels)184 static void asm_emit_endnode(void *e, struct label *labels)
185 {
186 	FILE *f = e;
187 	struct label *l;
188 
189 	fprintf(f, "\t/* FDT_END_NODE */\n");
190 	asm_emit_cell(e, FDT_END_NODE);
191 	for_each_label(labels, l) {
192 		fprintf(f, "\t.globl\t%s_end\n", l->label);
193 		fprintf(f, "%s_end:\n", l->label);
194 	}
195 }
196 
asm_emit_property(void * e,struct label * labels)197 static void asm_emit_property(void *e, struct label *labels)
198 {
199 	FILE *f = e;
200 	struct label *l;
201 
202 	for_each_label(labels, l) {
203 		fprintf(f, "\t.globl\t%s\n", l->label);
204 		fprintf(f, "%s:\n", l->label);
205 	}
206 	fprintf(f, "\t/* FDT_PROP */\n");
207 	asm_emit_cell(e, FDT_PROP);
208 }
209 
210 static struct emitter asm_emitter = {
211 	.cell = asm_emit_cell,
212 	.string = asm_emit_string,
213 	.align = asm_emit_align,
214 	.data = asm_emit_data,
215 	.beginnode = asm_emit_beginnode,
216 	.endnode = asm_emit_endnode,
217 	.property = asm_emit_property,
218 };
219 
stringtable_insert(struct data * d,const char * str)220 static int stringtable_insert(struct data *d, const char *str)
221 {
222 	int i;
223 
224 	/* FIXME: do this more efficiently? */
225 
226 	for (i = 0; i < d->len; i++) {
227 		if (streq(str, d->val + i))
228 			return i;
229 	}
230 
231 	*d = data_append_data(*d, str, strlen(str)+1);
232 	return i;
233 }
234 
flatten_tree(struct node * tree,struct emitter * emit,void * etarget,struct data * strbuf,struct version_info * vi)235 static void flatten_tree(struct node *tree, struct emitter *emit,
236 			 void *etarget, struct data *strbuf,
237 			 struct version_info *vi)
238 {
239 	struct property *prop;
240 	struct node *child;
241 	bool seen_name_prop = false;
242 
243 	if (tree->deleted)
244 		return;
245 
246 	emit->beginnode(etarget, tree->labels);
247 
248 	if (vi->flags & FTF_FULLPATH)
249 		emit->string(etarget, tree->fullpath, 0);
250 	else
251 		emit->string(etarget, tree->name, 0);
252 
253 	emit->align(etarget, sizeof(cell_t));
254 
255 	for_each_property(tree, prop) {
256 		int nameoff;
257 
258 		if (streq(prop->name, "name"))
259 			seen_name_prop = true;
260 
261 		nameoff = stringtable_insert(strbuf, prop->name);
262 
263 		emit->property(etarget, prop->labels);
264 		emit->cell(etarget, prop->val.len);
265 		emit->cell(etarget, nameoff);
266 
267 		if ((vi->flags & FTF_VARALIGN) && (prop->val.len >= 8))
268 			emit->align(etarget, 8);
269 
270 		emit->data(etarget, prop->val);
271 		emit->align(etarget, sizeof(cell_t));
272 	}
273 
274 	if ((vi->flags & FTF_NAMEPROPS) && !seen_name_prop) {
275 		emit->property(etarget, NULL);
276 		emit->cell(etarget, tree->basenamelen+1);
277 		emit->cell(etarget, stringtable_insert(strbuf, "name"));
278 
279 		if ((vi->flags & FTF_VARALIGN) && ((tree->basenamelen+1) >= 8))
280 			emit->align(etarget, 8);
281 
282 		emit->string(etarget, tree->name, tree->basenamelen);
283 		emit->align(etarget, sizeof(cell_t));
284 	}
285 
286 	for_each_child(tree, child) {
287 		flatten_tree(child, emit, etarget, strbuf, vi);
288 	}
289 
290 	emit->endnode(etarget, tree->labels);
291 }
292 
flatten_reserve_list(struct reserve_info * reservelist,struct version_info * vi)293 static struct data flatten_reserve_list(struct reserve_info *reservelist,
294 				 struct version_info *vi)
295 {
296 	struct reserve_info *re;
297 	struct data d = empty_data;
298 	int    j;
299 
300 	for (re = reservelist; re; re = re->next) {
301 		d = data_append_re(d, re->address, re->size);
302 	}
303 	/*
304 	 * Add additional reserved slots if the user asked for them.
305 	 */
306 	for (j = 0; j < reservenum; j++) {
307 		d = data_append_re(d, 0, 0);
308 	}
309 
310 	return d;
311 }
312 
make_fdt_header(struct fdt_header * fdt,struct version_info * vi,int reservesize,int dtsize,int strsize,int boot_cpuid_phys)313 static void make_fdt_header(struct fdt_header *fdt,
314 			    struct version_info *vi,
315 			    int reservesize, int dtsize, int strsize,
316 			    int boot_cpuid_phys)
317 {
318 	int reserve_off;
319 
320 	reservesize += sizeof(struct fdt_reserve_entry);
321 
322 	memset(fdt, 0xff, sizeof(*fdt));
323 
324 	fdt->magic = cpu_to_fdt32(FDT_MAGIC);
325 	fdt->version = cpu_to_fdt32(vi->version);
326 	fdt->last_comp_version = cpu_to_fdt32(vi->last_comp_version);
327 
328 	/* Reserve map should be doubleword aligned */
329 	reserve_off = ALIGN(vi->hdr_size, 8);
330 
331 	fdt->off_mem_rsvmap = cpu_to_fdt32(reserve_off);
332 	fdt->off_dt_struct = cpu_to_fdt32(reserve_off + reservesize);
333 	fdt->off_dt_strings = cpu_to_fdt32(reserve_off + reservesize
334 					  + dtsize);
335 	fdt->totalsize = cpu_to_fdt32(reserve_off + reservesize + dtsize + strsize);
336 
337 	if (vi->flags & FTF_BOOTCPUID)
338 		fdt->boot_cpuid_phys = cpu_to_fdt32(boot_cpuid_phys);
339 	if (vi->flags & FTF_STRTABSIZE)
340 		fdt->size_dt_strings = cpu_to_fdt32(strsize);
341 	if (vi->flags & FTF_STRUCTSIZE)
342 		fdt->size_dt_struct = cpu_to_fdt32(dtsize);
343 }
344 
dt_to_blob(FILE * f,struct dt_info * dti,int version)345 void dt_to_blob(FILE *f, struct dt_info *dti, int version)
346 {
347 	struct version_info *vi = NULL;
348 	int i;
349 	struct data blob       = empty_data;
350 	struct data reservebuf = empty_data;
351 	struct data dtbuf      = empty_data;
352 	struct data strbuf     = empty_data;
353 	struct fdt_header fdt;
354 	int padlen = 0;
355 
356 	for (i = 0; i < ARRAY_SIZE(version_table); i++) {
357 		if (version_table[i].version == version)
358 			vi = &version_table[i];
359 	}
360 	if (!vi)
361 		die("Unknown device tree blob version %d\n", version);
362 
363 	flatten_tree(dti->dt, &bin_emitter, &dtbuf, &strbuf, vi);
364 	bin_emit_cell(&dtbuf, FDT_END);
365 
366 	reservebuf = flatten_reserve_list(dti->reservelist, vi);
367 
368 	/* Make header */
369 	make_fdt_header(&fdt, vi, reservebuf.len, dtbuf.len, strbuf.len,
370 			dti->boot_cpuid_phys);
371 
372 	/*
373 	 * If the user asked for more space than is used, adjust the totalsize.
374 	 */
375 	if (minsize > 0) {
376 		padlen = minsize - fdt32_to_cpu(fdt.totalsize);
377 		if (padlen < 0) {
378 			padlen = 0;
379 			if (quiet < 1)
380 				fprintf(stderr,
381 					"Warning: blob size %"PRIu32" >= minimum size %d\n",
382 					fdt32_to_cpu(fdt.totalsize), minsize);
383 		}
384 	}
385 
386 	if (padsize > 0)
387 		padlen = padsize;
388 
389 	if (alignsize > 0)
390 		padlen = ALIGN(fdt32_to_cpu(fdt.totalsize) + padlen, alignsize)
391 			- fdt32_to_cpu(fdt.totalsize);
392 
393 	if (padlen > 0) {
394 		int tsize = fdt32_to_cpu(fdt.totalsize);
395 		tsize += padlen;
396 		fdt.totalsize = cpu_to_fdt32(tsize);
397 	}
398 
399 	/*
400 	 * Assemble the blob: start with the header, add with alignment
401 	 * the reserve buffer, add the reserve map terminating zeroes,
402 	 * the device tree itself, and finally the strings.
403 	 */
404 	blob = data_append_data(blob, &fdt, vi->hdr_size);
405 	blob = data_append_align(blob, 8);
406 	blob = data_merge(blob, reservebuf);
407 	blob = data_append_zeroes(blob, sizeof(struct fdt_reserve_entry));
408 	blob = data_merge(blob, dtbuf);
409 	blob = data_merge(blob, strbuf);
410 
411 	/*
412 	 * If the user asked for more space than is used, pad out the blob.
413 	 */
414 	if (padlen > 0)
415 		blob = data_append_zeroes(blob, padlen);
416 
417 	if (fwrite(blob.val, blob.len, 1, f) != 1) {
418 		if (ferror(f))
419 			die("Error writing device tree blob: %s\n",
420 			    strerror(errno));
421 		else
422 			die("Short write on device tree blob\n");
423 	}
424 
425 	/*
426 	 * data_merge() frees the right-hand element so only the blob
427 	 * remains to be freed.
428 	 */
429 	data_free(blob);
430 }
431 
dump_stringtable_asm(FILE * f,struct data strbuf)432 static void dump_stringtable_asm(FILE *f, struct data strbuf)
433 {
434 	const char *p;
435 	int len;
436 
437 	p = strbuf.val;
438 
439 	while (p < (strbuf.val + strbuf.len)) {
440 		len = strlen(p);
441 		fprintf(f, "\t.string \"%s\"\n", p);
442 		p += len+1;
443 	}
444 }
445 
dt_to_asm(FILE * f,struct dt_info * dti,int version)446 void dt_to_asm(FILE *f, struct dt_info *dti, int version)
447 {
448 	struct version_info *vi = NULL;
449 	int i;
450 	struct data strbuf = empty_data;
451 	struct reserve_info *re;
452 	const char *symprefix = "dt";
453 
454 	for (i = 0; i < ARRAY_SIZE(version_table); i++) {
455 		if (version_table[i].version == version)
456 			vi = &version_table[i];
457 	}
458 	if (!vi)
459 		die("Unknown device tree blob version %d\n", version);
460 
461 	fprintf(f, "/* autogenerated by dtc, do not edit */\n\n");
462 
463 	emit_label(f, symprefix, "blob_start");
464 	emit_label(f, symprefix, "header");
465 	fprintf(f, "\t/* magic */\n");
466 	asm_emit_cell(f, FDT_MAGIC);
467 	fprintf(f, "\t/* totalsize */\n");
468 	ASM_EMIT_BELONG(f, "_%s_blob_abs_end - _%s_blob_start",
469 			symprefix, symprefix);
470 	fprintf(f, "\t/* off_dt_struct */\n");
471 	ASM_EMIT_BELONG(f, "_%s_struct_start - _%s_blob_start",
472 		symprefix, symprefix);
473 	fprintf(f, "\t/* off_dt_strings */\n");
474 	ASM_EMIT_BELONG(f, "_%s_strings_start - _%s_blob_start",
475 		symprefix, symprefix);
476 	fprintf(f, "\t/* off_mem_rsvmap */\n");
477 	ASM_EMIT_BELONG(f, "_%s_reserve_map - _%s_blob_start",
478 		symprefix, symprefix);
479 	fprintf(f, "\t/* version */\n");
480 	asm_emit_cell(f, vi->version);
481 	fprintf(f, "\t/* last_comp_version */\n");
482 	asm_emit_cell(f, vi->last_comp_version);
483 
484 	if (vi->flags & FTF_BOOTCPUID) {
485 		fprintf(f, "\t/* boot_cpuid_phys */\n");
486 		asm_emit_cell(f, dti->boot_cpuid_phys);
487 	}
488 
489 	if (vi->flags & FTF_STRTABSIZE) {
490 		fprintf(f, "\t/* size_dt_strings */\n");
491 		ASM_EMIT_BELONG(f, "_%s_strings_end - _%s_strings_start",
492 				symprefix, symprefix);
493 	}
494 
495 	if (vi->flags & FTF_STRUCTSIZE) {
496 		fprintf(f, "\t/* size_dt_struct */\n");
497 		ASM_EMIT_BELONG(f, "_%s_struct_end - _%s_struct_start",
498 			symprefix, symprefix);
499 	}
500 
501 	/*
502 	 * Reserve map entries.
503 	 * Align the reserve map to a doubleword boundary.
504 	 * Each entry is an (address, size) pair of u64 values.
505 	 * Always supply a zero-sized temination entry.
506 	 */
507 	asm_emit_align(f, 8);
508 	emit_label(f, symprefix, "reserve_map");
509 
510 	fprintf(f, "/* Memory reserve map from source file */\n");
511 
512 	/*
513 	 * Use .long on high and low halves of u64s to avoid .quad
514 	 * as it appears .quad isn't available in some assemblers.
515 	 */
516 	for (re = dti->reservelist; re; re = re->next) {
517 		struct label *l;
518 
519 		for_each_label(re->labels, l) {
520 			fprintf(f, "\t.globl\t%s\n", l->label);
521 			fprintf(f, "%s:\n", l->label);
522 		}
523 		ASM_EMIT_BELONG(f, "0x%08x", (unsigned int)(re->address >> 32));
524 		ASM_EMIT_BELONG(f, "0x%08x",
525 				(unsigned int)(re->address & 0xffffffff));
526 		ASM_EMIT_BELONG(f, "0x%08x", (unsigned int)(re->size >> 32));
527 		ASM_EMIT_BELONG(f, "0x%08x", (unsigned int)(re->size & 0xffffffff));
528 	}
529 	for (i = 0; i < reservenum; i++) {
530 		fprintf(f, "\t.long\t0, 0\n\t.long\t0, 0\n");
531 	}
532 
533 	fprintf(f, "\t.long\t0, 0\n\t.long\t0, 0\n");
534 
535 	emit_label(f, symprefix, "struct_start");
536 	flatten_tree(dti->dt, &asm_emitter, f, &strbuf, vi);
537 
538 	fprintf(f, "\t/* FDT_END */\n");
539 	asm_emit_cell(f, FDT_END);
540 	emit_label(f, symprefix, "struct_end");
541 
542 	emit_label(f, symprefix, "strings_start");
543 	dump_stringtable_asm(f, strbuf);
544 	emit_label(f, symprefix, "strings_end");
545 
546 	emit_label(f, symprefix, "blob_end");
547 
548 	/*
549 	 * If the user asked for more space than is used, pad it out.
550 	 */
551 	if (minsize > 0) {
552 		fprintf(f, "\t.space\t%d - (_%s_blob_end - _%s_blob_start), 0\n",
553 			minsize, symprefix, symprefix);
554 	}
555 	if (padsize > 0) {
556 		fprintf(f, "\t.space\t%d, 0\n", padsize);
557 	}
558 	if (alignsize > 0)
559 		asm_emit_align(f, alignsize);
560 	emit_label(f, symprefix, "blob_abs_end");
561 
562 	data_free(strbuf);
563 }
564 
565 struct inbuf {
566 	char *base, *limit, *ptr;
567 };
568 
inbuf_init(struct inbuf * inb,void * base,void * limit)569 static void inbuf_init(struct inbuf *inb, void *base, void *limit)
570 {
571 	inb->base = base;
572 	inb->limit = limit;
573 	inb->ptr = inb->base;
574 }
575 
flat_read_chunk(struct inbuf * inb,void * p,int len)576 static void flat_read_chunk(struct inbuf *inb, void *p, int len)
577 {
578 	if ((inb->ptr + len) > inb->limit)
579 		die("Premature end of data parsing flat device tree\n");
580 
581 	memcpy(p, inb->ptr, len);
582 
583 	inb->ptr += len;
584 }
585 
flat_read_word(struct inbuf * inb)586 static uint32_t flat_read_word(struct inbuf *inb)
587 {
588 	fdt32_t val;
589 
590 	assert(((inb->ptr - inb->base) % sizeof(val)) == 0);
591 
592 	flat_read_chunk(inb, &val, sizeof(val));
593 
594 	return fdt32_to_cpu(val);
595 }
596 
flat_realign(struct inbuf * inb,int align)597 static void flat_realign(struct inbuf *inb, int align)
598 {
599 	int off = inb->ptr - inb->base;
600 
601 	inb->ptr = inb->base + ALIGN(off, align);
602 	if (inb->ptr > inb->limit)
603 		die("Premature end of data parsing flat device tree\n");
604 }
605 
flat_read_string(struct inbuf * inb)606 static char *flat_read_string(struct inbuf *inb)
607 {
608 	int len = 0;
609 	const char *p = inb->ptr;
610 	char *str;
611 
612 	do {
613 		if (p >= inb->limit)
614 			die("Premature end of data parsing flat device tree\n");
615 		len++;
616 	} while ((*p++) != '\0');
617 
618 	str = xstrdup(inb->ptr);
619 
620 	inb->ptr += len;
621 
622 	flat_realign(inb, sizeof(uint32_t));
623 
624 	return str;
625 }
626 
flat_read_data(struct inbuf * inb,int len)627 static struct data flat_read_data(struct inbuf *inb, int len)
628 {
629 	struct data d = empty_data;
630 
631 	if (len == 0)
632 		return empty_data;
633 
634 	d = data_grow_for(d, len);
635 	d.len = len;
636 
637 	flat_read_chunk(inb, d.val, len);
638 
639 	flat_realign(inb, sizeof(uint32_t));
640 
641 	return d;
642 }
643 
flat_read_stringtable(struct inbuf * inb,int offset)644 static char *flat_read_stringtable(struct inbuf *inb, int offset)
645 {
646 	const char *p;
647 
648 	p = inb->base + offset;
649 	while (1) {
650 		if (p >= inb->limit || p < inb->base)
651 			die("String offset %d overruns string table\n",
652 			    offset);
653 
654 		if (*p == '\0')
655 			break;
656 
657 		p++;
658 	}
659 
660 	return xstrdup(inb->base + offset);
661 }
662 
flat_read_property(struct inbuf * dtbuf,struct inbuf * strbuf,int flags)663 static struct property *flat_read_property(struct inbuf *dtbuf,
664 					   struct inbuf *strbuf, int flags)
665 {
666 	uint32_t proplen, stroff;
667 	char *name;
668 	struct data val;
669 
670 	proplen = flat_read_word(dtbuf);
671 	stroff = flat_read_word(dtbuf);
672 
673 	name = flat_read_stringtable(strbuf, stroff);
674 
675 	if ((flags & FTF_VARALIGN) && (proplen >= 8))
676 		flat_realign(dtbuf, 8);
677 
678 	val = flat_read_data(dtbuf, proplen);
679 
680 	return build_property(name, val, NULL);
681 }
682 
683 
flat_read_mem_reserve(struct inbuf * inb)684 static struct reserve_info *flat_read_mem_reserve(struct inbuf *inb)
685 {
686 	struct reserve_info *reservelist = NULL;
687 	struct reserve_info *new;
688 	struct fdt_reserve_entry re;
689 
690 	/*
691 	 * Each entry is a pair of u64 (addr, size) values for 4 cell_t's.
692 	 * List terminates at an entry with size equal to zero.
693 	 *
694 	 * First pass, count entries.
695 	 */
696 	while (1) {
697 		uint64_t address, size;
698 
699 		flat_read_chunk(inb, &re, sizeof(re));
700 		address  = fdt64_to_cpu(re.address);
701 		size = fdt64_to_cpu(re.size);
702 		if (size == 0)
703 			break;
704 
705 		new = build_reserve_entry(address, size);
706 		reservelist = add_reserve_entry(reservelist, new);
707 	}
708 
709 	return reservelist;
710 }
711 
712 
nodename_from_path(const char * ppath,const char * cpath)713 static char *nodename_from_path(const char *ppath, const char *cpath)
714 {
715 	int plen;
716 
717 	plen = strlen(ppath);
718 
719 	if (!strstarts(cpath, ppath))
720 		die("Path \"%s\" is not valid as a child of \"%s\"\n",
721 		    cpath, ppath);
722 
723 	/* root node is a special case */
724 	if (!streq(ppath, "/"))
725 		plen++;
726 
727 	return xstrdup(cpath + plen);
728 }
729 
unflatten_tree(struct inbuf * dtbuf,struct inbuf * strbuf,const char * parent_flatname,int flags)730 static struct node *unflatten_tree(struct inbuf *dtbuf,
731 				   struct inbuf *strbuf,
732 				   const char *parent_flatname, int flags)
733 {
734 	struct node *node;
735 	char *flatname;
736 	uint32_t val;
737 
738 	node = build_node(NULL, NULL, NULL);
739 
740 	flatname = flat_read_string(dtbuf);
741 
742 	if (flags & FTF_FULLPATH)
743 		node->name = nodename_from_path(parent_flatname, flatname);
744 	else
745 		node->name = flatname;
746 
747 	do {
748 		struct property *prop;
749 		struct node *child;
750 
751 		val = flat_read_word(dtbuf);
752 		switch (val) {
753 		case FDT_PROP:
754 			if (node->children)
755 				fprintf(stderr, "Warning: Flat tree input has "
756 					"subnodes preceding a property.\n");
757 			prop = flat_read_property(dtbuf, strbuf, flags);
758 			add_property(node, prop);
759 			break;
760 
761 		case FDT_BEGIN_NODE:
762 			child = unflatten_tree(dtbuf,strbuf, flatname, flags);
763 			add_child(node, child);
764 			break;
765 
766 		case FDT_END_NODE:
767 			break;
768 
769 		case FDT_END:
770 			die("Premature FDT_END in device tree blob\n");
771 			break;
772 
773 		case FDT_NOP:
774 			if (!(flags & FTF_NOPS))
775 				fprintf(stderr, "Warning: NOP tag found in flat tree"
776 					" version <16\n");
777 
778 			/* Ignore */
779 			break;
780 
781 		default:
782 			die("Invalid opcode word %08x in device tree blob\n",
783 			    val);
784 		}
785 	} while (val != FDT_END_NODE);
786 
787 	if (node->name != flatname) {
788 		free(flatname);
789 	}
790 
791 	return node;
792 }
793 
794 
dt_from_blob(const char * fname)795 struct dt_info *dt_from_blob(const char *fname)
796 {
797 	FILE *f;
798 	fdt32_t magic_buf, totalsize_buf;
799 	uint32_t magic, totalsize, version, size_dt, boot_cpuid_phys;
800 	uint32_t off_dt, off_str, off_mem_rsvmap;
801 	int rc;
802 	char *blob;
803 	struct fdt_header *fdt;
804 	char *p;
805 	struct inbuf dtbuf, strbuf;
806 	struct inbuf memresvbuf;
807 	int sizeleft;
808 	struct reserve_info *reservelist;
809 	struct node *tree;
810 	uint32_t val;
811 	int flags = 0;
812 
813 	f = srcfile_relative_open(fname, NULL);
814 
815 	rc = fread(&magic_buf, sizeof(magic_buf), 1, f);
816 	if (ferror(f))
817 		die("Error reading DT blob magic number: %s\n",
818 		    strerror(errno));
819 	if (rc < 1) {
820 		if (feof(f))
821 			die("EOF reading DT blob magic number\n");
822 		else
823 			die("Mysterious short read reading magic number\n");
824 	}
825 
826 	magic = fdt32_to_cpu(magic_buf);
827 	if (magic != FDT_MAGIC)
828 		die("Blob has incorrect magic number\n");
829 
830 	rc = fread(&totalsize_buf, sizeof(totalsize_buf), 1, f);
831 	if (ferror(f))
832 		die("Error reading DT blob size: %s\n", strerror(errno));
833 	if (rc < 1) {
834 		if (feof(f))
835 			die("EOF reading DT blob size\n");
836 		else
837 			die("Mysterious short read reading blob size\n");
838 	}
839 
840 	totalsize = fdt32_to_cpu(totalsize_buf);
841 	if (totalsize < FDT_V1_SIZE)
842 		die("DT blob size (%d) is too small\n", totalsize);
843 
844 	blob = xmalloc(totalsize);
845 
846 	fdt = (struct fdt_header *)blob;
847 	fdt->magic = cpu_to_fdt32(magic);
848 	fdt->totalsize = cpu_to_fdt32(totalsize);
849 
850 	sizeleft = totalsize - sizeof(magic) - sizeof(totalsize);
851 	p = blob + sizeof(magic)  + sizeof(totalsize);
852 
853 	while (sizeleft) {
854 		if (feof(f))
855 			die("EOF before reading %d bytes of DT blob\n",
856 			    totalsize);
857 
858 		rc = fread(p, 1, sizeleft, f);
859 		if (ferror(f))
860 			die("Error reading DT blob: %s\n",
861 			    strerror(errno));
862 
863 		sizeleft -= rc;
864 		p += rc;
865 	}
866 
867 	off_dt = fdt32_to_cpu(fdt->off_dt_struct);
868 	off_str = fdt32_to_cpu(fdt->off_dt_strings);
869 	off_mem_rsvmap = fdt32_to_cpu(fdt->off_mem_rsvmap);
870 	version = fdt32_to_cpu(fdt->version);
871 	boot_cpuid_phys = fdt32_to_cpu(fdt->boot_cpuid_phys);
872 
873 	if (off_mem_rsvmap >= totalsize)
874 		die("Mem Reserve structure offset exceeds total size\n");
875 
876 	if (off_dt >= totalsize)
877 		die("DT structure offset exceeds total size\n");
878 
879 	if (off_str > totalsize)
880 		die("String table offset exceeds total size\n");
881 
882 	if (version >= 3) {
883 		uint32_t size_str = fdt32_to_cpu(fdt->size_dt_strings);
884 		if ((off_str+size_str < off_str) || (off_str+size_str > totalsize))
885 			die("String table extends past total size\n");
886 		inbuf_init(&strbuf, blob + off_str, blob + off_str + size_str);
887 	} else {
888 		inbuf_init(&strbuf, blob + off_str, blob + totalsize);
889 	}
890 
891 	if (version >= 17) {
892 		size_dt = fdt32_to_cpu(fdt->size_dt_struct);
893 		if ((off_dt+size_dt < off_dt) || (off_dt+size_dt > totalsize))
894 			die("Structure block extends past total size\n");
895 	}
896 
897 	if (version < 16) {
898 		flags |= FTF_FULLPATH | FTF_NAMEPROPS | FTF_VARALIGN;
899 	} else {
900 		flags |= FTF_NOPS;
901 	}
902 
903 	inbuf_init(&memresvbuf,
904 		   blob + off_mem_rsvmap, blob + totalsize);
905 	inbuf_init(&dtbuf, blob + off_dt, blob + totalsize);
906 
907 	reservelist = flat_read_mem_reserve(&memresvbuf);
908 
909 	val = flat_read_word(&dtbuf);
910 
911 	if (val != FDT_BEGIN_NODE)
912 		die("Device tree blob doesn't begin with FDT_BEGIN_NODE (begins with 0x%08x)\n", val);
913 
914 	tree = unflatten_tree(&dtbuf, &strbuf, "", flags);
915 
916 	val = flat_read_word(&dtbuf);
917 	if (val != FDT_END)
918 		die("Device tree blob doesn't end with FDT_END\n");
919 
920 	free(blob);
921 
922 	fclose(f);
923 
924 	return build_dt_info(DTSF_V1, reservelist, tree, boot_cpuid_phys);
925 }
926