xref: /linux/scripts/dtc/flattree.c (revision a1ff5a7d78a036d6c2178ee5acd6ba4946243800)
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\t0x%02x\n" "\t.byte\t0x%02x\n"
128 		"\t.byte\t0x%02x\n" "\t.byte\t0x%02x\n",
129 		(val >> 24) & 0xff, (val >> 16) & 0xff,
130 		(val >> 8) & 0xff, val & 0xff);
131 }
132 
asm_emit_string(void * e,const char * str,int len)133 static void asm_emit_string(void *e, const char *str, int len)
134 {
135 	FILE *f = e;
136 
137 	if (len != 0)
138 		fprintf(f, "\t.asciz\t\"%.*s\"\n", len, str);
139 	else
140 		fprintf(f, "\t.asciz\t\"%s\"\n", str);
141 }
142 
asm_emit_align(void * e,int a)143 static void asm_emit_align(void *e, int a)
144 {
145 	FILE *f = e;
146 
147 	fprintf(f, "\t.balign\t%d, 0\n", a);
148 }
149 
asm_emit_data(void * e,struct data d)150 static void asm_emit_data(void *e, struct data d)
151 {
152 	FILE *f = e;
153 	unsigned int off = 0;
154 	struct marker *m = d.markers;
155 
156 	for_each_marker_of_type(m, LABEL)
157 		emit_offset_label(f, m->ref, m->offset);
158 
159 	while ((d.len - off) >= sizeof(uint32_t)) {
160 		asm_emit_cell(e, dtb_ld32(d.val + off));
161 		off += sizeof(uint32_t);
162 	}
163 
164 	while ((d.len - off) >= 1) {
165 		fprintf(f, "\t.byte\t0x%hhx\n", d.val[off]);
166 		off += 1;
167 	}
168 
169 	assert(off == d.len);
170 }
171 
asm_emit_beginnode(void * e,struct label * labels)172 static void asm_emit_beginnode(void *e, struct label *labels)
173 {
174 	FILE *f = e;
175 	struct label *l;
176 
177 	for_each_label(labels, l) {
178 		fprintf(f, "\t.globl\t%s\n", l->label);
179 		fprintf(f, "%s:\n", l->label);
180 	}
181 	fprintf(f, "\t/* FDT_BEGIN_NODE */\n");
182 	asm_emit_cell(e, FDT_BEGIN_NODE);
183 }
184 
asm_emit_endnode(void * e,struct label * labels)185 static void asm_emit_endnode(void *e, struct label *labels)
186 {
187 	FILE *f = e;
188 	struct label *l;
189 
190 	fprintf(f, "\t/* FDT_END_NODE */\n");
191 	asm_emit_cell(e, FDT_END_NODE);
192 	for_each_label(labels, l) {
193 		fprintf(f, "\t.globl\t%s_end\n", l->label);
194 		fprintf(f, "%s_end:\n", l->label);
195 	}
196 }
197 
asm_emit_property(void * e,struct label * labels)198 static void asm_emit_property(void *e, struct label *labels)
199 {
200 	FILE *f = e;
201 	struct label *l;
202 
203 	for_each_label(labels, l) {
204 		fprintf(f, "\t.globl\t%s\n", l->label);
205 		fprintf(f, "%s:\n", l->label);
206 	}
207 	fprintf(f, "\t/* FDT_PROP */\n");
208 	asm_emit_cell(e, FDT_PROP);
209 }
210 
211 static struct emitter asm_emitter = {
212 	.cell = asm_emit_cell,
213 	.string = asm_emit_string,
214 	.align = asm_emit_align,
215 	.data = asm_emit_data,
216 	.beginnode = asm_emit_beginnode,
217 	.endnode = asm_emit_endnode,
218 	.property = asm_emit_property,
219 };
220 
stringtable_insert(struct data * d,const char * str)221 static int stringtable_insert(struct data *d, const char *str)
222 {
223 	unsigned int i;
224 
225 	/* FIXME: do this more efficiently? */
226 
227 	for (i = 0; i < d->len; i++) {
228 		if (streq(str, d->val + i))
229 			return i;
230 	}
231 
232 	*d = data_append_data(*d, str, strlen(str)+1);
233 	return i;
234 }
235 
flatten_tree(struct node * tree,struct emitter * emit,void * etarget,struct data * strbuf,struct version_info * vi)236 static void flatten_tree(struct node *tree, struct emitter *emit,
237 			 void *etarget, struct data *strbuf,
238 			 struct version_info *vi)
239 {
240 	struct property *prop;
241 	struct node *child;
242 	bool seen_name_prop = false;
243 
244 	if (tree->deleted)
245 		return;
246 
247 	emit->beginnode(etarget, tree->labels);
248 
249 	if (vi->flags & FTF_FULLPATH)
250 		emit->string(etarget, tree->fullpath, 0);
251 	else
252 		emit->string(etarget, tree->name, 0);
253 
254 	emit->align(etarget, sizeof(cell_t));
255 
256 	for_each_property(tree, prop) {
257 		int nameoff;
258 
259 		if (streq(prop->name, "name"))
260 			seen_name_prop = true;
261 
262 		nameoff = stringtable_insert(strbuf, prop->name);
263 
264 		emit->property(etarget, prop->labels);
265 		emit->cell(etarget, prop->val.len);
266 		emit->cell(etarget, nameoff);
267 
268 		if ((vi->flags & FTF_VARALIGN) && (prop->val.len >= 8))
269 			emit->align(etarget, 8);
270 
271 		emit->data(etarget, prop->val);
272 		emit->align(etarget, sizeof(cell_t));
273 	}
274 
275 	if ((vi->flags & FTF_NAMEPROPS) && !seen_name_prop) {
276 		emit->property(etarget, NULL);
277 		emit->cell(etarget, tree->basenamelen+1);
278 		emit->cell(etarget, stringtable_insert(strbuf, "name"));
279 
280 		if ((vi->flags & FTF_VARALIGN) && ((tree->basenamelen+1) >= 8))
281 			emit->align(etarget, 8);
282 
283 		emit->string(etarget, tree->name, tree->basenamelen);
284 		emit->align(etarget, sizeof(cell_t));
285 	}
286 
287 	for_each_child(tree, child) {
288 		flatten_tree(child, emit, etarget, strbuf, vi);
289 	}
290 
291 	emit->endnode(etarget, tree->labels);
292 }
293 
flatten_reserve_list(struct reserve_info * reservelist,struct version_info * vi)294 static struct data flatten_reserve_list(struct reserve_info *reservelist,
295 				 struct version_info *vi)
296 {
297 	struct reserve_info *re;
298 	struct data d = empty_data;
299 	unsigned int j;
300 
301 	for (re = reservelist; re; re = re->next) {
302 		d = data_append_re(d, re->address, re->size);
303 	}
304 	/*
305 	 * Add additional reserved slots if the user asked for them.
306 	 */
307 	for (j = 0; j < reservenum; j++) {
308 		d = data_append_re(d, 0, 0);
309 	}
310 
311 	return d;
312 }
313 
make_fdt_header(struct fdt_header * fdt,struct version_info * vi,int reservesize,int dtsize,int strsize,int boot_cpuid_phys)314 static void make_fdt_header(struct fdt_header *fdt,
315 			    struct version_info *vi,
316 			    int reservesize, int dtsize, int strsize,
317 			    int boot_cpuid_phys)
318 {
319 	int reserve_off;
320 
321 	reservesize += sizeof(struct fdt_reserve_entry);
322 
323 	memset(fdt, 0xff, sizeof(*fdt));
324 
325 	fdt->magic = cpu_to_fdt32(FDT_MAGIC);
326 	fdt->version = cpu_to_fdt32(vi->version);
327 	fdt->last_comp_version = cpu_to_fdt32(vi->last_comp_version);
328 
329 	/* Reserve map should be doubleword aligned */
330 	reserve_off = ALIGN(vi->hdr_size, 8);
331 
332 	fdt->off_mem_rsvmap = cpu_to_fdt32(reserve_off);
333 	fdt->off_dt_struct = cpu_to_fdt32(reserve_off + reservesize);
334 	fdt->off_dt_strings = cpu_to_fdt32(reserve_off + reservesize
335 					  + dtsize);
336 	fdt->totalsize = cpu_to_fdt32(reserve_off + reservesize + dtsize + strsize);
337 
338 	if (vi->flags & FTF_BOOTCPUID)
339 		fdt->boot_cpuid_phys = cpu_to_fdt32(boot_cpuid_phys);
340 	if (vi->flags & FTF_STRTABSIZE)
341 		fdt->size_dt_strings = cpu_to_fdt32(strsize);
342 	if (vi->flags & FTF_STRUCTSIZE)
343 		fdt->size_dt_struct = cpu_to_fdt32(dtsize);
344 }
345 
dt_to_blob(FILE * f,struct dt_info * dti,int version)346 void dt_to_blob(FILE *f, struct dt_info *dti, int version)
347 {
348 	struct version_info *vi = NULL;
349 	unsigned int i;
350 	struct data blob       = empty_data;
351 	struct data reservebuf = empty_data;
352 	struct data dtbuf      = empty_data;
353 	struct data strbuf     = empty_data;
354 	struct fdt_header fdt;
355 	int padlen = 0;
356 
357 	for (i = 0; i < ARRAY_SIZE(version_table); i++) {
358 		if (version_table[i].version == version)
359 			vi = &version_table[i];
360 	}
361 	if (!vi)
362 		die("Unknown device tree blob version %d\n", version);
363 
364 	flatten_tree(dti->dt, &bin_emitter, &dtbuf, &strbuf, vi);
365 	bin_emit_cell(&dtbuf, FDT_END);
366 
367 	reservebuf = flatten_reserve_list(dti->reservelist, vi);
368 
369 	/* Make header */
370 	make_fdt_header(&fdt, vi, reservebuf.len, dtbuf.len, strbuf.len,
371 			dti->boot_cpuid_phys);
372 
373 	/*
374 	 * If the user asked for more space than is used, adjust the totalsize.
375 	 */
376 	if (minsize > 0) {
377 		padlen = minsize - fdt32_to_cpu(fdt.totalsize);
378 		if (padlen < 0) {
379 			padlen = 0;
380 			if (quiet < 1)
381 				fprintf(stderr,
382 					"Warning: blob size %"PRIu32" >= minimum size %d\n",
383 					fdt32_to_cpu(fdt.totalsize), minsize);
384 		}
385 	}
386 
387 	if (padsize > 0)
388 		padlen = padsize;
389 
390 	if (alignsize > 0)
391 		padlen = ALIGN(fdt32_to_cpu(fdt.totalsize) + padlen, alignsize)
392 			- fdt32_to_cpu(fdt.totalsize);
393 
394 	if (padlen > 0) {
395 		int tsize = fdt32_to_cpu(fdt.totalsize);
396 		tsize += padlen;
397 		fdt.totalsize = cpu_to_fdt32(tsize);
398 	}
399 
400 	/*
401 	 * Assemble the blob: start with the header, add with alignment
402 	 * the reserve buffer, add the reserve map terminating zeroes,
403 	 * the device tree itself, and finally the strings.
404 	 */
405 	blob = data_append_data(blob, &fdt, vi->hdr_size);
406 	blob = data_append_align(blob, 8);
407 	blob = data_merge(blob, reservebuf);
408 	blob = data_append_zeroes(blob, sizeof(struct fdt_reserve_entry));
409 	blob = data_merge(blob, dtbuf);
410 	blob = data_merge(blob, strbuf);
411 
412 	/*
413 	 * If the user asked for more space than is used, pad out the blob.
414 	 */
415 	if (padlen > 0)
416 		blob = data_append_zeroes(blob, padlen);
417 
418 	if (fwrite(blob.val, blob.len, 1, f) != 1) {
419 		if (ferror(f))
420 			die("Error writing device tree blob: %s\n",
421 			    strerror(errno));
422 		else
423 			die("Short write on device tree blob\n");
424 	}
425 
426 	/*
427 	 * data_merge() frees the right-hand element so only the blob
428 	 * remains to be freed.
429 	 */
430 	data_free(blob);
431 }
432 
dump_stringtable_asm(FILE * f,struct data strbuf)433 static void dump_stringtable_asm(FILE *f, struct data strbuf)
434 {
435 	const char *p;
436 	int len;
437 
438 	p = strbuf.val;
439 
440 	while (p < (strbuf.val + strbuf.len)) {
441 		len = strlen(p);
442 		fprintf(f, "\t.asciz \"%s\"\n", p);
443 		p += len+1;
444 	}
445 }
446 
dt_to_asm(FILE * f,struct dt_info * dti,int version)447 void dt_to_asm(FILE *f, struct dt_info *dti, int version)
448 {
449 	struct version_info *vi = NULL;
450 	unsigned int i;
451 	struct data strbuf = empty_data;
452 	struct reserve_info *re;
453 	const char *symprefix = "dt";
454 
455 	for (i = 0; i < ARRAY_SIZE(version_table); i++) {
456 		if (version_table[i].version == version)
457 			vi = &version_table[i];
458 	}
459 	if (!vi)
460 		die("Unknown device tree blob version %d\n", version);
461 
462 	fprintf(f, "/* autogenerated by dtc, do not edit */\n\n");
463 
464 	emit_label(f, symprefix, "blob_start");
465 	emit_label(f, symprefix, "header");
466 	fprintf(f, "\t/* magic */\n");
467 	asm_emit_cell(f, FDT_MAGIC);
468 	fprintf(f, "\t/* totalsize */\n");
469 	ASM_EMIT_BELONG(f, "_%s_blob_abs_end - _%s_blob_start",
470 			symprefix, symprefix);
471 	fprintf(f, "\t/* off_dt_struct */\n");
472 	ASM_EMIT_BELONG(f, "_%s_struct_start - _%s_blob_start",
473 		symprefix, symprefix);
474 	fprintf(f, "\t/* off_dt_strings */\n");
475 	ASM_EMIT_BELONG(f, "_%s_strings_start - _%s_blob_start",
476 		symprefix, symprefix);
477 	fprintf(f, "\t/* off_mem_rsvmap */\n");
478 	ASM_EMIT_BELONG(f, "_%s_reserve_map - _%s_blob_start",
479 		symprefix, symprefix);
480 	fprintf(f, "\t/* version */\n");
481 	asm_emit_cell(f, vi->version);
482 	fprintf(f, "\t/* last_comp_version */\n");
483 	asm_emit_cell(f, vi->last_comp_version);
484 
485 	if (vi->flags & FTF_BOOTCPUID) {
486 		fprintf(f, "\t/* boot_cpuid_phys */\n");
487 		asm_emit_cell(f, dti->boot_cpuid_phys);
488 	}
489 
490 	if (vi->flags & FTF_STRTABSIZE) {
491 		fprintf(f, "\t/* size_dt_strings */\n");
492 		ASM_EMIT_BELONG(f, "_%s_strings_end - _%s_strings_start",
493 				symprefix, symprefix);
494 	}
495 
496 	if (vi->flags & FTF_STRUCTSIZE) {
497 		fprintf(f, "\t/* size_dt_struct */\n");
498 		ASM_EMIT_BELONG(f, "_%s_struct_end - _%s_struct_start",
499 			symprefix, symprefix);
500 	}
501 
502 	/*
503 	 * Reserve map entries.
504 	 * Align the reserve map to a doubleword boundary.
505 	 * Each entry is an (address, size) pair of u64 values.
506 	 * Always supply a zero-sized temination entry.
507 	 */
508 	asm_emit_align(f, 8);
509 	emit_label(f, symprefix, "reserve_map");
510 
511 	fprintf(f, "/* Memory reserve map from source file */\n");
512 
513 	/*
514 	 * Use .long on high and low halves of u64s to avoid .quad
515 	 * as it appears .quad isn't available in some assemblers.
516 	 */
517 	for (re = dti->reservelist; re; re = re->next) {
518 		struct label *l;
519 
520 		for_each_label(re->labels, l) {
521 			fprintf(f, "\t.globl\t%s\n", l->label);
522 			fprintf(f, "%s:\n", l->label);
523 		}
524 		ASM_EMIT_BELONG(f, "0x%08x", (unsigned int)(re->address >> 32));
525 		ASM_EMIT_BELONG(f, "0x%08x",
526 				(unsigned int)(re->address & 0xffffffff));
527 		ASM_EMIT_BELONG(f, "0x%08x", (unsigned int)(re->size >> 32));
528 		ASM_EMIT_BELONG(f, "0x%08x", (unsigned int)(re->size & 0xffffffff));
529 	}
530 	for (i = 0; i < reservenum; i++) {
531 		fprintf(f, "\t.long\t0, 0\n\t.long\t0, 0\n");
532 	}
533 
534 	fprintf(f, "\t.long\t0, 0\n\t.long\t0, 0\n");
535 
536 	emit_label(f, symprefix, "struct_start");
537 	flatten_tree(dti->dt, &asm_emitter, f, &strbuf, vi);
538 
539 	fprintf(f, "\t/* FDT_END */\n");
540 	asm_emit_cell(f, FDT_END);
541 	emit_label(f, symprefix, "struct_end");
542 
543 	emit_label(f, symprefix, "strings_start");
544 	dump_stringtable_asm(f, strbuf);
545 	emit_label(f, symprefix, "strings_end");
546 
547 	emit_label(f, symprefix, "blob_end");
548 
549 	/*
550 	 * If the user asked for more space than is used, pad it out.
551 	 */
552 	if (minsize > 0) {
553 		fprintf(f, "\t.space\t%d - (_%s_blob_end - _%s_blob_start), 0\n",
554 			minsize, symprefix, symprefix);
555 	}
556 	if (padsize > 0) {
557 		fprintf(f, "\t.space\t%d, 0\n", padsize);
558 	}
559 	if (alignsize > 0)
560 		asm_emit_align(f, alignsize);
561 	emit_label(f, symprefix, "blob_abs_end");
562 
563 	data_free(strbuf);
564 }
565 
566 struct inbuf {
567 	char *base, *limit, *ptr;
568 };
569 
inbuf_init(struct inbuf * inb,void * base,void * limit)570 static void inbuf_init(struct inbuf *inb, void *base, void *limit)
571 {
572 	inb->base = base;
573 	inb->limit = limit;
574 	inb->ptr = inb->base;
575 }
576 
flat_read_chunk(struct inbuf * inb,void * p,int len)577 static void flat_read_chunk(struct inbuf *inb, void *p, int len)
578 {
579 	if ((inb->ptr + len) > inb->limit)
580 		die("Premature end of data parsing flat device tree\n");
581 
582 	memcpy(p, inb->ptr, len);
583 
584 	inb->ptr += len;
585 }
586 
flat_read_word(struct inbuf * inb)587 static uint32_t flat_read_word(struct inbuf *inb)
588 {
589 	fdt32_t val;
590 
591 	assert(((inb->ptr - inb->base) % sizeof(val)) == 0);
592 
593 	flat_read_chunk(inb, &val, sizeof(val));
594 
595 	return fdt32_to_cpu(val);
596 }
597 
flat_realign(struct inbuf * inb,int align)598 static void flat_realign(struct inbuf *inb, int align)
599 {
600 	int off = inb->ptr - inb->base;
601 
602 	inb->ptr = inb->base + ALIGN(off, align);
603 	if (inb->ptr > inb->limit)
604 		die("Premature end of data parsing flat device tree\n");
605 }
606 
flat_read_string(struct inbuf * inb)607 static const char *flat_read_string(struct inbuf *inb)
608 {
609 	int len = 0;
610 	const char *p = inb->ptr;
611 	const char *str;
612 
613 	do {
614 		if (p >= inb->limit)
615 			die("Premature end of data parsing flat device tree\n");
616 		len++;
617 	} while ((*p++) != '\0');
618 
619 	str = inb->ptr;
620 
621 	inb->ptr += len;
622 
623 	flat_realign(inb, sizeof(uint32_t));
624 
625 	return str;
626 }
627 
flat_read_data(struct inbuf * inb,int len)628 static struct data flat_read_data(struct inbuf *inb, int len)
629 {
630 	struct data d = empty_data;
631 
632 	if (len == 0)
633 		return empty_data;
634 
635 	d = data_grow_for(d, len);
636 	d.len = len;
637 
638 	flat_read_chunk(inb, d.val, len);
639 
640 	flat_realign(inb, sizeof(uint32_t));
641 
642 	return d;
643 }
644 
flat_read_stringtable(struct inbuf * inb,int offset)645 static char *flat_read_stringtable(struct inbuf *inb, int offset)
646 {
647 	const char *p;
648 
649 	p = inb->base + offset;
650 	while (1) {
651 		if (p >= inb->limit || p < inb->base)
652 			die("String offset %d overruns string table\n",
653 			    offset);
654 
655 		if (*p == '\0')
656 			break;
657 
658 		p++;
659 	}
660 
661 	return xstrdup(inb->base + offset);
662 }
663 
flat_read_property(struct inbuf * dtbuf,struct inbuf * strbuf,int flags)664 static struct property *flat_read_property(struct inbuf *dtbuf,
665 					   struct inbuf *strbuf, int flags)
666 {
667 	uint32_t proplen, stroff;
668 	char *name;
669 	struct data val;
670 
671 	proplen = flat_read_word(dtbuf);
672 	stroff = flat_read_word(dtbuf);
673 
674 	name = flat_read_stringtable(strbuf, stroff);
675 
676 	if ((flags & FTF_VARALIGN) && (proplen >= 8))
677 		flat_realign(dtbuf, 8);
678 
679 	val = flat_read_data(dtbuf, proplen);
680 
681 	return build_property(name, val, NULL);
682 }
683 
684 
flat_read_mem_reserve(struct inbuf * inb)685 static struct reserve_info *flat_read_mem_reserve(struct inbuf *inb)
686 {
687 	struct reserve_info *reservelist = NULL;
688 	struct reserve_info *new;
689 	struct fdt_reserve_entry re;
690 
691 	/*
692 	 * Each entry is a pair of u64 (addr, size) values for 4 cell_t's.
693 	 * List terminates at an entry with size equal to zero.
694 	 *
695 	 * First pass, count entries.
696 	 */
697 	while (1) {
698 		uint64_t address, size;
699 
700 		flat_read_chunk(inb, &re, sizeof(re));
701 		address  = fdt64_to_cpu(re.address);
702 		size = fdt64_to_cpu(re.size);
703 		if (size == 0)
704 			break;
705 
706 		new = build_reserve_entry(address, size);
707 		reservelist = add_reserve_entry(reservelist, new);
708 	}
709 
710 	return reservelist;
711 }
712 
713 
nodename_from_path(const char * ppath,const char * cpath)714 static const char *nodename_from_path(const char *ppath, const char *cpath)
715 {
716 	int plen;
717 
718 	plen = strlen(ppath);
719 
720 	if (!strstarts(cpath, ppath))
721 		die("Path \"%s\" is not valid as a child of \"%s\"\n",
722 		    cpath, ppath);
723 
724 	/* root node is a special case */
725 	if (!streq(ppath, "/"))
726 		plen++;
727 
728 	return cpath + plen;
729 }
730 
unflatten_tree(struct inbuf * dtbuf,struct inbuf * strbuf,const char * parent_flatname,int flags)731 static struct node *unflatten_tree(struct inbuf *dtbuf,
732 				   struct inbuf *strbuf,
733 				   const char *parent_flatname, int flags)
734 {
735 	struct node *node;
736 	const char *flatname;
737 	uint32_t val;
738 
739 	node = build_node(NULL, NULL, NULL);
740 
741 	flatname = flat_read_string(dtbuf);
742 
743 	if (flags & FTF_FULLPATH)
744 		node->name = xstrdup(nodename_from_path(parent_flatname,
745 							flatname));
746 	else
747 		node->name = xstrdup(flatname);
748 
749 	do {
750 		struct property *prop;
751 		struct node *child;
752 
753 		val = flat_read_word(dtbuf);
754 		switch (val) {
755 		case FDT_PROP:
756 			if (node->children)
757 				fprintf(stderr, "Warning: Flat tree input has "
758 					"subnodes preceding a property.\n");
759 			prop = flat_read_property(dtbuf, strbuf, flags);
760 			add_property(node, prop);
761 			break;
762 
763 		case FDT_BEGIN_NODE:
764 			child = unflatten_tree(dtbuf,strbuf, flatname, flags);
765 			add_child(node, child);
766 			break;
767 
768 		case FDT_END_NODE:
769 			break;
770 
771 		case FDT_END:
772 			die("Premature FDT_END in device tree blob\n");
773 			break;
774 
775 		case FDT_NOP:
776 			if (!(flags & FTF_NOPS))
777 				fprintf(stderr, "Warning: NOP tag found in flat tree"
778 					" version <16\n");
779 
780 			/* Ignore */
781 			break;
782 
783 		default:
784 			die("Invalid opcode word %08x in device tree blob\n",
785 			    val);
786 		}
787 	} while (val != FDT_END_NODE);
788 
789 	return node;
790 }
791 
792 
dt_from_blob(const char * fname)793 struct dt_info *dt_from_blob(const char *fname)
794 {
795 	FILE *f;
796 	fdt32_t magic_buf, totalsize_buf;
797 	uint32_t magic, totalsize, version, size_dt, boot_cpuid_phys;
798 	uint32_t off_dt, off_str, off_mem_rsvmap;
799 	int rc;
800 	char *blob;
801 	struct fdt_header *fdt;
802 	char *p;
803 	struct inbuf dtbuf, strbuf;
804 	struct inbuf memresvbuf;
805 	int sizeleft;
806 	struct reserve_info *reservelist;
807 	struct node *tree;
808 	uint32_t val;
809 	int flags = 0;
810 
811 	f = srcfile_relative_open(fname, NULL);
812 
813 	rc = fread(&magic_buf, sizeof(magic_buf), 1, f);
814 	if (ferror(f))
815 		die("Error reading DT blob magic number: %s\n",
816 		    strerror(errno));
817 	if (rc < 1) {
818 		if (feof(f))
819 			die("EOF reading DT blob magic number\n");
820 		else
821 			die("Mysterious short read reading magic number\n");
822 	}
823 
824 	magic = fdt32_to_cpu(magic_buf);
825 	if (magic != FDT_MAGIC)
826 		die("Blob has incorrect magic number\n");
827 
828 	rc = fread(&totalsize_buf, sizeof(totalsize_buf), 1, f);
829 	if (ferror(f))
830 		die("Error reading DT blob size: %s\n", strerror(errno));
831 	if (rc < 1) {
832 		if (feof(f))
833 			die("EOF reading DT blob size\n");
834 		else
835 			die("Mysterious short read reading blob size\n");
836 	}
837 
838 	totalsize = fdt32_to_cpu(totalsize_buf);
839 	if (totalsize < FDT_V1_SIZE)
840 		die("DT blob size (%d) is too small\n", totalsize);
841 
842 	blob = xmalloc(totalsize);
843 
844 	fdt = (struct fdt_header *)blob;
845 	fdt->magic = cpu_to_fdt32(magic);
846 	fdt->totalsize = cpu_to_fdt32(totalsize);
847 
848 	sizeleft = totalsize - sizeof(magic) - sizeof(totalsize);
849 	p = blob + sizeof(magic)  + sizeof(totalsize);
850 
851 	while (sizeleft) {
852 		if (feof(f))
853 			die("EOF before reading %d bytes of DT blob\n",
854 			    totalsize);
855 
856 		rc = fread(p, 1, sizeleft, f);
857 		if (ferror(f))
858 			die("Error reading DT blob: %s\n",
859 			    strerror(errno));
860 
861 		sizeleft -= rc;
862 		p += rc;
863 	}
864 
865 	off_dt = fdt32_to_cpu(fdt->off_dt_struct);
866 	off_str = fdt32_to_cpu(fdt->off_dt_strings);
867 	off_mem_rsvmap = fdt32_to_cpu(fdt->off_mem_rsvmap);
868 	version = fdt32_to_cpu(fdt->version);
869 	boot_cpuid_phys = fdt32_to_cpu(fdt->boot_cpuid_phys);
870 
871 	if (off_mem_rsvmap >= totalsize)
872 		die("Mem Reserve structure offset exceeds total size\n");
873 
874 	if (off_dt >= totalsize)
875 		die("DT structure offset exceeds total size\n");
876 
877 	if (off_str > totalsize)
878 		die("String table offset exceeds total size\n");
879 
880 	if (version >= 3) {
881 		uint32_t size_str = fdt32_to_cpu(fdt->size_dt_strings);
882 		if ((off_str+size_str < off_str) || (off_str+size_str > totalsize))
883 			die("String table extends past total size\n");
884 		inbuf_init(&strbuf, blob + off_str, blob + off_str + size_str);
885 	} else {
886 		inbuf_init(&strbuf, blob + off_str, blob + totalsize);
887 	}
888 
889 	if (version >= 17) {
890 		size_dt = fdt32_to_cpu(fdt->size_dt_struct);
891 		if ((off_dt+size_dt < off_dt) || (off_dt+size_dt > totalsize))
892 			die("Structure block extends past total size\n");
893 	}
894 
895 	if (version < 16) {
896 		flags |= FTF_FULLPATH | FTF_NAMEPROPS | FTF_VARALIGN;
897 	} else {
898 		flags |= FTF_NOPS;
899 	}
900 
901 	inbuf_init(&memresvbuf,
902 		   blob + off_mem_rsvmap, blob + totalsize);
903 	inbuf_init(&dtbuf, blob + off_dt, blob + totalsize);
904 
905 	reservelist = flat_read_mem_reserve(&memresvbuf);
906 
907 	val = flat_read_word(&dtbuf);
908 
909 	if (val != FDT_BEGIN_NODE)
910 		die("Device tree blob doesn't begin with FDT_BEGIN_NODE (begins with 0x%08x)\n", val);
911 
912 	tree = unflatten_tree(&dtbuf, &strbuf, "", flags);
913 
914 	val = flat_read_word(&dtbuf);
915 	if (val != FDT_END)
916 		die("Device tree blob doesn't end with FDT_END\n");
917 
918 	free(blob);
919 
920 	fclose(f);
921 
922 	return build_dt_info(DTSF_V1, reservelist, tree, boot_cpuid_phys);
923 }
924