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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 *, struct label *labels);
56 	void (*endnode)(void *, struct label *labels);
57 	void (*property)(void *, struct label *labels);
58 };
59 
bin_emit_cell(void * e,cell_t val)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 
bin_emit_string(void * e,char * str,int len)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 
bin_emit_align(void * e,int a)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 
bin_emit_data(void * e,struct data d)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 
bin_emit_beginnode(void * e,struct label * labels)92 static void bin_emit_beginnode(void *e, struct label *labels)
93 {
94 	bin_emit_cell(e, FDT_BEGIN_NODE);
95 }
96 
bin_emit_endnode(void * e,struct label * labels)97 static void bin_emit_endnode(void *e, struct label *labels)
98 {
99 	bin_emit_cell(e, FDT_END_NODE);
100 }
101 
bin_emit_property(void * e,struct label * labels)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 
emit_label(FILE * f,const char * prefix,const char * label)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 
emit_offset_label(FILE * f,const char * label,int offset)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 
asm_emit_cell(void * e,cell_t val)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 
asm_emit_string(void * e,char * str,int len)147 static void asm_emit_string(void *e, char *str, int len)
148 {
149 	FILE *f = e;
150 	char c = 0;
151 
152 	if (len != 0) {
153 		/* XXX: ewww */
154 		c = str[len];
155 		str[len] = '\0';
156 	}
157 
158 	fprintf(f, "\t.string\t\"%s\"\n", str);
159 
160 	if (len != 0) {
161 		str[len] = c;
162 	}
163 }
164 
asm_emit_align(void * e,int a)165 static void asm_emit_align(void *e, int a)
166 {
167 	FILE *f = e;
168 
169 	fprintf(f, "\t.balign\t%d, 0\n", a);
170 }
171 
asm_emit_data(void * e,struct data d)172 static void asm_emit_data(void *e, struct data d)
173 {
174 	FILE *f = e;
175 	int off = 0;
176 	struct marker *m = d.markers;
177 
178 	for_each_marker_of_type(m, LABEL)
179 		emit_offset_label(f, m->ref, m->offset);
180 
181 	while ((d.len - off) >= sizeof(uint32_t)) {
182 		asm_emit_cell(e, fdt32_to_cpu(*((uint32_t *)(d.val+off))));
183 		off += sizeof(uint32_t);
184 	}
185 
186 	while ((d.len - off) >= 1) {
187 		fprintf(f, "\t.byte\t0x%hhx\n", d.val[off]);
188 		off += 1;
189 	}
190 
191 	assert(off == d.len);
192 }
193 
asm_emit_beginnode(void * e,struct label * labels)194 static void asm_emit_beginnode(void *e, struct label *labels)
195 {
196 	FILE *f = e;
197 	struct label *l;
198 
199 	for_each_label(labels, l) {
200 		fprintf(f, "\t.globl\t%s\n", l->label);
201 		fprintf(f, "%s:\n", l->label);
202 	}
203 	fprintf(f, "\t/* FDT_BEGIN_NODE */\n");
204 	asm_emit_cell(e, FDT_BEGIN_NODE);
205 }
206 
asm_emit_endnode(void * e,struct label * labels)207 static void asm_emit_endnode(void *e, struct label *labels)
208 {
209 	FILE *f = e;
210 	struct label *l;
211 
212 	fprintf(f, "\t/* FDT_END_NODE */\n");
213 	asm_emit_cell(e, FDT_END_NODE);
214 	for_each_label(labels, l) {
215 		fprintf(f, "\t.globl\t%s_end\n", l->label);
216 		fprintf(f, "%s_end:\n", l->label);
217 	}
218 }
219 
asm_emit_property(void * e,struct label * labels)220 static void asm_emit_property(void *e, struct label *labels)
221 {
222 	FILE *f = e;
223 	struct label *l;
224 
225 	for_each_label(labels, l) {
226 		fprintf(f, "\t.globl\t%s\n", l->label);
227 		fprintf(f, "%s:\n", l->label);
228 	}
229 	fprintf(f, "\t/* FDT_PROP */\n");
230 	asm_emit_cell(e, FDT_PROP);
231 }
232 
233 static struct emitter asm_emitter = {
234 	.cell = asm_emit_cell,
235 	.string = asm_emit_string,
236 	.align = asm_emit_align,
237 	.data = asm_emit_data,
238 	.beginnode = asm_emit_beginnode,
239 	.endnode = asm_emit_endnode,
240 	.property = asm_emit_property,
241 };
242 
stringtable_insert(struct data * d,const char * str)243 static int stringtable_insert(struct data *d, const char *str)
244 {
245 	int i;
246 
247 	/* FIXME: do this more efficiently? */
248 
249 	for (i = 0; i < d->len; i++) {
250 		if (streq(str, d->val + i))
251 			return i;
252 	}
253 
254 	*d = data_append_data(*d, str, strlen(str)+1);
255 	return i;
256 }
257 
flatten_tree(struct node * tree,struct emitter * emit,void * etarget,struct data * strbuf,struct version_info * vi)258 static void flatten_tree(struct node *tree, struct emitter *emit,
259 			 void *etarget, struct data *strbuf,
260 			 struct version_info *vi)
261 {
262 	struct property *prop;
263 	struct node *child;
264 	int seen_name_prop = 0;
265 
266 	if (tree->deleted)
267 		return;
268 
269 	emit->beginnode(etarget, tree->labels);
270 
271 	if (vi->flags & FTF_FULLPATH)
272 		emit->string(etarget, tree->fullpath, 0);
273 	else
274 		emit->string(etarget, tree->name, 0);
275 
276 	emit->align(etarget, sizeof(cell_t));
277 
278 	for_each_property(tree, prop) {
279 		int nameoff;
280 
281 		if (streq(prop->name, "name"))
282 			seen_name_prop = 1;
283 
284 		nameoff = stringtable_insert(strbuf, prop->name);
285 
286 		emit->property(etarget, prop->labels);
287 		emit->cell(etarget, prop->val.len);
288 		emit->cell(etarget, nameoff);
289 
290 		if ((vi->flags & FTF_VARALIGN) && (prop->val.len >= 8))
291 			emit->align(etarget, 8);
292 
293 		emit->data(etarget, prop->val);
294 		emit->align(etarget, sizeof(cell_t));
295 	}
296 
297 	if ((vi->flags & FTF_NAMEPROPS) && !seen_name_prop) {
298 		emit->property(etarget, NULL);
299 		emit->cell(etarget, tree->basenamelen+1);
300 		emit->cell(etarget, stringtable_insert(strbuf, "name"));
301 
302 		if ((vi->flags & FTF_VARALIGN) && ((tree->basenamelen+1) >= 8))
303 			emit->align(etarget, 8);
304 
305 		emit->string(etarget, tree->name, tree->basenamelen);
306 		emit->align(etarget, sizeof(cell_t));
307 	}
308 
309 	for_each_child(tree, child) {
310 		flatten_tree(child, emit, etarget, strbuf, vi);
311 	}
312 
313 	emit->endnode(etarget, tree->labels);
314 }
315 
flatten_reserve_list(struct reserve_info * reservelist,struct version_info * vi)316 static struct data flatten_reserve_list(struct reserve_info *reservelist,
317 				 struct version_info *vi)
318 {
319 	struct reserve_info *re;
320 	struct data d = empty_data;
321 	static struct fdt_reserve_entry null_re = {0,0};
322 	int    j;
323 
324 	for (re = reservelist; re; re = re->next) {
325 		d = data_append_re(d, &re->re);
326 	}
327 	/*
328 	 * Add additional reserved slots if the user asked for them.
329 	 */
330 	for (j = 0; j < reservenum; j++) {
331 		d = data_append_re(d, &null_re);
332 	}
333 
334 	return d;
335 }
336 
make_fdt_header(struct fdt_header * fdt,struct version_info * vi,int reservesize,int dtsize,int strsize,int boot_cpuid_phys)337 static void make_fdt_header(struct fdt_header *fdt,
338 			    struct version_info *vi,
339 			    int reservesize, int dtsize, int strsize,
340 			    int boot_cpuid_phys)
341 {
342 	int reserve_off;
343 
344 	reservesize += sizeof(struct fdt_reserve_entry);
345 
346 	memset(fdt, 0xff, sizeof(*fdt));
347 
348 	fdt->magic = cpu_to_fdt32(FDT_MAGIC);
349 	fdt->version = cpu_to_fdt32(vi->version);
350 	fdt->last_comp_version = cpu_to_fdt32(vi->last_comp_version);
351 
352 	/* Reserve map should be doubleword aligned */
353 	reserve_off = ALIGN(vi->hdr_size, 8);
354 
355 	fdt->off_mem_rsvmap = cpu_to_fdt32(reserve_off);
356 	fdt->off_dt_struct = cpu_to_fdt32(reserve_off + reservesize);
357 	fdt->off_dt_strings = cpu_to_fdt32(reserve_off + reservesize
358 					  + dtsize);
359 	fdt->totalsize = cpu_to_fdt32(reserve_off + reservesize + dtsize + strsize);
360 
361 	if (vi->flags & FTF_BOOTCPUID)
362 		fdt->boot_cpuid_phys = cpu_to_fdt32(boot_cpuid_phys);
363 	if (vi->flags & FTF_STRTABSIZE)
364 		fdt->size_dt_strings = cpu_to_fdt32(strsize);
365 	if (vi->flags & FTF_STRUCTSIZE)
366 		fdt->size_dt_struct = cpu_to_fdt32(dtsize);
367 }
368 
dt_to_blob(FILE * f,struct boot_info * bi,int version)369 void dt_to_blob(FILE *f, struct boot_info *bi, int version)
370 {
371 	struct version_info *vi = NULL;
372 	int i;
373 	struct data blob       = empty_data;
374 	struct data reservebuf = empty_data;
375 	struct data dtbuf      = empty_data;
376 	struct data strbuf     = empty_data;
377 	struct fdt_header fdt;
378 	int padlen = 0;
379 
380 	for (i = 0; i < ARRAY_SIZE(version_table); i++) {
381 		if (version_table[i].version == version)
382 			vi = &version_table[i];
383 	}
384 	if (!vi)
385 		die("Unknown device tree blob version %d\n", version);
386 
387 	flatten_tree(bi->dt, &bin_emitter, &dtbuf, &strbuf, vi);
388 	bin_emit_cell(&dtbuf, FDT_END);
389 
390 	reservebuf = flatten_reserve_list(bi->reservelist, vi);
391 
392 	/* Make header */
393 	make_fdt_header(&fdt, vi, reservebuf.len, dtbuf.len, strbuf.len,
394 			bi->boot_cpuid_phys);
395 
396 	/*
397 	 * If the user asked for more space than is used, adjust the totalsize.
398 	 */
399 	if (minsize > 0) {
400 		padlen = minsize - fdt32_to_cpu(fdt.totalsize);
401 		if ((padlen < 0) && (quiet < 1))
402 			fprintf(stderr,
403 				"Warning: blob size %d >= minimum size %d\n",
404 				fdt32_to_cpu(fdt.totalsize), minsize);
405 	}
406 
407 	if (padsize > 0)
408 		padlen = padsize;
409 
410 	if (padlen > 0) {
411 		int tsize = fdt32_to_cpu(fdt.totalsize);
412 		tsize += padlen;
413 		fdt.totalsize = cpu_to_fdt32(tsize);
414 	}
415 
416 	/*
417 	 * Assemble the blob: start with the header, add with alignment
418 	 * the reserve buffer, add the reserve map terminating zeroes,
419 	 * the device tree itself, and finally the strings.
420 	 */
421 	blob = data_append_data(blob, &fdt, vi->hdr_size);
422 	blob = data_append_align(blob, 8);
423 	blob = data_merge(blob, reservebuf);
424 	blob = data_append_zeroes(blob, sizeof(struct fdt_reserve_entry));
425 	blob = data_merge(blob, dtbuf);
426 	blob = data_merge(blob, strbuf);
427 
428 	/*
429 	 * If the user asked for more space than is used, pad out the blob.
430 	 */
431 	if (padlen > 0)
432 		blob = data_append_zeroes(blob, padlen);
433 
434 	if (fwrite(blob.val, blob.len, 1, f) != 1) {
435 		if (ferror(f))
436 			die("Error writing device tree blob: %s\n",
437 			    strerror(errno));
438 		else
439 			die("Short write on device tree blob\n");
440 	}
441 
442 	/*
443 	 * data_merge() frees the right-hand element so only the blob
444 	 * remains to be freed.
445 	 */
446 	data_free(blob);
447 }
448 
dump_stringtable_asm(FILE * f,struct data strbuf)449 static void dump_stringtable_asm(FILE *f, struct data strbuf)
450 {
451 	const char *p;
452 	int len;
453 
454 	p = strbuf.val;
455 
456 	while (p < (strbuf.val + strbuf.len)) {
457 		len = strlen(p);
458 		fprintf(f, "\t.string \"%s\"\n", p);
459 		p += len+1;
460 	}
461 }
462 
dt_to_asm(FILE * f,struct boot_info * bi,int version)463 void dt_to_asm(FILE *f, struct boot_info *bi, int version)
464 {
465 	struct version_info *vi = NULL;
466 	int i;
467 	struct data strbuf = empty_data;
468 	struct reserve_info *re;
469 	const char *symprefix = "dt";
470 
471 	for (i = 0; i < ARRAY_SIZE(version_table); i++) {
472 		if (version_table[i].version == version)
473 			vi = &version_table[i];
474 	}
475 	if (!vi)
476 		die("Unknown device tree blob version %d\n", version);
477 
478 	fprintf(f, "/* autogenerated by dtc, do not edit */\n\n");
479 
480 	emit_label(f, symprefix, "blob_start");
481 	emit_label(f, symprefix, "header");
482 	fprintf(f, "\t/* magic */\n");
483 	asm_emit_cell(f, FDT_MAGIC);
484 	fprintf(f, "\t/* totalsize */\n");
485 	ASM_EMIT_BELONG(f, "_%s_blob_abs_end - _%s_blob_start",
486 			symprefix, symprefix);
487 	fprintf(f, "\t/* off_dt_struct */\n");
488 	ASM_EMIT_BELONG(f, "_%s_struct_start - _%s_blob_start",
489 		symprefix, symprefix);
490 	fprintf(f, "\t/* off_dt_strings */\n");
491 	ASM_EMIT_BELONG(f, "_%s_strings_start - _%s_blob_start",
492 		symprefix, symprefix);
493 	fprintf(f, "\t/* off_mem_rsvmap */\n");
494 	ASM_EMIT_BELONG(f, "_%s_reserve_map - _%s_blob_start",
495 		symprefix, symprefix);
496 	fprintf(f, "\t/* version */\n");
497 	asm_emit_cell(f, vi->version);
498 	fprintf(f, "\t/* last_comp_version */\n");
499 	asm_emit_cell(f, vi->last_comp_version);
500 
501 	if (vi->flags & FTF_BOOTCPUID) {
502 		fprintf(f, "\t/* boot_cpuid_phys */\n");
503 		asm_emit_cell(f, bi->boot_cpuid_phys);
504 	}
505 
506 	if (vi->flags & FTF_STRTABSIZE) {
507 		fprintf(f, "\t/* size_dt_strings */\n");
508 		ASM_EMIT_BELONG(f, "_%s_strings_end - _%s_strings_start",
509 				symprefix, symprefix);
510 	}
511 
512 	if (vi->flags & FTF_STRUCTSIZE) {
513 		fprintf(f, "\t/* size_dt_struct */\n");
514 		ASM_EMIT_BELONG(f, "_%s_struct_end - _%s_struct_start",
515 			symprefix, symprefix);
516 	}
517 
518 	/*
519 	 * Reserve map entries.
520 	 * Align the reserve map to a doubleword boundary.
521 	 * Each entry is an (address, size) pair of u64 values.
522 	 * Always supply a zero-sized temination entry.
523 	 */
524 	asm_emit_align(f, 8);
525 	emit_label(f, symprefix, "reserve_map");
526 
527 	fprintf(f, "/* Memory reserve map from source file */\n");
528 
529 	/*
530 	 * Use .long on high and low halfs of u64s to avoid .quad
531 	 * as it appears .quad isn't available in some assemblers.
532 	 */
533 	for (re = bi->reservelist; re; re = re->next) {
534 		struct label *l;
535 
536 		for_each_label(re->labels, l) {
537 			fprintf(f, "\t.globl\t%s\n", l->label);
538 			fprintf(f, "%s:\n", l->label);
539 		}
540 		ASM_EMIT_BELONG(f, "0x%08x", (unsigned int)(re->re.address >> 32));
541 		ASM_EMIT_BELONG(f, "0x%08x",
542 				(unsigned int)(re->re.address & 0xffffffff));
543 		ASM_EMIT_BELONG(f, "0x%08x", (unsigned int)(re->re.size >> 32));
544 		ASM_EMIT_BELONG(f, "0x%08x", (unsigned int)(re->re.size & 0xffffffff));
545 	}
546 	for (i = 0; i < reservenum; i++) {
547 		fprintf(f, "\t.long\t0, 0\n\t.long\t0, 0\n");
548 	}
549 
550 	fprintf(f, "\t.long\t0, 0\n\t.long\t0, 0\n");
551 
552 	emit_label(f, symprefix, "struct_start");
553 	flatten_tree(bi->dt, &asm_emitter, f, &strbuf, vi);
554 
555 	fprintf(f, "\t/* FDT_END */\n");
556 	asm_emit_cell(f, FDT_END);
557 	emit_label(f, symprefix, "struct_end");
558 
559 	emit_label(f, symprefix, "strings_start");
560 	dump_stringtable_asm(f, strbuf);
561 	emit_label(f, symprefix, "strings_end");
562 
563 	emit_label(f, symprefix, "blob_end");
564 
565 	/*
566 	 * If the user asked for more space than is used, pad it out.
567 	 */
568 	if (minsize > 0) {
569 		fprintf(f, "\t.space\t%d - (_%s_blob_end - _%s_blob_start), 0\n",
570 			minsize, symprefix, symprefix);
571 	}
572 	if (padsize > 0) {
573 		fprintf(f, "\t.space\t%d, 0\n", padsize);
574 	}
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 
inbuf_init(struct inbuf * inb,void * base,void * limit)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 
flat_read_chunk(struct inbuf * inb,void * p,int len)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 
flat_read_word(struct inbuf * inb)601 static uint32_t flat_read_word(struct inbuf *inb)
602 {
603 	uint32_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 
flat_realign(struct inbuf * inb,int align)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 
flat_read_string(struct inbuf * inb)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 
flat_read_data(struct inbuf * inb,int len)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 
flat_read_stringtable(struct inbuf * inb,int offset)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 
flat_read_property(struct inbuf * dtbuf,struct inbuf * strbuf,int flags)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 
flat_read_mem_reserve(struct inbuf * inb)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 		flat_read_chunk(inb, &re, sizeof(re));
713 		re.address  = fdt64_to_cpu(re.address);
714 		re.size = fdt64_to_cpu(re.size);
715 		if (re.size == 0)
716 			break;
717 
718 		new = build_reserve_entry(re.address, re.size);
719 		reservelist = add_reserve_entry(reservelist, new);
720 	}
721 
722 	return reservelist;
723 }
724 
725 
nodename_from_path(const char * ppath,const char * cpath)726 static char *nodename_from_path(const char *ppath, const char *cpath)
727 {
728 	int plen;
729 
730 	plen = strlen(ppath);
731 
732 	if (!strneq(ppath, cpath, plen))
733 		die("Path \"%s\" is not valid as a child of \"%s\"\n",
734 		    cpath, ppath);
735 
736 	/* root node is a special case */
737 	if (!streq(ppath, "/"))
738 		plen++;
739 
740 	return xstrdup(cpath + plen);
741 }
742 
unflatten_tree(struct inbuf * dtbuf,struct inbuf * strbuf,const char * parent_flatname,int flags)743 static struct node *unflatten_tree(struct inbuf *dtbuf,
744 				   struct inbuf *strbuf,
745 				   const char *parent_flatname, int flags)
746 {
747 	struct node *node;
748 	char *flatname;
749 	uint32_t val;
750 
751 	node = build_node(NULL, NULL);
752 
753 	flatname = flat_read_string(dtbuf);
754 
755 	if (flags & FTF_FULLPATH)
756 		node->name = nodename_from_path(parent_flatname, flatname);
757 	else
758 		node->name = flatname;
759 
760 	do {
761 		struct property *prop;
762 		struct node *child;
763 
764 		val = flat_read_word(dtbuf);
765 		switch (val) {
766 		case FDT_PROP:
767 			if (node->children)
768 				fprintf(stderr, "Warning: Flat tree input has "
769 					"subnodes preceding a property.\n");
770 			prop = flat_read_property(dtbuf, strbuf, flags);
771 			add_property(node, prop);
772 			break;
773 
774 		case FDT_BEGIN_NODE:
775 			child = unflatten_tree(dtbuf,strbuf, flatname, flags);
776 			add_child(node, child);
777 			break;
778 
779 		case FDT_END_NODE:
780 			break;
781 
782 		case FDT_END:
783 			die("Premature FDT_END in device tree blob\n");
784 			break;
785 
786 		case FDT_NOP:
787 			if (!(flags & FTF_NOPS))
788 				fprintf(stderr, "Warning: NOP tag found in flat tree"
789 					" version <16\n");
790 
791 			/* Ignore */
792 			break;
793 
794 		default:
795 			die("Invalid opcode word %08x in device tree blob\n",
796 			    val);
797 		}
798 	} while (val != FDT_END_NODE);
799 
800 	return node;
801 }
802 
803 
dt_from_blob(const char * fname)804 struct boot_info *dt_from_blob(const char *fname)
805 {
806 	FILE *f;
807 	uint32_t magic, totalsize, version, size_dt, boot_cpuid_phys;
808 	uint32_t off_dt, off_str, off_mem_rsvmap;
809 	int rc;
810 	char *blob;
811 	struct fdt_header *fdt;
812 	char *p;
813 	struct inbuf dtbuf, strbuf;
814 	struct inbuf memresvbuf;
815 	int sizeleft;
816 	struct reserve_info *reservelist;
817 	struct node *tree;
818 	uint32_t val;
819 	int flags = 0;
820 
821 	f = srcfile_relative_open(fname, NULL);
822 
823 	rc = fread(&magic, sizeof(magic), 1, f);
824 	if (ferror(f))
825 		die("Error reading DT blob magic number: %s\n",
826 		    strerror(errno));
827 	if (rc < 1) {
828 		if (feof(f))
829 			die("EOF reading DT blob magic number\n");
830 		else
831 			die("Mysterious short read reading magic number\n");
832 	}
833 
834 	magic = fdt32_to_cpu(magic);
835 	if (magic != FDT_MAGIC)
836 		die("Blob has incorrect magic number\n");
837 
838 	rc = fread(&totalsize, sizeof(totalsize), 1, f);
839 	if (ferror(f))
840 		die("Error reading DT blob size: %s\n", strerror(errno));
841 	if (rc < 1) {
842 		if (feof(f))
843 			die("EOF reading DT blob size\n");
844 		else
845 			die("Mysterious short read reading blob size\n");
846 	}
847 
848 	totalsize = fdt32_to_cpu(totalsize);
849 	if (totalsize < FDT_V1_SIZE)
850 		die("DT blob size (%d) is too small\n", totalsize);
851 
852 	blob = xmalloc(totalsize);
853 
854 	fdt = (struct fdt_header *)blob;
855 	fdt->magic = cpu_to_fdt32(magic);
856 	fdt->totalsize = cpu_to_fdt32(totalsize);
857 
858 	sizeleft = totalsize - sizeof(magic) - sizeof(totalsize);
859 	p = blob + sizeof(magic)  + sizeof(totalsize);
860 
861 	while (sizeleft) {
862 		if (feof(f))
863 			die("EOF before reading %d bytes of DT blob\n",
864 			    totalsize);
865 
866 		rc = fread(p, 1, sizeleft, f);
867 		if (ferror(f))
868 			die("Error reading DT blob: %s\n",
869 			    strerror(errno));
870 
871 		sizeleft -= rc;
872 		p += rc;
873 	}
874 
875 	off_dt = fdt32_to_cpu(fdt->off_dt_struct);
876 	off_str = fdt32_to_cpu(fdt->off_dt_strings);
877 	off_mem_rsvmap = fdt32_to_cpu(fdt->off_mem_rsvmap);
878 	version = fdt32_to_cpu(fdt->version);
879 	boot_cpuid_phys = fdt32_to_cpu(fdt->boot_cpuid_phys);
880 
881 	if (off_mem_rsvmap >= totalsize)
882 		die("Mem Reserve structure offset exceeds total size\n");
883 
884 	if (off_dt >= totalsize)
885 		die("DT structure offset exceeds total size\n");
886 
887 	if (off_str > totalsize)
888 		die("String table offset exceeds total size\n");
889 
890 	if (version >= 3) {
891 		uint32_t size_str = fdt32_to_cpu(fdt->size_dt_strings);
892 		if (off_str+size_str > totalsize)
893 			die("String table extends past total size\n");
894 		inbuf_init(&strbuf, blob + off_str, blob + off_str + size_str);
895 	} else {
896 		inbuf_init(&strbuf, blob + off_str, blob + totalsize);
897 	}
898 
899 	if (version >= 17) {
900 		size_dt = fdt32_to_cpu(fdt->size_dt_struct);
901 		if (off_dt+size_dt > totalsize)
902 			die("Structure block extends past total size\n");
903 	}
904 
905 	if (version < 16) {
906 		flags |= FTF_FULLPATH | FTF_NAMEPROPS | FTF_VARALIGN;
907 	} else {
908 		flags |= FTF_NOPS;
909 	}
910 
911 	inbuf_init(&memresvbuf,
912 		   blob + off_mem_rsvmap, blob + totalsize);
913 	inbuf_init(&dtbuf, blob + off_dt, blob + totalsize);
914 
915 	reservelist = flat_read_mem_reserve(&memresvbuf);
916 
917 	val = flat_read_word(&dtbuf);
918 
919 	if (val != FDT_BEGIN_NODE)
920 		die("Device tree blob doesn't begin with FDT_BEGIN_NODE (begins with 0x%08x)\n", val);
921 
922 	tree = unflatten_tree(&dtbuf, &strbuf, "", flags);
923 
924 	val = flat_read_word(&dtbuf);
925 	if (val != FDT_END)
926 		die("Device tree blob doesn't end with FDT_END\n");
927 
928 	free(blob);
929 
930 	fclose(f);
931 
932 	return build_boot_info(reservelist, tree, boot_cpuid_phys);
933 }
934