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1// SPDX-License-Identifier: (GPL-2.0-or-later OR BSD-2-Clause)
2/*
3 * libfdt - Flat Device Tree manipulation
4 * Copyright (C) 2006 David Gibson, IBM Corporation.
5 */
6#include "libfdt_env.h"
7
8#include <fdt.h>
9#include <libfdt.h>
10
11#include "libfdt_internal.h"
12
13static int fdt_nodename_eq_(const void *fdt, int offset,
14 const char *s, int len)
15{
16 int olen;
17 const char *p = fdt_get_name(fdt, offset, &olen);
18
19 if (!p || olen < len)
20 /* short match */
21 return 0;
22
23 if (memcmp(p, s, len) != 0)
24 return 0;
25
26 if (p[len] == '\0')
27 return 1;
28 else if (!memchr(s, '@', len) && (p[len] == '@'))
29 return 1;
30 else
31 return 0;
32}
33
34const char *fdt_get_string(const void *fdt, int stroffset, int *lenp)
35{
36 uint32_t absoffset = stroffset + fdt_off_dt_strings(fdt);
37 size_t len;
38 int err;
39 const char *s, *n;
40
41 err = fdt_ro_probe_(fdt);
42 if (err != 0)
43 goto fail;
44
45 err = -FDT_ERR_BADOFFSET;
46 if (absoffset >= fdt_totalsize(fdt))
47 goto fail;
48 len = fdt_totalsize(fdt) - absoffset;
49
50 if (fdt_magic(fdt) == FDT_MAGIC) {
51 if (stroffset < 0)
52 goto fail;
53 if (fdt_version(fdt) >= 17) {
54 if (stroffset >= fdt_size_dt_strings(fdt))
55 goto fail;
56 if ((fdt_size_dt_strings(fdt) - stroffset) < len)
57 len = fdt_size_dt_strings(fdt) - stroffset;
58 }
59 } else if (fdt_magic(fdt) == FDT_SW_MAGIC) {
60 if ((stroffset >= 0)
61 || (stroffset < -fdt_size_dt_strings(fdt)))
62 goto fail;
63 if ((-stroffset) < len)
64 len = -stroffset;
65 } else {
66 err = -FDT_ERR_INTERNAL;
67 goto fail;
68 }
69
70 s = (const char *)fdt + absoffset;
71 n = memchr(s, '\0', len);
72 if (!n) {
73 /* missing terminating NULL */
74 err = -FDT_ERR_TRUNCATED;
75 goto fail;
76 }
77
78 if (lenp)
79 *lenp = n - s;
80 return s;
81
82fail:
83 if (lenp)
84 *lenp = err;
85 return NULL;
86}
87
88const char *fdt_string(const void *fdt, int stroffset)
89{
90 return fdt_get_string(fdt, stroffset, NULL);
91}
92
93static int fdt_string_eq_(const void *fdt, int stroffset,
94 const char *s, int len)
95{
96 int slen;
97 const char *p = fdt_get_string(fdt, stroffset, &slen);
98
99 return p && (slen == len) && (memcmp(p, s, len) == 0);
100}
101
102int fdt_find_max_phandle(const void *fdt, uint32_t *phandle)
103{
104 uint32_t max = 0;
105 int offset = -1;
106
107 while (true) {
108 uint32_t value;
109
110 offset = fdt_next_node(fdt, offset, NULL);
111 if (offset < 0) {
112 if (offset == -FDT_ERR_NOTFOUND)
113 break;
114
115 return offset;
116 }
117
118 value = fdt_get_phandle(fdt, offset);
119
120 if (value > max)
121 max = value;
122 }
123
124 if (phandle)
125 *phandle = max;
126
127 return 0;
128}
129
130int fdt_generate_phandle(const void *fdt, uint32_t *phandle)
131{
132 uint32_t max;
133 int err;
134
135 err = fdt_find_max_phandle(fdt, &max);
136 if (err < 0)
137 return err;
138
139 if (max == FDT_MAX_PHANDLE)
140 return -FDT_ERR_NOPHANDLES;
141
142 if (phandle)
143 *phandle = max + 1;
144
145 return 0;
146}
147
148static const struct fdt_reserve_entry *fdt_mem_rsv(const void *fdt, int n)
149{
150 int offset = n * sizeof(struct fdt_reserve_entry);
151 int absoffset = fdt_off_mem_rsvmap(fdt) + offset;
152
153 if (absoffset < fdt_off_mem_rsvmap(fdt))
154 return NULL;
155 if (absoffset > fdt_totalsize(fdt) - sizeof(struct fdt_reserve_entry))
156 return NULL;
157 return fdt_mem_rsv_(fdt, n);
158}
159
160int fdt_get_mem_rsv(const void *fdt, int n, uint64_t *address, uint64_t *size)
161{
162 const struct fdt_reserve_entry *re;
163
164 FDT_RO_PROBE(fdt);
165 re = fdt_mem_rsv(fdt, n);
166 if (!re)
167 return -FDT_ERR_BADOFFSET;
168
169 *address = fdt64_ld(&re->address);
170 *size = fdt64_ld(&re->size);
171 return 0;
172}
173
174int fdt_num_mem_rsv(const void *fdt)
175{
176 int i;
177 const struct fdt_reserve_entry *re;
178
179 for (i = 0; (re = fdt_mem_rsv(fdt, i)) != NULL; i++) {
180 if (fdt64_ld(&re->size) == 0)
181 return i;
182 }
183 return -FDT_ERR_TRUNCATED;
184}
185
186static int nextprop_(const void *fdt, int offset)
187{
188 uint32_t tag;
189 int nextoffset;
190
191 do {
192 tag = fdt_next_tag(fdt, offset, &nextoffset);
193
194 switch (tag) {
195 case FDT_END:
196 if (nextoffset >= 0)
197 return -FDT_ERR_BADSTRUCTURE;
198 else
199 return nextoffset;
200
201 case FDT_PROP:
202 return offset;
203 }
204 offset = nextoffset;
205 } while (tag == FDT_NOP);
206
207 return -FDT_ERR_NOTFOUND;
208}
209
210int fdt_subnode_offset_namelen(const void *fdt, int offset,
211 const char *name, int namelen)
212{
213 int depth;
214
215 FDT_RO_PROBE(fdt);
216
217 for (depth = 0;
218 (offset >= 0) && (depth >= 0);
219 offset = fdt_next_node(fdt, offset, &depth))
220 if ((depth == 1)
221 && fdt_nodename_eq_(fdt, offset, name, namelen))
222 return offset;
223
224 if (depth < 0)
225 return -FDT_ERR_NOTFOUND;
226 return offset; /* error */
227}
228
229int fdt_subnode_offset(const void *fdt, int parentoffset,
230 const char *name)
231{
232 return fdt_subnode_offset_namelen(fdt, parentoffset, name, strlen(name));
233}
234
235int fdt_path_offset_namelen(const void *fdt, const char *path, int namelen)
236{
237 const char *end = path + namelen;
238 const char *p = path;
239 int offset = 0;
240
241 FDT_RO_PROBE(fdt);
242
243 /* see if we have an alias */
244 if (*path != '/') {
245 const char *q = memchr(path, '/', end - p);
246
247 if (!q)
248 q = end;
249
250 p = fdt_get_alias_namelen(fdt, p, q - p);
251 if (!p)
252 return -FDT_ERR_BADPATH;
253 offset = fdt_path_offset(fdt, p);
254
255 p = q;
256 }
257
258 while (p < end) {
259 const char *q;
260
261 while (*p == '/') {
262 p++;
263 if (p == end)
264 return offset;
265 }
266 q = memchr(p, '/', end - p);
267 if (! q)
268 q = end;
269
270 offset = fdt_subnode_offset_namelen(fdt, offset, p, q-p);
271 if (offset < 0)
272 return offset;
273
274 p = q;
275 }
276
277 return offset;
278}
279
280int fdt_path_offset(const void *fdt, const char *path)
281{
282 return fdt_path_offset_namelen(fdt, path, strlen(path));
283}
284
285const char *fdt_get_name(const void *fdt, int nodeoffset, int *len)
286{
287 const struct fdt_node_header *nh = fdt_offset_ptr_(fdt, nodeoffset);
288 const char *nameptr;
289 int err;
290
291 if (((err = fdt_ro_probe_(fdt)) != 0)
292 || ((err = fdt_check_node_offset_(fdt, nodeoffset)) < 0))
293 goto fail;
294
295 nameptr = nh->name;
296
297 if (fdt_version(fdt) < 0x10) {
298 /*
299 * For old FDT versions, match the naming conventions of V16:
300 * give only the leaf name (after all /). The actual tree
301 * contents are loosely checked.
302 */
303 const char *leaf;
304 leaf = strrchr(nameptr, '/');
305 if (leaf == NULL) {
306 err = -FDT_ERR_BADSTRUCTURE;
307 goto fail;
308 }
309 nameptr = leaf+1;
310 }
311
312 if (len)
313 *len = strlen(nameptr);
314
315 return nameptr;
316
317 fail:
318 if (len)
319 *len = err;
320 return NULL;
321}
322
323int fdt_first_property_offset(const void *fdt, int nodeoffset)
324{
325 int offset;
326
327 if ((offset = fdt_check_node_offset_(fdt, nodeoffset)) < 0)
328 return offset;
329
330 return nextprop_(fdt, offset);
331}
332
333int fdt_next_property_offset(const void *fdt, int offset)
334{
335 if ((offset = fdt_check_prop_offset_(fdt, offset)) < 0)
336 return offset;
337
338 return nextprop_(fdt, offset);
339}
340
341static const struct fdt_property *fdt_get_property_by_offset_(const void *fdt,
342 int offset,
343 int *lenp)
344{
345 int err;
346 const struct fdt_property *prop;
347
348 if ((err = fdt_check_prop_offset_(fdt, offset)) < 0) {
349 if (lenp)
350 *lenp = err;
351 return NULL;
352 }
353
354 prop = fdt_offset_ptr_(fdt, offset);
355
356 if (lenp)
357 *lenp = fdt32_ld(&prop->len);
358
359 return prop;
360}
361
362const struct fdt_property *fdt_get_property_by_offset(const void *fdt,
363 int offset,
364 int *lenp)
365{
366 /* Prior to version 16, properties may need realignment
367 * and this API does not work. fdt_getprop_*() will, however. */
368
369 if (fdt_version(fdt) < 0x10) {
370 if (lenp)
371 *lenp = -FDT_ERR_BADVERSION;
372 return NULL;
373 }
374
375 return fdt_get_property_by_offset_(fdt, offset, lenp);
376}
377
378static const struct fdt_property *fdt_get_property_namelen_(const void *fdt,
379 int offset,
380 const char *name,
381 int namelen,
382 int *lenp,
383 int *poffset)
384{
385 for (offset = fdt_first_property_offset(fdt, offset);
386 (offset >= 0);
387 (offset = fdt_next_property_offset(fdt, offset))) {
388 const struct fdt_property *prop;
389
390 if (!(prop = fdt_get_property_by_offset_(fdt, offset, lenp))) {
391 offset = -FDT_ERR_INTERNAL;
392 break;
393 }
394 if (fdt_string_eq_(fdt, fdt32_ld(&prop->nameoff),
395 name, namelen)) {
396 if (poffset)
397 *poffset = offset;
398 return prop;
399 }
400 }
401
402 if (lenp)
403 *lenp = offset;
404 return NULL;
405}
406
407
408const struct fdt_property *fdt_get_property_namelen(const void *fdt,
409 int offset,
410 const char *name,
411 int namelen, int *lenp)
412{
413 /* Prior to version 16, properties may need realignment
414 * and this API does not work. fdt_getprop_*() will, however. */
415 if (fdt_version(fdt) < 0x10) {
416 if (lenp)
417 *lenp = -FDT_ERR_BADVERSION;
418 return NULL;
419 }
420
421 return fdt_get_property_namelen_(fdt, offset, name, namelen, lenp,
422 NULL);
423}
424
425
426const struct fdt_property *fdt_get_property(const void *fdt,
427 int nodeoffset,
428 const char *name, int *lenp)
429{
430 return fdt_get_property_namelen(fdt, nodeoffset, name,
431 strlen(name), lenp);
432}
433
434const void *fdt_getprop_namelen(const void *fdt, int nodeoffset,
435 const char *name, int namelen, int *lenp)
436{
437 int poffset;
438 const struct fdt_property *prop;
439
440 prop = fdt_get_property_namelen_(fdt, nodeoffset, name, namelen, lenp,
441 &poffset);
442 if (!prop)
443 return NULL;
444
445 /* Handle realignment */
446 if (fdt_version(fdt) < 0x10 && (poffset + sizeof(*prop)) % 8 &&
447 fdt32_ld(&prop->len) >= 8)
448 return prop->data + 4;
449 return prop->data;
450}
451
452const void *fdt_getprop_by_offset(const void *fdt, int offset,
453 const char **namep, int *lenp)
454{
455 const struct fdt_property *prop;
456
457 prop = fdt_get_property_by_offset_(fdt, offset, lenp);
458 if (!prop)
459 return NULL;
460 if (namep) {
461 const char *name;
462 int namelen;
463 name = fdt_get_string(fdt, fdt32_ld(&prop->nameoff),
464 &namelen);
465 if (!name) {
466 if (lenp)
467 *lenp = namelen;
468 return NULL;
469 }
470 *namep = name;
471 }
472
473 /* Handle realignment */
474 if (fdt_version(fdt) < 0x10 && (offset + sizeof(*prop)) % 8 &&
475 fdt32_ld(&prop->len) >= 8)
476 return prop->data + 4;
477 return prop->data;
478}
479
480const void *fdt_getprop(const void *fdt, int nodeoffset,
481 const char *name, int *lenp)
482{
483 return fdt_getprop_namelen(fdt, nodeoffset, name, strlen(name), lenp);
484}
485
486uint32_t fdt_get_phandle(const void *fdt, int nodeoffset)
487{
488 const fdt32_t *php;
489 int len;
490
491 /* FIXME: This is a bit sub-optimal, since we potentially scan
492 * over all the properties twice. */
493 php = fdt_getprop(fdt, nodeoffset, "phandle", &len);
494 if (!php || (len != sizeof(*php))) {
495 php = fdt_getprop(fdt, nodeoffset, "linux,phandle", &len);
496 if (!php || (len != sizeof(*php)))
497 return 0;
498 }
499
500 return fdt32_ld(php);
501}
502
503const char *fdt_get_alias_namelen(const void *fdt,
504 const char *name, int namelen)
505{
506 int aliasoffset;
507
508 aliasoffset = fdt_path_offset(fdt, "/aliases");
509 if (aliasoffset < 0)
510 return NULL;
511
512 return fdt_getprop_namelen(fdt, aliasoffset, name, namelen, NULL);
513}
514
515const char *fdt_get_alias(const void *fdt, const char *name)
516{
517 return fdt_get_alias_namelen(fdt, name, strlen(name));
518}
519
520int fdt_get_path(const void *fdt, int nodeoffset, char *buf, int buflen)
521{
522 int pdepth = 0, p = 0;
523 int offset, depth, namelen;
524 const char *name;
525
526 FDT_RO_PROBE(fdt);
527
528 if (buflen < 2)
529 return -FDT_ERR_NOSPACE;
530
531 for (offset = 0, depth = 0;
532 (offset >= 0) && (offset <= nodeoffset);
533 offset = fdt_next_node(fdt, offset, &depth)) {
534 while (pdepth > depth) {
535 do {
536 p--;
537 } while (buf[p-1] != '/');
538 pdepth--;
539 }
540
541 if (pdepth >= depth) {
542 name = fdt_get_name(fdt, offset, &namelen);
543 if (!name)
544 return namelen;
545 if ((p + namelen + 1) <= buflen) {
546 memcpy(buf + p, name, namelen);
547 p += namelen;
548 buf[p++] = '/';
549 pdepth++;
550 }
551 }
552
553 if (offset == nodeoffset) {
554 if (pdepth < (depth + 1))
555 return -FDT_ERR_NOSPACE;
556
557 if (p > 1) /* special case so that root path is "/", not "" */
558 p--;
559 buf[p] = '\0';
560 return 0;
561 }
562 }
563
564 if ((offset == -FDT_ERR_NOTFOUND) || (offset >= 0))
565 return -FDT_ERR_BADOFFSET;
566 else if (offset == -FDT_ERR_BADOFFSET)
567 return -FDT_ERR_BADSTRUCTURE;
568
569 return offset; /* error from fdt_next_node() */
570}
571
572int fdt_supernode_atdepth_offset(const void *fdt, int nodeoffset,
573 int supernodedepth, int *nodedepth)
574{
575 int offset, depth;
576 int supernodeoffset = -FDT_ERR_INTERNAL;
577
578 FDT_RO_PROBE(fdt);
579
580 if (supernodedepth < 0)
581 return -FDT_ERR_NOTFOUND;
582
583 for (offset = 0, depth = 0;
584 (offset >= 0) && (offset <= nodeoffset);
585 offset = fdt_next_node(fdt, offset, &depth)) {
586 if (depth == supernodedepth)
587 supernodeoffset = offset;
588
589 if (offset == nodeoffset) {
590 if (nodedepth)
591 *nodedepth = depth;
592
593 if (supernodedepth > depth)
594 return -FDT_ERR_NOTFOUND;
595 else
596 return supernodeoffset;
597 }
598 }
599
600 if ((offset == -FDT_ERR_NOTFOUND) || (offset >= 0))
601 return -FDT_ERR_BADOFFSET;
602 else if (offset == -FDT_ERR_BADOFFSET)
603 return -FDT_ERR_BADSTRUCTURE;
604
605 return offset; /* error from fdt_next_node() */
606}
607
608int fdt_node_depth(const void *fdt, int nodeoffset)
609{
610 int nodedepth;
611 int err;
612
613 err = fdt_supernode_atdepth_offset(fdt, nodeoffset, 0, &nodedepth);
614 if (err)
615 return (err < 0) ? err : -FDT_ERR_INTERNAL;
616 return nodedepth;
617}
618
619int fdt_parent_offset(const void *fdt, int nodeoffset)
620{
621 int nodedepth = fdt_node_depth(fdt, nodeoffset);
622
623 if (nodedepth < 0)
624 return nodedepth;
625 return fdt_supernode_atdepth_offset(fdt, nodeoffset,
626 nodedepth - 1, NULL);
627}
628
629int fdt_node_offset_by_prop_value(const void *fdt, int startoffset,
630 const char *propname,
631 const void *propval, int proplen)
632{
633 int offset;
634 const void *val;
635 int len;
636
637 FDT_RO_PROBE(fdt);
638
639 /* FIXME: The algorithm here is pretty horrible: we scan each
640 * property of a node in fdt_getprop(), then if that didn't
641 * find what we want, we scan over them again making our way
642 * to the next node. Still it's the easiest to implement
643 * approach; performance can come later. */
644 for (offset = fdt_next_node(fdt, startoffset, NULL);
645 offset >= 0;
646 offset = fdt_next_node(fdt, offset, NULL)) {
647 val = fdt_getprop(fdt, offset, propname, &len);
648 if (val && (len == proplen)
649 && (memcmp(val, propval, len) == 0))
650 return offset;
651 }
652
653 return offset; /* error from fdt_next_node() */
654}
655
656int fdt_node_offset_by_phandle(const void *fdt, uint32_t phandle)
657{
658 int offset;
659
660 if ((phandle == 0) || (phandle == -1))
661 return -FDT_ERR_BADPHANDLE;
662
663 FDT_RO_PROBE(fdt);
664
665 /* FIXME: The algorithm here is pretty horrible: we
666 * potentially scan each property of a node in
667 * fdt_get_phandle(), then if that didn't find what
668 * we want, we scan over them again making our way to the next
669 * node. Still it's the easiest to implement approach;
670 * performance can come later. */
671 for (offset = fdt_next_node(fdt, -1, NULL);
672 offset >= 0;
673 offset = fdt_next_node(fdt, offset, NULL)) {
674 if (fdt_get_phandle(fdt, offset) == phandle)
675 return offset;
676 }
677
678 return offset; /* error from fdt_next_node() */
679}
680
681int fdt_stringlist_contains(const char *strlist, int listlen, const char *str)
682{
683 int len = strlen(str);
684 const char *p;
685
686 while (listlen >= len) {
687 if (memcmp(str, strlist, len+1) == 0)
688 return 1;
689 p = memchr(strlist, '\0', listlen);
690 if (!p)
691 return 0; /* malformed strlist.. */
692 listlen -= (p-strlist) + 1;
693 strlist = p + 1;
694 }
695 return 0;
696}
697
698int fdt_stringlist_count(const void *fdt, int nodeoffset, const char *property)
699{
700 const char *list, *end;
701 int length, count = 0;
702
703 list = fdt_getprop(fdt, nodeoffset, property, &length);
704 if (!list)
705 return length;
706
707 end = list + length;
708
709 while (list < end) {
710 length = strnlen(list, end - list) + 1;
711
712 /* Abort if the last string isn't properly NUL-terminated. */
713 if (list + length > end)
714 return -FDT_ERR_BADVALUE;
715
716 list += length;
717 count++;
718 }
719
720 return count;
721}
722
723int fdt_stringlist_search(const void *fdt, int nodeoffset, const char *property,
724 const char *string)
725{
726 int length, len, idx = 0;
727 const char *list, *end;
728
729 list = fdt_getprop(fdt, nodeoffset, property, &length);
730 if (!list)
731 return length;
732
733 len = strlen(string) + 1;
734 end = list + length;
735
736 while (list < end) {
737 length = strnlen(list, end - list) + 1;
738
739 /* Abort if the last string isn't properly NUL-terminated. */
740 if (list + length > end)
741 return -FDT_ERR_BADVALUE;
742
743 if (length == len && memcmp(list, string, length) == 0)
744 return idx;
745
746 list += length;
747 idx++;
748 }
749
750 return -FDT_ERR_NOTFOUND;
751}
752
753const char *fdt_stringlist_get(const void *fdt, int nodeoffset,
754 const char *property, int idx,
755 int *lenp)
756{
757 const char *list, *end;
758 int length;
759
760 list = fdt_getprop(fdt, nodeoffset, property, &length);
761 if (!list) {
762 if (lenp)
763 *lenp = length;
764
765 return NULL;
766 }
767
768 end = list + length;
769
770 while (list < end) {
771 length = strnlen(list, end - list) + 1;
772
773 /* Abort if the last string isn't properly NUL-terminated. */
774 if (list + length > end) {
775 if (lenp)
776 *lenp = -FDT_ERR_BADVALUE;
777
778 return NULL;
779 }
780
781 if (idx == 0) {
782 if (lenp)
783 *lenp = length - 1;
784
785 return list;
786 }
787
788 list += length;
789 idx--;
790 }
791
792 if (lenp)
793 *lenp = -FDT_ERR_NOTFOUND;
794
795 return NULL;
796}
797
798int fdt_node_check_compatible(const void *fdt, int nodeoffset,
799 const char *compatible)
800{
801 const void *prop;
802 int len;
803
804 prop = fdt_getprop(fdt, nodeoffset, "compatible", &len);
805 if (!prop)
806 return len;
807
808 return !fdt_stringlist_contains(prop, len, compatible);
809}
810
811int fdt_node_offset_by_compatible(const void *fdt, int startoffset,
812 const char *compatible)
813{
814 int offset, err;
815
816 FDT_RO_PROBE(fdt);
817
818 /* FIXME: The algorithm here is pretty horrible: we scan each
819 * property of a node in fdt_node_check_compatible(), then if
820 * that didn't find what we want, we scan over them again
821 * making our way to the next node. Still it's the easiest to
822 * implement approach; performance can come later. */
823 for (offset = fdt_next_node(fdt, startoffset, NULL);
824 offset >= 0;
825 offset = fdt_next_node(fdt, offset, NULL)) {
826 err = fdt_node_check_compatible(fdt, offset, compatible);
827 if ((err < 0) && (err != -FDT_ERR_NOTFOUND))
828 return err;
829 else if (err == 0)
830 return offset;
831 }
832
833 return offset; /* error from fdt_next_node() */
834}
835
836int fdt_check_full(const void *fdt, size_t bufsize)
837{
838 int err;
839 int num_memrsv;
840 int offset, nextoffset = 0;
841 uint32_t tag;
842 unsigned depth = 0;
843 const void *prop;
844 const char *propname;
845
846 if (bufsize < FDT_V1_SIZE)
847 return -FDT_ERR_TRUNCATED;
848 err = fdt_check_header(fdt);
849 if (err != 0)
850 return err;
851 if (bufsize < fdt_totalsize(fdt))
852 return -FDT_ERR_TRUNCATED;
853
854 num_memrsv = fdt_num_mem_rsv(fdt);
855 if (num_memrsv < 0)
856 return num_memrsv;
857
858 while (1) {
859 offset = nextoffset;
860 tag = fdt_next_tag(fdt, offset, &nextoffset);
861
862 if (nextoffset < 0)
863 return nextoffset;
864
865 switch (tag) {
866 case FDT_NOP:
867 break;
868
869 case FDT_END:
870 if (depth != 0)
871 return -FDT_ERR_BADSTRUCTURE;
872 return 0;
873
874 case FDT_BEGIN_NODE:
875 depth++;
876 if (depth > INT_MAX)
877 return -FDT_ERR_BADSTRUCTURE;
878 break;
879
880 case FDT_END_NODE:
881 if (depth == 0)
882 return -FDT_ERR_BADSTRUCTURE;
883 depth--;
884 break;
885
886 case FDT_PROP:
887 prop = fdt_getprop_by_offset(fdt, offset, &propname,
888 &err);
889 if (!prop)
890 return err;
891 break;
892
893 default:
894 return -FDT_ERR_INTERNAL;
895 }
896 }
897}
1// SPDX-License-Identifier: (GPL-2.0-or-later OR BSD-2-Clause)
2/*
3 * libfdt - Flat Device Tree manipulation
4 * Copyright (C) 2006 David Gibson, IBM Corporation.
5 */
6#include "libfdt_env.h"
7
8#include <fdt.h>
9#include <libfdt.h>
10
11#include "libfdt_internal.h"
12
13static int fdt_nodename_eq_(const void *fdt, int offset,
14 const char *s, int len)
15{
16 int olen;
17 const char *p = fdt_get_name(fdt, offset, &olen);
18
19 if (!p || olen < len)
20 /* short match */
21 return 0;
22
23 if (memcmp(p, s, len) != 0)
24 return 0;
25
26 if (p[len] == '\0')
27 return 1;
28 else if (!memchr(s, '@', len) && (p[len] == '@'))
29 return 1;
30 else
31 return 0;
32}
33
34const char *fdt_get_string(const void *fdt, int stroffset, int *lenp)
35{
36 int32_t totalsize;
37 uint32_t absoffset;
38 size_t len;
39 int err;
40 const char *s, *n;
41
42 if (can_assume(VALID_INPUT)) {
43 s = (const char *)fdt + fdt_off_dt_strings(fdt) + stroffset;
44
45 if (lenp)
46 *lenp = strlen(s);
47 return s;
48 }
49 totalsize = fdt_ro_probe_(fdt);
50 err = totalsize;
51 if (totalsize < 0)
52 goto fail;
53
54 err = -FDT_ERR_BADOFFSET;
55 absoffset = stroffset + fdt_off_dt_strings(fdt);
56 if (absoffset >= totalsize)
57 goto fail;
58 len = totalsize - absoffset;
59
60 if (fdt_magic(fdt) == FDT_MAGIC) {
61 if (stroffset < 0)
62 goto fail;
63 if (can_assume(LATEST) || fdt_version(fdt) >= 17) {
64 if (stroffset >= fdt_size_dt_strings(fdt))
65 goto fail;
66 if ((fdt_size_dt_strings(fdt) - stroffset) < len)
67 len = fdt_size_dt_strings(fdt) - stroffset;
68 }
69 } else if (fdt_magic(fdt) == FDT_SW_MAGIC) {
70 if ((stroffset >= 0)
71 || (stroffset < -fdt_size_dt_strings(fdt)))
72 goto fail;
73 if ((-stroffset) < len)
74 len = -stroffset;
75 } else {
76 err = -FDT_ERR_INTERNAL;
77 goto fail;
78 }
79
80 s = (const char *)fdt + absoffset;
81 n = memchr(s, '\0', len);
82 if (!n) {
83 /* missing terminating NULL */
84 err = -FDT_ERR_TRUNCATED;
85 goto fail;
86 }
87
88 if (lenp)
89 *lenp = n - s;
90 return s;
91
92fail:
93 if (lenp)
94 *lenp = err;
95 return NULL;
96}
97
98const char *fdt_string(const void *fdt, int stroffset)
99{
100 return fdt_get_string(fdt, stroffset, NULL);
101}
102
103static int fdt_string_eq_(const void *fdt, int stroffset,
104 const char *s, int len)
105{
106 int slen;
107 const char *p = fdt_get_string(fdt, stroffset, &slen);
108
109 return p && (slen == len) && (memcmp(p, s, len) == 0);
110}
111
112int fdt_find_max_phandle(const void *fdt, uint32_t *phandle)
113{
114 uint32_t max = 0;
115 int offset = -1;
116
117 while (true) {
118 uint32_t value;
119
120 offset = fdt_next_node(fdt, offset, NULL);
121 if (offset < 0) {
122 if (offset == -FDT_ERR_NOTFOUND)
123 break;
124
125 return offset;
126 }
127
128 value = fdt_get_phandle(fdt, offset);
129
130 if (value > max)
131 max = value;
132 }
133
134 if (phandle)
135 *phandle = max;
136
137 return 0;
138}
139
140int fdt_generate_phandle(const void *fdt, uint32_t *phandle)
141{
142 uint32_t max;
143 int err;
144
145 err = fdt_find_max_phandle(fdt, &max);
146 if (err < 0)
147 return err;
148
149 if (max == FDT_MAX_PHANDLE)
150 return -FDT_ERR_NOPHANDLES;
151
152 if (phandle)
153 *phandle = max + 1;
154
155 return 0;
156}
157
158static const struct fdt_reserve_entry *fdt_mem_rsv(const void *fdt, int n)
159{
160 int offset = n * sizeof(struct fdt_reserve_entry);
161 int absoffset = fdt_off_mem_rsvmap(fdt) + offset;
162
163 if (!can_assume(VALID_INPUT)) {
164 if (absoffset < fdt_off_mem_rsvmap(fdt))
165 return NULL;
166 if (absoffset > fdt_totalsize(fdt) -
167 sizeof(struct fdt_reserve_entry))
168 return NULL;
169 }
170 return fdt_mem_rsv_(fdt, n);
171}
172
173int fdt_get_mem_rsv(const void *fdt, int n, uint64_t *address, uint64_t *size)
174{
175 const struct fdt_reserve_entry *re;
176
177 FDT_RO_PROBE(fdt);
178 re = fdt_mem_rsv(fdt, n);
179 if (!can_assume(VALID_INPUT) && !re)
180 return -FDT_ERR_BADOFFSET;
181
182 *address = fdt64_ld(&re->address);
183 *size = fdt64_ld(&re->size);
184 return 0;
185}
186
187int fdt_num_mem_rsv(const void *fdt)
188{
189 int i;
190 const struct fdt_reserve_entry *re;
191
192 for (i = 0; (re = fdt_mem_rsv(fdt, i)) != NULL; i++) {
193 if (fdt64_ld(&re->size) == 0)
194 return i;
195 }
196 return -FDT_ERR_TRUNCATED;
197}
198
199static int nextprop_(const void *fdt, int offset)
200{
201 uint32_t tag;
202 int nextoffset;
203
204 do {
205 tag = fdt_next_tag(fdt, offset, &nextoffset);
206
207 switch (tag) {
208 case FDT_END:
209 if (nextoffset >= 0)
210 return -FDT_ERR_BADSTRUCTURE;
211 else
212 return nextoffset;
213
214 case FDT_PROP:
215 return offset;
216 }
217 offset = nextoffset;
218 } while (tag == FDT_NOP);
219
220 return -FDT_ERR_NOTFOUND;
221}
222
223int fdt_subnode_offset_namelen(const void *fdt, int offset,
224 const char *name, int namelen)
225{
226 int depth;
227
228 FDT_RO_PROBE(fdt);
229
230 for (depth = 0;
231 (offset >= 0) && (depth >= 0);
232 offset = fdt_next_node(fdt, offset, &depth))
233 if ((depth == 1)
234 && fdt_nodename_eq_(fdt, offset, name, namelen))
235 return offset;
236
237 if (depth < 0)
238 return -FDT_ERR_NOTFOUND;
239 return offset; /* error */
240}
241
242int fdt_subnode_offset(const void *fdt, int parentoffset,
243 const char *name)
244{
245 return fdt_subnode_offset_namelen(fdt, parentoffset, name, strlen(name));
246}
247
248int fdt_path_offset_namelen(const void *fdt, const char *path, int namelen)
249{
250 const char *end = path + namelen;
251 const char *p = path;
252 int offset = 0;
253
254 FDT_RO_PROBE(fdt);
255
256 /* see if we have an alias */
257 if (*path != '/') {
258 const char *q = memchr(path, '/', end - p);
259
260 if (!q)
261 q = end;
262
263 p = fdt_get_alias_namelen(fdt, p, q - p);
264 if (!p)
265 return -FDT_ERR_BADPATH;
266 offset = fdt_path_offset(fdt, p);
267
268 p = q;
269 }
270
271 while (p < end) {
272 const char *q;
273
274 while (*p == '/') {
275 p++;
276 if (p == end)
277 return offset;
278 }
279 q = memchr(p, '/', end - p);
280 if (! q)
281 q = end;
282
283 offset = fdt_subnode_offset_namelen(fdt, offset, p, q-p);
284 if (offset < 0)
285 return offset;
286
287 p = q;
288 }
289
290 return offset;
291}
292
293int fdt_path_offset(const void *fdt, const char *path)
294{
295 return fdt_path_offset_namelen(fdt, path, strlen(path));
296}
297
298const char *fdt_get_name(const void *fdt, int nodeoffset, int *len)
299{
300 const struct fdt_node_header *nh = fdt_offset_ptr_(fdt, nodeoffset);
301 const char *nameptr;
302 int err;
303
304 if (((err = fdt_ro_probe_(fdt)) < 0)
305 || ((err = fdt_check_node_offset_(fdt, nodeoffset)) < 0))
306 goto fail;
307
308 nameptr = nh->name;
309
310 if (!can_assume(LATEST) && fdt_version(fdt) < 0x10) {
311 /*
312 * For old FDT versions, match the naming conventions of V16:
313 * give only the leaf name (after all /). The actual tree
314 * contents are loosely checked.
315 */
316 const char *leaf;
317 leaf = strrchr(nameptr, '/');
318 if (leaf == NULL) {
319 err = -FDT_ERR_BADSTRUCTURE;
320 goto fail;
321 }
322 nameptr = leaf+1;
323 }
324
325 if (len)
326 *len = strlen(nameptr);
327
328 return nameptr;
329
330 fail:
331 if (len)
332 *len = err;
333 return NULL;
334}
335
336int fdt_first_property_offset(const void *fdt, int nodeoffset)
337{
338 int offset;
339
340 if ((offset = fdt_check_node_offset_(fdt, nodeoffset)) < 0)
341 return offset;
342
343 return nextprop_(fdt, offset);
344}
345
346int fdt_next_property_offset(const void *fdt, int offset)
347{
348 if ((offset = fdt_check_prop_offset_(fdt, offset)) < 0)
349 return offset;
350
351 return nextprop_(fdt, offset);
352}
353
354static const struct fdt_property *fdt_get_property_by_offset_(const void *fdt,
355 int offset,
356 int *lenp)
357{
358 int err;
359 const struct fdt_property *prop;
360
361 if (!can_assume(VALID_INPUT) &&
362 (err = fdt_check_prop_offset_(fdt, offset)) < 0) {
363 if (lenp)
364 *lenp = err;
365 return NULL;
366 }
367
368 prop = fdt_offset_ptr_(fdt, offset);
369
370 if (lenp)
371 *lenp = fdt32_ld(&prop->len);
372
373 return prop;
374}
375
376const struct fdt_property *fdt_get_property_by_offset(const void *fdt,
377 int offset,
378 int *lenp)
379{
380 /* Prior to version 16, properties may need realignment
381 * and this API does not work. fdt_getprop_*() will, however. */
382
383 if (!can_assume(LATEST) && fdt_version(fdt) < 0x10) {
384 if (lenp)
385 *lenp = -FDT_ERR_BADVERSION;
386 return NULL;
387 }
388
389 return fdt_get_property_by_offset_(fdt, offset, lenp);
390}
391
392static const struct fdt_property *fdt_get_property_namelen_(const void *fdt,
393 int offset,
394 const char *name,
395 int namelen,
396 int *lenp,
397 int *poffset)
398{
399 for (offset = fdt_first_property_offset(fdt, offset);
400 (offset >= 0);
401 (offset = fdt_next_property_offset(fdt, offset))) {
402 const struct fdt_property *prop;
403
404 prop = fdt_get_property_by_offset_(fdt, offset, lenp);
405 if (!can_assume(LIBFDT_FLAWLESS) && !prop) {
406 offset = -FDT_ERR_INTERNAL;
407 break;
408 }
409 if (fdt_string_eq_(fdt, fdt32_ld(&prop->nameoff),
410 name, namelen)) {
411 if (poffset)
412 *poffset = offset;
413 return prop;
414 }
415 }
416
417 if (lenp)
418 *lenp = offset;
419 return NULL;
420}
421
422
423const struct fdt_property *fdt_get_property_namelen(const void *fdt,
424 int offset,
425 const char *name,
426 int namelen, int *lenp)
427{
428 /* Prior to version 16, properties may need realignment
429 * and this API does not work. fdt_getprop_*() will, however. */
430 if (!can_assume(LATEST) && fdt_version(fdt) < 0x10) {
431 if (lenp)
432 *lenp = -FDT_ERR_BADVERSION;
433 return NULL;
434 }
435
436 return fdt_get_property_namelen_(fdt, offset, name, namelen, lenp,
437 NULL);
438}
439
440
441const struct fdt_property *fdt_get_property(const void *fdt,
442 int nodeoffset,
443 const char *name, int *lenp)
444{
445 return fdt_get_property_namelen(fdt, nodeoffset, name,
446 strlen(name), lenp);
447}
448
449const void *fdt_getprop_namelen(const void *fdt, int nodeoffset,
450 const char *name, int namelen, int *lenp)
451{
452 int poffset;
453 const struct fdt_property *prop;
454
455 prop = fdt_get_property_namelen_(fdt, nodeoffset, name, namelen, lenp,
456 &poffset);
457 if (!prop)
458 return NULL;
459
460 /* Handle realignment */
461 if (!can_assume(LATEST) && fdt_version(fdt) < 0x10 &&
462 (poffset + sizeof(*prop)) % 8 && fdt32_ld(&prop->len) >= 8)
463 return prop->data + 4;
464 return prop->data;
465}
466
467const void *fdt_getprop_by_offset(const void *fdt, int offset,
468 const char **namep, int *lenp)
469{
470 const struct fdt_property *prop;
471
472 prop = fdt_get_property_by_offset_(fdt, offset, lenp);
473 if (!prop)
474 return NULL;
475 if (namep) {
476 const char *name;
477 int namelen;
478
479 if (!can_assume(VALID_INPUT)) {
480 name = fdt_get_string(fdt, fdt32_ld(&prop->nameoff),
481 &namelen);
482 if (!name) {
483 if (lenp)
484 *lenp = namelen;
485 return NULL;
486 }
487 *namep = name;
488 } else {
489 *namep = fdt_string(fdt, fdt32_ld(&prop->nameoff));
490 }
491 }
492
493 /* Handle realignment */
494 if (!can_assume(LATEST) && fdt_version(fdt) < 0x10 &&
495 (offset + sizeof(*prop)) % 8 && fdt32_ld(&prop->len) >= 8)
496 return prop->data + 4;
497 return prop->data;
498}
499
500const void *fdt_getprop(const void *fdt, int nodeoffset,
501 const char *name, int *lenp)
502{
503 return fdt_getprop_namelen(fdt, nodeoffset, name, strlen(name), lenp);
504}
505
506uint32_t fdt_get_phandle(const void *fdt, int nodeoffset)
507{
508 const fdt32_t *php;
509 int len;
510
511 /* FIXME: This is a bit sub-optimal, since we potentially scan
512 * over all the properties twice. */
513 php = fdt_getprop(fdt, nodeoffset, "phandle", &len);
514 if (!php || (len != sizeof(*php))) {
515 php = fdt_getprop(fdt, nodeoffset, "linux,phandle", &len);
516 if (!php || (len != sizeof(*php)))
517 return 0;
518 }
519
520 return fdt32_ld(php);
521}
522
523const char *fdt_get_alias_namelen(const void *fdt,
524 const char *name, int namelen)
525{
526 int aliasoffset;
527
528 aliasoffset = fdt_path_offset(fdt, "/aliases");
529 if (aliasoffset < 0)
530 return NULL;
531
532 return fdt_getprop_namelen(fdt, aliasoffset, name, namelen, NULL);
533}
534
535const char *fdt_get_alias(const void *fdt, const char *name)
536{
537 return fdt_get_alias_namelen(fdt, name, strlen(name));
538}
539
540int fdt_get_path(const void *fdt, int nodeoffset, char *buf, int buflen)
541{
542 int pdepth = 0, p = 0;
543 int offset, depth, namelen;
544 const char *name;
545
546 FDT_RO_PROBE(fdt);
547
548 if (buflen < 2)
549 return -FDT_ERR_NOSPACE;
550
551 for (offset = 0, depth = 0;
552 (offset >= 0) && (offset <= nodeoffset);
553 offset = fdt_next_node(fdt, offset, &depth)) {
554 while (pdepth > depth) {
555 do {
556 p--;
557 } while (buf[p-1] != '/');
558 pdepth--;
559 }
560
561 if (pdepth >= depth) {
562 name = fdt_get_name(fdt, offset, &namelen);
563 if (!name)
564 return namelen;
565 if ((p + namelen + 1) <= buflen) {
566 memcpy(buf + p, name, namelen);
567 p += namelen;
568 buf[p++] = '/';
569 pdepth++;
570 }
571 }
572
573 if (offset == nodeoffset) {
574 if (pdepth < (depth + 1))
575 return -FDT_ERR_NOSPACE;
576
577 if (p > 1) /* special case so that root path is "/", not "" */
578 p--;
579 buf[p] = '\0';
580 return 0;
581 }
582 }
583
584 if ((offset == -FDT_ERR_NOTFOUND) || (offset >= 0))
585 return -FDT_ERR_BADOFFSET;
586 else if (offset == -FDT_ERR_BADOFFSET)
587 return -FDT_ERR_BADSTRUCTURE;
588
589 return offset; /* error from fdt_next_node() */
590}
591
592int fdt_supernode_atdepth_offset(const void *fdt, int nodeoffset,
593 int supernodedepth, int *nodedepth)
594{
595 int offset, depth;
596 int supernodeoffset = -FDT_ERR_INTERNAL;
597
598 FDT_RO_PROBE(fdt);
599
600 if (supernodedepth < 0)
601 return -FDT_ERR_NOTFOUND;
602
603 for (offset = 0, depth = 0;
604 (offset >= 0) && (offset <= nodeoffset);
605 offset = fdt_next_node(fdt, offset, &depth)) {
606 if (depth == supernodedepth)
607 supernodeoffset = offset;
608
609 if (offset == nodeoffset) {
610 if (nodedepth)
611 *nodedepth = depth;
612
613 if (supernodedepth > depth)
614 return -FDT_ERR_NOTFOUND;
615 else
616 return supernodeoffset;
617 }
618 }
619
620 if (!can_assume(VALID_INPUT)) {
621 if ((offset == -FDT_ERR_NOTFOUND) || (offset >= 0))
622 return -FDT_ERR_BADOFFSET;
623 else if (offset == -FDT_ERR_BADOFFSET)
624 return -FDT_ERR_BADSTRUCTURE;
625 }
626
627 return offset; /* error from fdt_next_node() */
628}
629
630int fdt_node_depth(const void *fdt, int nodeoffset)
631{
632 int nodedepth;
633 int err;
634
635 err = fdt_supernode_atdepth_offset(fdt, nodeoffset, 0, &nodedepth);
636 if (err)
637 return (can_assume(LIBFDT_FLAWLESS) || err < 0) ? err :
638 -FDT_ERR_INTERNAL;
639 return nodedepth;
640}
641
642int fdt_parent_offset(const void *fdt, int nodeoffset)
643{
644 int nodedepth = fdt_node_depth(fdt, nodeoffset);
645
646 if (nodedepth < 0)
647 return nodedepth;
648 return fdt_supernode_atdepth_offset(fdt, nodeoffset,
649 nodedepth - 1, NULL);
650}
651
652int fdt_node_offset_by_prop_value(const void *fdt, int startoffset,
653 const char *propname,
654 const void *propval, int proplen)
655{
656 int offset;
657 const void *val;
658 int len;
659
660 FDT_RO_PROBE(fdt);
661
662 /* FIXME: The algorithm here is pretty horrible: we scan each
663 * property of a node in fdt_getprop(), then if that didn't
664 * find what we want, we scan over them again making our way
665 * to the next node. Still it's the easiest to implement
666 * approach; performance can come later. */
667 for (offset = fdt_next_node(fdt, startoffset, NULL);
668 offset >= 0;
669 offset = fdt_next_node(fdt, offset, NULL)) {
670 val = fdt_getprop(fdt, offset, propname, &len);
671 if (val && (len == proplen)
672 && (memcmp(val, propval, len) == 0))
673 return offset;
674 }
675
676 return offset; /* error from fdt_next_node() */
677}
678
679int fdt_node_offset_by_phandle(const void *fdt, uint32_t phandle)
680{
681 int offset;
682
683 if ((phandle == 0) || (phandle == -1))
684 return -FDT_ERR_BADPHANDLE;
685
686 FDT_RO_PROBE(fdt);
687
688 /* FIXME: The algorithm here is pretty horrible: we
689 * potentially scan each property of a node in
690 * fdt_get_phandle(), then if that didn't find what
691 * we want, we scan over them again making our way to the next
692 * node. Still it's the easiest to implement approach;
693 * performance can come later. */
694 for (offset = fdt_next_node(fdt, -1, NULL);
695 offset >= 0;
696 offset = fdt_next_node(fdt, offset, NULL)) {
697 if (fdt_get_phandle(fdt, offset) == phandle)
698 return offset;
699 }
700
701 return offset; /* error from fdt_next_node() */
702}
703
704int fdt_stringlist_contains(const char *strlist, int listlen, const char *str)
705{
706 int len = strlen(str);
707 const char *p;
708
709 while (listlen >= len) {
710 if (memcmp(str, strlist, len+1) == 0)
711 return 1;
712 p = memchr(strlist, '\0', listlen);
713 if (!p)
714 return 0; /* malformed strlist.. */
715 listlen -= (p-strlist) + 1;
716 strlist = p + 1;
717 }
718 return 0;
719}
720
721int fdt_stringlist_count(const void *fdt, int nodeoffset, const char *property)
722{
723 const char *list, *end;
724 int length, count = 0;
725
726 list = fdt_getprop(fdt, nodeoffset, property, &length);
727 if (!list)
728 return length;
729
730 end = list + length;
731
732 while (list < end) {
733 length = strnlen(list, end - list) + 1;
734
735 /* Abort if the last string isn't properly NUL-terminated. */
736 if (list + length > end)
737 return -FDT_ERR_BADVALUE;
738
739 list += length;
740 count++;
741 }
742
743 return count;
744}
745
746int fdt_stringlist_search(const void *fdt, int nodeoffset, const char *property,
747 const char *string)
748{
749 int length, len, idx = 0;
750 const char *list, *end;
751
752 list = fdt_getprop(fdt, nodeoffset, property, &length);
753 if (!list)
754 return length;
755
756 len = strlen(string) + 1;
757 end = list + length;
758
759 while (list < end) {
760 length = strnlen(list, end - list) + 1;
761
762 /* Abort if the last string isn't properly NUL-terminated. */
763 if (list + length > end)
764 return -FDT_ERR_BADVALUE;
765
766 if (length == len && memcmp(list, string, length) == 0)
767 return idx;
768
769 list += length;
770 idx++;
771 }
772
773 return -FDT_ERR_NOTFOUND;
774}
775
776const char *fdt_stringlist_get(const void *fdt, int nodeoffset,
777 const char *property, int idx,
778 int *lenp)
779{
780 const char *list, *end;
781 int length;
782
783 list = fdt_getprop(fdt, nodeoffset, property, &length);
784 if (!list) {
785 if (lenp)
786 *lenp = length;
787
788 return NULL;
789 }
790
791 end = list + length;
792
793 while (list < end) {
794 length = strnlen(list, end - list) + 1;
795
796 /* Abort if the last string isn't properly NUL-terminated. */
797 if (list + length > end) {
798 if (lenp)
799 *lenp = -FDT_ERR_BADVALUE;
800
801 return NULL;
802 }
803
804 if (idx == 0) {
805 if (lenp)
806 *lenp = length - 1;
807
808 return list;
809 }
810
811 list += length;
812 idx--;
813 }
814
815 if (lenp)
816 *lenp = -FDT_ERR_NOTFOUND;
817
818 return NULL;
819}
820
821int fdt_node_check_compatible(const void *fdt, int nodeoffset,
822 const char *compatible)
823{
824 const void *prop;
825 int len;
826
827 prop = fdt_getprop(fdt, nodeoffset, "compatible", &len);
828 if (!prop)
829 return len;
830
831 return !fdt_stringlist_contains(prop, len, compatible);
832}
833
834int fdt_node_offset_by_compatible(const void *fdt, int startoffset,
835 const char *compatible)
836{
837 int offset, err;
838
839 FDT_RO_PROBE(fdt);
840
841 /* FIXME: The algorithm here is pretty horrible: we scan each
842 * property of a node in fdt_node_check_compatible(), then if
843 * that didn't find what we want, we scan over them again
844 * making our way to the next node. Still it's the easiest to
845 * implement approach; performance can come later. */
846 for (offset = fdt_next_node(fdt, startoffset, NULL);
847 offset >= 0;
848 offset = fdt_next_node(fdt, offset, NULL)) {
849 err = fdt_node_check_compatible(fdt, offset, compatible);
850 if ((err < 0) && (err != -FDT_ERR_NOTFOUND))
851 return err;
852 else if (err == 0)
853 return offset;
854 }
855
856 return offset; /* error from fdt_next_node() */
857}