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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 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 >= (unsigned)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 ((unsigned)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 unsigned int sw_stroffset = -stroffset;
71
72 if ((stroffset >= 0) ||
73 (sw_stroffset > fdt_size_dt_strings(fdt)))
74 goto fail;
75 if (sw_stroffset < len)
76 len = sw_stroffset;
77 } else {
78 err = -FDT_ERR_INTERNAL;
79 goto fail;
80 }
81
82 s = (const char *)fdt + absoffset;
83 n = memchr(s, '\0', len);
84 if (!n) {
85 /* missing terminating NULL */
86 err = -FDT_ERR_TRUNCATED;
87 goto fail;
88 }
89
90 if (lenp)
91 *lenp = n - s;
92 return s;
93
94fail:
95 if (lenp)
96 *lenp = err;
97 return NULL;
98}
99
100const char *fdt_string(const void *fdt, int stroffset)
101{
102 return fdt_get_string(fdt, stroffset, NULL);
103}
104
105static int fdt_string_eq_(const void *fdt, int stroffset,
106 const char *s, int len)
107{
108 int slen;
109 const char *p = fdt_get_string(fdt, stroffset, &slen);
110
111 return p && (slen == len) && (memcmp(p, s, len) == 0);
112}
113
114int fdt_find_max_phandle(const void *fdt, uint32_t *phandle)
115{
116 uint32_t max = 0;
117 int offset = -1;
118
119 while (true) {
120 uint32_t value;
121
122 offset = fdt_next_node(fdt, offset, NULL);
123 if (offset < 0) {
124 if (offset == -FDT_ERR_NOTFOUND)
125 break;
126
127 return offset;
128 }
129
130 value = fdt_get_phandle(fdt, offset);
131
132 if (value > max)
133 max = value;
134 }
135
136 if (phandle)
137 *phandle = max;
138
139 return 0;
140}
141
142int fdt_generate_phandle(const void *fdt, uint32_t *phandle)
143{
144 uint32_t max;
145 int err;
146
147 err = fdt_find_max_phandle(fdt, &max);
148 if (err < 0)
149 return err;
150
151 if (max == FDT_MAX_PHANDLE)
152 return -FDT_ERR_NOPHANDLES;
153
154 if (phandle)
155 *phandle = max + 1;
156
157 return 0;
158}
159
160static const struct fdt_reserve_entry *fdt_mem_rsv(const void *fdt, int n)
161{
162 unsigned int offset = n * sizeof(struct fdt_reserve_entry);
163 unsigned int absoffset = fdt_off_mem_rsvmap(fdt) + offset;
164
165 if (!can_assume(VALID_INPUT)) {
166 if (absoffset < fdt_off_mem_rsvmap(fdt))
167 return NULL;
168 if (absoffset > fdt_totalsize(fdt) -
169 sizeof(struct fdt_reserve_entry))
170 return NULL;
171 }
172 return fdt_mem_rsv_(fdt, n);
173}
174
175int fdt_get_mem_rsv(const void *fdt, int n, uint64_t *address, uint64_t *size)
176{
177 const struct fdt_reserve_entry *re;
178
179 FDT_RO_PROBE(fdt);
180 re = fdt_mem_rsv(fdt, n);
181 if (!can_assume(VALID_INPUT) && !re)
182 return -FDT_ERR_BADOFFSET;
183
184 *address = fdt64_ld_(&re->address);
185 *size = fdt64_ld_(&re->size);
186 return 0;
187}
188
189int fdt_num_mem_rsv(const void *fdt)
190{
191 int i;
192 const struct fdt_reserve_entry *re;
193
194 for (i = 0; (re = fdt_mem_rsv(fdt, i)) != NULL; i++) {
195 if (fdt64_ld_(&re->size) == 0)
196 return i;
197 }
198 return -FDT_ERR_TRUNCATED;
199}
200
201static int nextprop_(const void *fdt, int offset)
202{
203 uint32_t tag;
204 int nextoffset;
205
206 do {
207 tag = fdt_next_tag(fdt, offset, &nextoffset);
208
209 switch (tag) {
210 case FDT_END:
211 if (nextoffset >= 0)
212 return -FDT_ERR_BADSTRUCTURE;
213 else
214 return nextoffset;
215
216 case FDT_PROP:
217 return offset;
218 }
219 offset = nextoffset;
220 } while (tag == FDT_NOP);
221
222 return -FDT_ERR_NOTFOUND;
223}
224
225int fdt_subnode_offset_namelen(const void *fdt, int offset,
226 const char *name, int namelen)
227{
228 int depth;
229
230 FDT_RO_PROBE(fdt);
231
232 for (depth = 0;
233 (offset >= 0) && (depth >= 0);
234 offset = fdt_next_node(fdt, offset, &depth))
235 if ((depth == 1)
236 && fdt_nodename_eq_(fdt, offset, name, namelen))
237 return offset;
238
239 if (depth < 0)
240 return -FDT_ERR_NOTFOUND;
241 return offset; /* error */
242}
243
244int fdt_subnode_offset(const void *fdt, int parentoffset,
245 const char *name)
246{
247 return fdt_subnode_offset_namelen(fdt, parentoffset, name, strlen(name));
248}
249
250int fdt_path_offset_namelen(const void *fdt, const char *path, int namelen)
251{
252 const char *end = path + namelen;
253 const char *p = path;
254 int offset = 0;
255
256 FDT_RO_PROBE(fdt);
257
258 /* see if we have an alias */
259 if (*path != '/') {
260 const char *q = memchr(path, '/', end - p);
261
262 if (!q)
263 q = end;
264
265 p = fdt_get_alias_namelen(fdt, p, q - p);
266 if (!p)
267 return -FDT_ERR_BADPATH;
268 offset = fdt_path_offset(fdt, p);
269
270 p = q;
271 }
272
273 while (p < end) {
274 const char *q;
275
276 while (*p == '/') {
277 p++;
278 if (p == end)
279 return offset;
280 }
281 q = memchr(p, '/', end - p);
282 if (! q)
283 q = end;
284
285 offset = fdt_subnode_offset_namelen(fdt, offset, p, q-p);
286 if (offset < 0)
287 return offset;
288
289 p = q;
290 }
291
292 return offset;
293}
294
295int fdt_path_offset(const void *fdt, const char *path)
296{
297 return fdt_path_offset_namelen(fdt, path, strlen(path));
298}
299
300const char *fdt_get_name(const void *fdt, int nodeoffset, int *len)
301{
302 const struct fdt_node_header *nh = fdt_offset_ptr_(fdt, nodeoffset);
303 const char *nameptr;
304 int err;
305
306 if (((err = fdt_ro_probe_(fdt)) < 0)
307 || ((err = fdt_check_node_offset_(fdt, nodeoffset)) < 0))
308 goto fail;
309
310 nameptr = nh->name;
311
312 if (!can_assume(LATEST) && fdt_version(fdt) < 0x10) {
313 /*
314 * For old FDT versions, match the naming conventions of V16:
315 * give only the leaf name (after all /). The actual tree
316 * contents are loosely checked.
317 */
318 const char *leaf;
319 leaf = strrchr(nameptr, '/');
320 if (leaf == NULL) {
321 err = -FDT_ERR_BADSTRUCTURE;
322 goto fail;
323 }
324 nameptr = leaf+1;
325 }
326
327 if (len)
328 *len = strlen(nameptr);
329
330 return nameptr;
331
332 fail:
333 if (len)
334 *len = err;
335 return NULL;
336}
337
338int fdt_first_property_offset(const void *fdt, int nodeoffset)
339{
340 int offset;
341
342 if ((offset = fdt_check_node_offset_(fdt, nodeoffset)) < 0)
343 return offset;
344
345 return nextprop_(fdt, offset);
346}
347
348int fdt_next_property_offset(const void *fdt, int offset)
349{
350 if ((offset = fdt_check_prop_offset_(fdt, offset)) < 0)
351 return offset;
352
353 return nextprop_(fdt, offset);
354}
355
356static const struct fdt_property *fdt_get_property_by_offset_(const void *fdt,
357 int offset,
358 int *lenp)
359{
360 int err;
361 const struct fdt_property *prop;
362
363 if (!can_assume(VALID_INPUT) &&
364 (err = fdt_check_prop_offset_(fdt, offset)) < 0) {
365 if (lenp)
366 *lenp = err;
367 return NULL;
368 }
369
370 prop = fdt_offset_ptr_(fdt, offset);
371
372 if (lenp)
373 *lenp = fdt32_ld_(&prop->len);
374
375 return prop;
376}
377
378const struct fdt_property *fdt_get_property_by_offset(const void *fdt,
379 int offset,
380 int *lenp)
381{
382 /* Prior to version 16, properties may need realignment
383 * and this API does not work. fdt_getprop_*() will, however. */
384
385 if (!can_assume(LATEST) && fdt_version(fdt) < 0x10) {
386 if (lenp)
387 *lenp = -FDT_ERR_BADVERSION;
388 return NULL;
389 }
390
391 return fdt_get_property_by_offset_(fdt, offset, lenp);
392}
393
394static const struct fdt_property *fdt_get_property_namelen_(const void *fdt,
395 int offset,
396 const char *name,
397 int namelen,
398 int *lenp,
399 int *poffset)
400{
401 for (offset = fdt_first_property_offset(fdt, offset);
402 (offset >= 0);
403 (offset = fdt_next_property_offset(fdt, offset))) {
404 const struct fdt_property *prop;
405
406 prop = fdt_get_property_by_offset_(fdt, offset, lenp);
407 if (!can_assume(LIBFDT_FLAWLESS) && !prop) {
408 offset = -FDT_ERR_INTERNAL;
409 break;
410 }
411 if (fdt_string_eq_(fdt, fdt32_ld_(&prop->nameoff),
412 name, namelen)) {
413 if (poffset)
414 *poffset = offset;
415 return prop;
416 }
417 }
418
419 if (lenp)
420 *lenp = offset;
421 return NULL;
422}
423
424
425const struct fdt_property *fdt_get_property_namelen(const void *fdt,
426 int offset,
427 const char *name,
428 int namelen, int *lenp)
429{
430 /* Prior to version 16, properties may need realignment
431 * and this API does not work. fdt_getprop_*() will, however. */
432 if (!can_assume(LATEST) && fdt_version(fdt) < 0x10) {
433 if (lenp)
434 *lenp = -FDT_ERR_BADVERSION;
435 return NULL;
436 }
437
438 return fdt_get_property_namelen_(fdt, offset, name, namelen, lenp,
439 NULL);
440}
441
442
443const struct fdt_property *fdt_get_property(const void *fdt,
444 int nodeoffset,
445 const char *name, int *lenp)
446{
447 return fdt_get_property_namelen(fdt, nodeoffset, name,
448 strlen(name), lenp);
449}
450
451const void *fdt_getprop_namelen(const void *fdt, int nodeoffset,
452 const char *name, int namelen, int *lenp)
453{
454 int poffset;
455 const struct fdt_property *prop;
456
457 prop = fdt_get_property_namelen_(fdt, nodeoffset, name, namelen, lenp,
458 &poffset);
459 if (!prop)
460 return NULL;
461
462 /* Handle realignment */
463 if (!can_assume(LATEST) && fdt_version(fdt) < 0x10 &&
464 (poffset + sizeof(*prop)) % 8 && fdt32_ld_(&prop->len) >= 8)
465 return prop->data + 4;
466 return prop->data;
467}
468
469const void *fdt_getprop_by_offset(const void *fdt, int offset,
470 const char **namep, int *lenp)
471{
472 const struct fdt_property *prop;
473
474 prop = fdt_get_property_by_offset_(fdt, offset, lenp);
475 if (!prop)
476 return NULL;
477 if (namep) {
478 const char *name;
479 int namelen;
480
481 if (!can_assume(VALID_INPUT)) {
482 name = fdt_get_string(fdt, fdt32_ld_(&prop->nameoff),
483 &namelen);
484 *namep = name;
485 if (!name) {
486 if (lenp)
487 *lenp = namelen;
488 return NULL;
489 }
490 } else {
491 *namep = fdt_string(fdt, fdt32_ld_(&prop->nameoff));
492 }
493 }
494
495 /* Handle realignment */
496 if (!can_assume(LATEST) && fdt_version(fdt) < 0x10 &&
497 (offset + sizeof(*prop)) % 8 && fdt32_ld_(&prop->len) >= 8)
498 return prop->data + 4;
499 return prop->data;
500}
501
502const void *fdt_getprop(const void *fdt, int nodeoffset,
503 const char *name, int *lenp)
504{
505 return fdt_getprop_namelen(fdt, nodeoffset, name, strlen(name), lenp);
506}
507
508uint32_t fdt_get_phandle(const void *fdt, int nodeoffset)
509{
510 const fdt32_t *php;
511 int len;
512
513 /* FIXME: This is a bit sub-optimal, since we potentially scan
514 * over all the properties twice. */
515 php = fdt_getprop(fdt, nodeoffset, "phandle", &len);
516 if (!php || (len != sizeof(*php))) {
517 php = fdt_getprop(fdt, nodeoffset, "linux,phandle", &len);
518 if (!php || (len != sizeof(*php)))
519 return 0;
520 }
521
522 return fdt32_ld_(php);
523}
524
525const char *fdt_get_alias_namelen(const void *fdt,
526 const char *name, int namelen)
527{
528 int aliasoffset;
529
530 aliasoffset = fdt_path_offset(fdt, "/aliases");
531 if (aliasoffset < 0)
532 return NULL;
533
534 return fdt_getprop_namelen(fdt, aliasoffset, name, namelen, NULL);
535}
536
537const char *fdt_get_alias(const void *fdt, const char *name)
538{
539 return fdt_get_alias_namelen(fdt, name, strlen(name));
540}
541
542int fdt_get_path(const void *fdt, int nodeoffset, char *buf, int buflen)
543{
544 int pdepth = 0, p = 0;
545 int offset, depth, namelen;
546 const char *name;
547
548 FDT_RO_PROBE(fdt);
549
550 if (buflen < 2)
551 return -FDT_ERR_NOSPACE;
552
553 for (offset = 0, depth = 0;
554 (offset >= 0) && (offset <= nodeoffset);
555 offset = fdt_next_node(fdt, offset, &depth)) {
556 while (pdepth > depth) {
557 do {
558 p--;
559 } while (buf[p-1] != '/');
560 pdepth--;
561 }
562
563 if (pdepth >= depth) {
564 name = fdt_get_name(fdt, offset, &namelen);
565 if (!name)
566 return namelen;
567 if ((p + namelen + 1) <= buflen) {
568 memcpy(buf + p, name, namelen);
569 p += namelen;
570 buf[p++] = '/';
571 pdepth++;
572 }
573 }
574
575 if (offset == nodeoffset) {
576 if (pdepth < (depth + 1))
577 return -FDT_ERR_NOSPACE;
578
579 if (p > 1) /* special case so that root path is "/", not "" */
580 p--;
581 buf[p] = '\0';
582 return 0;
583 }
584 }
585
586 if ((offset == -FDT_ERR_NOTFOUND) || (offset >= 0))
587 return -FDT_ERR_BADOFFSET;
588 else if (offset == -FDT_ERR_BADOFFSET)
589 return -FDT_ERR_BADSTRUCTURE;
590
591 return offset; /* error from fdt_next_node() */
592}
593
594int fdt_supernode_atdepth_offset(const void *fdt, int nodeoffset,
595 int supernodedepth, int *nodedepth)
596{
597 int offset, depth;
598 int supernodeoffset = -FDT_ERR_INTERNAL;
599
600 FDT_RO_PROBE(fdt);
601
602 if (supernodedepth < 0)
603 return -FDT_ERR_NOTFOUND;
604
605 for (offset = 0, depth = 0;
606 (offset >= 0) && (offset <= nodeoffset);
607 offset = fdt_next_node(fdt, offset, &depth)) {
608 if (depth == supernodedepth)
609 supernodeoffset = offset;
610
611 if (offset == nodeoffset) {
612 if (nodedepth)
613 *nodedepth = depth;
614
615 if (supernodedepth > depth)
616 return -FDT_ERR_NOTFOUND;
617 else
618 return supernodeoffset;
619 }
620 }
621
622 if (!can_assume(VALID_INPUT)) {
623 if ((offset == -FDT_ERR_NOTFOUND) || (offset >= 0))
624 return -FDT_ERR_BADOFFSET;
625 else if (offset == -FDT_ERR_BADOFFSET)
626 return -FDT_ERR_BADSTRUCTURE;
627 }
628
629 return offset; /* error from fdt_next_node() */
630}
631
632int fdt_node_depth(const void *fdt, int nodeoffset)
633{
634 int nodedepth;
635 int err;
636
637 err = fdt_supernode_atdepth_offset(fdt, nodeoffset, 0, &nodedepth);
638 if (err)
639 return (can_assume(LIBFDT_FLAWLESS) || err < 0) ? err :
640 -FDT_ERR_INTERNAL;
641 return nodedepth;
642}
643
644int fdt_parent_offset(const void *fdt, int nodeoffset)
645{
646 int nodedepth = fdt_node_depth(fdt, nodeoffset);
647
648 if (nodedepth < 0)
649 return nodedepth;
650 return fdt_supernode_atdepth_offset(fdt, nodeoffset,
651 nodedepth - 1, NULL);
652}
653
654int fdt_node_offset_by_prop_value(const void *fdt, int startoffset,
655 const char *propname,
656 const void *propval, int proplen)
657{
658 int offset;
659 const void *val;
660 int len;
661
662 FDT_RO_PROBE(fdt);
663
664 /* FIXME: The algorithm here is pretty horrible: we scan each
665 * property of a node in fdt_getprop(), then if that didn't
666 * find what we want, we scan over them again making our way
667 * to the next node. Still it's the easiest to implement
668 * approach; performance can come later. */
669 for (offset = fdt_next_node(fdt, startoffset, NULL);
670 offset >= 0;
671 offset = fdt_next_node(fdt, offset, NULL)) {
672 val = fdt_getprop(fdt, offset, propname, &len);
673 if (val && (len == proplen)
674 && (memcmp(val, propval, len) == 0))
675 return offset;
676 }
677
678 return offset; /* error from fdt_next_node() */
679}
680
681int fdt_node_offset_by_phandle(const void *fdt, uint32_t phandle)
682{
683 int offset;
684
685 if ((phandle == 0) || (phandle == ~0U))
686 return -FDT_ERR_BADPHANDLE;
687
688 FDT_RO_PROBE(fdt);
689
690 /* FIXME: The algorithm here is pretty horrible: we
691 * potentially scan each property of a node in
692 * fdt_get_phandle(), then if that didn't find what
693 * we want, we scan over them again making our way to the next
694 * node. Still it's the easiest to implement approach;
695 * performance can come later. */
696 for (offset = fdt_next_node(fdt, -1, NULL);
697 offset >= 0;
698 offset = fdt_next_node(fdt, offset, NULL)) {
699 if (fdt_get_phandle(fdt, offset) == phandle)
700 return offset;
701 }
702
703 return offset; /* error from fdt_next_node() */
704}
705
706int fdt_stringlist_contains(const char *strlist, int listlen, const char *str)
707{
708 int len = strlen(str);
709 const char *p;
710
711 while (listlen >= len) {
712 if (memcmp(str, strlist, len+1) == 0)
713 return 1;
714 p = memchr(strlist, '\0', listlen);
715 if (!p)
716 return 0; /* malformed strlist.. */
717 listlen -= (p-strlist) + 1;
718 strlist = p + 1;
719 }
720 return 0;
721}
722
723int fdt_stringlist_count(const void *fdt, int nodeoffset, const char *property)
724{
725 const char *list, *end;
726 int length, count = 0;
727
728 list = fdt_getprop(fdt, nodeoffset, property, &length);
729 if (!list)
730 return length;
731
732 end = list + length;
733
734 while (list < end) {
735 length = strnlen(list, end - list) + 1;
736
737 /* Abort if the last string isn't properly NUL-terminated. */
738 if (list + length > end)
739 return -FDT_ERR_BADVALUE;
740
741 list += length;
742 count++;
743 }
744
745 return count;
746}
747
748int fdt_stringlist_search(const void *fdt, int nodeoffset, const char *property,
749 const char *string)
750{
751 int length, len, idx = 0;
752 const char *list, *end;
753
754 list = fdt_getprop(fdt, nodeoffset, property, &length);
755 if (!list)
756 return length;
757
758 len = strlen(string) + 1;
759 end = list + length;
760
761 while (list < end) {
762 length = strnlen(list, end - list) + 1;
763
764 /* Abort if the last string isn't properly NUL-terminated. */
765 if (list + length > end)
766 return -FDT_ERR_BADVALUE;
767
768 if (length == len && memcmp(list, string, length) == 0)
769 return idx;
770
771 list += length;
772 idx++;
773 }
774
775 return -FDT_ERR_NOTFOUND;
776}
777
778const char *fdt_stringlist_get(const void *fdt, int nodeoffset,
779 const char *property, int idx,
780 int *lenp)
781{
782 const char *list, *end;
783 int length;
784
785 list = fdt_getprop(fdt, nodeoffset, property, &length);
786 if (!list) {
787 if (lenp)
788 *lenp = length;
789
790 return NULL;
791 }
792
793 end = list + length;
794
795 while (list < end) {
796 length = strnlen(list, end - list) + 1;
797
798 /* Abort if the last string isn't properly NUL-terminated. */
799 if (list + length > end) {
800 if (lenp)
801 *lenp = -FDT_ERR_BADVALUE;
802
803 return NULL;
804 }
805
806 if (idx == 0) {
807 if (lenp)
808 *lenp = length - 1;
809
810 return list;
811 }
812
813 list += length;
814 idx--;
815 }
816
817 if (lenp)
818 *lenp = -FDT_ERR_NOTFOUND;
819
820 return NULL;
821}
822
823int fdt_node_check_compatible(const void *fdt, int nodeoffset,
824 const char *compatible)
825{
826 const void *prop;
827 int len;
828
829 prop = fdt_getprop(fdt, nodeoffset, "compatible", &len);
830 if (!prop)
831 return len;
832
833 return !fdt_stringlist_contains(prop, len, compatible);
834}
835
836int fdt_node_offset_by_compatible(const void *fdt, int startoffset,
837 const char *compatible)
838{
839 int offset, err;
840
841 FDT_RO_PROBE(fdt);
842
843 /* FIXME: The algorithm here is pretty horrible: we scan each
844 * property of a node in fdt_node_check_compatible(), then if
845 * that didn't find what we want, we scan over them again
846 * making our way to the next node. Still it's the easiest to
847 * implement approach; performance can come later. */
848 for (offset = fdt_next_node(fdt, startoffset, NULL);
849 offset >= 0;
850 offset = fdt_next_node(fdt, offset, NULL)) {
851 err = fdt_node_check_compatible(fdt, offset, compatible);
852 if ((err < 0) && (err != -FDT_ERR_NOTFOUND))
853 return err;
854 else if (err == 0)
855 return offset;
856 }
857
858 return offset; /* error from fdt_next_node() */
859}
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}