4 * libfdt - Flat Device Tree manipulation
5 * Copyright (C) 2006 David Gibson, IBM Corporation.
7 * libfdt is dual licensed: you can use it either under the terms of
8 * the GPL, or the BSD license, at your option.
10 * a) This library is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License as
12 * published by the Free Software Foundation; either version 2 of the
13 * License, or (at your option) any later version.
15 * This library is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
20 * You should have received a copy of the GNU General Public
21 * License along with this library; if not, write to the Free
22 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
27 * b) Redistribution and use in source and binary forms, with or
28 * without modification, are permitted provided that the following
31 * 1. Redistributions of source code must retain the above
32 * copyright notice, this list of conditions and the following
34 * 2. Redistributions in binary form must reproduce the above
35 * copyright notice, this list of conditions and the following
36 * disclaimer in the documentation and/or other materials
37 * provided with the distribution.
39 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
40 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
41 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
42 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
43 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
44 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
45 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
46 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
47 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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51 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
54 #include <libfdt_env.h>
57 #define FDT_FIRST_SUPPORTED_VERSION 0x10
58 #define FDT_LAST_SUPPORTED_VERSION 0x11
60 /* Error codes: informative error codes */
61 #define FDT_ERR_NOTFOUND 1
62 /* FDT_ERR_NOTFOUND: The requested node or property does not exist */
63 #define FDT_ERR_EXISTS 2
64 /* FDT_ERR_EXISTS: Attempted to create a node or property which
66 #define FDT_ERR_NOSPACE 3
67 /* FDT_ERR_NOSPACE: Operation needed to expand the device
68 * tree, but its buffer did not have sufficient space to
69 * contain the expanded tree. Use fdt_open_into() to move the
70 * device tree to a buffer with more space. */
72 /* Error codes: codes for bad parameters */
73 #define FDT_ERR_BADOFFSET 4
74 /* FDT_ERR_BADOFFSET: Function was passed a structure block
75 * offset which is out-of-bounds, or which points to an
76 * unsuitable part of the structure for the operation. */
77 #define FDT_ERR_BADPATH 5
78 /* FDT_ERR_BADPATH: Function was passed a badly formatted path
79 * (e.g. missing a leading / for a function which requires an
81 #define FDT_ERR_BADPHANDLE 6
82 /* FDT_ERR_BADPHANDLE: Function was passed an invalid phandle
83 * value. phandle values of 0 and -1 are not permitted. */
84 #define FDT_ERR_BADSTATE 7
85 /* FDT_ERR_BADSTATE: Function was passed an incomplete device
86 * tree created by the sequential-write functions, which is
87 * not sufficiently complete for the requested operation. */
89 /* Error codes: codes for bad device tree blobs */
90 #define FDT_ERR_TRUNCATED 8
91 /* FDT_ERR_TRUNCATED: Structure block of the given device tree
92 * ends without an FDT_END tag. */
93 #define FDT_ERR_BADMAGIC 9
94 /* FDT_ERR_BADMAGIC: Given "device tree" appears not to be a
95 * device tree at all - it is missing the flattened device
96 * tree magic number. */
97 #define FDT_ERR_BADVERSION 10
98 /* FDT_ERR_BADVERSION: Given device tree has a version which
99 * can't be handled by the requested operation. For
100 * read-write functions, this may mean that fdt_open_into() is
101 * required to convert the tree to the expected version. */
102 #define FDT_ERR_BADSTRUCTURE 11
103 /* FDT_ERR_BADSTRUCTURE: Given device tree has a corrupt
104 * structure block or other serious error (e.g. misnested
105 * nodes, or subnodes preceding properties). */
106 #define FDT_ERR_BADLAYOUT 12
107 /* FDT_ERR_BADLAYOUT: For read-write functions, the given
108 * device tree has it's sub-blocks in an order that the
109 * function can't handle (memory reserve map, then structure,
110 * then strings). Use fdt_open_into() to reorganize the tree
111 * into a form suitable for the read-write operations. */
113 /* "Can't happen" error indicating a bug in libfdt */
114 #define FDT_ERR_INTERNAL 13
115 /* FDT_ERR_INTERNAL: libfdt has failed an internal assertion.
116 * Should never be returned, if it is, it indicates a bug in
119 /* Errors in device tree content */
120 #define FDT_ERR_BADNCELLS 14
121 /* FDT_ERR_BADNCELLS: Device tree has a #address-cells, #size-cells
122 * or similar property with a bad format or value */
124 #define FDT_ERR_TOODEEP 15
125 /* FDT_ERR_TOODEEP: The depth of a node has exceeded the internal
126 * libfdt limit. This can happen if you have more than
127 * FDT_MAX_DEPTH nested nodes. */
129 #define FDT_ERR_MAX 15
131 /**********************************************************************/
132 /* Low-level functions (you probably don't need these) */
133 /**********************************************************************/
135 const void *fdt_offset_ptr(const void *fdt, int offset, unsigned int checklen);
136 static inline void *fdt_offset_ptr_w(void *fdt, int offset, int checklen)
138 return (void *)(uintptr_t)fdt_offset_ptr(fdt, offset, checklen);
141 uint32_t fdt_next_tag(const void *fdt, int offset, int *nextoffset);
143 /**********************************************************************/
144 /* Traversal functions */
145 /**********************************************************************/
147 int fdt_next_node(const void *fdt, int offset, int *depth);
150 * fdt_first_subnode() - get offset of first direct subnode
153 * @offset: Offset of node to check
154 * @return offset of first subnode, or -FDT_ERR_NOTFOUND if there is none
156 int fdt_first_subnode(const void *fdt, int offset);
159 * fdt_next_subnode() - get offset of next direct subnode
161 * After first calling fdt_first_subnode(), call this function repeatedly to
162 * get direct subnodes of a parent node.
165 * @offset: Offset of previous subnode
166 * @return offset of next subnode, or -FDT_ERR_NOTFOUND if there are no more
169 int fdt_next_subnode(const void *fdt, int offset);
172 * fdt_for_each_subnode - iterate over all subnodes of a parent
174 * This is actually a wrapper around a for loop and would be used like so:
176 * fdt_for_each_subnode(fdt, node, parent) {
182 * Note that this is implemented as a macro and node is used as iterator in
183 * the loop. It should therefore be a locally allocated variable. The parent
184 * variable on the other hand is never modified, so it can be constant or
187 * @fdt: FDT blob (const void *)
188 * @node: child node (int)
189 * @parent: parent node (int)
191 #define fdt_for_each_subnode(fdt, node, parent) \
192 for (node = fdt_first_subnode(fdt, parent); \
194 node = fdt_next_subnode(fdt, node))
196 /**********************************************************************/
197 /* General functions */
198 /**********************************************************************/
200 #define fdt_get_header(fdt, field) \
201 (fdt32_to_cpu(((const struct fdt_header *)(fdt))->field))
202 #define fdt_magic(fdt) (fdt_get_header(fdt, magic))
203 #define fdt_totalsize(fdt) (fdt_get_header(fdt, totalsize))
204 #define fdt_off_dt_struct(fdt) (fdt_get_header(fdt, off_dt_struct))
205 #define fdt_off_dt_strings(fdt) (fdt_get_header(fdt, off_dt_strings))
206 #define fdt_off_mem_rsvmap(fdt) (fdt_get_header(fdt, off_mem_rsvmap))
207 #define fdt_version(fdt) (fdt_get_header(fdt, version))
208 #define fdt_last_comp_version(fdt) (fdt_get_header(fdt, last_comp_version))
209 #define fdt_boot_cpuid_phys(fdt) (fdt_get_header(fdt, boot_cpuid_phys))
210 #define fdt_size_dt_strings(fdt) (fdt_get_header(fdt, size_dt_strings))
211 #define fdt_size_dt_struct(fdt) (fdt_get_header(fdt, size_dt_struct))
213 #define __fdt_set_hdr(name) \
214 static inline void fdt_set_##name(void *fdt, uint32_t val) \
216 struct fdt_header *fdth = (struct fdt_header *)fdt; \
217 fdth->name = cpu_to_fdt32(val); \
219 __fdt_set_hdr(magic);
220 __fdt_set_hdr(totalsize);
221 __fdt_set_hdr(off_dt_struct);
222 __fdt_set_hdr(off_dt_strings);
223 __fdt_set_hdr(off_mem_rsvmap);
224 __fdt_set_hdr(version);
225 __fdt_set_hdr(last_comp_version);
226 __fdt_set_hdr(boot_cpuid_phys);
227 __fdt_set_hdr(size_dt_strings);
228 __fdt_set_hdr(size_dt_struct);
232 * fdt_check_header - sanity check a device tree or possible device tree
233 * @fdt: pointer to data which might be a flattened device tree
235 * fdt_check_header() checks that the given buffer contains what
236 * appears to be a flattened device tree with sane information in its
240 * 0, if the buffer appears to contain a valid device tree
242 * -FDT_ERR_BADVERSION,
243 * -FDT_ERR_BADSTATE, standard meanings, as above
245 int fdt_check_header(const void *fdt);
248 * fdt_move - move a device tree around in memory
249 * @fdt: pointer to the device tree to move
250 * @buf: pointer to memory where the device is to be moved
251 * @bufsize: size of the memory space at buf
253 * fdt_move() relocates, if possible, the device tree blob located at
254 * fdt to the buffer at buf of size bufsize. The buffer may overlap
255 * with the existing device tree blob at fdt. Therefore,
256 * fdt_move(fdt, fdt, fdt_totalsize(fdt))
257 * should always succeed.
261 * -FDT_ERR_NOSPACE, bufsize is insufficient to contain the device tree
263 * -FDT_ERR_BADVERSION,
264 * -FDT_ERR_BADSTATE, standard meanings
266 int fdt_move(const void *fdt, void *buf, int bufsize);
268 /**********************************************************************/
269 /* Read-only functions */
270 /**********************************************************************/
273 * fdt_string - retrieve a string from the strings block of a device tree
274 * @fdt: pointer to the device tree blob
275 * @stroffset: offset of the string within the strings block (native endian)
277 * fdt_string() retrieves a pointer to a single string from the
278 * strings block of the device tree blob at fdt.
281 * a pointer to the string, on success
282 * NULL, if stroffset is out of bounds
284 const char *fdt_string(const void *fdt, int stroffset);
287 * fdt_get_max_phandle - retrieves the highest phandle in a tree
288 * @fdt: pointer to the device tree blob
290 * fdt_get_max_phandle retrieves the highest phandle in the given
291 * device tree. This will ignore badly formatted phandles, or phandles
292 * with a value of 0 or -1.
295 * the highest phandle on success
296 * 0, if no phandle was found in the device tree
297 * -1, if an error occurred
299 uint32_t fdt_get_max_phandle(const void *fdt);
302 * fdt_num_mem_rsv - retrieve the number of memory reserve map entries
303 * @fdt: pointer to the device tree blob
305 * Returns the number of entries in the device tree blob's memory
306 * reservation map. This does not include the terminating 0,0 entry
307 * or any other (0,0) entries reserved for expansion.
310 * the number of entries
312 int fdt_num_mem_rsv(const void *fdt);
315 * fdt_get_mem_rsv - retrieve one memory reserve map entry
316 * @fdt: pointer to the device tree blob
317 * @address, @size: pointers to 64-bit variables
319 * On success, *address and *size will contain the address and size of
320 * the n-th reserve map entry from the device tree blob, in
321 * native-endian format.
326 * -FDT_ERR_BADVERSION,
327 * -FDT_ERR_BADSTATE, standard meanings
329 int fdt_get_mem_rsv(const void *fdt, int n, uint64_t *address, uint64_t *size);
332 * fdt_subnode_offset_namelen - find a subnode based on substring
333 * @fdt: pointer to the device tree blob
334 * @parentoffset: structure block offset of a node
335 * @name: name of the subnode to locate
336 * @namelen: number of characters of name to consider
338 * Identical to fdt_subnode_offset(), but only examine the first
339 * namelen characters of name for matching the subnode name. This is
340 * useful for finding subnodes based on a portion of a larger string,
341 * such as a full path.
343 int fdt_subnode_offset_namelen(const void *fdt, int parentoffset,
344 const char *name, int namelen);
346 * fdt_subnode_offset - find a subnode of a given node
347 * @fdt: pointer to the device tree blob
348 * @parentoffset: structure block offset of a node
349 * @name: name of the subnode to locate
351 * fdt_subnode_offset() finds a subnode of the node at structure block
352 * offset parentoffset with the given name. name may include a unit
353 * address, in which case fdt_subnode_offset() will find the subnode
354 * with that unit address, or the unit address may be omitted, in
355 * which case fdt_subnode_offset() will find an arbitrary subnode
356 * whose name excluding unit address matches the given name.
359 * structure block offset of the requested subnode (>=0), on success
360 * -FDT_ERR_NOTFOUND, if the requested subnode does not exist
361 * -FDT_ERR_BADOFFSET, if parentoffset did not point to an FDT_BEGIN_NODE
364 * -FDT_ERR_BADVERSION,
366 * -FDT_ERR_BADSTRUCTURE,
367 * -FDT_ERR_TRUNCATED, standard meanings.
369 int fdt_subnode_offset(const void *fdt, int parentoffset, const char *name);
372 * fdt_path_offset_namelen - find a tree node by its full path
373 * @fdt: pointer to the device tree blob
374 * @path: full path of the node to locate
375 * @namelen: number of characters of path to consider
377 * Identical to fdt_path_offset(), but only consider the first namelen
378 * characters of path as the path name.
380 int fdt_path_offset_namelen(const void *fdt, const char *path, int namelen);
383 * fdt_path_offset - find a tree node by its full path
384 * @fdt: pointer to the device tree blob
385 * @path: full path of the node to locate
387 * fdt_path_offset() finds a node of a given path in the device tree.
388 * Each path component may omit the unit address portion, but the
389 * results of this are undefined if any such path component is
390 * ambiguous (that is if there are multiple nodes at the relevant
391 * level matching the given component, differentiated only by unit
395 * structure block offset of the node with the requested path (>=0), on
397 * -FDT_ERR_BADPATH, given path does not begin with '/' or is invalid
398 * -FDT_ERR_NOTFOUND, if the requested node does not exist
400 * -FDT_ERR_BADVERSION,
402 * -FDT_ERR_BADSTRUCTURE,
403 * -FDT_ERR_TRUNCATED, standard meanings.
405 static inline int fdt_path_offset(const void *fdt, const char *path)
407 return fdt_path_offset_namelen(fdt, path, strlen(path));
411 * fdt_get_name - retrieve the name of a given node
412 * @fdt: pointer to the device tree blob
413 * @nodeoffset: structure block offset of the starting node
414 * @lenp: pointer to an integer variable (will be overwritten) or NULL
416 * fdt_get_name() retrieves the name (including unit address) of the
417 * device tree node at structure block offset nodeoffset. If lenp is
418 * non-NULL, the length of this name is also returned, in the integer
419 * pointed to by lenp.
422 * pointer to the node's name, on success
423 * If lenp is non-NULL, *lenp contains the length of that name
426 * if lenp is non-NULL *lenp contains an error code (<0):
427 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE
430 * -FDT_ERR_BADVERSION,
431 * -FDT_ERR_BADSTATE, standard meanings
433 const char *fdt_get_name(const void *fdt, int nodeoffset, int *lenp);
436 * fdt_first_property_offset - find the offset of a node's first property
437 * @fdt: pointer to the device tree blob
438 * @nodeoffset: structure block offset of a node
440 * fdt_first_property_offset() finds the first property of the node at
441 * the given structure block offset.
444 * structure block offset of the property (>=0), on success
445 * -FDT_ERR_NOTFOUND, if the requested node has no properties
446 * -FDT_ERR_BADOFFSET, if nodeoffset did not point to an FDT_BEGIN_NODE tag
448 * -FDT_ERR_BADVERSION,
450 * -FDT_ERR_BADSTRUCTURE,
451 * -FDT_ERR_TRUNCATED, standard meanings.
453 int fdt_first_property_offset(const void *fdt, int nodeoffset);
456 * fdt_next_property_offset - step through a node's properties
457 * @fdt: pointer to the device tree blob
458 * @offset: structure block offset of a property
460 * fdt_next_property_offset() finds the property immediately after the
461 * one at the given structure block offset. This will be a property
462 * of the same node as the given property.
465 * structure block offset of the next property (>=0), on success
466 * -FDT_ERR_NOTFOUND, if the given property is the last in its node
467 * -FDT_ERR_BADOFFSET, if nodeoffset did not point to an FDT_PROP tag
469 * -FDT_ERR_BADVERSION,
471 * -FDT_ERR_BADSTRUCTURE,
472 * -FDT_ERR_TRUNCATED, standard meanings.
474 int fdt_next_property_offset(const void *fdt, int offset);
477 * fdt_for_each_property_offset - iterate over all properties of a node
479 * @property_offset: property offset (int, lvalue)
480 * @fdt: FDT blob (const void *)
481 * @node: node offset (int)
483 * This is actually a wrapper around a for loop and would be used like so:
485 * fdt_for_each_property_offset(property, fdt, node) {
490 * if ((property < 0) && (property != -FDT_ERR_NOT_FOUND)) {
494 * Note that this is implemented as a macro and property is used as
495 * iterator in the loop. The node variable can be constant or even a
498 #define fdt_for_each_property_offset(property, fdt, node) \
499 for (property = fdt_first_property_offset(fdt, node); \
501 property = fdt_next_property_offset(fdt, property))
504 * fdt_get_property_by_offset - retrieve the property at a given offset
505 * @fdt: pointer to the device tree blob
506 * @offset: offset of the property to retrieve
507 * @lenp: pointer to an integer variable (will be overwritten) or NULL
509 * fdt_get_property_by_offset() retrieves a pointer to the
510 * fdt_property structure within the device tree blob at the given
511 * offset. If lenp is non-NULL, the length of the property value is
512 * also returned, in the integer pointed to by lenp.
515 * pointer to the structure representing the property
516 * if lenp is non-NULL, *lenp contains the length of the property
519 * if lenp is non-NULL, *lenp contains an error code (<0):
520 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_PROP tag
522 * -FDT_ERR_BADVERSION,
524 * -FDT_ERR_BADSTRUCTURE,
525 * -FDT_ERR_TRUNCATED, standard meanings
527 const struct fdt_property *fdt_get_property_by_offset(const void *fdt,
532 * fdt_get_property_namelen - find a property based on substring
533 * @fdt: pointer to the device tree blob
534 * @nodeoffset: offset of the node whose property to find
535 * @name: name of the property to find
536 * @namelen: number of characters of name to consider
537 * @lenp: pointer to an integer variable (will be overwritten) or NULL
539 * Identical to fdt_get_property(), but only examine the first namelen
540 * characters of name for matching the property name.
542 const struct fdt_property *fdt_get_property_namelen(const void *fdt,
545 int namelen, int *lenp);
548 * fdt_get_property - find a given property in a given node
549 * @fdt: pointer to the device tree blob
550 * @nodeoffset: offset of the node whose property to find
551 * @name: name of the property to find
552 * @lenp: pointer to an integer variable (will be overwritten) or NULL
554 * fdt_get_property() retrieves a pointer to the fdt_property
555 * structure within the device tree blob corresponding to the property
556 * named 'name' of the node at offset nodeoffset. If lenp is
557 * non-NULL, the length of the property value is also returned, in the
558 * integer pointed to by lenp.
561 * pointer to the structure representing the property
562 * if lenp is non-NULL, *lenp contains the length of the property
565 * if lenp is non-NULL, *lenp contains an error code (<0):
566 * -FDT_ERR_NOTFOUND, node does not have named property
567 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE
570 * -FDT_ERR_BADVERSION,
572 * -FDT_ERR_BADSTRUCTURE,
573 * -FDT_ERR_TRUNCATED, standard meanings
575 const struct fdt_property *fdt_get_property(const void *fdt, int nodeoffset,
576 const char *name, int *lenp);
577 static inline struct fdt_property *fdt_get_property_w(void *fdt, int nodeoffset,
581 return (struct fdt_property *)(uintptr_t)
582 fdt_get_property(fdt, nodeoffset, name, lenp);
586 * fdt_getprop_by_offset - retrieve the value of a property at a given offset
587 * @fdt: pointer to the device tree blob
588 * @ffset: offset of the property to read
589 * @namep: pointer to a string variable (will be overwritten) or NULL
590 * @lenp: pointer to an integer variable (will be overwritten) or NULL
592 * fdt_getprop_by_offset() retrieves a pointer to the value of the
593 * property at structure block offset 'offset' (this will be a pointer
594 * to within the device blob itself, not a copy of the value). If
595 * lenp is non-NULL, the length of the property value is also
596 * returned, in the integer pointed to by lenp. If namep is non-NULL,
597 * the property's namne will also be returned in the char * pointed to
598 * by namep (this will be a pointer to within the device tree's string
599 * block, not a new copy of the name).
602 * pointer to the property's value
603 * if lenp is non-NULL, *lenp contains the length of the property
605 * if namep is non-NULL *namep contiains a pointer to the property
608 * if lenp is non-NULL, *lenp contains an error code (<0):
609 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_PROP tag
611 * -FDT_ERR_BADVERSION,
613 * -FDT_ERR_BADSTRUCTURE,
614 * -FDT_ERR_TRUNCATED, standard meanings
616 const void *fdt_getprop_by_offset(const void *fdt, int offset,
617 const char **namep, int *lenp);
620 * fdt_getprop_namelen - get property value based on substring
621 * @fdt: pointer to the device tree blob
622 * @nodeoffset: offset of the node whose property to find
623 * @name: name of the property to find
624 * @namelen: number of characters of name to consider
625 * @lenp: pointer to an integer variable (will be overwritten) or NULL
627 * Identical to fdt_getprop(), but only examine the first namelen
628 * characters of name for matching the property name.
630 const void *fdt_getprop_namelen(const void *fdt, int nodeoffset,
631 const char *name, int namelen, int *lenp);
632 static inline void *fdt_getprop_namelen_w(void *fdt, int nodeoffset,
633 const char *name, int namelen,
636 return (void *)(uintptr_t)fdt_getprop_namelen(fdt, nodeoffset, name,
641 * fdt_getprop - retrieve the value of a given property
642 * @fdt: pointer to the device tree blob
643 * @nodeoffset: offset of the node whose property to find
644 * @name: name of the property to find
645 * @lenp: pointer to an integer variable (will be overwritten) or NULL
647 * fdt_getprop() retrieves a pointer to the value of the property
648 * named 'name' of the node at offset nodeoffset (this will be a
649 * pointer to within the device blob itself, not a copy of the value).
650 * If lenp is non-NULL, the length of the property value is also
651 * returned, in the integer pointed to by lenp.
654 * pointer to the property's value
655 * if lenp is non-NULL, *lenp contains the length of the property
658 * if lenp is non-NULL, *lenp contains an error code (<0):
659 * -FDT_ERR_NOTFOUND, node does not have named property
660 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE
663 * -FDT_ERR_BADVERSION,
665 * -FDT_ERR_BADSTRUCTURE,
666 * -FDT_ERR_TRUNCATED, standard meanings
668 const void *fdt_getprop(const void *fdt, int nodeoffset,
669 const char *name, int *lenp);
670 static inline void *fdt_getprop_w(void *fdt, int nodeoffset,
671 const char *name, int *lenp)
673 return (void *)(uintptr_t)fdt_getprop(fdt, nodeoffset, name, lenp);
677 * fdt_get_phandle - retrieve the phandle of a given node
678 * @fdt: pointer to the device tree blob
679 * @nodeoffset: structure block offset of the node
681 * fdt_get_phandle() retrieves the phandle of the device tree node at
682 * structure block offset nodeoffset.
685 * the phandle of the node at nodeoffset, on success (!= 0, != -1)
686 * 0, if the node has no phandle, or another error occurs
688 uint32_t fdt_get_phandle(const void *fdt, int nodeoffset);
691 * fdt_get_alias_namelen - get alias based on substring
692 * @fdt: pointer to the device tree blob
693 * @name: name of the alias th look up
694 * @namelen: number of characters of name to consider
696 * Identical to fdt_get_alias(), but only examine the first namelen
697 * characters of name for matching the alias name.
699 const char *fdt_get_alias_namelen(const void *fdt,
700 const char *name, int namelen);
703 * fdt_get_alias - retrieve the path referenced by a given alias
704 * @fdt: pointer to the device tree blob
705 * @name: name of the alias th look up
707 * fdt_get_alias() retrieves the value of a given alias. That is, the
708 * value of the property named 'name' in the node /aliases.
711 * a pointer to the expansion of the alias named 'name', if it exists
712 * NULL, if the given alias or the /aliases node does not exist
714 const char *fdt_get_alias(const void *fdt, const char *name);
717 * fdt_get_path - determine the full path of a node
718 * @fdt: pointer to the device tree blob
719 * @nodeoffset: offset of the node whose path to find
720 * @buf: character buffer to contain the returned path (will be overwritten)
721 * @buflen: size of the character buffer at buf
723 * fdt_get_path() computes the full path of the node at offset
724 * nodeoffset, and records that path in the buffer at buf.
726 * NOTE: This function is expensive, as it must scan the device tree
727 * structure from the start to nodeoffset.
731 * buf contains the absolute path of the node at
732 * nodeoffset, as a NUL-terminated string.
733 * -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
734 * -FDT_ERR_NOSPACE, the path of the given node is longer than (bufsize-1)
735 * characters and will not fit in the given buffer.
737 * -FDT_ERR_BADVERSION,
739 * -FDT_ERR_BADSTRUCTURE, standard meanings
741 int fdt_get_path(const void *fdt, int nodeoffset, char *buf, int buflen);
744 * fdt_supernode_atdepth_offset - find a specific ancestor of a node
745 * @fdt: pointer to the device tree blob
746 * @nodeoffset: offset of the node whose parent to find
747 * @supernodedepth: depth of the ancestor to find
748 * @nodedepth: pointer to an integer variable (will be overwritten) or NULL
750 * fdt_supernode_atdepth_offset() finds an ancestor of the given node
751 * at a specific depth from the root (where the root itself has depth
752 * 0, its immediate subnodes depth 1 and so forth). So
753 * fdt_supernode_atdepth_offset(fdt, nodeoffset, 0, NULL);
754 * will always return 0, the offset of the root node. If the node at
755 * nodeoffset has depth D, then:
756 * fdt_supernode_atdepth_offset(fdt, nodeoffset, D, NULL);
757 * will return nodeoffset itself.
759 * NOTE: This function is expensive, as it must scan the device tree
760 * structure from the start to nodeoffset.
763 * structure block offset of the node at node offset's ancestor
764 * of depth supernodedepth (>=0), on success
765 * -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
766 * -FDT_ERR_NOTFOUND, supernodedepth was greater than the depth of
769 * -FDT_ERR_BADVERSION,
771 * -FDT_ERR_BADSTRUCTURE, standard meanings
773 int fdt_supernode_atdepth_offset(const void *fdt, int nodeoffset,
774 int supernodedepth, int *nodedepth);
777 * fdt_node_depth - find the depth of a given node
778 * @fdt: pointer to the device tree blob
779 * @nodeoffset: offset of the node whose parent to find
781 * fdt_node_depth() finds the depth of a given node. The root node
782 * has depth 0, its immediate subnodes depth 1 and so forth.
784 * NOTE: This function is expensive, as it must scan the device tree
785 * structure from the start to nodeoffset.
788 * depth of the node at nodeoffset (>=0), on success
789 * -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
791 * -FDT_ERR_BADVERSION,
793 * -FDT_ERR_BADSTRUCTURE, standard meanings
795 int fdt_node_depth(const void *fdt, int nodeoffset);
798 * fdt_parent_offset - find the parent of a given node
799 * @fdt: pointer to the device tree blob
800 * @nodeoffset: offset of the node whose parent to find
802 * fdt_parent_offset() locates the parent node of a given node (that
803 * is, it finds the offset of the node which contains the node at
804 * nodeoffset as a subnode).
806 * NOTE: This function is expensive, as it must scan the device tree
807 * structure from the start to nodeoffset, *twice*.
810 * structure block offset of the parent of the node at nodeoffset
812 * -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
814 * -FDT_ERR_BADVERSION,
816 * -FDT_ERR_BADSTRUCTURE, standard meanings
818 int fdt_parent_offset(const void *fdt, int nodeoffset);
821 * fdt_node_offset_by_prop_value - find nodes with a given property value
822 * @fdt: pointer to the device tree blob
823 * @startoffset: only find nodes after this offset
824 * @propname: property name to check
825 * @propval: property value to search for
826 * @proplen: length of the value in propval
828 * fdt_node_offset_by_prop_value() returns the offset of the first
829 * node after startoffset, which has a property named propname whose
830 * value is of length proplen and has value equal to propval; or if
831 * startoffset is -1, the very first such node in the tree.
833 * To iterate through all nodes matching the criterion, the following
835 * offset = fdt_node_offset_by_prop_value(fdt, -1, propname,
837 * while (offset != -FDT_ERR_NOTFOUND) {
839 * offset = fdt_node_offset_by_prop_value(fdt, offset, propname,
843 * Note the -1 in the first call to the function, if 0 is used here
844 * instead, the function will never locate the root node, even if it
845 * matches the criterion.
848 * structure block offset of the located node (>= 0, >startoffset),
850 * -FDT_ERR_NOTFOUND, no node matching the criterion exists in the
851 * tree after startoffset
852 * -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
854 * -FDT_ERR_BADVERSION,
856 * -FDT_ERR_BADSTRUCTURE, standard meanings
858 int fdt_node_offset_by_prop_value(const void *fdt, int startoffset,
859 const char *propname,
860 const void *propval, int proplen);
863 * fdt_node_offset_by_phandle - find the node with a given phandle
864 * @fdt: pointer to the device tree blob
865 * @phandle: phandle value
867 * fdt_node_offset_by_phandle() returns the offset of the node
868 * which has the given phandle value. If there is more than one node
869 * in the tree with the given phandle (an invalid tree), results are
873 * structure block offset of the located node (>= 0), on success
874 * -FDT_ERR_NOTFOUND, no node with that phandle exists
875 * -FDT_ERR_BADPHANDLE, given phandle value was invalid (0 or -1)
877 * -FDT_ERR_BADVERSION,
879 * -FDT_ERR_BADSTRUCTURE, standard meanings
881 int fdt_node_offset_by_phandle(const void *fdt, uint32_t phandle);
884 * fdt_node_check_compatible: check a node's compatible property
885 * @fdt: pointer to the device tree blob
886 * @nodeoffset: offset of a tree node
887 * @compatible: string to match against
890 * fdt_node_check_compatible() returns 0 if the given node contains a
891 * 'compatible' property with the given string as one of its elements,
892 * it returns non-zero otherwise, or on error.
895 * 0, if the node has a 'compatible' property listing the given string
896 * 1, if the node has a 'compatible' property, but it does not list
898 * -FDT_ERR_NOTFOUND, if the given node has no 'compatible' property
899 * -FDT_ERR_BADOFFSET, if nodeoffset does not refer to a BEGIN_NODE tag
901 * -FDT_ERR_BADVERSION,
903 * -FDT_ERR_BADSTRUCTURE, standard meanings
905 int fdt_node_check_compatible(const void *fdt, int nodeoffset,
906 const char *compatible);
909 * fdt_node_offset_by_compatible - find nodes with a given 'compatible' value
910 * @fdt: pointer to the device tree blob
911 * @startoffset: only find nodes after this offset
912 * @compatible: 'compatible' string to match against
914 * fdt_node_offset_by_compatible() returns the offset of the first
915 * node after startoffset, which has a 'compatible' property which
916 * lists the given compatible string; or if startoffset is -1, the
917 * very first such node in the tree.
919 * To iterate through all nodes matching the criterion, the following
921 * offset = fdt_node_offset_by_compatible(fdt, -1, compatible);
922 * while (offset != -FDT_ERR_NOTFOUND) {
924 * offset = fdt_node_offset_by_compatible(fdt, offset, compatible);
927 * Note the -1 in the first call to the function, if 0 is used here
928 * instead, the function will never locate the root node, even if it
929 * matches the criterion.
932 * structure block offset of the located node (>= 0, >startoffset),
934 * -FDT_ERR_NOTFOUND, no node matching the criterion exists in the
935 * tree after startoffset
936 * -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
938 * -FDT_ERR_BADVERSION,
940 * -FDT_ERR_BADSTRUCTURE, standard meanings
942 int fdt_node_offset_by_compatible(const void *fdt, int startoffset,
943 const char *compatible);
946 * fdt_stringlist_contains - check a string list property for a string
947 * @strlist: Property containing a list of strings to check
948 * @listlen: Length of property
949 * @str: String to search for
951 * This is a utility function provided for convenience. The list contains
952 * one or more strings, each terminated by \0, as is found in a device tree
953 * "compatible" property.
955 * @return: 1 if the string is found in the list, 0 not found, or invalid list
957 int fdt_stringlist_contains(const char *strlist, int listlen, const char *str);
960 * fdt_count_strings - count the number of strings in a string list
961 * @fdt: pointer to the device tree blob
962 * @node: offset of the node
963 * @property: name of the property containing the string list
964 * @return: the number of strings in the given property
966 int fdt_count_strings(const void *fdt, int node, const char *property);
969 * fdt_find_string - find a string in a string list and return its index
970 * @fdt: pointer to the device tree blob
971 * @node: offset of the node
972 * @property: name of the property containing the string list
973 * @string: string to look up in the string list
974 * @return: the index of the string or negative on error
976 int fdt_find_string(const void *fdt, int node, const char *property,
980 * fdt_get_string_index() - obtain the string at a given index in a string list
981 * @fdt: pointer to the device tree blob
982 * @node: offset of the node
983 * @property: name of the property containing the string list
984 * @index: index of the string to return
985 * @output: return location for the string
986 * @return: 0 if the string was found or a negative error code otherwise
988 int fdt_get_string_index(const void *fdt, int node, const char *property,
989 int index, const char **output);
992 * fdt_get_string() - obtain the first string in a string list
993 * @fdt: pointer to the device tree blob
994 * @node: offset of the node
995 * @property: name of the property containing the string list
996 * @output: return location for the string
997 * @return: 0 if the string was found or a negative error code otherwise
999 * This is a shortcut for:
1001 * fdt_get_string_index(fdt, node, property, 0, output).
1003 int fdt_get_string(const void *fdt, int node, const char *property,
1004 const char **output);
1006 /**********************************************************************/
1007 /* Read-only functions (addressing related) */
1008 /**********************************************************************/
1011 * FDT_MAX_NCELLS - maximum value for #address-cells and #size-cells
1013 * This is the maximum value for #address-cells, #size-cells and
1014 * similar properties that will be processed by libfdt. IEE1275
1015 * requires that OF implementations handle values up to 4.
1016 * Implementations may support larger values, but in practice higher
1017 * values aren't used.
1019 #define FDT_MAX_NCELLS 4
1022 * fdt_address_cells - retrieve address size for a bus represented in the tree
1023 * @fdt: pointer to the device tree blob
1024 * @nodeoffset: offset of the node to find the address size for
1026 * When the node has a valid #address-cells property, returns its value.
1029 * 0 <= n < FDT_MAX_NCELLS, on success
1030 * 2, if the node has no #address-cells property
1031 * -FDT_ERR_BADNCELLS, if the node has a badly formatted or invalid
1032 * #address-cells property
1033 * -FDT_ERR_BADMAGIC,
1034 * -FDT_ERR_BADVERSION,
1035 * -FDT_ERR_BADSTATE,
1036 * -FDT_ERR_BADSTRUCTURE,
1037 * -FDT_ERR_TRUNCATED, standard meanings
1039 int fdt_address_cells(const void *fdt, int nodeoffset);
1042 * fdt_size_cells - retrieve address range size for a bus represented in the
1044 * @fdt: pointer to the device tree blob
1045 * @nodeoffset: offset of the node to find the address range size for
1047 * When the node has a valid #size-cells property, returns its value.
1050 * 0 <= n < FDT_MAX_NCELLS, on success
1051 * 2, if the node has no #address-cells property
1052 * -FDT_ERR_BADNCELLS, if the node has a badly formatted or invalid
1053 * #size-cells property
1054 * -FDT_ERR_BADMAGIC,
1055 * -FDT_ERR_BADVERSION,
1056 * -FDT_ERR_BADSTATE,
1057 * -FDT_ERR_BADSTRUCTURE,
1058 * -FDT_ERR_TRUNCATED, standard meanings
1060 int fdt_size_cells(const void *fdt, int nodeoffset);
1063 /**********************************************************************/
1064 /* Write-in-place functions */
1065 /**********************************************************************/
1068 * fdt_setprop_inplace_namelen_partial - change a property's value,
1070 * @fdt: pointer to the device tree blob
1071 * @nodeoffset: offset of the node whose property to change
1072 * @name: name of the property to change
1073 * @namelen: number of characters of name to consider
1074 * @idx: index of the property to change in the array
1075 * @val: pointer to data to replace the property value with
1076 * @len: length of the property value
1078 * Identical to fdt_setprop_inplace(), but modifies the given property
1079 * starting from the given index, and using only the first characters
1080 * of the name. It is useful when you want to manipulate only one value of
1081 * an array and you have a string that doesn't end with \0.
1083 int fdt_setprop_inplace_namelen_partial(void *fdt, int nodeoffset,
1084 const char *name, int namelen,
1085 uint32_t idx, const void *val,
1089 * fdt_setprop_inplace - change a property's value, but not its size
1090 * @fdt: pointer to the device tree blob
1091 * @nodeoffset: offset of the node whose property to change
1092 * @name: name of the property to change
1093 * @val: pointer to data to replace the property value with
1094 * @len: length of the property value
1096 * fdt_setprop_inplace() replaces the value of a given property with
1097 * the data in val, of length len. This function cannot change the
1098 * size of a property, and so will only work if len is equal to the
1099 * current length of the property.
1101 * This function will alter only the bytes in the blob which contain
1102 * the given property value, and will not alter or move any other part
1107 * -FDT_ERR_NOSPACE, if len is not equal to the property's current length
1108 * -FDT_ERR_NOTFOUND, node does not have the named property
1109 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1110 * -FDT_ERR_BADMAGIC,
1111 * -FDT_ERR_BADVERSION,
1112 * -FDT_ERR_BADSTATE,
1113 * -FDT_ERR_BADSTRUCTURE,
1114 * -FDT_ERR_TRUNCATED, standard meanings
1116 int fdt_setprop_inplace(void *fdt, int nodeoffset, const char *name,
1117 const void *val, int len);
1120 * fdt_setprop_inplace_u32 - change the value of a 32-bit integer property
1121 * @fdt: pointer to the device tree blob
1122 * @nodeoffset: offset of the node whose property to change
1123 * @name: name of the property to change
1124 * @val: 32-bit integer value to replace the property with
1126 * fdt_setprop_inplace_u32() replaces the value of a given property
1127 * with the 32-bit integer value in val, converting val to big-endian
1128 * if necessary. This function cannot change the size of a property,
1129 * and so will only work if the property already exists and has length
1132 * This function will alter only the bytes in the blob which contain
1133 * the given property value, and will not alter or move any other part
1138 * -FDT_ERR_NOSPACE, if the property's length is not equal to 4
1139 * -FDT_ERR_NOTFOUND, node does not have the named property
1140 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1141 * -FDT_ERR_BADMAGIC,
1142 * -FDT_ERR_BADVERSION,
1143 * -FDT_ERR_BADSTATE,
1144 * -FDT_ERR_BADSTRUCTURE,
1145 * -FDT_ERR_TRUNCATED, standard meanings
1147 static inline int fdt_setprop_inplace_u32(void *fdt, int nodeoffset,
1148 const char *name, uint32_t val)
1150 fdt32_t tmp = cpu_to_fdt32(val);
1151 return fdt_setprop_inplace(fdt, nodeoffset, name, &tmp, sizeof(tmp));
1155 * fdt_setprop_inplace_u64 - change the value of a 64-bit integer property
1156 * @fdt: pointer to the device tree blob
1157 * @nodeoffset: offset of the node whose property to change
1158 * @name: name of the property to change
1159 * @val: 64-bit integer value to replace the property with
1161 * fdt_setprop_inplace_u64() replaces the value of a given property
1162 * with the 64-bit integer value in val, converting val to big-endian
1163 * if necessary. This function cannot change the size of a property,
1164 * and so will only work if the property already exists and has length
1167 * This function will alter only the bytes in the blob which contain
1168 * the given property value, and will not alter or move any other part
1173 * -FDT_ERR_NOSPACE, if the property's length is not equal to 8
1174 * -FDT_ERR_NOTFOUND, node does not have the named property
1175 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1176 * -FDT_ERR_BADMAGIC,
1177 * -FDT_ERR_BADVERSION,
1178 * -FDT_ERR_BADSTATE,
1179 * -FDT_ERR_BADSTRUCTURE,
1180 * -FDT_ERR_TRUNCATED, standard meanings
1182 static inline int fdt_setprop_inplace_u64(void *fdt, int nodeoffset,
1183 const char *name, uint64_t val)
1185 fdt64_t tmp = cpu_to_fdt64(val);
1186 return fdt_setprop_inplace(fdt, nodeoffset, name, &tmp, sizeof(tmp));
1190 * fdt_setprop_inplace_cell - change the value of a single-cell property
1192 * This is an alternative name for fdt_setprop_inplace_u32()
1194 static inline int fdt_setprop_inplace_cell(void *fdt, int nodeoffset,
1195 const char *name, uint32_t val)
1197 return fdt_setprop_inplace_u32(fdt, nodeoffset, name, val);
1201 * fdt_nop_property - replace a property with nop tags
1202 * @fdt: pointer to the device tree blob
1203 * @nodeoffset: offset of the node whose property to nop
1204 * @name: name of the property to nop
1206 * fdt_nop_property() will replace a given property's representation
1207 * in the blob with FDT_NOP tags, effectively removing it from the
1210 * This function will alter only the bytes in the blob which contain
1211 * the property, and will not alter or move any other part of the
1216 * -FDT_ERR_NOTFOUND, node does not have the named property
1217 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1218 * -FDT_ERR_BADMAGIC,
1219 * -FDT_ERR_BADVERSION,
1220 * -FDT_ERR_BADSTATE,
1221 * -FDT_ERR_BADSTRUCTURE,
1222 * -FDT_ERR_TRUNCATED, standard meanings
1224 int fdt_nop_property(void *fdt, int nodeoffset, const char *name);
1227 * fdt_nop_node - replace a node (subtree) with nop tags
1228 * @fdt: pointer to the device tree blob
1229 * @nodeoffset: offset of the node to nop
1231 * fdt_nop_node() will replace a given node's representation in the
1232 * blob, including all its subnodes, if any, with FDT_NOP tags,
1233 * effectively removing it from the tree.
1235 * This function will alter only the bytes in the blob which contain
1236 * the node and its properties and subnodes, and will not alter or
1237 * move any other part of the tree.
1241 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1242 * -FDT_ERR_BADMAGIC,
1243 * -FDT_ERR_BADVERSION,
1244 * -FDT_ERR_BADSTATE,
1245 * -FDT_ERR_BADSTRUCTURE,
1246 * -FDT_ERR_TRUNCATED, standard meanings
1248 int fdt_nop_node(void *fdt, int nodeoffset);
1250 /**********************************************************************/
1251 /* Sequential write functions */
1252 /**********************************************************************/
1254 int fdt_create(void *buf, int bufsize);
1255 int fdt_resize(void *fdt, void *buf, int bufsize);
1256 int fdt_add_reservemap_entry(void *fdt, uint64_t addr, uint64_t size);
1257 int fdt_finish_reservemap(void *fdt);
1258 int fdt_begin_node(void *fdt, const char *name);
1259 int fdt_property(void *fdt, const char *name, const void *val, int len);
1260 static inline int fdt_property_u32(void *fdt, const char *name, uint32_t val)
1262 fdt32_t tmp = cpu_to_fdt32(val);
1263 return fdt_property(fdt, name, &tmp, sizeof(tmp));
1265 static inline int fdt_property_u64(void *fdt, const char *name, uint64_t val)
1267 fdt64_t tmp = cpu_to_fdt64(val);
1268 return fdt_property(fdt, name, &tmp, sizeof(tmp));
1270 static inline int fdt_property_cell(void *fdt, const char *name, uint32_t val)
1272 return fdt_property_u32(fdt, name, val);
1276 * fdt_property_placeholder - add a new property and return a ptr to its value
1278 * @fdt: pointer to the device tree blob
1279 * @name: name of property to add
1280 * @len: length of property value in bytes
1281 * @valp: returns a pointer to where where the value should be placed
1285 * -FDT_ERR_BADMAGIC,
1286 * -FDT_ERR_NOSPACE, standard meanings
1288 int fdt_property_placeholder(void *fdt, const char *name, int len, void **valp);
1290 #define fdt_property_string(fdt, name, str) \
1291 fdt_property(fdt, name, str, strlen(str)+1)
1292 int fdt_end_node(void *fdt);
1293 int fdt_finish(void *fdt);
1295 /**********************************************************************/
1296 /* Read-write functions */
1297 /**********************************************************************/
1299 int fdt_create_empty_tree(void *buf, int bufsize);
1300 int fdt_open_into(const void *fdt, void *buf, int bufsize);
1301 int fdt_pack(void *fdt);
1304 * fdt_add_mem_rsv - add one memory reserve map entry
1305 * @fdt: pointer to the device tree blob
1306 * @address, @size: 64-bit values (native endian)
1308 * Adds a reserve map entry to the given blob reserving a region at
1309 * address address of length size.
1311 * This function will insert data into the reserve map and will
1312 * therefore change the indexes of some entries in the table.
1316 * -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1317 * contain the new reservation entry
1318 * -FDT_ERR_BADMAGIC,
1319 * -FDT_ERR_BADVERSION,
1320 * -FDT_ERR_BADSTATE,
1321 * -FDT_ERR_BADSTRUCTURE,
1322 * -FDT_ERR_BADLAYOUT,
1323 * -FDT_ERR_TRUNCATED, standard meanings
1325 int fdt_add_mem_rsv(void *fdt, uint64_t address, uint64_t size);
1328 * fdt_del_mem_rsv - remove a memory reserve map entry
1329 * @fdt: pointer to the device tree blob
1330 * @n: entry to remove
1332 * fdt_del_mem_rsv() removes the n-th memory reserve map entry from
1335 * This function will delete data from the reservation table and will
1336 * therefore change the indexes of some entries in the table.
1340 * -FDT_ERR_NOTFOUND, there is no entry of the given index (i.e. there
1341 * are less than n+1 reserve map entries)
1342 * -FDT_ERR_BADMAGIC,
1343 * -FDT_ERR_BADVERSION,
1344 * -FDT_ERR_BADSTATE,
1345 * -FDT_ERR_BADSTRUCTURE,
1346 * -FDT_ERR_BADLAYOUT,
1347 * -FDT_ERR_TRUNCATED, standard meanings
1349 int fdt_del_mem_rsv(void *fdt, int n);
1352 * fdt_set_name - change the name of a given node
1353 * @fdt: pointer to the device tree blob
1354 * @nodeoffset: structure block offset of a node
1355 * @name: name to give the node
1357 * fdt_set_name() replaces the name (including unit address, if any)
1358 * of the given node with the given string. NOTE: this function can't
1359 * efficiently check if the new name is unique amongst the given
1360 * node's siblings; results are undefined if this function is invoked
1361 * with a name equal to one of the given node's siblings.
1363 * This function may insert or delete data from the blob, and will
1364 * therefore change the offsets of some existing nodes.
1368 * -FDT_ERR_NOSPACE, there is insufficient free space in the blob
1369 * to contain the new name
1370 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1371 * -FDT_ERR_BADMAGIC,
1372 * -FDT_ERR_BADVERSION,
1373 * -FDT_ERR_BADSTATE, standard meanings
1375 int fdt_set_name(void *fdt, int nodeoffset, const char *name);
1378 * fdt_setprop - create or change a property
1379 * @fdt: pointer to the device tree blob
1380 * @nodeoffset: offset of the node whose property to change
1381 * @name: name of the property to change
1382 * @val: pointer to data to set the property value to
1383 * @len: length of the property value
1385 * fdt_setprop() sets the value of the named property in the given
1386 * node to the given value and length, creating the property if it
1387 * does not already exist.
1389 * This function may insert or delete data from the blob, and will
1390 * therefore change the offsets of some existing nodes.
1394 * -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1395 * contain the new property value
1396 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1397 * -FDT_ERR_BADLAYOUT,
1398 * -FDT_ERR_BADMAGIC,
1399 * -FDT_ERR_BADVERSION,
1400 * -FDT_ERR_BADSTATE,
1401 * -FDT_ERR_BADSTRUCTURE,
1402 * -FDT_ERR_BADLAYOUT,
1403 * -FDT_ERR_TRUNCATED, standard meanings
1405 int fdt_setprop(void *fdt, int nodeoffset, const char *name,
1406 const void *val, int len);
1409 * fdt_setprop_u32 - set a property to a 32-bit integer
1410 * @fdt: pointer to the device tree blob
1411 * @nodeoffset: offset of the node whose property to change
1412 * @name: name of the property to change
1413 * @val: 32-bit integer value for the property (native endian)
1415 * fdt_setprop_u32() sets the value of the named property in the given
1416 * node to the given 32-bit integer value (converting to big-endian if
1417 * necessary), or creates a new property with that value if it does
1418 * not already exist.
1420 * This function may insert or delete data from the blob, and will
1421 * therefore change the offsets of some existing nodes.
1425 * -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1426 * contain the new property value
1427 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1428 * -FDT_ERR_BADLAYOUT,
1429 * -FDT_ERR_BADMAGIC,
1430 * -FDT_ERR_BADVERSION,
1431 * -FDT_ERR_BADSTATE,
1432 * -FDT_ERR_BADSTRUCTURE,
1433 * -FDT_ERR_BADLAYOUT,
1434 * -FDT_ERR_TRUNCATED, standard meanings
1436 static inline int fdt_setprop_u32(void *fdt, int nodeoffset, const char *name,
1439 fdt32_t tmp = cpu_to_fdt32(val);
1440 return fdt_setprop(fdt, nodeoffset, name, &tmp, sizeof(tmp));
1444 * fdt_setprop_u64 - set a property to a 64-bit integer
1445 * @fdt: pointer to the device tree blob
1446 * @nodeoffset: offset of the node whose property to change
1447 * @name: name of the property to change
1448 * @val: 64-bit integer value for the property (native endian)
1450 * fdt_setprop_u64() sets the value of the named property in the given
1451 * node to the given 64-bit integer value (converting to big-endian if
1452 * necessary), or creates a new property with that value if it does
1453 * not already exist.
1455 * This function may insert or delete data from the blob, and will
1456 * therefore change the offsets of some existing nodes.
1460 * -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1461 * contain the new property value
1462 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1463 * -FDT_ERR_BADLAYOUT,
1464 * -FDT_ERR_BADMAGIC,
1465 * -FDT_ERR_BADVERSION,
1466 * -FDT_ERR_BADSTATE,
1467 * -FDT_ERR_BADSTRUCTURE,
1468 * -FDT_ERR_BADLAYOUT,
1469 * -FDT_ERR_TRUNCATED, standard meanings
1471 static inline int fdt_setprop_u64(void *fdt, int nodeoffset, const char *name,
1474 fdt64_t tmp = cpu_to_fdt64(val);
1475 return fdt_setprop(fdt, nodeoffset, name, &tmp, sizeof(tmp));
1479 * fdt_setprop_cell - set a property to a single cell value
1481 * This is an alternative name for fdt_setprop_u32()
1483 static inline int fdt_setprop_cell(void *fdt, int nodeoffset, const char *name,
1486 return fdt_setprop_u32(fdt, nodeoffset, name, val);
1490 * fdt_setprop_string - set a property to a string value
1491 * @fdt: pointer to the device tree blob
1492 * @nodeoffset: offset of the node whose property to change
1493 * @name: name of the property to change
1494 * @str: string value for the property
1496 * fdt_setprop_string() sets the value of the named property in the
1497 * given node to the given string value (using the length of the
1498 * string to determine the new length of the property), or creates a
1499 * new property with that value if it does not already exist.
1501 * This function may insert or delete data from the blob, and will
1502 * therefore change the offsets of some existing nodes.
1506 * -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1507 * contain the new property value
1508 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1509 * -FDT_ERR_BADLAYOUT,
1510 * -FDT_ERR_BADMAGIC,
1511 * -FDT_ERR_BADVERSION,
1512 * -FDT_ERR_BADSTATE,
1513 * -FDT_ERR_BADSTRUCTURE,
1514 * -FDT_ERR_BADLAYOUT,
1515 * -FDT_ERR_TRUNCATED, standard meanings
1517 #define fdt_setprop_string(fdt, nodeoffset, name, str) \
1518 fdt_setprop((fdt), (nodeoffset), (name), (str), strlen(str)+1)
1521 * fdt_appendprop - append to or create a property
1522 * @fdt: pointer to the device tree blob
1523 * @nodeoffset: offset of the node whose property to change
1524 * @name: name of the property to append to
1525 * @val: pointer to data to append to the property value
1526 * @len: length of the data to append to the property value
1528 * fdt_appendprop() appends the value to the named property in the
1529 * given node, creating the property if it does not already exist.
1531 * This function may insert data into the blob, and will therefore
1532 * change the offsets of some existing nodes.
1536 * -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1537 * contain the new property value
1538 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1539 * -FDT_ERR_BADLAYOUT,
1540 * -FDT_ERR_BADMAGIC,
1541 * -FDT_ERR_BADVERSION,
1542 * -FDT_ERR_BADSTATE,
1543 * -FDT_ERR_BADSTRUCTURE,
1544 * -FDT_ERR_BADLAYOUT,
1545 * -FDT_ERR_TRUNCATED, standard meanings
1547 int fdt_appendprop(void *fdt, int nodeoffset, const char *name,
1548 const void *val, int len);
1551 * fdt_appendprop_u32 - append a 32-bit integer value to a property
1552 * @fdt: pointer to the device tree blob
1553 * @nodeoffset: offset of the node whose property to change
1554 * @name: name of the property to change
1555 * @val: 32-bit integer value to append to the property (native endian)
1557 * fdt_appendprop_u32() appends the given 32-bit integer value
1558 * (converting to big-endian if necessary) to the value of the named
1559 * property in the given node, or creates a new property with that
1560 * value if it does not already exist.
1562 * This function may insert data into the blob, and will therefore
1563 * change the offsets of some existing nodes.
1567 * -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1568 * contain the new property value
1569 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1570 * -FDT_ERR_BADLAYOUT,
1571 * -FDT_ERR_BADMAGIC,
1572 * -FDT_ERR_BADVERSION,
1573 * -FDT_ERR_BADSTATE,
1574 * -FDT_ERR_BADSTRUCTURE,
1575 * -FDT_ERR_BADLAYOUT,
1576 * -FDT_ERR_TRUNCATED, standard meanings
1578 static inline int fdt_appendprop_u32(void *fdt, int nodeoffset,
1579 const char *name, uint32_t val)
1581 fdt32_t tmp = cpu_to_fdt32(val);
1582 return fdt_appendprop(fdt, nodeoffset, name, &tmp, sizeof(tmp));
1586 * fdt_appendprop_u64 - append a 64-bit integer value to a property
1587 * @fdt: pointer to the device tree blob
1588 * @nodeoffset: offset of the node whose property to change
1589 * @name: name of the property to change
1590 * @val: 64-bit integer value to append to the property (native endian)
1592 * fdt_appendprop_u64() appends the given 64-bit integer value
1593 * (converting to big-endian if necessary) to the value of the named
1594 * property in the given node, or creates a new property with that
1595 * value if it does not already exist.
1597 * This function may insert data into the blob, and will therefore
1598 * change the offsets of some existing nodes.
1602 * -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1603 * contain the new property value
1604 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1605 * -FDT_ERR_BADLAYOUT,
1606 * -FDT_ERR_BADMAGIC,
1607 * -FDT_ERR_BADVERSION,
1608 * -FDT_ERR_BADSTATE,
1609 * -FDT_ERR_BADSTRUCTURE,
1610 * -FDT_ERR_BADLAYOUT,
1611 * -FDT_ERR_TRUNCATED, standard meanings
1613 static inline int fdt_appendprop_u64(void *fdt, int nodeoffset,
1614 const char *name, uint64_t val)
1616 fdt64_t tmp = cpu_to_fdt64(val);
1617 return fdt_appendprop(fdt, nodeoffset, name, &tmp, sizeof(tmp));
1621 * fdt_appendprop_cell - append a single cell value to a property
1623 * This is an alternative name for fdt_appendprop_u32()
1625 static inline int fdt_appendprop_cell(void *fdt, int nodeoffset,
1626 const char *name, uint32_t val)
1628 return fdt_appendprop_u32(fdt, nodeoffset, name, val);
1632 * fdt_appendprop_string - append a string to a property
1633 * @fdt: pointer to the device tree blob
1634 * @nodeoffset: offset of the node whose property to change
1635 * @name: name of the property to change
1636 * @str: string value to append to the property
1638 * fdt_appendprop_string() appends the given string to the value of
1639 * the named property in the given node, or creates a new property
1640 * with that value if it does not already exist.
1642 * This function may insert data into the blob, and will therefore
1643 * change the offsets of some existing nodes.
1647 * -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1648 * contain the new property value
1649 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1650 * -FDT_ERR_BADLAYOUT,
1651 * -FDT_ERR_BADMAGIC,
1652 * -FDT_ERR_BADVERSION,
1653 * -FDT_ERR_BADSTATE,
1654 * -FDT_ERR_BADSTRUCTURE,
1655 * -FDT_ERR_BADLAYOUT,
1656 * -FDT_ERR_TRUNCATED, standard meanings
1658 #define fdt_appendprop_string(fdt, nodeoffset, name, str) \
1659 fdt_appendprop((fdt), (nodeoffset), (name), (str), strlen(str)+1)
1662 * fdt_delprop - delete a property
1663 * @fdt: pointer to the device tree blob
1664 * @nodeoffset: offset of the node whose property to nop
1665 * @name: name of the property to nop
1667 * fdt_del_property() will delete the given property.
1669 * This function will delete data from the blob, and will therefore
1670 * change the offsets of some existing nodes.
1674 * -FDT_ERR_NOTFOUND, node does not have the named property
1675 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1676 * -FDT_ERR_BADLAYOUT,
1677 * -FDT_ERR_BADMAGIC,
1678 * -FDT_ERR_BADVERSION,
1679 * -FDT_ERR_BADSTATE,
1680 * -FDT_ERR_BADSTRUCTURE,
1681 * -FDT_ERR_TRUNCATED, standard meanings
1683 int fdt_delprop(void *fdt, int nodeoffset, const char *name);
1686 * fdt_add_subnode_namelen - creates a new node based on substring
1687 * @fdt: pointer to the device tree blob
1688 * @parentoffset: structure block offset of a node
1689 * @name: name of the subnode to locate
1690 * @namelen: number of characters of name to consider
1692 * Identical to fdt_add_subnode(), but use only the first namelen
1693 * characters of name as the name of the new node. This is useful for
1694 * creating subnodes based on a portion of a larger string, such as a
1697 int fdt_add_subnode_namelen(void *fdt, int parentoffset,
1698 const char *name, int namelen);
1701 * fdt_add_subnode - creates a new node
1702 * @fdt: pointer to the device tree blob
1703 * @parentoffset: structure block offset of a node
1704 * @name: name of the subnode to locate
1706 * fdt_add_subnode() creates a new node as a subnode of the node at
1707 * structure block offset parentoffset, with the given name (which
1708 * should include the unit address, if any).
1710 * This function will insert data into the blob, and will therefore
1711 * change the offsets of some existing nodes.
1714 * structure block offset of the created nodeequested subnode (>=0), on
1716 * -FDT_ERR_NOTFOUND, if the requested subnode does not exist
1717 * -FDT_ERR_BADOFFSET, if parentoffset did not point to an FDT_BEGIN_NODE
1719 * -FDT_ERR_EXISTS, if the node at parentoffset already has a subnode of
1721 * -FDT_ERR_NOSPACE, if there is insufficient free space in the
1722 * blob to contain the new node
1724 * -FDT_ERR_BADLAYOUT
1725 * -FDT_ERR_BADMAGIC,
1726 * -FDT_ERR_BADVERSION,
1727 * -FDT_ERR_BADSTATE,
1728 * -FDT_ERR_BADSTRUCTURE,
1729 * -FDT_ERR_TRUNCATED, standard meanings.
1731 int fdt_add_subnode(void *fdt, int parentoffset, const char *name);
1734 * fdt_del_node - delete a node (subtree)
1735 * @fdt: pointer to the device tree blob
1736 * @nodeoffset: offset of the node to nop
1738 * fdt_del_node() will remove the given node, including all its
1739 * subnodes if any, from the blob.
1741 * This function will delete data from the blob, and will therefore
1742 * change the offsets of some existing nodes.
1746 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1747 * -FDT_ERR_BADLAYOUT,
1748 * -FDT_ERR_BADMAGIC,
1749 * -FDT_ERR_BADVERSION,
1750 * -FDT_ERR_BADSTATE,
1751 * -FDT_ERR_BADSTRUCTURE,
1752 * -FDT_ERR_TRUNCATED, standard meanings
1754 int fdt_del_node(void *fdt, int nodeoffset);
1757 * fdt_overlay_apply - Applies a DT overlay on a base DT
1758 * @fdt: pointer to the base device tree blob
1759 * @fdto: pointer to the device tree overlay blob
1761 * fdt_overlay_apply() will apply the given device tree overlay on the
1762 * given base device tree.
1764 * Expect the base device tree to be modified, even if the function
1769 * -FDT_ERR_NOSPACE, there's not enough space in the base device tree
1770 * -FDT_ERR_NOTFOUND, the overlay points to some inexistant nodes or
1771 * properties in the base DT
1772 * -FDT_ERR_BADPHANDLE, the phandles in the overlay do not have the right
1774 * -FDT_ERR_INTERNAL,
1775 * -FDT_ERR_BADLAYOUT,
1776 * -FDT_ERR_BADMAGIC,
1777 * -FDT_ERR_BADOFFSET,
1779 * -FDT_ERR_BADVERSION,
1780 * -FDT_ERR_BADSTRUCTURE,
1781 * -FDT_ERR_BADSTATE,
1782 * -FDT_ERR_TRUNCATED, standard meanings
1784 int fdt_overlay_apply(void *fdt, void *fdto);
1786 /**********************************************************************/
1787 /* Debugging / informational functions */
1788 /**********************************************************************/
1790 const char *fdt_strerror(int errval);
1793 * fdt_remove_unused_strings() - Remove any unused strings from an FDT
1795 * This creates a new device tree in @new with unused strings removed. The
1796 * called can then use fdt_pack() to minimise the space consumed.
1798 * @old: Old device tree blog
1799 * @new: Place to put new device tree blob, which must be as large as
1803 * -FDT_ERR_BADOFFSET, corrupt device tree
1804 * -FDT_ERR_NOSPACE, out of space, which should not happen unless there
1805 * is something very wrong with the device tree input
1807 int fdt_remove_unused_strings(const void *old, void *new);
1815 * Flags for fdt_find_regions()
1817 * Add a region for the string table (always the last region)
1819 #define FDT_REG_ADD_STRING_TAB (1 << 0)
1822 * Add all supernodes of a matching node/property, useful for creating a
1825 #define FDT_REG_SUPERNODES (1 << 1)
1827 /* Add the FDT_BEGIN_NODE tags of subnodes, including their names */
1828 #define FDT_REG_DIRECT_SUBNODES (1 << 2)
1830 /* Add all subnodes of a matching node */
1831 #define FDT_REG_ALL_SUBNODES (1 << 3)
1833 /* Add a region for the mem_rsvmap table (always the first region) */
1834 #define FDT_REG_ADD_MEM_RSVMAP (1 << 4)
1836 /* Indicates what an fdt part is (node, property, value) */
1837 #define FDT_IS_NODE (1 << 0)
1838 #define FDT_IS_PROP (1 << 1)
1839 #define FDT_IS_VALUE (1 << 2) /* not supported */
1840 #define FDT_IS_COMPAT (1 << 3) /* used internally */
1841 #define FDT_NODE_HAS_PROP (1 << 4) /* node contains prop */
1843 #define FDT_ANY_GLOBAL (FDT_IS_NODE | FDT_IS_PROP | FDT_IS_VALUE | \
1845 #define FDT_IS_ANY 0x1f /* all the above */
1847 /* We set a reasonable limit on the number of nested nodes */
1848 #define FDT_MAX_DEPTH 32
1850 /* Decribes what we want to include from the current tag */
1853 WANT_NODES_ONLY, /* No properties */
1854 WANT_NODES_AND_PROPS, /* Everything for one level */
1855 WANT_ALL_NODES_AND_PROPS /* Everything for all levels */
1858 /* Keeps track of the state at parent nodes */
1859 struct fdt_subnode_stack {
1860 int offset; /* Offset of node */
1861 enum want_t want; /* The 'want' value here */
1862 int included; /* 1 if we included this node, 0 if not */
1865 struct fdt_region_ptrs {
1866 int depth; /* Current tree depth */
1867 int done; /* What we have completed scanning */
1868 enum want_t want; /* What we are currently including */
1869 char *end; /* Pointer to end of full node path */
1870 int nextoffset; /* Next node offset to check */
1873 /* The state of our finding algortihm */
1874 struct fdt_region_state {
1875 struct fdt_subnode_stack stack[FDT_MAX_DEPTH]; /* node stack */
1876 struct fdt_region *region; /* Contains list of regions found */
1877 int count; /* Numnber of regions found */
1878 const void *fdt; /* FDT blob */
1879 int max_regions; /* Maximum regions to find */
1880 int can_merge; /* 1 if we can merge with previous region */
1881 int start; /* Start position of current region */
1882 struct fdt_region_ptrs ptrs; /* Pointers for what we are up to */
1886 * fdt_find_regions() - find regions in device tree
1888 * Given a list of nodes to include and properties to exclude, find
1889 * the regions of the device tree which describe those included parts.
1891 * The intent is to get a list of regions which will be invariant provided
1892 * those parts are invariant. For example, if you request a list of regions
1893 * for all nodes but exclude the property "data", then you will get the
1894 * same region contents regardless of any change to "data" properties.
1896 * This function can be used to produce a byte-stream to send to a hashing
1897 * function to verify that critical parts of the FDT have not changed.
1899 * Nodes which are given in 'inc' are included in the region list, as
1900 * are the names of the immediate subnodes nodes (but not the properties
1901 * or subnodes of those subnodes).
1903 * For eaxample "/" means to include the root node, all root properties
1904 * and the FDT_BEGIN_NODE and FDT_END_NODE of all subnodes of /. The latter
1905 * ensures that we capture the names of the subnodes. In a hashing situation
1906 * it prevents the root node from changing at all Any change to non-excluded
1907 * properties, names of subnodes or number of subnodes would be detected.
1909 * When used with FITs this provides the ability to hash and sign parts of
1910 * the FIT based on different configurations in the FIT. Then it is
1911 * impossible to change anything about that configuration (include images
1912 * attached to the configuration), but it may be possible to add new
1913 * configurations, new images or new signatures within the existing
1916 * Adding new properties to a device tree may result in the string table
1917 * being extended (if the new property names are different from those
1918 * already added). This function can optionally include a region for
1919 * the string table so that this can be part of the hash too.
1921 * The device tree header is not included in the list.
1923 * @fdt: Device tree to check
1924 * @inc: List of node paths to included
1925 * @inc_count: Number of node paths in list
1926 * @exc_prop: List of properties names to exclude
1927 * @exc_prop_count: Number of properties in exclude list
1928 * @region: Returns list of regions
1929 * @max_region: Maximum length of region list
1930 * @path: Pointer to a temporary string for the function to use for
1931 * building path names
1932 * @path_len: Length of path, must be large enough to hold the longest
1934 * @add_string_tab: 1 to add a region for the string table
1935 * @return number of regions in list. If this is >max_regions then the
1936 * region array was exhausted. You should increase max_regions and try
1939 int fdt_find_regions(const void *fdt, char * const inc[], int inc_count,
1940 char * const exc_prop[], int exc_prop_count,
1941 struct fdt_region region[], int max_regions,
1942 char *path, int path_len, int add_string_tab);
1945 * fdt_first_region() - find regions in device tree
1947 * Given a nodes and properties to include and properties to exclude, find
1948 * the regions of the device tree which describe those included parts.
1950 * The use for this function is twofold. Firstly it provides a convenient
1951 * way of performing a structure-aware grep of the tree. For example it is
1952 * possible to grep for a node and get all the properties associated with
1953 * that node. Trees can be subsetted easily, by specifying the nodes that
1954 * are required, and then writing out the regions returned by this function.
1955 * This is useful for small resource-constrained systems, such as boot
1956 * loaders, which want to use an FDT but do not need to know about all of
1959 * Secondly it makes it easy to hash parts of the tree and detect changes.
1960 * The intent is to get a list of regions which will be invariant provided
1961 * those parts are invariant. For example, if you request a list of regions
1962 * for all nodes but exclude the property "data", then you will get the
1963 * same region contents regardless of any change to "data" properties.
1965 * This function can be used to produce a byte-stream to send to a hashing
1966 * function to verify that critical parts of the FDT have not changed.
1967 * Note that semantically null changes in order could still cause false
1968 * hash misses. Such reordering might happen if the tree is regenerated
1969 * from source, and nodes are reordered (the bytes-stream will be emitted
1970 * in a different order and mnay hash functions will detect this). However
1971 * if an existing tree is modified using libfdt functions, such as
1972 * fdt_add_subnode() and fdt_setprop(), then this problem is avoided.
1974 * The nodes/properties to include/exclude are defined by a function
1975 * provided by the caller. This function is called for each node and
1976 * property, and must return:
1978 * 0 - to exclude this part
1979 * 1 - to include this part
1980 * -1 - for FDT_IS_PROP only: no information is available, so include
1981 * if its containing node is included
1983 * The last case is only used to deal with properties. Often a property is
1984 * included if its containing node is included - this is the case where
1985 * -1 is returned.. However if the property is specifically required to be
1986 * included/excluded, then 0 or 1 can be returned. Note that including a
1987 * property when the FDT_REG_SUPERNODES flag is given will force its
1988 * containing node to be included since it is not valid to have a property
1989 * that is not in a node.
1991 * Using the information provided, the inclusion of a node can be controlled
1992 * either by a node name or its compatible string, or any other property
1993 * that the function can determine.
1995 * As an example, including node "/" means to include the root node and all
1996 * root properties. A flag provides a way of also including supernodes (of
1997 * which there is none for the root node), and another flag includes
1998 * immediate subnodes, so in this case we would get the FDT_BEGIN_NODE and
1999 * FDT_END_NODE of all subnodes of /.
2001 * The subnode feature helps in a hashing situation since it prevents the
2002 * root node from changing at all. Any change to non-excluded properties,
2003 * names of subnodes or number of subnodes would be detected.
2005 * When used with FITs this provides the ability to hash and sign parts of
2006 * the FIT based on different configurations in the FIT. Then it is
2007 * impossible to change anything about that configuration (include images
2008 * attached to the configuration), but it may be possible to add new
2009 * configurations, new images or new signatures within the existing
2012 * Adding new properties to a device tree may result in the string table
2013 * being extended (if the new property names are different from those
2014 * already added). This function can optionally include a region for
2015 * the string table so that this can be part of the hash too. This is always
2018 * The FDT also has a mem_rsvmap table which can also be included, and is
2019 * always the first region if so.
2021 * The device tree header is not included in the region list. Since the
2022 * contents of the FDT are changing (shrinking, often), the caller will need
2023 * to regenerate the header anyway.
2025 * @fdt: Device tree to check
2026 * @h_include: Function to call to determine whether to include a part or
2029 * @priv: Private pointer as passed to fdt_find_regions()
2030 * @fdt: Pointer to FDT blob
2031 * @offset: Offset of this node / property
2032 * @type: Type of this part, FDT_IS_...
2033 * @data: Pointer to data (node name, property name, compatible
2034 * string, value (not yet supported)
2035 * @size: Size of data, or 0 if none
2036 * @return 0 to exclude, 1 to include, -1 if no information is
2038 * @priv: Private pointer passed to h_include
2039 * @region: Returns list of regions, sorted by offset
2040 * @max_regions: Maximum length of region list
2041 * @path: Pointer to a temporary string for the function to use for
2042 * building path names
2043 * @path_len: Length of path, must be large enough to hold the longest
2045 * @flags: Various flags that control the region algortihm, see
2047 * @return number of regions in list. If this is >max_regions then the
2048 * region array was exhausted. You should increase max_regions and try
2049 * the call again. Only the first max_regions elements are available in the
2052 * On error a -ve value is return, which can be:
2054 * -FDT_ERR_BADSTRUCTURE (too deep or more END tags than BEGIN tags
2055 * -FDT_ERR_BADLAYOUT
2056 * -FDT_ERR_NOSPACE (path area is too small)
2058 int fdt_first_region(const void *fdt,
2059 int (*h_include)(void *priv, const void *fdt, int offset,
2060 int type, const char *data, int size),
2061 void *priv, struct fdt_region *region,
2062 char *path, int path_len, int flags,
2063 struct fdt_region_state *info);
2065 /** fdt_next_region() - find next region
2067 * See fdt_first_region() for full description. This function finds the
2068 * next region according to the provided parameters, which must be the same
2069 * as passed to fdt_first_region().
2071 * This function can additionally return -FDT_ERR_NOTFOUND when there are no
2074 int fdt_next_region(const void *fdt,
2075 int (*h_include)(void *priv, const void *fdt, int offset,
2076 int type, const char *data, int size),
2077 void *priv, struct fdt_region *region,
2078 char *path, int path_len, int flags,
2079 struct fdt_region_state *info);
2082 * fdt_add_alias_regions() - find aliases that point to existing regions
2084 * Once a device tree grep is complete some of the nodes will be present
2085 * and some will have been dropped. This function checks all the alias nodes
2086 * to figure out which points point to nodes which are still present. These
2087 * aliases need to be kept, along with the nodes they reference.
2089 * Given a list of regions function finds the aliases that still apply and
2090 * adds more regions to the list for these. This function is called after
2091 * fdt_next_region() has finished returning regions and requires the same
2094 * @fdt: Device tree file to reference
2095 * @region: List of regions that will be kept
2096 * @count: Number of regions
2097 * @max_regions: Number of entries that can fit in @region
2098 * @info: Region state as returned from fdt_next_region()
2099 * @return new number of regions in @region (i.e. count + the number added)
2100 * or -FDT_ERR_NOSPACE if there was not enough space.
2102 int fdt_add_alias_regions(const void *fdt, struct fdt_region *region, int count,
2103 int max_regions, struct fdt_region_state *info);
2105 #endif /* _LIBFDT_H */