Initial commit of Open Source release

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 1168 insertions, 0 deletions

diff --git a/libfdt/libfdt.h b/libfdt/libfdt.h
new file mode 100644
index 0000000..0035bf7
--- /dev/null
+++ b/libfdt/libfdt.h
@@ -0,0 +1,1168 @@
+#ifndef _LIBFDT_H
+#define _LIBFDT_H
+/*
+ * libfdt - Flat Device Tree manipulation
+ * Copyright (C) 2006 David Gibson, IBM Corporation.
+ *
+ * libfdt is dual licensed: you can use it either under the terms of
+ * the GPL, or the BSD license, at your option.
+ *
+ *  a) This library is free software; you can redistribute it and/or
+ *     modify it under the terms of the GNU General Public License as
+ *     published by the Free Software Foundation; either version 2 of the
+ *     License, or (at your option) any later version.
+ *
+ *     This library is distributed in the hope that it will be useful,
+ *     but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *     GNU General Public License for more details.
+ *
+ *     You should have received a copy of the GNU General Public
+ *     License along with this library; if not, write to the Free
+ *     Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
+ *     MA 02110-1301 USA
+ *
+ * Alternatively,
+ *
+ *  b) Redistribution and use in source and binary forms, with or
+ *     without modification, are permitted provided that the following
+ *     conditions are met:
+ *
+ *     1. Redistributions of source code must retain the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer.
+ *     2. Redistributions in binary form must reproduce the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer in the documentation and/or other materials
+ *        provided with the distribution.
+ *
+ *     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
+ *     CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ *     INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ *     MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ *     DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ *     CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ *     NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ *     LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ *     HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ *     CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ *     OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
+ *     EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <libfdt_env.h>
+#include <fdt.h>
+
+#define FDT_FIRST_SUPPORTED_VERSION	0x10
+#define FDT_LAST_SUPPORTED_VERSION	0x11
+
+/* Error codes: informative error codes */
+#define FDT_ERR_NOTFOUND	1
+	/* FDT_ERR_NOTFOUND: The requested node or property does not exist */
+#define FDT_ERR_EXISTS		2
+	/* FDT_ERR_EXISTS: Attemped to create a node or property which
+	 * already exists */
+#define FDT_ERR_NOSPACE		3
+	/* FDT_ERR_NOSPACE: Operation needed to expand the device
+	 * tree, but its buffer did not have sufficient space to
+	 * contain the expanded tree. Use fdt_open_into() to move the
+	 * device tree to a buffer with more space. */
+
+/* Error codes: codes for bad parameters */
+#define FDT_ERR_BADOFFSET	4
+	/* FDT_ERR_BADOFFSET: Function was passed a structure block
+	 * offset which is out-of-bounds, or which points to an
+	 * unsuitable part of the structure for the operation. */
+#define FDT_ERR_BADPATH		5
+	/* FDT_ERR_BADPATH: Function was passed a badly formatted path
+	 * (e.g. missing a leading / for a function which requires an
+	 * absolute path) */
+#define FDT_ERR_BADPHANDLE	6
+	/* FDT_ERR_BADPHANDLE: Function was passed an invalid phandle
+	 * value.  phandle values of 0 and -1 are not permitted. */
+#define FDT_ERR_BADSTATE	7
+	/* FDT_ERR_BADSTATE: Function was passed an incomplete device
+	 * tree created by the sequential-write functions, which is
+	 * not sufficiently complete for the requested operation. */
+
+/* Error codes: codes for bad device tree blobs */
+#define FDT_ERR_TRUNCATED	8
+	/* FDT_ERR_TRUNCATED: Structure block of the given device tree
+	 * ends without an FDT_END tag. */
+#define FDT_ERR_BADMAGIC	9
+	/* FDT_ERR_BADMAGIC: Given "device tree" appears not to be a
+	 * device tree at all - it is missing the flattened device
+	 * tree magic number. */
+#define FDT_ERR_BADVERSION	10
+	/* FDT_ERR_BADVERSION: Given device tree has a version which
+	 * can't be handled by the requested operation.  For
+	 * read-write functions, this may mean that fdt_open_into() is
+	 * required to convert the tree to the expected version. */
+#define FDT_ERR_BADSTRUCTURE	11
+	/* FDT_ERR_BADSTRUCTURE: Given device tree has a corrupt
+	 * structure block or other serious error (e.g. misnested
+	 * nodes, or subnodes preceding properties). */
+#define FDT_ERR_BADLAYOUT	12
+	/* FDT_ERR_BADLAYOUT: For read-write functions, the given
+	 * device tree has it's sub-blocks in an order that the
+	 * function can't handle (memory reserve map, then structure,
+	 * then strings).  Use fdt_open_into() to reorganize the tree
+	 * into a form suitable for the read-write operations. */
+
+/* "Can't happen" error indicating a bug in libfdt */
+#define FDT_ERR_INTERNAL	13
+	/* FDT_ERR_INTERNAL: libfdt has failed an internal assertion.
+	 * Should never be returned, if it is, it indicates a bug in
+	 * libfdt itself. */
+
+#define FDT_ERR_MAX		13
+
+/**********************************************************************/
+/* Low-level functions (you probably don't need these)                */
+/**********************************************************************/
+
+const void *fdt_offset_ptr(const void *fdt, int offset, unsigned int checklen);
+static inline void *fdt_offset_ptr_w(void *fdt, int offset, int checklen)
+{
+	return (void *)(uintptr_t)fdt_offset_ptr(fdt, offset, checklen);
+}
+
+uint32_t fdt_next_tag(const void *fdt, int offset, int *nextoffset);
+
+/**********************************************************************/
+/* Traversal functions                                                */
+/**********************************************************************/
+
+int fdt_next_node(const void *fdt, int offset, int *depth);
+
+/**********************************************************************/
+/* General functions                                                  */
+/**********************************************************************/
+
+#define fdt_get_header(fdt, field) \
+	(fdt32_to_cpu(((const struct fdt_header *)(fdt))->field))
+#define fdt_magic(fdt) 			(fdt_get_header(fdt, magic))
+#define fdt_totalsize(fdt)		(fdt_get_header(fdt, totalsize))
+#define fdt_off_dt_struct(fdt)		(fdt_get_header(fdt, off_dt_struct))
+#define fdt_off_dt_strings(fdt)		(fdt_get_header(fdt, off_dt_strings))
+#define fdt_off_mem_rsvmap(fdt)		(fdt_get_header(fdt, off_mem_rsvmap))
+#define fdt_version(fdt)		(fdt_get_header(fdt, version))
+#define fdt_last_comp_version(fdt) 	(fdt_get_header(fdt, last_comp_version))
+#define fdt_boot_cpuid_phys(fdt) 	(fdt_get_header(fdt, boot_cpuid_phys))
+#define fdt_size_dt_strings(fdt) 	(fdt_get_header(fdt, size_dt_strings))
+#define fdt_size_dt_struct(fdt)		(fdt_get_header(fdt, size_dt_struct))
+
+#define __fdt_set_hdr(name) \
+	static inline void fdt_set_##name(void *fdt, uint32_t val) \
+	{ \
+		struct fdt_header *fdth = (struct fdt_header*)fdt; \
+		fdth->name = cpu_to_fdt32(val); \
+	}
+__fdt_set_hdr(magic);
+__fdt_set_hdr(totalsize);
+__fdt_set_hdr(off_dt_struct);
+__fdt_set_hdr(off_dt_strings);
+__fdt_set_hdr(off_mem_rsvmap);
+__fdt_set_hdr(version);
+__fdt_set_hdr(last_comp_version);
+__fdt_set_hdr(boot_cpuid_phys);
+__fdt_set_hdr(size_dt_strings);
+__fdt_set_hdr(size_dt_struct);
+#undef __fdt_set_hdr
+
+/**
+ * fdt_check_header - sanity check a device tree or possible device tree
+ * @fdt: pointer to data which might be a flattened device tree
+ *
+ * fdt_check_header() checks that the given buffer contains what
+ * appears to be a flattened device tree with sane information in its
+ * header.
+ *
+ * returns:
+ *     0, if the buffer appears to contain a valid device tree
+ *     -FDT_ERR_BADMAGIC,
+ *     -FDT_ERR_BADVERSION,
+ *     -FDT_ERR_BADSTATE, standard meanings, as above
+ */
+int fdt_check_header(const void *fdt);
+
+/**
+ * fdt_move - move a device tree around in memory
+ * @fdt: pointer to the device tree to move
+ * @buf: pointer to memory where the device is to be moved
+ * @bufsize: size of the memory space at buf
+ *
+ * fdt_move() relocates, if possible, the device tree blob located at
+ * fdt to the buffer at buf of size bufsize.  The buffer may overlap
+ * with the existing device tree blob at fdt.  Therefore,
+ *     fdt_move(fdt, fdt, fdt_totalsize(fdt))
+ * should always succeed.
+ *
+ * returns:
+ *     0, on success
+ *     -FDT_ERR_NOSPACE, bufsize is insufficient to contain the device tree
+ *     -FDT_ERR_BADMAGIC,
+ *     -FDT_ERR_BADVERSION,
+ *     -FDT_ERR_BADSTATE, standard meanings
+ */
+int fdt_move(const void *fdt, void *buf, int bufsize);
+
+/**********************************************************************/
+/* Read-only functions                                                */
+/**********************************************************************/
+
+/**
+ * fdt_string - retrieve a string from the strings block of a device tree
+ * @fdt: pointer to the device tree blob
+ * @stroffset: offset of the string within the strings block (native endian)
+ *
+ * fdt_string() retrieves a pointer to a single string from the
+ * strings block of the device tree blob at fdt.
+ *
+ * returns:
+ *     a pointer to the string, on success
+ *     NULL, if stroffset is out of bounds
+ */
+const char *fdt_string(const void *fdt, int stroffset);
+
+/**
+ * fdt_num_mem_rsv - retrieve the number of memory reserve map entries
+ * @fdt: pointer to the device tree blob
+ *
+ * Returns the number of entries in the device tree blob's memory
+ * reservation map.  This does not include the terminating 0,0 entry
+ * or any other (0,0) entries reserved for expansion.
+ *
+ * returns:
+ *     the number of entries
+ */
+int fdt_num_mem_rsv(const void *fdt);
+
+/**
+ * fdt_get_mem_rsv - retrieve one memory reserve map entry
+ * @fdt: pointer to the device tree blob
+ * @address, @size: pointers to 64-bit variables
+ *
+ * On success, *address and *size will contain the address and size of
+ * the n-th reserve map entry from the device tree blob, in
+ * native-endian format.
+ *
+ * returns:
+ *     0, on success
+ *     -FDT_ERR_BADMAGIC,
+ *     -FDT_ERR_BADVERSION,
+ *     -FDT_ERR_BADSTATE, standard meanings
+ */
+int fdt_get_mem_rsv(const void *fdt, int n, uint64_t *address, uint64_t *size);
+
+/**
+ * fdt_subnode_offset_namelen - find a subnode based on substring
+ * @fdt: pointer to the device tree blob
+ * @parentoffset: structure block offset of a node
+ * @name: name of the subnode to locate
+ * @namelen: number of characters of name to consider
+ *
+ * Identical to fdt_subnode_offset(), but only examine the first
+ * namelen characters of name for matching the subnode name.  This is
+ * useful for finding subnodes based on a portion of a larger string,
+ * such as a full path.
+ */
+int fdt_subnode_offset_namelen(const void *fdt, int parentoffset,
+			       const char *name, int namelen);
+/**
+ * fdt_sibling_offset_namelen - find sibling node based on substring
+ * @fdt: pointer to the device tree blob
+ * @fromoffset: node to start from
+ * @name: name of the subnode to locate
+ * @namelen: number of characters of name to consider
+ *
+ * Typically used to continue the search started with
+ * fdt_subnode_offset_namelen() using the same matching rules.
+ */
+int fdt_sibling_offset_namelen(const void *fdt, int fromoffset,
+			       const char *name, int namelen);
+/**
+ * fdt_subnode_offset - find a subnode of a given node
+ * @fdt: pointer to the device tree blob
+ * @parentoffset: structure block offset of a node
+ * @name: name of the subnode to locate
+ *
+ * fdt_subnode_offset() finds a subnode of the node at structure block
+ * offset parentoffset with the given name.  name may include a unit
+ * address, in which case fdt_subnode_offset() will find the subnode
+ * with that unit address, or the unit address may be omitted, in
+ * which case fdt_subnode_offset() will find an arbitrary subnode
+ * whose name excluding unit address matches the given name.
+ *
+ * returns:
+ *	structure block offset of the requested subnode (>=0), on success
+ *	-FDT_ERR_NOTFOUND, if the requested subnode does not exist
+ *	-FDT_ERR_BADOFFSET, if parentoffset did not point to an FDT_BEGIN_NODE tag
+ *      -FDT_ERR_BADMAGIC,
+ *	-FDT_ERR_BADVERSION,
+ *	-FDT_ERR_BADSTATE,
+ *	-FDT_ERR_BADSTRUCTURE,
+ *	-FDT_ERR_TRUNCATED, standard meanings.
+ */
+int fdt_subnode_offset(const void *fdt, int parentoffset, const char *name);
+
+/**
+ * fdt_sibling_offset - find a sibling of a given node by name
+ * @fdt: pointer to the device tree blob
+ * @fromoffset: structure block offset of a node
+ * @name: name of the subnode to locate
+ *
+ * Typically used to continue the search started with fdt_subnode_offset()
+ * using the same matching rules.
+ *
+ * returns:
+ *	structure block offset of the requested subnode (>=0), on success
+ *	-FDT_ERR_NOTFOUND, if the requested subnode does not exist
+ *	-FDT_ERR_BADOFFSET, if parentoffset did not point to an FDT_BEGIN_NODE tag
+ *      -FDT_ERR_BADMAGIC,
+ *	-FDT_ERR_BADVERSION,
+ *	-FDT_ERR_BADSTATE,
+ *	-FDT_ERR_BADSTRUCTURE,
+ *	-FDT_ERR_TRUNCATED, standard meanings.
+ */
+int fdt_sibling_offset(const void *fdt, int fromoffset, const char *name);
+
+/**
+ * fdt_path_offset - find a tree node by its full path
+ * @fdt: pointer to the device tree blob
+ * @path: full path of the node to locate
+ *
+ * fdt_path_offset() finds a node of a given path in the device tree.
+ * Each path component may omit the unit address portion, but the
+ * results of this are undefined if any such path component is
+ * ambiguous (that is if there are multiple nodes at the relevant
+ * level matching the given component, differentiated only by unit
+ * address).
+ *
+ * returns:
+ *	structure block offset of the node with the requested path (>=0), on success
+ *	-FDT_ERR_BADPATH, given path does not begin with '/' or is invalid
+ *	-FDT_ERR_NOTFOUND, if the requested node does not exist
+ *      -FDT_ERR_BADMAGIC,
+ *	-FDT_ERR_BADVERSION,
+ *	-FDT_ERR_BADSTATE,
+ *	-FDT_ERR_BADSTRUCTURE,
+ *	-FDT_ERR_TRUNCATED, standard meanings.
+ */
+int fdt_path_offset(const void *fdt, const char *path);
+
+/**
+ * fdt_get_name - retrieve the name of a given node
+ * @fdt: pointer to the device tree blob
+ * @nodeoffset: structure block offset of the starting node
+ * @lenp: pointer to an integer variable (will be overwritten) or NULL
+ *
+ * fdt_get_name() retrieves the name (including unit address) of the
+ * device tree node at structure block offset nodeoffset.  If lenp is
+ * non-NULL, the length of this name is also returned, in the integer
+ * pointed to by lenp.
+ *
+ * returns:
+ *	pointer to the node's name, on success
+ *		If lenp is non-NULL, *lenp contains the length of that name (>=0)
+ *	NULL, on error
+ *		if lenp is non-NULL *lenp contains an error code (<0):
+ *		-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
+ *		-FDT_ERR_BADMAGIC,
+ *		-FDT_ERR_BADVERSION,
+ *		-FDT_ERR_BADSTATE, standard meanings
+ */
+const char *fdt_get_name(const void *fdt, int nodeoffset, int *lenp);
+
+/**
+ * fdt_get_property_namelen - find a property based on substring
+ * @fdt: pointer to the device tree blob
+ * @nodeoffset: offset of the node whose property to find
+ * @name: name of the property to find
+ * @namelen: number of characters of name to consider
+ * @lenp: pointer to an integer variable (will be overwritten) or NULL
+ *
+ * Identical to fdt_get_property_namelen(), but only examine the first
+ * namelen characters of name for matching the property name.
+ */
+const struct fdt_property *fdt_get_property_namelen(const void *fdt,
+						    int nodeoffset,
+						    const char *name,
+						    int namelen, int *lenp);
+
+/**
+ * fdt_get_property - find a given property in a given node
+ * @fdt: pointer to the device tree blob
+ * @nodeoffset: offset of the node whose property to find
+ * @name: name of the property to find
+ * @lenp: pointer to an integer variable (will be overwritten) or NULL
+ *
+ * fdt_get_property() retrieves a pointer to the fdt_property
+ * structure within the device tree blob corresponding to the property
+ * named 'name' of the node at offset nodeoffset.  If lenp is
+ * non-NULL, the length of the property value is also returned, in the
+ * integer pointed to by lenp.
+ *
+ * returns:
+ *	pointer to the structure representing the property
+ *		if lenp is non-NULL, *lenp contains the length of the property
+ *		value (>=0)
+ *	NULL, on error
+ *		if lenp is non-NULL, *lenp contains an error code (<0):
+ *		-FDT_ERR_NOTFOUND, node does not have named property
+ *		-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
+ *		-FDT_ERR_BADMAGIC,
+ *		-FDT_ERR_BADVERSION,
+ *		-FDT_ERR_BADSTATE,
+ *		-FDT_ERR_BADSTRUCTURE,
+ *		-FDT_ERR_TRUNCATED, standard meanings
+ */
+const struct fdt_property *fdt_get_property(const void *fdt, int nodeoffset,
+					    const char *name, int *lenp);
+static inline struct fdt_property *fdt_get_property_w(void *fdt, int nodeoffset,
+						      const char *name,
+						      int *lenp)
+{
+	return (struct fdt_property *)(uintptr_t)
+		fdt_get_property(fdt, nodeoffset, name, lenp);
+}
+
+/**
+ * fdt_getprop_namelen - get property value based on substring
+ * @fdt: pointer to the device tree blob
+ * @nodeoffset: offset of the node whose property to find
+ * @name: name of the property to find
+ * @namelen: number of characters of name to consider
+ * @lenp: pointer to an integer variable (will be overwritten) or NULL
+ *
+ * Identical to fdt_getprop(), but only examine the first namelen
+ * characters of name for matching the property name.
+ */
+const void *fdt_getprop_namelen(const void *fdt, int nodeoffset,
+				const char *name, int namelen, int *lenp);
+
+/**
+ * fdt_getprop - retrieve the value of a given property
+ * @fdt: pointer to the device tree blob
+ * @nodeoffset: offset of the node whose property to find
+ * @name: name of the property to find
+ * @lenp: pointer to an integer variable (will be overwritten) or NULL
+ *
+ * fdt_getprop() retrieves a pointer to the value of the property
+ * named 'name' of the node at offset nodeoffset (this will be a
+ * pointer to within the device blob itself, not a copy of the value).
+ * If lenp is non-NULL, the length of the property value is also
+ * returned, in the integer pointed to by lenp.
+ *
+ * returns:
+ *	pointer to the property's value
+ *		if lenp is non-NULL, *lenp contains the length of the property
+ *		value (>=0)
+ *	NULL, on error
+ *		if lenp is non-NULL, *lenp contains an error code (<0):
+ *		-FDT_ERR_NOTFOUND, node does not have named property
+ *		-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
+ *		-FDT_ERR_BADMAGIC,
+ *		-FDT_ERR_BADVERSION,
+ *		-FDT_ERR_BADSTATE,
+ *		-FDT_ERR_BADSTRUCTURE,
+ *		-FDT_ERR_TRUNCATED, standard meanings
+ */
+const void *fdt_getprop(const void *fdt, int nodeoffset,
+			const char *name, int *lenp);
+static inline void *fdt_getprop_w(void *fdt, int nodeoffset,
+				  const char *name, int *lenp)
+{
+	return (void *)(uintptr_t)fdt_getprop(fdt, nodeoffset, name, lenp);
+}
+
+/**
+ * fdt_get_phandle - retrieve the phandle of a given node
+ * @fdt: pointer to the device tree blob
+ * @nodeoffset: structure block offset of the node
+ *
+ * fdt_get_phandle() retrieves the phandle of the device tree node at
+ * structure block offset nodeoffset.
+ *
+ * returns:
+ *	the phandle of the node at nodeoffset, on success (!= 0, != -1)
+ *	0, if the node has no phandle, or another error occurs
+ */
+uint32_t fdt_get_phandle(const void *fdt, int nodeoffset);
+
+/**
+ * fdt_get_alias_namelen - get alias based on substring
+ * @fdt: pointer to the device tree blob
+ * @name: name of the alias th look up
+ * @namelen: number of characters of name to consider
+ *
+ * Identical to fdt_get_alias(), but only examine the first namelen
+ * characters of name for matching the alias name.
+ */
+const char *fdt_get_alias_namelen(const void *fdt,
+				  const char *name, int namelen);
+
+/**
+ * fdt_get_alias - retreive the path referenced by a given alias
+ * @fdt: pointer to the device tree blob
+ * @name: name of the alias th look up
+ *
+ * fdt_get_alias() retrieves the value of a given alias.  That is, the
+ * value of the property named 'name' in the node /aliases.
+ *
+ * returns:
+ *	a pointer to the expansion of the alias named 'name', of it exists
+ *	NULL, if the given alias or the /aliases node does not exist
+ */
+const char *fdt_get_alias(const void *fdt, const char *name);
+
+/**
+ * fdt_get_path - determine the full path of a node
+ * @fdt: pointer to the device tree blob
+ * @nodeoffset: offset of the node whose path to find
+ * @buf: character buffer to contain the returned path (will be overwritten)
+ * @buflen: size of the character buffer at buf
+ *
+ * fdt_get_path() computes the full path of the node at offset
+ * nodeoffset, and records that path in the buffer at buf.
+ *
+ * NOTE: This function is expensive, as it must scan the device tree
+ * structure from the start to nodeoffset.
+ *
+ * returns:
+ *	0, on success
+ *		buf contains the absolute path of the node at
+ *		nodeoffset, as a NUL-terminated string.
+ * 	-FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
+ *	-FDT_ERR_NOSPACE, the path of the given node is longer than (bufsize-1)
+ *		characters and will not fit in the given buffer.
+ *	-FDT_ERR_BADMAGIC,
+ *	-FDT_ERR_BADVERSION,
+ *	-FDT_ERR_BADSTATE,
+ *	-FDT_ERR_BADSTRUCTURE, standard meanings
+ */
+int fdt_get_path(const void *fdt, int nodeoffset, char *buf, int buflen);
+
+/**
+ * fdt_supernode_atdepth_offset - find a specific ancestor of a node
+ * @fdt: pointer to the device tree blob
+ * @nodeoffset: offset of the node whose parent to find
+ * @supernodedepth: depth of the ancestor to find
+ * @nodedepth: pointer to an integer variable (will be overwritten) or NULL
+ *
+ * fdt_supernode_atdepth_offset() finds an ancestor of the given node
+ * at a specific depth from the root (where the root itself has depth
+ * 0, its immediate subnodes depth 1 and so forth).  So
+ *	fdt_supernode_atdepth_offset(fdt, nodeoffset, 0, NULL);
+ * will always return 0, the offset of the root node.  If the node at
+ * nodeoffset has depth D, then:
+ *	fdt_supernode_atdepth_offset(fdt, nodeoffset, D, NULL);
+ * will return nodeoffset itself.
+ *
+ * NOTE: This function is expensive, as it must scan the device tree
+ * structure from the start to nodeoffset.
+ *
+ * returns:
+
+ *	structure block offset of the node at node offset's ancestor
+ *		of depth supernodedepth (>=0), on success
+ * 	-FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
+*	-FDT_ERR_NOTFOUND, supernodedepth was greater than the depth of nodeoffset
+ *	-FDT_ERR_BADMAGIC,
+ *	-FDT_ERR_BADVERSION,
+ *	-FDT_ERR_BADSTATE,
+ *	-FDT_ERR_BADSTRUCTURE, standard meanings
+ */
+int fdt_supernode_atdepth_offset(const void *fdt, int nodeoffset,
+				 int supernodedepth, int *nodedepth);
+
+/**
+ * fdt_node_depth - find the depth of a given node
+ * @fdt: pointer to the device tree blob
+ * @nodeoffset: offset of the node whose parent to find
+ *
+ * fdt_node_depth() finds the depth of a given node.  The root node
+ * has depth 0, its immediate subnodes depth 1 and so forth.
+ *
+ * NOTE: This function is expensive, as it must scan the device tree
+ * structure from the start to nodeoffset.
+ *
+ * returns:
+ *	depth of the node at nodeoffset (>=0), on success
+ * 	-FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
+ *	-FDT_ERR_BADMAGIC,
+ *	-FDT_ERR_BADVERSION,
+ *	-FDT_ERR_BADSTATE,
+ *	-FDT_ERR_BADSTRUCTURE, standard meanings
+ */
+int fdt_node_depth(const void *fdt, int nodeoffset);
+
+/**
+ * fdt_parent_offset - find the parent of a given node
+ * @fdt: pointer to the device tree blob
+ * @nodeoffset: offset of the node whose parent to find
+ *
+ * fdt_parent_offset() locates the parent node of a given node (that
+ * is, it finds the offset of the node which contains the node at
+ * nodeoffset as a subnode).
+ *
+ * NOTE: This function is expensive, as it must scan the device tree
+ * structure from the start to nodeoffset, *twice*.
+ *
+ * returns:
+ *	structure block offset of the parent of the node at nodeoffset
+ *		(>=0), on success
+ * 	-FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
+ *	-FDT_ERR_BADMAGIC,
+ *	-FDT_ERR_BADVERSION,
+ *	-FDT_ERR_BADSTATE,
+ *	-FDT_ERR_BADSTRUCTURE, standard meanings
+ */
+int fdt_parent_offset(const void *fdt, int nodeoffset);
+
+/**
+ * fdt_node_offset_by_prop_value - find nodes with a given property value
+ * @fdt: pointer to the device tree blob
+ * @startoffset: only find nodes after this offset
+ * @propname: property name to check
+ * @propval: property value to search for
+ * @proplen: length of the value in propval
+ *
+ * fdt_node_offset_by_prop_value() returns the offset of the first
+ * node after startoffset, which has a property named propname whose
+ * value is of length proplen and has value equal to propval; or if
+ * startoffset is -1, the very first such node in the tree.
+ *
+ * To iterate through all nodes matching the criterion, the following
+ * idiom can be used:
+ *	offset = fdt_node_offset_by_prop_value(fdt, -1, propname,
+ *					       propval, proplen);
+ *	while (offset != -FDT_ERR_NOTFOUND) {
+ *		// other code here
+ *		offset = fdt_node_offset_by_prop_value(fdt, offset, propname,
+ *						       propval, proplen);
+ *	}
+ *
+ * Note the -1 in the first call to the function, if 0 is used here
+ * instead, the function will never locate the root node, even if it
+ * matches the criterion.
+ *
+ * returns:
+ *	structure block offset of the located node (>= 0, >startoffset),
+ *		 on success
+ *	-FDT_ERR_NOTFOUND, no node matching the criterion exists in the
+ *		tree after startoffset
+ * 	-FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
+ *	-FDT_ERR_BADMAGIC,
+ *	-FDT_ERR_BADVERSION,
+ *	-FDT_ERR_BADSTATE,
+ *	-FDT_ERR_BADSTRUCTURE, standard meanings
+ */
+int fdt_node_offset_by_prop_value(const void *fdt, int startoffset,
+				  const char *propname,
+				  const void *propval, int proplen);
+
+/**
+ * fdt_node_offset_by_phandle - find the node with a given phandle
+ * @fdt: pointer to the device tree blob
+ * @phandle: phandle value
+ *
+ * fdt_node_offset_by_phandle() returns the offset of the node
+ * which has the given phandle value.  If there is more than one node
+ * in the tree with the given phandle (an invalid tree), results are
+ * undefined.
+ *
+ * returns:
+ *	structure block offset of the located node (>= 0), on success
+ *	-FDT_ERR_NOTFOUND, no node with that phandle exists
+ *	-FDT_ERR_BADPHANDLE, given phandle value was invalid (0 or -1)
+ *	-FDT_ERR_BADMAGIC,
+ *	-FDT_ERR_BADVERSION,
+ *	-FDT_ERR_BADSTATE,
+ *	-FDT_ERR_BADSTRUCTURE, standard meanings
+ */
+int fdt_node_offset_by_phandle(const void *fdt, uint32_t phandle);
+
+/**
+ * fdt_node_check_compatible: check a node's compatible property
+ * @fdt: pointer to the device tree blob
+ * @nodeoffset: offset of a tree node
+ * @compatible: string to match against
+ *
+ *
+ * fdt_node_check_compatible() returns 0 if the given node contains a
+ * 'compatible' property with the given string as one of its elements,
+ * it returns non-zero otherwise, or on error.
+ *
+ * returns:
+ *	0, if the node has a 'compatible' property listing the given string
+ *	1, if the node has a 'compatible' property, but it does not list
+ *		the given string
+ *	-FDT_ERR_NOTFOUND, if the given node has no 'compatible' property
+ * 	-FDT_ERR_BADOFFSET, if nodeoffset does not refer to a BEGIN_NODE tag
+ *	-FDT_ERR_BADMAGIC,
+ *	-FDT_ERR_BADVERSION,
+ *	-FDT_ERR_BADSTATE,
+ *	-FDT_ERR_BADSTRUCTURE, standard meanings
+ */
+int fdt_node_check_compatible(const void *fdt, int nodeoffset,
+			      const char *compatible);
+
+/**
+ * fdt_node_offset_by_compatible - find nodes with a given 'compatible' value
+ * @fdt: pointer to the device tree blob
+ * @startoffset: only find nodes after this offset
+ * @compatible: 'compatible' string to match against
+ *
+ * fdt_node_offset_by_compatible() returns the offset of the first
+ * node after startoffset, which has a 'compatible' property which
+ * lists the given compatible string; or if startoffset is -1, the
+ * very first such node in the tree.
+ *
+ * To iterate through all nodes matching the criterion, the following
+ * idiom can be used:
+ *	offset = fdt_node_offset_by_compatible(fdt, -1, compatible);
+ *	while (offset != -FDT_ERR_NOTFOUND) {
+ *		// other code here
+ *		offset = fdt_node_offset_by_compatible(fdt, offset, compatible);
+ *	}
+ *
+ * Note the -1 in the first call to the function, if 0 is used here
+ * instead, the function will never locate the root node, even if it
+ * matches the criterion.
+ *
+ * returns:
+ *	structure block offset of the located node (>= 0, >startoffset),
+ *		 on success
+ *	-FDT_ERR_NOTFOUND, no node matching the criterion exists in the
+ *		tree after startoffset
+ * 	-FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
+ *	-FDT_ERR_BADMAGIC,
+ *	-FDT_ERR_BADVERSION,
+ *	-FDT_ERR_BADSTATE,
+ *	-FDT_ERR_BADSTRUCTURE, standard meanings
+ */
+int fdt_node_offset_by_compatible(const void *fdt, int startoffset,
+				  const char *compatible);
+
+/**********************************************************************/
+/* Write-in-place functions                                           */
+/**********************************************************************/
+
+/**
+ * fdt_setprop_inplace - change a property's value, but not its size
+ * @fdt: pointer to the device tree blob
+ * @nodeoffset: offset of the node whose property to change
+ * @name: name of the property to change
+ * @val: pointer to data to replace the property value with
+ * @len: length of the property value
+ *
+ * fdt_setprop_inplace() replaces the value of a given property with
+ * the data in val, of length len.  This function cannot change the
+ * size of a property, and so will only work if len is equal to the
+ * current length of the property.
+ *
+ * This function will alter only the bytes in the blob which contain
+ * the given property value, and will not alter or move any other part
+ * of the tree.
+ *
+ * returns:
+ *	0, on success
+ *	-FDT_ERR_NOSPACE, if len is not equal to the property's current length
+ *	-FDT_ERR_NOTFOUND, node does not have the named property
+ *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
+ *	-FDT_ERR_BADMAGIC,
+ *	-FDT_ERR_BADVERSION,
+ *	-FDT_ERR_BADSTATE,
+ *	-FDT_ERR_BADSTRUCTURE,
+ *	-FDT_ERR_TRUNCATED, standard meanings
+ */
+int fdt_setprop_inplace(void *fdt, int nodeoffset, const char *name,
+			const void *val, int len);
+
+/**
+ * fdt_setprop_inplace_cell - change the value of a single-cell property
+ * @fdt: pointer to the device tree blob
+ * @nodeoffset: offset of the node whose property to change
+ * @name: name of the property to change
+ * @val: cell (32-bit integer) value to replace the property with
+ *
+ * fdt_setprop_inplace_cell() replaces the value of a given property
+ * with the 32-bit integer cell value in val, converting val to
+ * big-endian if necessary.  This function cannot change the size of a
+ * property, and so will only work if the property already exists and
+ * has length 4.
+ *
+ * This function will alter only the bytes in the blob which contain
+ * the given property value, and will not alter or move any other part
+ * of the tree.
+ *
+ * returns:
+ *	0, on success
+ *	-FDT_ERR_NOSPACE, if the property's length is not equal to 4
+  *	-FDT_ERR_NOTFOUND, node does not have the named property
+ *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
+ *	-FDT_ERR_BADMAGIC,
+ *	-FDT_ERR_BADVERSION,
+ *	-FDT_ERR_BADSTATE,
+ *	-FDT_ERR_BADSTRUCTURE,
+ *	-FDT_ERR_TRUNCATED, standard meanings
+ */
+static inline int fdt_setprop_inplace_cell(void *fdt, int nodeoffset,
+					   const char *name, uint32_t val)
+{
+	val = cpu_to_fdt32(val);
+	return fdt_setprop_inplace(fdt, nodeoffset, name, &val, sizeof(val));
+}
+
+/**
+ * fdt_nop_property - replace a property with nop tags
+ * @fdt: pointer to the device tree blob
+ * @nodeoffset: offset of the node whose property to nop
+ * @name: name of the property to nop
+ *
+ * fdt_nop_property() will replace a given property's representation
+ * in the blob with FDT_NOP tags, effectively removing it from the
+ * tree.
+ *
+ * This function will alter only the bytes in the blob which contain
+ * the property, and will not alter or move any other part of the
+ * tree.
+ *
+ * returns:
+ *	0, on success
+ *	-FDT_ERR_NOTFOUND, node does not have the named property
+ *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
+ *	-FDT_ERR_BADMAGIC,
+ *	-FDT_ERR_BADVERSION,
+ *	-FDT_ERR_BADSTATE,
+ *	-FDT_ERR_BADSTRUCTURE,
+ *	-FDT_ERR_TRUNCATED, standard meanings
+ */
+int fdt_nop_property(void *fdt, int nodeoffset, const char *name);
+
+/**
+ * fdt_nop_node - replace a node (subtree) with nop tags
+ * @fdt: pointer to the device tree blob
+ * @nodeoffset: offset of the node to nop
+ *
+ * fdt_nop_node() will replace a given node's representation in the
+ * blob, including all its subnodes, if any, with FDT_NOP tags,
+ * effectively removing it from the tree.
+ *
+ * This function will alter only the bytes in the blob which contain
+ * the node and its properties and subnodes, and will not alter or
+ * move any other part of the tree.
+ *
+ * returns:
+ *	0, on success
+ *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
+ *	-FDT_ERR_BADMAGIC,
+ *	-FDT_ERR_BADVERSION,
+ *	-FDT_ERR_BADSTATE,
+ *	-FDT_ERR_BADSTRUCTURE,
+ *	-FDT_ERR_TRUNCATED, standard meanings
+ */
+int fdt_nop_node(void *fdt, int nodeoffset);
+
+/**********************************************************************/
+/* Sequential write functions                                         */
+/**********************************************************************/
+
+int fdt_create(void *buf, int bufsize);
+int fdt_add_reservemap_entry(void *fdt, uint64_t addr, uint64_t size);
+int fdt_finish_reservemap(void *fdt);
+int fdt_begin_node(void *fdt, const char *name);
+int fdt_property(void *fdt, const char *name, const void *val, int len);
+static inline int fdt_property_cell(void *fdt, const char *name, uint32_t val)
+{
+	val = cpu_to_fdt32(val);
+	return fdt_property(fdt, name, &val, sizeof(val));
+}
+#define fdt_property_string(fdt, name, str) \
+	fdt_property(fdt, name, str, strlen(str)+1)
+int fdt_property_cells_v(void *fdt, unsigned const char *name, int count,
+			 va_list args);
+int fdt_property_cells(void *fdt, unsigned const char *name, int count, ...);
+int fdt_end_node(void *fdt);
+int fdt_finish(void *fdt);
+
+/**********************************************************************/
+/* Read-write functions                                               */
+/**********************************************************************/
+
+int fdt_open_into(const void *fdt, void *buf, int bufsize);
+int fdt_pack(void *fdt);
+
+/**
+ * fdt_add_mem_rsv - add one memory reserve map entry
+ * @fdt: pointer to the device tree blob
+ * @address, @size: 64-bit values (native endian)
+ *
+ * Adds a reserve map entry to the given blob reserving a region at
+ * address address of length size.
+ *
+ * This function will insert data into the reserve map and will
+ * therefore change the indexes of some entries in the table.
+ *
+ * returns:
+ *	0, on success
+ *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
+ *		contain the new reservation entry
+ *	-FDT_ERR_BADMAGIC,
+ *	-FDT_ERR_BADVERSION,
+ *	-FDT_ERR_BADSTATE,
+ *	-FDT_ERR_BADSTRUCTURE,
+ *	-FDT_ERR_BADLAYOUT,
+ *	-FDT_ERR_TRUNCATED, standard meanings
+ */
+int fdt_add_mem_rsv(void *fdt, uint64_t address, uint64_t size);
+
+/**
+ * fdt_del_mem_rsv - remove a memory reserve map entry
+ * @fdt: pointer to the device tree blob
+ * @n: entry to remove
+ *
+ * fdt_del_mem_rsv() removes the n-th memory reserve map entry from
+ * the blob.
+ *
+ * This function will delete data from the reservation table and will
+ * therefore change the indexes of some entries in the table.
+ *
+ * returns:
+ *	0, on success
+ *	-FDT_ERR_NOTFOUND, there is no entry of the given index (i.e. there
+ *		are less than n+1 reserve map entries)
+ *	-FDT_ERR_BADMAGIC,
+ *	-FDT_ERR_BADVERSION,
+ *	-FDT_ERR_BADSTATE,
+ *	-FDT_ERR_BADSTRUCTURE,
+ *	-FDT_ERR_BADLAYOUT,
+ *	-FDT_ERR_TRUNCATED, standard meanings
+ */
+int fdt_del_mem_rsv(void *fdt, int n);
+
+/**
+ * fdt_set_name - change the name of a given node
+ * @fdt: pointer to the device tree blob
+ * @nodeoffset: structure block offset of a node
+ * @name: name to give the node
+ *
+ * fdt_set_name() replaces the name (including unit address, if any)
+ * of the given node with the given string.  NOTE: this function can't
+ * efficiently check if the new name is unique amongst the given
+ * node's siblings; results are undefined if this function is invoked
+ * with a name equal to one of the given node's siblings.
+ *
+ * This function may insert or delete data from the blob, and will
+ * therefore change the offsets of some existing nodes.
+ *
+ * returns:
+ *	0, on success
+ *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob
+ *		to contain the new name
+ *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
+ *	-FDT_ERR_BADMAGIC,
+ *	-FDT_ERR_BADVERSION,
+ *	-FDT_ERR_BADSTATE, standard meanings
+ */
+int fdt_set_name(void *fdt, int nodeoffset, const char *name);
+
+/**
+ * fdt_setprop - create or change a property
+ * @fdt: pointer to the device tree blob
+ * @nodeoffset: offset of the node whose property to change
+ * @name: name of the property to change
+ * @val: pointer to data to set the property value to
+ * @len: length of the property value
+ *
+ * fdt_setprop() sets the value of the named property in the given
+ * node to the given value and length, creating the property if it
+ * does not already exist.
+ *
+ * This function may insert or delete data from the blob, and will
+ * therefore change the offsets of some existing nodes.
+ *
+ * returns:
+ *	0, on success
+ *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
+ *		contain the new property value
+ *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
+ *	-FDT_ERR_BADLAYOUT,
+ *	-FDT_ERR_BADMAGIC,
+ *	-FDT_ERR_BADVERSION,
+ *	-FDT_ERR_BADSTATE,
+ *	-FDT_ERR_BADSTRUCTURE,
+ *	-FDT_ERR_BADLAYOUT,
+ *	-FDT_ERR_TRUNCATED, standard meanings
+ */
+int fdt_setprop(void *fdt, int nodeoffset, const char *name,
+		const void *val, int len);
+
+/**
+ * fdt_setprop_cell - set a property to a single cell value
+ * @fdt: pointer to the device tree blob
+ * @nodeoffset: offset of the node whose property to change
+ * @name: name of the property to change
+ * @val: 32-bit integer value for the property (native endian)
+ *
+ * fdt_setprop_cell() sets the value of the named property in the
+ * given node to the given cell value (converting to big-endian if
+ * necessary), or creates a new property with that value if it does
+ * not already exist.
+ *
+ * This function may insert or delete data from the blob, and will
+ * therefore change the offsets of some existing nodes.
+ *
+ * returns:
+ *	0, on success
+ *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
+ *		contain the new property value
+ *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
+ *	-FDT_ERR_BADLAYOUT,
+ *	-FDT_ERR_BADMAGIC,
+ *	-FDT_ERR_BADVERSION,
+ *	-FDT_ERR_BADSTATE,
+ *	-FDT_ERR_BADSTRUCTURE,
+ *	-FDT_ERR_BADLAYOUT,
+ *	-FDT_ERR_TRUNCATED, standard meanings
+ */
+static inline int fdt_setprop_cell(void *fdt, int nodeoffset, const char *name,
+				   uint32_t val)
+{
+	val = cpu_to_fdt32(val);
+	return fdt_setprop(fdt, nodeoffset, name, &val, sizeof(val));
+}
+
+/**
+ * fdt_setprop_string - set a property to a string value
+ * @fdt: pointer to the device tree blob
+ * @nodeoffset: offset of the node whose property to change
+ * @name: name of the property to change
+ * @str: string value for the property
+ *
+ * fdt_setprop_string() sets the value of the named property in the
+ * given node to the given string value (using the length of the
+ * string to determine the new length of the property), or creates a
+ * new property with that value if it does not already exist.
+ *
+ * This function may insert or delete data from the blob, and will
+ * therefore change the offsets of some existing nodes.
+ *
+ * returns:
+ *	0, on success
+ *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
+ *		contain the new property value
+ *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
+ *	-FDT_ERR_BADLAYOUT,
+ *	-FDT_ERR_BADMAGIC,
+ *	-FDT_ERR_BADVERSION,
+ *	-FDT_ERR_BADSTATE,
+ *	-FDT_ERR_BADSTRUCTURE,
+ *	-FDT_ERR_BADLAYOUT,
+ *	-FDT_ERR_TRUNCATED, standard meanings
+ */
+#define fdt_setprop_string(fdt, nodeoffset, name, str) \
+	fdt_setprop((fdt), (nodeoffset), (name), (str), strlen(str)+1)
+
+/**
+ * fdt_delprop - delete a property
+ * @fdt: pointer to the device tree blob
+ * @nodeoffset: offset of the node whose property to nop
+ * @name: name of the property to nop
+ *
+ * fdt_del_property() will delete the given property.
+ *
+ * This function will delete data from the blob, and will therefore
+ * change the offsets of some existing nodes.
+ *
+ * returns:
+ *	0, on success
+ *	-FDT_ERR_NOTFOUND, node does not have the named property
+ *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
+ *	-FDT_ERR_BADLAYOUT,
+ *	-FDT_ERR_BADMAGIC,
+ *	-FDT_ERR_BADVERSION,
+ *	-FDT_ERR_BADSTATE,
+ *	-FDT_ERR_BADSTRUCTURE,
+ *	-FDT_ERR_TRUNCATED, standard meanings
+ */
+int fdt_delprop(void *fdt, int nodeoffset, const char *name);
+
+/**
+ * fdt_add_subnode_namelen - creates a new node based on substring
+ * @fdt: pointer to the device tree blob
+ * @parentoffset: structure block offset of a node
+ * @name: name of the subnode to locate
+ * @namelen: number of characters of name to consider
+ *
+ * Identical to fdt_add_subnode(), but use only the first namelen
+ * characters of name as the name of the new node.  This is useful for
+ * creating subnodes based on a portion of a larger string, such as a
+ * full path.
+ */
+int fdt_add_subnode_namelen(void *fdt, int parentoffset,
+			    const char *name, int namelen);
+
+/**
+ * fdt_add_subnode - creates a new node
+ * @fdt: pointer to the device tree blob
+ * @parentoffset: structure block offset of a node
+ * @name: name of the subnode to locate
+ *
+ * fdt_add_subnode() creates a new node as a subnode of the node at
+ * structure block offset parentoffset, with the given name (which
+ * should include the unit address, if any).
+ *
+ * This function will insert data into the blob, and will therefore
+ * change the offsets of some existing nodes.
+
+ * returns:
+ *	structure block offset of the created nodeequested subnode (>=0), on success
+ *	-FDT_ERR_NOTFOUND, if the requested subnode does not exist
+ *	-FDT_ERR_BADOFFSET, if parentoffset did not point to an FDT_BEGIN_NODE tag
+ *	-FDT_ERR_EXISTS, if the node at parentoffset already has a subnode of
+ *		the given name
+ *	-FDT_ERR_NOSPACE, if there is insufficient free space in the
+ *		blob to contain the new node
+ *	-FDT_ERR_NOSPACE
+ *	-FDT_ERR_BADLAYOUT
+ *      -FDT_ERR_BADMAGIC,
+ *	-FDT_ERR_BADVERSION,
+ *	-FDT_ERR_BADSTATE,
+ *	-FDT_ERR_BADSTRUCTURE,
+ *	-FDT_ERR_TRUNCATED, standard meanings.
+ */
+int fdt_add_subnode(void *fdt, int parentoffset, const char *name);
+
+/**
+ * fdt_del_node - delete a node (subtree)
+ * @fdt: pointer to the device tree blob
+ * @nodeoffset: offset of the node to nop
+ *
+ * fdt_del_node() will remove the given node, including all its
+ * subnodes if any, from the blob.
+ *
+ * This function will delete data from the blob, and will therefore
+ * change the offsets of some existing nodes.
+ *
+ * returns:
+ *	0, on success
+ *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
+ *	-FDT_ERR_BADLAYOUT,
+ *	-FDT_ERR_BADMAGIC,
+ *	-FDT_ERR_BADVERSION,
+ *	-FDT_ERR_BADSTATE,
+ *	-FDT_ERR_BADSTRUCTURE,
+ *	-FDT_ERR_TRUNCATED, standard meanings
+ */
+int fdt_del_node(void *fdt, int nodeoffset);
+
+/**********************************************************************/
+/* Debugging / informational functions                                */
+/**********************************************************************/
+
+const char *fdt_strerror(int errval);
+
+#endif /* _LIBFDT_H */