FreeBSD/Linux Kernel Cross Reference
sys/contrib/libfdt/libfdt.h

     #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     0x02
    #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: Attempted 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.
             * This can be caused either by an invalid phandle property
             * length, or the phandle value was either 0 or -1, which 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. */
   
   /* Errors in device tree content */
   #define FDT_ERR_BADNCELLS       14
           /* FDT_ERR_BADNCELLS: Device tree has a #address-cells, #size-cells
            * or similar property with a bad format or value */
   
   #define FDT_ERR_BADVALUE        15
           /* FDT_ERR_BADVALUE: Device tree has a property with an unexpected
            * value. For example: a property expected to contain a string list
            * is not NUL-terminated within the length of its value. */
   
   #define FDT_ERR_BADOVERLAY      16
           /* FDT_ERR_BADOVERLAY: The device tree overlay, while
            * correctly structured, cannot be applied due to some
            * unexpected or missing value, property or node. */
   
   #define FDT_ERR_NOPHANDLES      17
           /* FDT_ERR_NOPHANDLES: The device tree doesn't have any
            * phandle available anymore without causing an overflow */
   
   #define FDT_ERR_MAX             17
   
   /**********************************************************************/
   /* Low-level functions (you probably don't need these)                */
   /**********************************************************************/
   
   #ifndef SWIG /* This function is not useful in Python */
   const void *fdt_offset_ptr(const void *fdt, int offset, unsigned int checklen);
   #endif
   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);
   
   /**
    * fdt_first_subnode() - get offset of first direct subnode
    *
    * @fdt:        FDT blob
    * @offset:     Offset of node to check
    * @return offset of first subnode, or -FDT_ERR_NOTFOUND if there is none
    */
   int fdt_first_subnode(const void *fdt, int offset);
   
   /**
    * fdt_next_subnode() - get offset of next direct subnode
    *
    * After first calling fdt_first_subnode(), call this function repeatedly to
    * get direct subnodes of a parent node.
    *
    * @fdt:        FDT blob
    * @offset:     Offset of previous subnode
    * @return offset of next subnode, or -FDT_ERR_NOTFOUND if there are no more
    * subnodes
    */
   int fdt_next_subnode(const void *fdt, int offset);
   
   /**
    * fdt_for_each_subnode - iterate over all subnodes of a parent
    *
    * @node:       child node (int, lvalue)
    * @fdt:        FDT blob (const void *)
    * @parent:     parent node (int)
    *
    * This is actually a wrapper around a for loop and would be used like so:
    *
    *      fdt_for_each_subnode(node, fdt, parent) {
    *              Use node
    *              ...
    *      }
    *
    *      if ((node < 0) && (node != -FDT_ERR_NOT_FOUND)) {
    *              Error handling
    *      }
    *
    * Note that this is implemented as a macro and @node is used as
    * iterator in the loop. The parent variable be constant or even a
    * literal.
    *
    */
   #define fdt_for_each_subnode(node, fdt, parent)         \
           for (node = fdt_first_subnode(fdt, parent);     \
                node >= 0;                                 \
                node = fdt_next_subnode(fdt, node))
   
   /**********************************************************************/
   /* 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_get_max_phandle - retrieves the highest phandle in a tree
    * @fdt: pointer to the device tree blob
    *
    * fdt_get_max_phandle retrieves the highest phandle in the given
    * device tree. This will ignore badly formatted phandles, or phandles
    * with a value of 0 or -1.
    *
    * returns:
    *      the highest phandle on success
    *      0, if no phandle was found in the device tree
    *      -1, if an error occurred
    */
   uint32_t fdt_get_max_phandle(const void *fdt);
   
   /**
    * 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.
    */
   #ifndef SWIG /* Not available in Python */
   int fdt_subnode_offset_namelen(const void *fdt, int parentoffset,
                                  const char *name, int namelen);
   #endif
   /**
    * 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_path_offset_namelen - find a tree node by its full path
    * @fdt: pointer to the device tree blob
    * @path: full path of the node to locate
    * @namelen: number of characters of path to consider
    *
    * Identical to fdt_path_offset(), but only consider the first namelen
    * characters of path as the path name.
    */
   #ifndef SWIG /* Not available in Python */
   int fdt_path_offset_namelen(const void *fdt, const char *path, int namelen);
   #endif
   
   /**
    * 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_first_property_offset - find the offset of a node's first property
    * @fdt: pointer to the device tree blob
    * @nodeoffset: structure block offset of a node
    *
    * fdt_first_property_offset() finds the first property of the node at
    * the given structure block offset.
    *
    * returns:
    *      structure block offset of the property (>=0), on success
    *      -FDT_ERR_NOTFOUND, if the requested node has no properties
    *      -FDT_ERR_BADOFFSET, if nodeoffset 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_first_property_offset(const void *fdt, int nodeoffset);
   
   /**
    * fdt_next_property_offset - step through a node's properties
    * @fdt: pointer to the device tree blob
    * @offset: structure block offset of a property
    *
    * fdt_next_property_offset() finds the property immediately after the
    * one at the given structure block offset.  This will be a property
    * of the same node as the given property.
    *
    * returns:
    *      structure block offset of the next property (>=0), on success
    *      -FDT_ERR_NOTFOUND, if the given property is the last in its node
    *      -FDT_ERR_BADOFFSET, if nodeoffset did not point to an FDT_PROP tag
    *      -FDT_ERR_BADMAGIC,
    *      -FDT_ERR_BADVERSION,
    *      -FDT_ERR_BADSTATE,
    *      -FDT_ERR_BADSTRUCTURE,
    *      -FDT_ERR_TRUNCATED, standard meanings.
    */
   int fdt_next_property_offset(const void *fdt, int offset);
   
   /**
    * fdt_for_each_property_offset - iterate over all properties of a node
    *
    * @property_offset:    property offset (int, lvalue)
    * @fdt:                FDT blob (const void *)
    * @node:               node offset (int)
    *
    * This is actually a wrapper around a for loop and would be used like so:
    *
    *      fdt_for_each_property_offset(property, fdt, node) {
    *              Use property
    *              ...
    *      }
    *
    *      if ((property < 0) && (property != -FDT_ERR_NOT_FOUND)) {
    *              Error handling
    *      }
    *
    * Note that this is implemented as a macro and property is used as
    * iterator in the loop. The node variable can be constant or even a
    * literal.
    */
   #define fdt_for_each_property_offset(property, fdt, node)       \
           for (property = fdt_first_property_offset(fdt, node);   \
                property >= 0;                                     \
                property = fdt_next_property_offset(fdt, property))
   
   /**
    * fdt_get_property_by_offset - retrieve the property at a given offset
    * @fdt: pointer to the device tree blob
    * @offset: offset of the property to retrieve
    * @lenp: pointer to an integer variable (will be overwritten) or NULL
    *
    * fdt_get_property_by_offset() retrieves a pointer to the
    * fdt_property structure within the device tree blob at the given
    * offset.  If lenp is non-NULL, the length of the property value is
    * also returned, in the integer pointed to by lenp.
    *
    * Note that this code only works on device tree versions >= 16. fdt_getprop()
    * works on all versions.
    *
    * 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_BADOFFSET, nodeoffset did not point to FDT_PROP 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_by_offset(const void *fdt,
                                                         int offset,
                                                         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(), but only examine the first namelen
    * characters of name for matching the property name.
    */
   #ifndef SWIG /* Not available in Python */
   const struct fdt_property *fdt_get_property_namelen(const void *fdt,
                                                       int nodeoffset,
                                                       const char *name,
                                                       int namelen, int *lenp);
   #endif
   
   /**
    * 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_by_offset - retrieve the value of a property at a given offset
    * @fdt: pointer to the device tree blob
    * @ffset: offset of the property to read
    * @namep: pointer to a string variable (will be overwritten) or NULL
    * @lenp: pointer to an integer variable (will be overwritten) or NULL
    *
    * fdt_getprop_by_offset() retrieves a pointer to the value of the
    * property at structure block offset 'offset' (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.  If namep is non-NULL,
    * the property's namne will also be returned in the char * pointed to
    * by namep (this will be a pointer to within the device tree's string
    * block, not a new copy of the name).
    *
    * returns:
    *      pointer to the property's value
    *              if lenp is non-NULL, *lenp contains the length of the property
    *              value (>=0)
    *              if namep is non-NULL *namep contiains a pointer to the property
    *              name.
    *      NULL, on error
    *              if lenp is non-NULL, *lenp contains an error code (<0):
    *              -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_PROP tag
    *              -FDT_ERR_BADMAGIC,
    *              -FDT_ERR_BADVERSION,
    *              -FDT_ERR_BADSTATE,
    *              -FDT_ERR_BADSTRUCTURE,
    *              -FDT_ERR_TRUNCATED, standard meanings
    */
   #ifndef SWIG /* This function is not useful in Python */
   const void *fdt_getprop_by_offset(const void *fdt, int offset,
                                     const char **namep, int *lenp);
   #endif
   
   /**
    * 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.
    */
   #ifndef SWIG /* Not available in Python */
   const void *fdt_getprop_namelen(const void *fdt, int nodeoffset,
                                   const char *name, int namelen, int *lenp);
   static inline void *fdt_getprop_namelen_w(void *fdt, int nodeoffset,
                                             const char *name, int namelen,
                                             int *lenp)
   {
           return (void *)(uintptr_t)fdt_getprop_namelen(fdt, nodeoffset, name,
                                                         namelen, lenp);
   }
   #endif
   
   /**
    * 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.
    */
   #ifndef SWIG /* Not available in Python */
   const char *fdt_get_alias_namelen(const void *fdt,
                                     const char *name, int namelen);
   #endif
   
   /**
    * fdt_get_alias - retrieve 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', if 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);
   
   /**
    * fdt_stringlist_contains - check a string list property for a string
    * @strlist: Property containing a list of strings to check
    * @listlen: Length of property
    * @str: String to search for
    *
    * This is a utility function provided for convenience. The list contains
    * one or more strings, each terminated by \0, as is found in a device tree
    * "compatible" property.
    *
    * @return: 1 if the string is found in the list, 0 not found, or invalid list
    */
   int fdt_stringlist_contains(const char *strlist, int listlen, const char *str);
   
   /**
    * fdt_stringlist_count - count the number of strings in a string list
    * @fdt: pointer to the device tree blob
    * @nodeoffset: offset of a tree node
    * @property: name of the property containing the string list
    * @return:
    *   the number of strings in the given property
    *   -FDT_ERR_BADVALUE if the property value is not NUL-terminated
    *   -FDT_ERR_NOTFOUND if the property does not exist
    */
   int fdt_stringlist_count(const void *fdt, int nodeoffset, const char *property);
   
   /**
    * fdt_stringlist_search - find a string in a string list and return its index
   * @fdt: pointer to the device tree blob
   * @nodeoffset: offset of a tree node
   * @property: name of the property containing the string list
   * @string: string to look up in the string list
   *
   * Note that it is possible for this function to succeed on property values
   * that are not NUL-terminated. That's because the function will stop after
   * finding the first occurrence of @string. This can for example happen with
   * small-valued cell properties, such as #address-cells, when searching for
   * the empty string.
   *
   * @return:
   *   the index of the string in the list of strings
   *   -FDT_ERR_BADVALUE if the property value is not NUL-terminated
   *   -FDT_ERR_NOTFOUND if the property does not exist or does not contain
   *                     the given string
   */
  int fdt_stringlist_search(const void *fdt, int nodeoffset, const char *property,
                            const char *string);
  
  /**
   * fdt_stringlist_get() - obtain the string at a given index in a string list
   * @fdt: pointer to the device tree blob
   * @nodeoffset: offset of a tree node
   * @property: name of the property containing the string list
   * @index: index of the string to return
   * @lenp: return location for the string length or an error code on failure
   *
   * Note that this will successfully extract strings from properties with
   * non-NUL-terminated values. For example on small-valued cell properties
   * this function will return the empty string.
   *
   * If non-NULL, the length of the string (on success) or a negative error-code
   * (on failure) will be stored in the integer pointer to by lenp.
   *
   * @return:
   *   A pointer to the string at the given index in the string list or NULL on
   *   failure. On success the length of the string will be stored in the memory
   *   location pointed to by the lenp parameter, if non-NULL. On failure one of
   *   the following negative error codes will be returned in the lenp parameter
   *   (if non-NULL):
   *     -FDT_ERR_BADVALUE if the property value is not NUL-terminated
   *     -FDT_ERR_NOTFOUND if the property does not exist
   */
  const char *fdt_stringlist_get(const void *fdt, int nodeoffset,
                                 const char *property, int index,
                                 int *lenp);
  
  /**********************************************************************/
  /* Read-only functions (addressing related)                           */
  /**********************************************************************/
  
  /**
   * FDT_MAX_NCELLS - maximum value for #address-cells and #size-cells
   *
   * This is the maximum value for #address-cells, #size-cells and
   * similar properties that will be processed by libfdt.  IEE1275
   * requires that OF implementations handle values up to 4.
   * Implementations may support larger values, but in practice higher
   * values aren't used.
   */
  #define FDT_MAX_NCELLS          4
  
  /**
   * fdt_address_cells - retrieve address size for a bus represented in the tree
   * @fdt: pointer to the device tree blob
   * @nodeoffset: offset of the node to find the address size for
   *
   * When the node has a valid #address-cells property, returns its value.
   *
   * returns:
   *      0 <= n < FDT_MAX_NCELLS, on success
   *      2, if the node has no #address-cells property
   *      -FDT_ERR_BADNCELLS, if the node has a badly formatted or invalid
   *              #address-cells property
   *      -FDT_ERR_BADMAGIC,
   *      -FDT_ERR_BADVERSION,
   *      -FDT_ERR_BADSTATE,
   *      -FDT_ERR_BADSTRUCTURE,
   *      -FDT_ERR_TRUNCATED, standard meanings
   */
  int fdt_address_cells(const void *fdt, int nodeoffset);
  
  /**
   * fdt_size_cells - retrieve address range size for a bus represented in the
   *                  tree
   * @fdt: pointer to the device tree blob
   * @nodeoffset: offset of the node to find the address range size for
   *
   * When the node has a valid #size-cells property, returns its value.
   *
   * returns:
   *      0 <= n < FDT_MAX_NCELLS, on success
   *      2, if the node has no #address-cells property
   *      -FDT_ERR_BADNCELLS, if the node has a badly formatted or invalid
   *              #size-cells property
   *      -FDT_ERR_BADMAGIC,
   *      -FDT_ERR_BADVERSION,
   *      -FDT_ERR_BADSTATE,
   *      -FDT_ERR_BADSTRUCTURE,
   *      -FDT_ERR_TRUNCATED, standard meanings
   */
  int fdt_size_cells(const void *fdt, int nodeoffset);
  
  
  /**********************************************************************/
  /* Write-in-place functions                                           */
  /**********************************************************************/
  
  /**
   * fdt_setprop_inplace_namelen_partial - 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
   * @namelen: number of characters of name to consider
   * @idx: index of the property to change in the array
   * @val: pointer to data to replace the property value with
   * @len: length of the property value
   *
   * Identical to fdt_setprop_inplace(), but modifies the given property
   * starting from the given index, and using only the first characters
   * of the name. It is useful when you want to manipulate only one value of
   * an array and you have a string that doesn't end with \0.
   */
  #ifndef SWIG /* Not available in Python */
  int fdt_setprop_inplace_namelen_partial(void *fdt, int nodeoffset,
                                          const char *name, int namelen,
                                          uint32_t idx, const void *val,
                                          int len);
  #endif
  
  /**
   * 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
   */
  #ifndef SWIG /* Not available in Python */
  int fdt_setprop_inplace(void *fdt, int nodeoffset, const char *name,
                          const void *val, int len);
  #endif
  
  /**
   * fdt_setprop_inplace_u32 - change the value of a 32-bit integer 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: 32-bit integer value to replace the property with
   *
   * fdt_setprop_inplace_u32() replaces the value of a given property
   * with the 32-bit integer 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_u32(void *fdt, int nodeoffset,
                                            const char *name, uint32_t val)
  {
          fdt32_t tmp = cpu_to_fdt32(val);
          return fdt_setprop_inplace(fdt, nodeoffset, name, &tmp, sizeof(tmp));
  }
  
  /**
   * fdt_setprop_inplace_u64 - change the value of a 64-bit integer 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: 64-bit integer value to replace the property with
   *
   * fdt_setprop_inplace_u64() replaces the value of a given property
   * with the 64-bit integer 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
   * 8.
   *
   * 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 8
   *      -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_u64(void *fdt, int nodeoffset,
                                            const char *name, uint64_t val)
  {
          fdt64_t tmp = cpu_to_fdt64(val);
          return fdt_setprop_inplace(fdt, nodeoffset, name, &tmp, sizeof(tmp));
  }
  
  /**
   * fdt_setprop_inplace_cell - change the value of a single-cell property
   *
   * This is an alternative name for fdt_setprop_inplace_u32()
   */
  static inline int fdt_setprop_inplace_cell(void *fdt, int nodeoffset,
                                             const char *name, uint32_t val)
  {
          return fdt_setprop_inplace_u32(fdt, nodeoffset, name, 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_resize(void *fdt, 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_u32(void *fdt, const char *name, uint32_t val)
  {
          fdt32_t tmp = cpu_to_fdt32(val);
          return fdt_property(fdt, name, &tmp, sizeof(tmp));
  }
  static inline int fdt_property_u64(void *fdt, const char *name, uint64_t val)
  {
          fdt64_t tmp = cpu_to_fdt64(val);
          return fdt_property(fdt, name, &tmp, sizeof(tmp));
  }
  static inline int fdt_property_cell(void *fdt, const char *name, uint32_t val)
  {
          return fdt_property_u32(fdt, name, val);
  }
  
  /**
   * fdt_property_placeholder - add a new property and return a ptr to its value
   *
   * @fdt: pointer to the device tree blob
   * @name: name of property to add
   * @len: length of property value in bytes
   * @valp: returns a pointer to where where the value should be placed
   *
   * returns:
   *      0, on success
   *      -FDT_ERR_BADMAGIC,
   *      -FDT_ERR_NOSPACE, standard meanings
   */
  int fdt_property_placeholder(void *fdt, const char *name, int len, void **valp);
  
  #define fdt_property_string(fdt, name, str) \
          fdt_property(fdt, name, str, strlen(str)+1)
  int fdt_end_node(void *fdt);
  int fdt_finish(void *fdt);
  
  /**********************************************************************/
  /* Read-write functions                                               */
  /**********************************************************************/
  
  int fdt_create_empty_tree(void *buf, int bufsize);
  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_placeholder - allocate space for 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
   * @len: length of the property value
   * @prop_data: return pointer to property data
   *
   * fdt_setprop_placeholer() allocates the named property in the given node.
   * If the property exists it is resized. In either case a pointer to the
   * property data is returned.
   *
   * 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_placeholder(void *fdt, int nodeoffset, const char *name,
                              int len, void **prop_data);
  
  /**
   * fdt_setprop_u32 - set a property to a 32-bit integer
   * @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_u32() sets the value of the named property in the given
   * node to the given 32-bit integer 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_u32(void *fdt, int nodeoffset, const char *name,
                                    uint32_t val)
  {
          fdt32_t tmp = cpu_to_fdt32(val);
          return fdt_setprop(fdt, nodeoffset, name, &tmp, sizeof(tmp));
  }
  
  /**
   * fdt_setprop_u64 - set a property to a 64-bit integer
   * @fdt: pointer to the device tree blob
   * @nodeoffset: offset of the node whose property to change
   * @name: name of the property to change
   * @val: 64-bit integer value for the property (native endian)
   *
   * fdt_setprop_u64() sets the value of the named property in the given
   * node to the given 64-bit integer 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_u64(void *fdt, int nodeoffset, const char *name,
                                    uint64_t val)
  {
          fdt64_t tmp = cpu_to_fdt64(val);
          return fdt_setprop(fdt, nodeoffset, name, &tmp, sizeof(tmp));
  }
  
  /**
   * fdt_setprop_cell - set a property to a single cell value
   *
   * This is an alternative name for fdt_setprop_u32()
   */
  static inline int fdt_setprop_cell(void *fdt, int nodeoffset, const char *name,
                                     uint32_t val)
  {
          return fdt_setprop_u32(fdt, nodeoffset, name, 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_setprop_empty - set a property to an empty value
   * @fdt: pointer to the device tree blob
   * @nodeoffset: offset of the node whose property to change
   * @name: name of the property to change
   *
   * fdt_setprop_empty() sets the value of the named property in the
   * given node to an empty (zero length) value, or creates a new empty
   * 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
   */
  #define fdt_setprop_empty(fdt, nodeoffset, name) \
          fdt_setprop((fdt), (nodeoffset), (name), NULL, 0)
  
  /**
   * fdt_appendprop - append to or create a property
   * @fdt: pointer to the device tree blob
   * @nodeoffset: offset of the node whose property to change
   * @name: name of the property to append to
   * @val: pointer to data to append to the property value
   * @len: length of the data to append to the property value
   *
   * fdt_appendprop() appends the value to the named property in the
   * given node, creating the property if it does not already exist.
   *
   * This function may insert data into 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_appendprop(void *fdt, int nodeoffset, const char *name,
                     const void *val, int len);
  
  /**
   * fdt_appendprop_u32 - append a 32-bit integer value to 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: 32-bit integer value to append to the property (native endian)
   *
   * fdt_appendprop_u32() appends the given 32-bit integer value
   * (converting to big-endian if necessary) to the value of the named
   * property in the given node, or creates a new property with that
   * value if it does not already exist.
   *
   * This function may insert data into 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_appendprop_u32(void *fdt, int nodeoffset,
                                       const char *name, uint32_t val)
  {
          fdt32_t tmp = cpu_to_fdt32(val);
          return fdt_appendprop(fdt, nodeoffset, name, &tmp, sizeof(tmp));
  }
  
  /**
   * fdt_appendprop_u64 - append a 64-bit integer value to 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: 64-bit integer value to append to the property (native endian)
   *
   * fdt_appendprop_u64() appends the given 64-bit integer value
   * (converting to big-endian if necessary) to the value of the named
   * property in the given node, or creates a new property with that
   * value if it does not already exist.
   *
   * This function may insert data into 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_appendprop_u64(void *fdt, int nodeoffset,
                                       const char *name, uint64_t val)
  {
          fdt64_t tmp = cpu_to_fdt64(val);
          return fdt_appendprop(fdt, nodeoffset, name, &tmp, sizeof(tmp));
  }
  
  /**
   * fdt_appendprop_cell - append a single cell value to a property
   *
   * This is an alternative name for fdt_appendprop_u32()
   */
  static inline int fdt_appendprop_cell(void *fdt, int nodeoffset,
                                        const char *name, uint32_t val)
  {
          return fdt_appendprop_u32(fdt, nodeoffset, name, val);
  }
  
  /**
   * fdt_appendprop_string - append a string to 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
   * @str: string value to append to the property
   *
   * fdt_appendprop_string() appends the given string to the value of
   * the named property in the given node, or creates a new property
   * with that value if it does not already exist.
   *
   * This function may insert data into 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_appendprop_string(fdt, nodeoffset, name, str) \
          fdt_appendprop((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.
   */
  #ifndef SWIG /* Not available in Python */
  int fdt_add_subnode_namelen(void *fdt, int parentoffset,
                              const char *name, int namelen);
  #endif
  
  /**
   * 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);
  
  /**
   * fdt_overlay_apply - Applies a DT overlay on a base DT
   * @fdt: pointer to the base device tree blob
   * @fdto: pointer to the device tree overlay blob
   *
   * fdt_overlay_apply() will apply the given device tree overlay on the
   * given base device tree.
   *
   * Expect the base device tree to be modified, even if the function
   * returns an error.
   *
   * returns:
   *      0, on success
   *      -FDT_ERR_NOSPACE, there's not enough space in the base device tree
   *      -FDT_ERR_NOTFOUND, the overlay points to some inexistant nodes or
   *              properties in the base DT
   *      -FDT_ERR_BADPHANDLE,
   *      -FDT_ERR_BADOVERLAY,
   *      -FDT_ERR_NOPHANDLES,
   *      -FDT_ERR_INTERNAL,
   *      -FDT_ERR_BADLAYOUT,
   *      -FDT_ERR_BADMAGIC,
   *      -FDT_ERR_BADOFFSET,
   *      -FDT_ERR_BADPATH,
   *      -FDT_ERR_BADVERSION,
   *      -FDT_ERR_BADSTRUCTURE,
   *      -FDT_ERR_BADSTATE,
   *      -FDT_ERR_TRUNCATED, standard meanings
   */
  int fdt_overlay_apply(void *fdt, void *fdto);
  
  /**********************************************************************/
  /* Debugging / informational functions                                */
  /**********************************************************************/
  
  const char *fdt_strerror(int errval);
  
  #endif /* LIBFDT_H */

Cache object: db612a07a7bc5981a00ea01f3e0f6334