TOMOYO Linux Cross Reference
Linux/scripts/dtc/libfdt/libfdt.h

   /* SPDX-License-Identifier: (GPL-2.0-or-later OR BSD-2-Clause) */
   #ifndef LIBFDT_H
   #define LIBFDT_H
   /*
    * libfdt - Flat Device Tree manipulation
    * Copyright (C) 2006 David Gibson, IBM Corporation.
    */
   
   #include "libfdt_env.h"
  #include "fdt.h"
  
  #ifdef __cplusplus
  extern "C" {
  #endif
  
  #define FDT_FIRST_SUPPORTED_VERSION     0x02
  #define FDT_LAST_COMPATIBLE_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: 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: FDT or a sub-block is improperly
           * terminated (overflows, goes outside allowed bounds, or
           * isn't properly terminated).  */
  #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_BADFLAGS        18
         /* FDT_ERR_BADFLAGS: The function was passed a flags field that
          * contains invalid flags or an invalid combination of flags. */
 
 #define FDT_ERR_ALIGNMENT       19
         /* FDT_ERR_ALIGNMENT: The device tree base address is not 8-byte
          * aligned. */
 
 #define FDT_ERR_MAX             19
 
 /* constants */
 #define FDT_MAX_PHANDLE 0xfffffffe
         /* Valid values for phandles range from 1 to 2^32-2. */
 
 /**********************************************************************/
 /* 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);
 
 /*
  * External helpers to access words from a device tree blob. They're built
  * to work even with unaligned pointers on platforms (such as ARMv5) that don't
  * like unaligned loads and stores.
  */
 static inline uint16_t fdt16_ld(const fdt16_t *p)
 {
         const uint8_t *bp = (const uint8_t *)p;
 
         return ((uint16_t)bp[0] << 8) | bp[1];
 }
 
 static inline uint32_t fdt32_ld(const fdt32_t *p)
 {
         const uint8_t *bp = (const uint8_t *)p;
 
         return ((uint32_t)bp[0] << 24)
                 | ((uint32_t)bp[1] << 16)
                 | ((uint32_t)bp[2] << 8)
                 | bp[3];
 }
 
 static inline void fdt32_st(void *property, uint32_t value)
 {
         uint8_t *bp = (uint8_t *)property;
 
         bp[0] = value >> 24;
         bp[1] = (value >> 16) & 0xff;
         bp[2] = (value >> 8) & 0xff;
         bp[3] = value & 0xff;
 }
 
 static inline uint64_t fdt64_ld(const fdt64_t *p)
 {
         const uint8_t *bp = (const uint8_t *)p;
 
         return ((uint64_t)bp[0] << 56)
                 | ((uint64_t)bp[1] << 48)
                 | ((uint64_t)bp[2] << 40)
                 | ((uint64_t)bp[3] << 32)
                 | ((uint64_t)bp[4] << 24)
                 | ((uint64_t)bp[5] << 16)
                 | ((uint64_t)bp[6] << 8)
                 | bp[7];
 }
 
 static inline void fdt64_st(void *property, uint64_t value)
 {
         uint8_t *bp = (uint8_t *)property;
 
         bp[0] = value >> 56;
         bp[1] = (value >> 48) & 0xff;
         bp[2] = (value >> 40) & 0xff;
         bp[3] = (value >> 32) & 0xff;
         bp[4] = (value >> 24) & 0xff;
         bp[5] = (value >> 16) & 0xff;
         bp[6] = (value >> 8) & 0xff;
         bp[7] = value & 0xff;
 }
 
 /**********************************************************************/
 /* 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
  * @fdt:        FDT blob
  * @offset:     Offset of previous subnode
  *
  * After first calling fdt_first_subnode(), call this function repeatedly to
  * get direct subnodes of a parent node.
  *
  * 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_NOTFOUND)) {
  *              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_ld(&((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_header_size - return the size of the tree's header
  * @fdt: pointer to a flattened device tree
  *
  * Return: size of DTB header in bytes
  */
 size_t fdt_header_size(const void *fdt);
 
 /**
  * fdt_header_size_ - internal function to get header size from a version number
  * @version: devicetree version number
  *
  * Return: size of DTB header in bytes
  */
 size_t fdt_header_size_(uint32_t version);
 
 /**
  * fdt_check_header - sanity check a device tree header
  * @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, and that the header contains
  * valid information (to the extent that can be determined from the
  * header alone).
  *
  * returns:
  *     0, if the buffer appears to contain a valid device tree
  *     -FDT_ERR_BADMAGIC,
  *     -FDT_ERR_BADVERSION,
  *     -FDT_ERR_BADSTATE,
  *     -FDT_ERR_TRUNCATED, 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                                                */
 /**********************************************************************/
 
 int fdt_check_full(const void *fdt, size_t bufsize);
 
 /**
  * fdt_get_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)
  * @lenp: optional pointer to return the string's length
  *
  * fdt_get_string() retrieves a pointer to a single string from the
  * strings block of the device tree blob at fdt, and optionally also
  * returns the string's length in *lenp.
  *
  * returns:
  *     a pointer to the string, on success
  *     NULL, if stroffset is out of bounds, or doesn't point to a valid string
  */
 const char *fdt_get_string(const void *fdt, int stroffset, int *lenp);
 
 /**
  * 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, or doesn't point to a valid string
  */
 const char *fdt_string(const void *fdt, int stroffset);
 
 /**
  * fdt_find_max_phandle - find and return the highest phandle in a tree
  * @fdt: pointer to the device tree blob
  * @phandle: return location for the highest phandle value found in the tree
  *
  * fdt_find_max_phandle() finds the highest phandle value in the given device
  * tree. The value returned in @phandle is only valid if the function returns
  * success.
  *
  * returns:
  *     0 on success or a negative error code on failure
  */
 int fdt_find_max_phandle(const void *fdt, uint32_t *phandle);
 
 /**
  * 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.
  *
  * This function is deprecated in favour of fdt_find_max_phandle().
  *
  * returns:
  *      the highest phandle on success
  *      0, if no phandle was found in the device tree
  *      -1, if an error occurred
  */
 static inline uint32_t fdt_get_max_phandle(const void *fdt)
 {
         uint32_t phandle;
         int err;
 
         err = fdt_find_max_phandle(fdt, &phandle);
         if (err < 0)
                 return (uint32_t)-1;
 
         return phandle;
 }
 
 /**
  * fdt_generate_phandle - return a new, unused phandle for a device tree blob
  * @fdt: pointer to the device tree blob
  * @phandle: return location for the new phandle
  *
  * Walks the device tree blob and looks for the highest phandle value. On
  * success, the new, unused phandle value (one higher than the previously
  * highest phandle value in the device tree blob) will be returned in the
  * @phandle parameter.
  *
  * Return: 0 on success or a negative error-code on failure
  */
 int fdt_generate_phandle(const void *fdt, uint32_t *phandle);
 
 /**
  * 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
  * @n: index of reserve map entry
  * @address: pointer to 64-bit variable to hold the start address
  * @size: pointer to 64-bit variable to hold the size of the entry
  *
  * 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.
  *
  * Return: offset of the subnode or -FDT_ERR_NOTFOUND if name not found.
  */
 #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.
  *
  * Return: offset of the node or negative libfdt error value otherwise
  */
 #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).
  *
  * If the path is not absolute (i.e. does not begin with '/'), the
  * first component is treated as an alias.  That is, the property by
  * that name is looked up in the /aliases node, and the value of that
  * property used in place of that first component.
  *
  * For example, for this small fragment
  *
  * / {
  *     aliases {
  *         i2c2 = &foo; // RHS compiles to "/soc@0/i2c@30a40000/eeprom@52"
  *     };
  *     soc@0 {
  *         foo: i2c@30a40000 {
  *             bar: eeprom@52 {
  *             };
  *         };
  *     };
  * };
  *
  * these would be equivalent:
  *
  *   /soc@0/i2c@30a40000/eeprom@52
  *   i2c2/eeprom@52
  *
  * returns:
  *      structure block offset of the node with the requested path (>=0), on
  *              success
  *      -FDT_ERR_BADPATH, given path does not begin with '/' and the first
  *              component is not a valid alias
  *      -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:   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_NOTFOUND)) {
  *              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);
 static inline struct fdt_property *fdt_get_property_by_offset_w(void *fdt,
                                                                 int offset,
                                                                 int *lenp)
 {
         return (struct fdt_property *)(uintptr_t)
                 fdt_get_property_by_offset(fdt, offset, 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.
  *
  * Return: pointer to the structure representing the property, or NULL
  *         if not found
  */
 #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
  * @offset: 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.
  *
  * Return: pointer to the property's value or NULL on error
  */
 #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.
  *
  * Return: a pointer to the expansion of the alias named @name, if it exists,
  *         NULL otherwise
  */
 #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_symbol_namelen - get symbol based on substring
  * @fdt: pointer to the device tree blob
  * @name: name of the symbol to look up
  * @namelen: number of characters of name to consider
  *
  * Identical to fdt_get_symbol(), but only examine the first @namelen
  * characters of @name for matching the symbol name.
  *
  * Return: a pointer to the expansion of the symbol named @name, if it exists,
  *         NULL otherwise
  */
 #ifndef SWIG /* Not available in Python */
 const char *fdt_get_symbol_namelen(const void *fdt,
                                    const char *name, int namelen);
 #endif
 
 /**
  * fdt_get_symbol - retrieve the path referenced by a given symbol
  * @fdt: pointer to the device tree blob
  * @name: name of the symbol to look up
  *
  * fdt_get_symbol() retrieves the value of a given symbol.  That is,
  * the value of the property named @name in the node
  * /__symbols__. Such a node exists only for a device tree blob that
  * has been compiled with the -@ dtc option. Each property corresponds
  * to a label appearing in the device tree source, with the name of
  * the property being the label and the value being the full path of
  * the node it is attached to.
  *
  * returns:
  *      a pointer to the expansion of the symbol named 'name', if it exists
  *      NULL, if the given symbol or the /__symbols__ node does not exist
  */
 const char *fdt_get_symbol(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
  *      1, if the node has no #size-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.
  *
  * Return: 0 on success, negative libfdt error value otherwise
  */
 #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
  * @fdt: pointer to the device tree blob
  * @nodeoffset: offset of the node containing the property
  * @name: name of the property to change the value of
  * @val: new value of the 32-bit cell
  *
  * This is an alternative name for fdt_setprop_inplace_u32()
  * Return: 0 on success, negative libfdt error number otherwise.
  */
 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                                         */
 /**********************************************************************/
 
 /* fdt_create_with_flags flags */
 #define FDT_CREATE_FLAG_NO_NAME_DEDUP 0x1
         /* FDT_CREATE_FLAG_NO_NAME_DEDUP: Do not try to de-duplicate property
          * names in the fdt. This can result in faster creation times, but
          * a larger fdt. */
 
 #define FDT_CREATE_FLAGS_ALL    (FDT_CREATE_FLAG_NO_NAME_DEDUP)
 
 /**
  * fdt_create_with_flags - begin creation of a new fdt
  * @buf: pointer to memory allocated where fdt will be created
  * @bufsize: size of the memory space at fdt
  * @flags: a valid combination of FDT_CREATE_FLAG_ flags, or 0.
  *
  * fdt_create_with_flags() begins the process of creating a new fdt with
  * the sequential write interface.
  *
  * fdt creation process must end with fdt_finish() to produce a valid fdt.
  *
  * returns:
  *      0, on success
  *      -FDT_ERR_NOSPACE, bufsize is insufficient for a minimal fdt
  *      -FDT_ERR_BADFLAGS, flags is not valid
  */
 int fdt_create_with_flags(void *buf, int bufsize, uint32_t flags);
 
 /**
  * fdt_create - begin creation of a new fdt
  * @buf: pointer to memory allocated where fdt will be created
  * @bufsize: size of the memory space at fdt
  *
  * fdt_create() is equivalent to fdt_create_with_flags() with flags=0.
  *
  * returns:
  *      0, on success
  *      -FDT_ERR_NOSPACE, bufsize is insufficient for a minimal fdt
  */
 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));
 }
 
 #ifndef SWIG /* Not available in Python */
 static inline int fdt_property_cell(void *fdt, const char *name, uint32_t val)
 {
         return fdt_property_u32(fdt, name, val);
 }
 #endif
 
 /**
  * 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: 64-bit start address of the reserve map entry
  * @size: 64-bit size of the reserved region
  *
  * 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
  * @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)
  *
  * This is an alternative name for fdt_setprop_u32()
  *
  * Return: 0 on success, negative libfdt error value otherwise.
  */
 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
  * @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)
  *
  * This is an alternative name for fdt_appendprop_u32()
  *
  * Return: 0 on success, negative libfdt error value otherwise.
  */
 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_appendprop_addrrange - append a address range property
  * @fdt: pointer to the device tree blob
  * @parent: offset of the parent node
  * @nodeoffset: offset of the node to add a property at
  * @name: name of property
  * @addr: start address of a given range
  * @size: size of a given range
  *
  * fdt_appendprop_addrrange() appends an address range value (start
  * address and size) 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.
  *
  * Cell sizes are determined by parent's #address-cells and #size-cells.
  *
  * This function may insert data into the blob, and will therefore
  * change the offsets of some existing nodes.
  *
  * returns:
  *      0, on success
  *      -FDT_ERR_BADLAYOUT,
  *      -FDT_ERR_BADMAGIC,
  *      -FDT_ERR_BADNCELLS, if the node has a badly formatted or invalid
  *              #address-cells property
  *      -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
  *      -FDT_ERR_BADSTATE,
  *      -FDT_ERR_BADSTRUCTURE,
  *      -FDT_ERR_BADVERSION,
  *      -FDT_ERR_BADVALUE, addr or size doesn't fit to respective cells size
  *      -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
  *              contain a new property
  *      -FDT_ERR_TRUNCATED, standard meanings
  */
 int fdt_appendprop_addrrange(void *fdt, int parent, int nodeoffset,
                              const char *name, uint64_t addr, uint64_t size);
 
 /**
  * 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 create
  * @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.
  *
  * Return: structure block offset of the created subnode (>=0),
  *         negative libfdt error value otherwise
  */
 #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);
 
 /**
  * fdt_overlay_target_offset - retrieves the offset of a fragment's target
  * @fdt: Base device tree blob
  * @fdto: Device tree overlay blob
  * @fragment_offset: node offset of the fragment in the overlay
  * @pathp: pointer which receives the path of the target (or NULL)
  *
  * fdt_overlay_target_offset() retrieves the target offset in the base
  * device tree of a fragment, no matter how the actual targeting is
  * done (through a phandle or a path)
  *
  * returns:
  *      the targeted node offset in the base device tree
  *      Negative error code on error
  */
 int fdt_overlay_target_offset(const void *fdt, const void *fdto,
                               int fragment_offset, char const **pathp);
 
 /**********************************************************************/
 /* Debugging / informational functions                                */
 /**********************************************************************/
 
 const char *fdt_strerror(int errval);
 
 #ifdef __cplusplus
 }
 #endif
 
 #endif /* LIBFDT_H */
 

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