libfdt/fdt_ro.c - platform/external/u-boot - Gitiles

 /*
  * libfdt - Flat Device Tree manipulation
  * Copyright (C) 2006 David Gibson, IBM Corporation.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public License
  * as published by the Free Software Foundation; either version 2.1 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
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser 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
  */
 #include "config.h"
 #if CONFIG_OF_LIBFDT

 #include "libfdt_env.h"

 #include <fdt.h>
 #include <libfdt.h>

 #include "libfdt_internal.h"

 #define CHECK_HEADER(fdt)	{ \
 	int err; \
 	if ((err = fdt_check_header(fdt)) != 0) \
 		return err; \
 }

 static int offset_streq(const void *fdt, int offset,
 			const char *s, int len)
 {
 	const char *p = fdt_offset_ptr(fdt, offset, len+1);

 	if (! p)
 		/* short match */
 		return 0;

 	if (memcmp(p, s, len) != 0)
 		return 0;

 	if (p[len] != '\0')
 		return 0;

 	return 1;
 }

 /*
  * Checks if the property name matches.
  */
 static int prop_name_eq(const void *fdt, int offset, const char *name,
 			struct fdt_property **prop, int *lenp)
 {
 	int namestroff, len;

 	*prop = fdt_offset_ptr_typed(fdt, offset, *prop);
 	if (! *prop)
 		return -FDT_ERR_BADSTRUCTURE;

 	namestroff = fdt32_to_cpu((*prop)->nameoff);
 	if (streq(fdt_string(fdt, namestroff), name)) {
 		len = fdt32_to_cpu((*prop)->len);
 		*prop = fdt_offset_ptr(fdt, offset,
 				       sizeof(**prop) + len);
 		if (*prop) {
 			if (lenp)
 				*lenp = len;
 			return 1;
 		} else
 			return -FDT_ERR_BADSTRUCTURE;
 	}
 	return 0;
 }

 /*
  * Return a pointer to the string at the given string offset.
  */
 char *fdt_string(const void *fdt, int stroffset)
 {
 	return (char *)fdt + fdt_off_dt_strings(fdt) + stroffset;
 }

 /*
  * Check if the specified node is compatible by comparing the tokens
  * in its "compatible" property with the specified string:
  *
  *   nodeoffset - starting place of the node
  *   compat     - the string to match to one of the tokens in the
  *                "compatible" list.
  */
 int fdt_node_is_compatible(const void *fdt, int nodeoffset,
 			   const char *compat)
 {
 	const char* cp;
 	int cplen, len;

 	cp = fdt_getprop(fdt, nodeoffset, "compatible", &cplen);
 	if (cp == NULL)
 		return 0;
 	while (cplen > 0) {
 		if (strncmp(cp, compat, strlen(compat)) == 0)
 			return 1;
 		len = strlen(cp) + 1;
 		cp += len;
 		cplen -= len;
 	}

 	return 0;
 }

 /*
  * Find a node by its device type property. On success, the offset of that
  * node is returned or an error code otherwise:
  *
  *   nodeoffset - the node to start searching from or 0, the node you pass
  *                will not be searched, only the next one will; typically,
  *                you pass 0 to start the search and then what the previous
  *                call returned.
  *   type       - the device type string to match against.
  */
 int fdt_find_node_by_type(const void *fdt, int nodeoffset, const char *type)
 {
 	int offset, nextoffset;
 	struct fdt_property *prop;
 	uint32_t tag;
 	int len, ret;

 	CHECK_HEADER(fdt);

 	tag = fdt_next_tag(fdt, nodeoffset, &nextoffset, NULL);
 	if (tag != FDT_BEGIN_NODE)
 		return -FDT_ERR_BADOFFSET;
 	if (nodeoffset)
 		nodeoffset = 0;	/* start searching with next node */

 	while (1) {
 		offset = nextoffset;
 		tag = fdt_next_tag(fdt, offset, &nextoffset, NULL);

 		switch (tag) {
 		case FDT_BEGIN_NODE:
 			nodeoffset = offset;
 			break;

 		case FDT_PROP:
 			if (nodeoffset == 0)
 				break;
 			ret = prop_name_eq(fdt, offset, "device_type",
 					   &prop, &len);
 			if (ret < 0)
 				return ret;
 			else if (ret > 0 &&
 				 strncmp(prop->data, type, len - 1) == 0)
 			    return nodeoffset;
 			break;

 		case FDT_END_NODE:
 		case FDT_NOP:
 			break;

 		case FDT_END:
 			return -FDT_ERR_NOTFOUND;

 		default:
 			return -FDT_ERR_BADSTRUCTURE;
 		}
 	}
 }

 /*
  * Find a node based on its device type and one of the tokens in its its
  * "compatible" property. On success, the offset of that node is returned
  * or an error code otherwise:
  *
  *   nodeoffset - the node to start searching from or 0, the node you pass
  *                will not be searched, only the next one will; typically,
  *                you pass 0 to start the search and then what the previous
  *                call returned.
  *   type       - the device type string to match against.
  *   compat     - the string to match to one of the tokens in the
  *                "compatible" list.
  */
 int fdt_find_compatible_node(const void *fdt, int nodeoffset,
 			     const char *type, const char *compat)
 {
 	int offset;

 	offset = fdt_find_node_by_type(fdt, nodeoffset, type);
 	if (offset < 0 || fdt_node_is_compatible(fdt, offset, compat))
 		return offset;

 	return -FDT_ERR_NOTFOUND;
 }

 /*
  * Return the node offset of the node specified by:
  *   parentoffset - starting place (0 to start at the root)
  *   name         - name being searched for
  *   namelen      - length of the name: typically strlen(name)
  *
  * Notes:
  *   If the start node has subnodes, the subnodes are _not_ searched for the
  *     requested name.
  */
 int fdt_subnode_offset_namelen(const void *fdt, int parentoffset,
 			       const char *name, int namelen)
 {
 	int level = 0;
 	uint32_t tag;
 	int offset, nextoffset;

 	CHECK_HEADER(fdt);

 	tag = fdt_next_tag(fdt, parentoffset, &nextoffset, NULL);
 	if (tag != FDT_BEGIN_NODE)
 		return -FDT_ERR_BADOFFSET;

 	do {
 		offset = nextoffset;
 		tag = fdt_next_tag(fdt, offset, &nextoffset, NULL);

 		switch (tag) {
 		case FDT_END:
 			return -FDT_ERR_TRUNCATED;

 		case FDT_BEGIN_NODE:
 			level++;
 			/*
 			 * If we are nested down levels, ignore the strings
 			 * until we get back to the proper level.
 			 */
 			if (level != 1)
 				continue;

 			/* Return the offset if this is "our" string. */
 			if (offset_streq(fdt, offset+FDT_TAGSIZE, name, namelen))
 				return offset;
 			break;

 		case FDT_END_NODE:
 			level--;
 			break;

 		case FDT_PROP:
 		case FDT_NOP:
 			break;

 		default:
 			return -FDT_ERR_BADSTRUCTURE;
 		}
 	} while (level >= 0);

 	return -FDT_ERR_NOTFOUND;
 }

 /*
  * See fdt_subnode_offset_namelen()
  */
 int fdt_subnode_offset(const void *fdt, int parentoffset,
 		       const char *name)
 {
 	return fdt_subnode_offset_namelen(fdt, parentoffset, name, strlen(name));
 }

 /*
  * Searches for the node corresponding to the given path and returns the
  * offset of that node.
  */
 int fdt_find_node_by_path(const void *fdt, const char *path)
 {
 	const char *end = path + strlen(path);
 	const char *p = path;
 	int offset = 0;

 	CHECK_HEADER(fdt);

 	/* Paths must be absolute */
 	if (*path != '/')
 		return -FDT_ERR_BADPATH;

 	/* Handle the root path: root offset is 0 */
 	if (strcmp(path, "/") == 0)
 		return 0;

 	while (*p) {
 		const char *q;

 		/* Skip path separator(s) */
 		while (*p == '/')
 			p++;
 		if (! *p)
 			return -FDT_ERR_BADPATH;

 		/*
 		 * Find the next path separator.  The characters between
 		 * p and q are the next segment of the the path to find.
 		 */
 		q = strchr(p, '/');
 		if (! q)
 			q = end;

 		/*
 		 * Find the offset corresponding to the this path segment.
 		 */
 		offset = fdt_subnode_offset_namelen(fdt, offset, p, q-p);

 		/* Oops, error, abort abort abort */
 		if (offset < 0)
 			return offset;

 		p = q;
 	}

 	return offset;
 }

 /*
  * Given the offset of a node and a name of a property in that node, return
  * a pointer to the property struct.
  */
 struct fdt_property *fdt_get_property(const void *fdt,
 				      int nodeoffset,
 				      const char *name, int *lenp)
 {
 	int level = 0;
 	uint32_t tag;
 	struct fdt_property *prop;
 	int offset, nextoffset;
 	int err;

 	if ((err = fdt_check_header(fdt)) != 0)
 		goto fail;

 	err = -FDT_ERR_BADOFFSET;
 	if (nodeoffset % FDT_TAGSIZE)
 		goto fail;

 	tag = fdt_next_tag(fdt, nodeoffset, &nextoffset, NULL);
 	if (tag != FDT_BEGIN_NODE)
 		goto fail;

 	do {
 		offset = nextoffset;

 		tag = fdt_next_tag(fdt, offset, &nextoffset, NULL);
 		switch (tag) {
 		case FDT_END:
 			err = -FDT_ERR_TRUNCATED;
 			goto fail;

 		case FDT_BEGIN_NODE:
 			level++;
 			break;

 		case FDT_END_NODE:
 			level--;
 			break;

 		case FDT_PROP:
 			/*
 			 * If we are nested down levels, ignore the strings
 			 * until we get back to the proper level.
 			 */
 			if (level != 0)
 				continue;

 			err = prop_name_eq(fdt, offset, name, &prop, lenp);
 			if (err > 0)
 				return prop;
 			else if (err < 0)
 				goto fail;
 			break;

 		case FDT_NOP:
 			break;

 		default:
 			err = -FDT_ERR_BADSTRUCTURE;
 			goto fail;
 		}
 	} while (level >= 0);

 	err = -FDT_ERR_NOTFOUND;
 fail:
 	if (lenp)
 		*lenp = err;
 	return NULL;
 }

 /*
  * Given the offset of a node and a name of a property in that node, return
  * a pointer to the property data (ONLY).
  */
 void *fdt_getprop(const void *fdt, int nodeoffset,
 		  const char *name, int *lenp)
 {
 	const struct fdt_property *prop;

 	prop = fdt_get_property(fdt, nodeoffset, name, lenp);
 	if (! prop)
 		return NULL;

 	return (void *)prop->data;
 }


 uint32_t fdt_next_tag(const void *fdt, int offset, int *nextoffset, char **namep)
 {
 	const uint32_t *tagp, *lenp;
 	uint32_t tag;
 	const char *p;

 	if (offset % FDT_TAGSIZE)
 		return -1;

 	tagp = fdt_offset_ptr(fdt, offset, FDT_TAGSIZE);
 	if (! tagp)
 		return FDT_END; /* premature end */
 	tag = fdt32_to_cpu(*tagp);
 	offset += FDT_TAGSIZE;

 	switch (tag) {
 	case FDT_BEGIN_NODE:
 		if(namep)
 			*namep = fdt_offset_ptr(fdt, offset, 1);

 		/* skip name */
 		do {
 			p = fdt_offset_ptr(fdt, offset++, 1);
 		} while (p && (*p != '\0'));
 		if (! p)
 			return FDT_END;
 		break;
 	case FDT_PROP:
 		lenp = fdt_offset_ptr(fdt, offset, sizeof(*lenp));
 		if (! lenp)
 			return FDT_END;
 		/*
 		 * Get the property and set the namep to the name.
 		 */
 		if(namep) {
 			struct fdt_property *prop;

 			prop = fdt_offset_ptr_typed(fdt, offset - FDT_TAGSIZE, prop);
 			if (! prop)
 				return -FDT_ERR_BADSTRUCTURE;
 			*namep = fdt_string(fdt, fdt32_to_cpu(prop->nameoff));
 		}
 		/* skip name offset, length and value */
 		offset += 2*FDT_TAGSIZE + fdt32_to_cpu(*lenp);
 		break;
 	}

 	if (nextoffset)
 		*nextoffset = ALIGN(offset, FDT_TAGSIZE);

 	return tag;
 }

 /*
  * Return the number of used reserve map entries and total slots available.
  */
 int fdt_num_reservemap(void *fdt, int *used, int *total)
 {
 	struct fdt_reserve_entry *re;
 	int  start;
 	int  end;
 	int  err = fdt_check_header(fdt);

 	if (err != 0)
 		return err;

 	start = fdt_off_mem_rsvmap(fdt);

 	/*
 	 * Convention is that the reserve map is before the dt_struct,
 	 * but it does not have to be.
 	 */
 	end = fdt_totalsize(fdt);
 	if (end > fdt_off_dt_struct(fdt))
 		end = fdt_off_dt_struct(fdt);
 	if (end > fdt_off_dt_strings(fdt))
 		end = fdt_off_dt_strings(fdt);

 	/*
 	 * Since the reserved area list is zero terminated, you get one fewer.
 	 */
 	if (total)
 		*total = ((end - start) / sizeof(struct fdt_reserve_entry)) - 1;

 	if (used) {
 		*used = 0;
 		while (start < end) {
 			re = (struct fdt_reserve_entry *)(fdt + start);
 			if (re->size == 0)
 				return 0;	/* zero size terminates the list */

 			*used += 1;
 			start += sizeof(struct fdt_reserve_entry);
 		}
 		/*
 		 * If we get here, there was no zero size termination.
 		 */
 		return -FDT_ERR_BADLAYOUT;
 	}
 	return 0;
 }

 /*
  * Return the nth reserve map entry.
  */
 int fdt_get_reservemap(void *fdt, int n, struct fdt_reserve_entry *re)
 {
 	int  used;
 	int  total;
 	int  err;

 	err = fdt_num_reservemap(fdt, &used, &total);
 	if (err != 0)
 		return err;

 	if (n >= total)
 		return -FDT_ERR_NOSPACE;
 	if (re) {
 		*re = *(struct fdt_reserve_entry *)
 			_fdt_offset_ptr(fdt, n * sizeof(struct fdt_reserve_entry));
 	}
 	return 0;
 }

 #endif /* CONFIG_OF_LIBFDT */
	/*
	* libfdt - Flat Device Tree manipulation
	* Copyright (C) 2006 David Gibson, IBM Corporation.
	*
	* This library is free software; you can redistribute it and/or
	* modify it under the terms of the GNU Lesser General Public License
	* as published by the Free Software Foundation; either version 2.1 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
	* Lesser General Public License for more details.
	*
	* You should have received a copy of the GNU Lesser 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
	*/
	#include "config.h"
	#if CONFIG_OF_LIBFDT

	#include "libfdt_env.h"

	#include <fdt.h>
	#include <libfdt.h>

	#include "libfdt_internal.h"

	#define CHECK_HEADER(fdt) { \
	int err; \
	if ((err = fdt_check_header(fdt)) != 0) \
	return err; \
	}

	static int offset_streq(const void *fdt, int offset,
	const char *s, int len)
	{
	const char *p = fdt_offset_ptr(fdt, offset, len+1);

	if (! p)
	/* short match */
	return 0;

	if (memcmp(p, s, len) != 0)
	return 0;

	if (p[len] != '\0')
	return 0;

	return 1;
	}

	/*
	* Checks if the property name matches.
	*/
	static int prop_name_eq(const void fdt, int offset, const char name,
	struct fdt_property *prop, int lenp)
	{
	int namestroff, len;

	prop = fdt_offset_ptr_typed(fdt, offset, prop);
	if (! *prop)
	return -FDT_ERR_BADSTRUCTURE;

	namestroff = fdt32_to_cpu((*prop)->nameoff);
	if (streq(fdt_string(fdt, namestroff), name)) {
	len = fdt32_to_cpu((*prop)->len);
	*prop = fdt_offset_ptr(fdt, offset,
	sizeof(**prop) + len);
	if (*prop) {
	if (lenp)
	*lenp = len;
	return 1;
	} else
	return -FDT_ERR_BADSTRUCTURE;
	}
	return 0;
	}

	/*
	* Return a pointer to the string at the given string offset.
	*/
	char fdt_string(const void fdt, int stroffset)
	{
	return (char *)fdt + fdt_off_dt_strings(fdt) + stroffset;
	}

	/*
	* Check if the specified node is compatible by comparing the tokens
	* in its "compatible" property with the specified string:
	*
	* nodeoffset - starting place of the node
	* compat - the string to match to one of the tokens in the
	* "compatible" list.
	*/
	int fdt_node_is_compatible(const void *fdt, int nodeoffset,
	const char *compat)
	{
	const char* cp;
	int cplen, len;

	cp = fdt_getprop(fdt, nodeoffset, "compatible", &cplen);
	if (cp == NULL)
	return 0;
	while (cplen > 0) {
	if (strncmp(cp, compat, strlen(compat)) == 0)
	return 1;
	len = strlen(cp) + 1;
	cp += len;
	cplen -= len;
	}

	return 0;
	}

	/*
	* Find a node by its device type property. On success, the offset of that
	* node is returned or an error code otherwise:
	*
	* nodeoffset - the node to start searching from or 0, the node you pass
	* will not be searched, only the next one will; typically,
	* you pass 0 to start the search and then what the previous
	* call returned.
	* type - the device type string to match against.
	*/
	int fdt_find_node_by_type(const void fdt, int nodeoffset, const char type)
	{
	int offset, nextoffset;
	struct fdt_property *prop;
	uint32_t tag;
	int len, ret;

	CHECK_HEADER(fdt);

	tag = fdt_next_tag(fdt, nodeoffset, &nextoffset, NULL);
	if (tag != FDT_BEGIN_NODE)
	return -FDT_ERR_BADOFFSET;
	if (nodeoffset)
	nodeoffset = 0; /* start searching with next node */

	while (1) {
	offset = nextoffset;
	tag = fdt_next_tag(fdt, offset, &nextoffset, NULL);

	switch (tag) {
	case FDT_BEGIN_NODE:
	nodeoffset = offset;
	break;

	case FDT_PROP:
	if (nodeoffset == 0)
	break;
	ret = prop_name_eq(fdt, offset, "device_type",
	&prop, &len);
	if (ret < 0)
	return ret;
	else if (ret > 0 &&
	strncmp(prop->data, type, len - 1) == 0)
	return nodeoffset;
	break;

	case FDT_END_NODE:
	case FDT_NOP:
	break;

	case FDT_END:
	return -FDT_ERR_NOTFOUND;

	default:
	return -FDT_ERR_BADSTRUCTURE;
	}
	}
	}

	/*
	* Find a node based on its device type and one of the tokens in its its
	* "compatible" property. On success, the offset of that node is returned
	* or an error code otherwise:
	*
	* nodeoffset - the node to start searching from or 0, the node you pass
	* will not be searched, only the next one will; typically,
	* you pass 0 to start the search and then what the previous
	* call returned.
	* type - the device type string to match against.
	* compat - the string to match to one of the tokens in the
	* "compatible" list.
	*/
	int fdt_find_compatible_node(const void *fdt, int nodeoffset,
	const char type, const char compat)
	{
	int offset;

	offset = fdt_find_node_by_type(fdt, nodeoffset, type);
	if (offset < 0 \|\| fdt_node_is_compatible(fdt, offset, compat))
	return offset;

	return -FDT_ERR_NOTFOUND;
	}

	/*
	* Return the node offset of the node specified by:
	* parentoffset - starting place (0 to start at the root)
	* name - name being searched for
	* namelen - length of the name: typically strlen(name)
	*
	* Notes:
	* If the start node has subnodes, the subnodes are _not_ searched for the
	* requested name.
	*/
	int fdt_subnode_offset_namelen(const void *fdt, int parentoffset,
	const char *name, int namelen)
	{
	int level = 0;
	uint32_t tag;
	int offset, nextoffset;

	CHECK_HEADER(fdt);

	tag = fdt_next_tag(fdt, parentoffset, &nextoffset, NULL);
	if (tag != FDT_BEGIN_NODE)
	return -FDT_ERR_BADOFFSET;

	do {
	offset = nextoffset;
	tag = fdt_next_tag(fdt, offset, &nextoffset, NULL);

	switch (tag) {
	case FDT_END:
	return -FDT_ERR_TRUNCATED;

	case FDT_BEGIN_NODE:
	level++;
	/*
	* If we are nested down levels, ignore the strings
	* until we get back to the proper level.
	*/
	if (level != 1)
	continue;

	/* Return the offset if this is "our" string. */
	if (offset_streq(fdt, offset+FDT_TAGSIZE, name, namelen))
	return offset;
	break;

	case FDT_END_NODE:
	level--;
	break;

	case FDT_PROP:
	case FDT_NOP:
	break;

	default:
	return -FDT_ERR_BADSTRUCTURE;
	}
	} while (level >= 0);

	return -FDT_ERR_NOTFOUND;
	}

	/*
	* See fdt_subnode_offset_namelen()
	*/
	int fdt_subnode_offset(const void *fdt, int parentoffset,
	const char *name)
	{
	return fdt_subnode_offset_namelen(fdt, parentoffset, name, strlen(name));
	}

	/*
	* Searches for the node corresponding to the given path and returns the
	* offset of that node.
	*/
	int fdt_find_node_by_path(const void fdt, const char path)
	{
	const char *end = path + strlen(path);
	const char *p = path;
	int offset = 0;

	CHECK_HEADER(fdt);

	/* Paths must be absolute */
	if (*path != '/')
	return -FDT_ERR_BADPATH;

	/* Handle the root path: root offset is 0 */
	if (strcmp(path, "/") == 0)
	return 0;

	while (*p) {
	const char *q;

	/* Skip path separator(s) */
	while (*p == '/')
	p++;
	if (! *p)
	return -FDT_ERR_BADPATH;

	/*
	* Find the next path separator. The characters between
	* p and q are the next segment of the the path to find.
	*/
	q = strchr(p, '/');
	if (! q)
	q = end;

	/*
	* Find the offset corresponding to the this path segment.
	*/
	offset = fdt_subnode_offset_namelen(fdt, offset, p, q-p);

	/* Oops, error, abort abort abort */
	if (offset < 0)
	return offset;

	p = q;
	}

	return offset;
	}

	/*
	* Given the offset of a node and a name of a property in that node, return
	* a pointer to the property struct.
	*/
	struct fdt_property fdt_get_property(const void fdt,
	int nodeoffset,
	const char name, int lenp)
	{
	int level = 0;
	uint32_t tag;
	struct fdt_property *prop;
	int offset, nextoffset;
	int err;

	if ((err = fdt_check_header(fdt)) != 0)
	goto fail;

	err = -FDT_ERR_BADOFFSET;
	if (nodeoffset % FDT_TAGSIZE)
	goto fail;

	tag = fdt_next_tag(fdt, nodeoffset, &nextoffset, NULL);
	if (tag != FDT_BEGIN_NODE)
	goto fail;

	do {
	offset = nextoffset;

	tag = fdt_next_tag(fdt, offset, &nextoffset, NULL);
	switch (tag) {
	case FDT_END:
	err = -FDT_ERR_TRUNCATED;
	goto fail;

	case FDT_BEGIN_NODE:
	level++;
	break;

	case FDT_END_NODE:
	level--;
	break;

	case FDT_PROP:
	/*
	* If we are nested down levels, ignore the strings
	* until we get back to the proper level.
	*/
	if (level != 0)
	continue;

	err = prop_name_eq(fdt, offset, name, &prop, lenp);
	if (err > 0)
	return prop;
	else if (err < 0)
	goto fail;
	break;

	case FDT_NOP:
	break;

	default:
	err = -FDT_ERR_BADSTRUCTURE;
	goto fail;
	}
	} while (level >= 0);

	err = -FDT_ERR_NOTFOUND;
	fail:
	if (lenp)
	*lenp = err;
	return NULL;
	}

	/*
	* Given the offset of a node and a name of a property in that node, return
	* a pointer to the property data (ONLY).
	*/
	void fdt_getprop(const void fdt, int nodeoffset,
	const char name, int lenp)
	{
	const struct fdt_property *prop;

	prop = fdt_get_property(fdt, nodeoffset, name, lenp);
	if (! prop)
	return NULL;

	return (void *)prop->data;
	}


	uint32_t fdt_next_tag(const void fdt, int offset, int nextoffset, char **namep)
	{
	const uint32_t tagp, lenp;
	uint32_t tag;
	const char *p;

	if (offset % FDT_TAGSIZE)
	return -1;

	tagp = fdt_offset_ptr(fdt, offset, FDT_TAGSIZE);
	if (! tagp)
	return FDT_END; /* premature end */
	tag = fdt32_to_cpu(*tagp);
	offset += FDT_TAGSIZE;

	switch (tag) {
	case FDT_BEGIN_NODE:
	if(namep)
	*namep = fdt_offset_ptr(fdt, offset, 1);

	/* skip name */
	do {
	p = fdt_offset_ptr(fdt, offset++, 1);
	} while (p && (*p != '\0'));
	if (! p)
	return FDT_END;
	break;
	case FDT_PROP:
	lenp = fdt_offset_ptr(fdt, offset, sizeof(*lenp));
	if (! lenp)
	return FDT_END;
	/*
	* Get the property and set the namep to the name.
	*/
	if(namep) {
	struct fdt_property *prop;

	prop = fdt_offset_ptr_typed(fdt, offset - FDT_TAGSIZE, prop);
	if (! prop)
	return -FDT_ERR_BADSTRUCTURE;
	*namep = fdt_string(fdt, fdt32_to_cpu(prop->nameoff));
	}
	/* skip name offset, length and value */
	offset += 2FDT_TAGSIZE + fdt32_to_cpu(lenp);
	break;
	}

	if (nextoffset)
	*nextoffset = ALIGN(offset, FDT_TAGSIZE);

	return tag;
	}

	/*
	* Return the number of used reserve map entries and total slots available.
	*/
	int fdt_num_reservemap(void fdt, int used, int *total)
	{
	struct fdt_reserve_entry *re;
	int start;
	int end;
	int err = fdt_check_header(fdt);

	if (err != 0)
	return err;

	start = fdt_off_mem_rsvmap(fdt);

	/*
	* Convention is that the reserve map is before the dt_struct,
	* but it does not have to be.
	*/
	end = fdt_totalsize(fdt);
	if (end > fdt_off_dt_struct(fdt))
	end = fdt_off_dt_struct(fdt);
	if (end > fdt_off_dt_strings(fdt))
	end = fdt_off_dt_strings(fdt);

	/*
	* Since the reserved area list is zero terminated, you get one fewer.
	*/
	if (total)
	*total = ((end - start) / sizeof(struct fdt_reserve_entry)) - 1;

	if (used) {
	*used = 0;
	while (start < end) {
	re = (struct fdt_reserve_entry *)(fdt + start);
	if (re->size == 0)
	return 0; /* zero size terminates the list */

	*used += 1;
	start += sizeof(struct fdt_reserve_entry);
	}
	/*
	* If we get here, there was no zero size termination.
	*/
	return -FDT_ERR_BADLAYOUT;
	}
	return 0;
	}

	/*
	* Return the nth reserve map entry.
	*/
	int fdt_get_reservemap(void fdt, int n, struct fdt_reserve_entry re)
	{
	int used;
	int total;
	int err;

	err = fdt_num_reservemap(fdt, &used, &total);
	if (err != 0)
	return err;

	if (n >= total)
	return -FDT_ERR_NOSPACE;
	if (re) {
	re = (struct fdt_reserve_entry *)
	_fdt_offset_ptr(fdt, n * sizeof(struct fdt_reserve_entry));
	}
	return 0;
	}

	#endif /* CONFIG_OF_LIBFDT */