libfdt: Import libfdt source (2 of 2)

This adds the applicable libfdt source files (unmodified) and a README
to explain where the source came from.

libfdt/fdt_ro.c

+/*
+ * 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 "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;
+}
+
+char *fdt_string(const void *fdt, int stroffset)
+{
+	return (char *)fdt + fdt_off_dt_strings(fdt) + stroffset;
+}
+
+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);
+	if (tag != FDT_BEGIN_NODE)
+		return -FDT_ERR_BADOFFSET;
+
+	do {
+		offset = nextoffset;
+		tag = _fdt_next_tag(fdt, offset, &nextoffset);
+
+		switch (tag) {
+		case FDT_END:
+			return -FDT_ERR_TRUNCATED;
+
+		case FDT_BEGIN_NODE:
+			level++;
+			if (level != 1)
+				continue;
+			if (offset_streq(fdt, offset+FDT_TAGSIZE, name, namelen))
+				/* Found it! */
+				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;
+}
+
+int fdt_subnode_offset(const void *fdt, int parentoffset,
+		       const char *name)
+{
+	return fdt_subnode_offset_namelen(fdt, parentoffset, name, strlen(name));
+}
+
+int fdt_path_offset(const void *fdt, const char *path)
+{
+	const char *end = path + strlen(path);
+	const char *p = path;
+	int offset = 0;
+
+	CHECK_HEADER(fdt);
+
+	if (*path != '/')
+		return -FDT_ERR_BADPATH;
+
+	while (*p) {
+		const char *q;
+
+		while (*p == '/')
+			p++;
+		if (! *p)
+			return -FDT_ERR_BADPATH;
+		q = strchr(p, '/');
+		if (! q)
+			q = end;
+
+		offset = fdt_subnode_offset_namelen(fdt, offset, p, q-p);
+		if (offset < 0)
+			return offset;
+
+		p = q;
+	}
+
+	return offset;	
+}
+
+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 namestroff;
+	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);
+	if (tag != FDT_BEGIN_NODE)
+		goto fail;
+
+	do {
+		offset = nextoffset;
+
+		tag = _fdt_next_tag(fdt, offset, &nextoffset);
+		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 (level != 0)
+				continue;
+
+			err = -FDT_ERR_BADSTRUCTURE;
+			prop = fdt_offset_ptr_typed(fdt, offset, prop);
+			if (! prop)
+				goto fail;
+			namestroff = fdt32_to_cpu(prop->nameoff);
+			if (streq(fdt_string(fdt, namestroff), name)) {
+				/* Found it! */
+				int len = fdt32_to_cpu(prop->len);
+				prop = fdt_offset_ptr(fdt, offset,
+						      sizeof(*prop)+len);
+				if (! prop)
+					goto fail;
+
+				if (lenp)
+					*lenp = len;
+				
+				return prop;
+			}
+			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;
+}
+
+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 prop->data;
+}

libfdt/fdt_rw.c

+/*
+ * 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 "libfdt_env.h"
+
+#include <fdt.h>
+#include <libfdt.h>
+
+#include "libfdt_internal.h"
+
+static int rw_check_header(void *fdt)
+{
+	int err;
+
+	if ((err = _fdt_check_header(fdt)))
+		return err;
+	if (fdt_version(fdt) < 0x11)
+		return -FDT_ERR_BADVERSION;
+	if (fdt_off_mem_rsvmap(fdt) < ALIGN(sizeof(struct fdt_header), 8))
+		return -FDT_ERR_BADLAYOUT;
+	if (fdt_off_dt_struct(fdt) <
+	    (fdt_off_mem_rsvmap(fdt) + sizeof(struct fdt_reserve_entry)))
+		return -FDT_ERR_BADLAYOUT;
+	if (fdt_off_dt_strings(fdt) <
+	    (fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt)))
+		return -FDT_ERR_BADLAYOUT;
+	if (fdt_totalsize(fdt) <
+	    (fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt)))
+		return -FDT_ERR_BADLAYOUT;
+	return 0;
+}
+
+#define RW_CHECK_HEADER(fdt) \
+	{ \
+		int err; \
+		if ((err = rw_check_header(fdt)) != 0) \
+			return err; \
+	}
+
+static inline int _blob_data_size(void *fdt)
+{
+	return fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt);
+}
+
+static int _blob_splice(void *fdt, void *p, int oldlen, int newlen)
+{
+	void *end = fdt + _blob_data_size(fdt);
+
+	if (((p + oldlen) < p) || ((p + oldlen) > end))
+		return -FDT_ERR_BADOFFSET;
+	if ((end - oldlen + newlen) > (fdt + fdt_totalsize(fdt)))
+		return -FDT_ERR_NOSPACE;
+	memmove(p + newlen, p + oldlen, end - p - oldlen);
+	return 0;
+}
+
+static int _blob_splice_struct(void *fdt, void *p,
+			       int oldlen, int newlen)
+{
+	int delta = newlen - oldlen;
+	int err;
+
+	if ((err = _blob_splice(fdt, p, oldlen, newlen)))
+		return err;
+
+	fdt_set_header(fdt, size_dt_struct, fdt_size_dt_struct(fdt) + delta);
+	fdt_set_header(fdt, off_dt_strings, fdt_off_dt_strings(fdt) + delta);
+	return 0;
+}
+
+static int _blob_splice_string(void *fdt, int newlen)
+{
+	void *p = fdt + fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt);
+	int err;
+
+	if ((err = _blob_splice(fdt, p, 0, newlen)))
+		return err;
+
+	fdt_set_header(fdt, size_dt_strings, fdt_size_dt_strings(fdt) + newlen);
+	return 0;
+}
+
+static int _find_add_string(void *fdt, const char *s)
+{
+	char *strtab = (char *)fdt + fdt_off_dt_strings(fdt);
+	const char *p;
+	char *new;
+	int len = strlen(s) + 1;
+	int err;
+
+	p = _fdt_find_string(strtab, fdt_size_dt_strings(fdt), s);
+	if (p)
+		/* found it */
+		return (p - strtab);
+
+	new = strtab + fdt_size_dt_strings(fdt);
+	err = _blob_splice_string(fdt, len);
+	if (err)
+		return err;
+
+	memcpy(new, s, len);
+	return (new - strtab);
+}
+
+static int _resize_property(void *fdt, int nodeoffset, const char *name, int len,
+			    struct fdt_property **prop)
+{
+	int oldlen;
+	int err;
+
+	*prop = fdt_get_property(fdt, nodeoffset, name, &oldlen);
+	if (! (*prop))
+		return oldlen;
+
+	if ((err = _blob_splice_struct(fdt, (*prop)->data,
+				       ALIGN(oldlen, FDT_TAGSIZE),
+				       ALIGN(len, FDT_TAGSIZE))))
+		return err;
+
+	(*prop)->len = cpu_to_fdt32(len);
+	return 0;
+}
+
+static int _add_property(void *fdt, int nodeoffset, const char *name, int len,
+			 struct fdt_property **prop)
+{
+	uint32_t tag;
+	int proplen;
+	int nextoffset;
+	int namestroff;
+	int err;
+
+	tag = _fdt_next_tag(fdt, nodeoffset, &nextoffset);
+	if (tag != FDT_BEGIN_NODE)
+		return -FDT_ERR_BADOFFSET;
+
+	namestroff = _find_add_string(fdt, name);
+	if (namestroff < 0)
+		return namestroff;
+
+	*prop = _fdt_offset_ptr(fdt, nextoffset);
+	proplen = sizeof(**prop) + ALIGN(len, FDT_TAGSIZE);
+
+	err = _blob_splice_struct(fdt, *prop, 0, proplen);
+	if (err)
+		return err;
+
+	(*prop)->tag = cpu_to_fdt32(FDT_PROP);
+	(*prop)->nameoff = cpu_to_fdt32(namestroff);
+	(*prop)->len = cpu_to_fdt32(len);
+	return 0;
+}
+
+int fdt_setprop(void *fdt, int nodeoffset, const char *name,
+		const void *val, int len)
+{
+	struct fdt_property *prop;
+	int err;
+
+	if ((err = rw_check_header(fdt)))
+		return err;
+
+	err = _resize_property(fdt, nodeoffset, name, len, &prop);
+	if (err == -FDT_ERR_NOTFOUND)
+		err = _add_property(fdt, nodeoffset, name, len, &prop);
+	if (err)
+		return err;
+
+	memcpy(prop->data, val, len);
+	return 0;
+}
+
+int fdt_delprop(void *fdt, int nodeoffset, const char *name)
+{
+	struct fdt_property *prop;
+	int len, proplen;
+
+	RW_CHECK_HEADER(fdt);
+
+	prop = fdt_get_property(fdt, nodeoffset, name, &len);
+	if (! prop)
+		return len;
+
+	proplen = sizeof(*prop) + ALIGN(len, FDT_TAGSIZE);
+	return _blob_splice_struct(fdt, prop, proplen, 0);
+}
+
+int fdt_add_subnode_namelen(void *fdt, int parentoffset,
+			    const char *name, int namelen)
+{
+	struct fdt_node_header *nh;
+	int offset, nextoffset;
+	int nodelen;
+	int err;
+	uint32_t tag;
+	uint32_t *endtag;
+
+	RW_CHECK_HEADER(fdt);
+
+	offset = fdt_subnode_offset_namelen(fdt, parentoffset, name, namelen);
+	if (offset >= 0)
+		return -FDT_ERR_EXISTS;
+	else if (offset != -FDT_ERR_NOTFOUND)
+		return offset;
+
+	/* Try to place the new node after the parent's properties */
+	_fdt_next_tag(fdt, parentoffset, &nextoffset); /* skip the BEGIN_NODE */
+	do {
+		offset = nextoffset;
+		tag = _fdt_next_tag(fdt, offset, &nextoffset);
+	} while (tag == FDT_PROP);
+
+	nh = _fdt_offset_ptr(fdt, offset);
+	nodelen = sizeof(*nh) + ALIGN(namelen+1, FDT_TAGSIZE) + FDT_TAGSIZE;
+
+	err = _blob_splice_struct(fdt, nh, 0, nodelen);
+	if (err)
+		return err;
+
+	nh->tag = cpu_to_fdt32(FDT_BEGIN_NODE);
+	memset(nh->name, 0, ALIGN(namelen+1, FDT_TAGSIZE));
+	memcpy(nh->name, name, namelen);
+	endtag = (uint32_t *)((void *)nh + nodelen - FDT_TAGSIZE);
+	*endtag = cpu_to_fdt32(FDT_END_NODE);
+
+	return offset;
+}
+
+int fdt_add_subnode(void *fdt, int parentoffset, const char *name)
+{
+	return fdt_add_subnode_namelen(fdt, parentoffset, name, strlen(name));
+}
+
+int fdt_del_node(void *fdt, int nodeoffset)
+{
+	int endoffset;
+
+	endoffset = _fdt_node_end_offset(fdt, nodeoffset);
+	if (endoffset < 0)
+		return endoffset;
+
+	return _blob_splice_struct(fdt, _fdt_offset_ptr(fdt, nodeoffset),
+				   endoffset - nodeoffset, 0);
+}
+
+int fdt_open_into(void *fdt, void *buf, int bufsize)
+{
+	int err;
+
+	err = fdt_move(fdt, buf, bufsize);
+	if (err)
+		return err;
+
+	fdt = buf;
+
+	fdt_set_header(fdt, totalsize, bufsize);
+
+	/* FIXME: re-order if necessary */
+
+	err = rw_check_header(fdt);
+	if (err)
+		return err;
+
+	return 0;
+}
+
+int fdt_pack(void *fdt)
+{
+	int err;
+
+	err = rw_check_header(fdt);
+	if (err)
+		return err;
+
+	/* FIXME: pack components */
+	fdt_set_header(fdt, totalsize, _blob_data_size(fdt));
+	return 0;
+}

libfdt/fdt_sw.c

+/*
+ * 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 "libfdt_env.h"
+
+#include <fdt.h>
+#include <libfdt.h>
+
+#include "libfdt_internal.h"
+
+static int check_header_sw(void *fdt)
+{
+	if (fdt_magic(fdt) != SW_MAGIC)
+		return -FDT_ERR_BADMAGIC;
+	return 0;
+}
+
+static void *grab_space(void *fdt, int len)
+{
+	int offset = fdt_size_dt_struct(fdt);
+	int spaceleft;
+
+	spaceleft = fdt_totalsize(fdt) - fdt_off_dt_struct(fdt)
+		- fdt_size_dt_strings(fdt);
+
+	if ((offset + len < offset) || (offset + len > spaceleft))
+		return NULL;
+
+	fdt_set_header(fdt, size_dt_struct, offset + len);
+	return fdt_offset_ptr(fdt, offset, len);
+}
+
+int fdt_create(void *buf, int bufsize)
+{
+	void *fdt = buf;
+
+	if (bufsize < sizeof(struct fdt_header))
+		return -FDT_ERR_NOSPACE;
+
+	memset(buf, 0, bufsize);
+
+	fdt_set_header(fdt, magic, SW_MAGIC);
+	fdt_set_header(fdt, version, FDT_LAST_SUPPORTED_VERSION);
+	fdt_set_header(fdt, last_comp_version, FDT_FIRST_SUPPORTED_VERSION);
+	fdt_set_header(fdt, totalsize, bufsize);
+
+	fdt_set_header(fdt, off_mem_rsvmap, ALIGN(sizeof(struct fdt_header),
+					      sizeof(struct fdt_reserve_entry)));
+	fdt_set_header(fdt, off_dt_struct, fdt_off_mem_rsvmap(fdt));
+	fdt_set_header(fdt, off_dt_strings, bufsize);
+
+	return 0;
+}
+
+int fdt_add_reservemap_entry(void *fdt, uint64_t addr, uint64_t size)
+{
+	struct fdt_reserve_entry *re;
+	int err = check_header_sw(fdt);
+	int offset;
+
+	if (err)
+		return err;
+	if (fdt_size_dt_struct(fdt))
+		return -FDT_ERR_BADSTATE;
+
+	offset = fdt_off_dt_struct(fdt);
+	if ((offset + sizeof(*re)) > fdt_totalsize(fdt))
+		return -FDT_ERR_NOSPACE;
+
+	re = (struct fdt_reserve_entry *)((void *)fdt + offset);
+	re->address = cpu_to_fdt64(addr);
+	re->size = cpu_to_fdt64(size);
+
+	fdt_set_header(fdt, off_dt_struct, offset + sizeof(*re));
+
+	return 0;
+}
+
+int fdt_finish_reservemap(void *fdt)
+{
+	return fdt_add_reservemap_entry(fdt, 0, 0);
+}
+
+int fdt_begin_node(void *fdt, const char *name)
+{
+	struct fdt_node_header *nh;
+	int err = check_header_sw(fdt);
+	int namelen = strlen(name) + 1;
+
+	if (err)
+		return err;
+
+	nh = grab_space(fdt, sizeof(*nh) + ALIGN(namelen, FDT_TAGSIZE));
+	if (! nh)
+		return -FDT_ERR_NOSPACE;
+
+	nh->tag = cpu_to_fdt32(FDT_BEGIN_NODE);
+	memcpy(nh->name, name, namelen);
+	return 0;
+}
+
+int fdt_end_node(void *fdt)
+{
+	uint32_t *en;
+	int err = check_header_sw(fdt);
+
+	if (err)
+		return err;
+
+	en = grab_space(fdt, FDT_TAGSIZE);
+	if (! en)
+		return -FDT_ERR_NOSPACE;
+
+	*en = cpu_to_fdt32(FDT_END_NODE);
+	return 0;
+}
+
+static int find_add_string(void *fdt, const char *s)
+{
+	char *strtab = (char *)fdt + fdt_totalsize(fdt);
+	const char *p;
+	int strtabsize = fdt_size_dt_strings(fdt);
+	int len = strlen(s) + 1;
+	int struct_top, offset;
+
+	p = _fdt_find_string(strtab - strtabsize, strtabsize, s);
+	if (p)
+		return p - strtab;
+
+	/* Add it */
+	offset = -strtabsize - len;
+	struct_top = fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt);
+	if (fdt_totalsize(fdt) + offset < struct_top)
+		return 0; /* no more room :( */
+
+	memcpy(strtab + offset, s, len);
+	fdt_set_header(fdt, size_dt_strings, strtabsize + len);
+	return offset;
+}
+
+int fdt_property(void *fdt, const char *name, const void *val, int len)
+{
+	struct fdt_property *prop;
+	int err = check_header_sw(fdt);
+	int nameoff;
+
+	if (err)
+		return err;
+
+	nameoff = find_add_string(fdt, name);
+	if (nameoff == 0)
+		return -FDT_ERR_NOSPACE;
+
+	prop = grab_space(fdt, sizeof(*prop) + ALIGN(len, FDT_TAGSIZE));
+	if (! prop)
+		return -FDT_ERR_NOSPACE;
+
+	prop->tag = cpu_to_fdt32(FDT_PROP);
+	prop->nameoff = cpu_to_fdt32(nameoff);
+	prop->len = cpu_to_fdt32(len);
+	memcpy(prop->data, val, len);
+	return 0;
+}
+
+int fdt_finish(void *fdt)
+{
+	int err = check_header_sw(fdt);
+	char *p = (char *)fdt;
+	uint32_t *end;
+	int oldstroffset, newstroffset;
+	uint32_t tag;
+	int offset, nextoffset;
+
+	if (err)
+		return err;
+
+	/* Add terminator */
+	end = grab_space(fdt, sizeof(*end));
+	if (! end)
+		return -FDT_ERR_NOSPACE;
+	*end = cpu_to_fdt32(FDT_END);
+
+	/* Relocate the string table */
+	oldstroffset = fdt_totalsize(fdt) - fdt_size_dt_strings(fdt);
+	newstroffset = fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt);
+	memmove(p + newstroffset, p + oldstroffset, fdt_size_dt_strings(fdt));
+	fdt_set_header(fdt, off_dt_strings, newstroffset);
+
+	/* Walk the structure, correcting string offsets */
+	offset = 0;
+	while ((tag = _fdt_next_tag(fdt, offset, &nextoffset)) != FDT_END) {
+		if (tag == FDT_PROP) {
+			struct fdt_property *prop = fdt_offset_ptr(fdt, offset,
+								   sizeof(*prop));
+			int nameoff;
+
+			if (! prop)
+				return -FDT_ERR_BADSTRUCTURE;
+
+			nameoff = fdt32_to_cpu(prop->nameoff);
+			nameoff += fdt_size_dt_strings(fdt);
+			prop->nameoff = cpu_to_fdt32(nameoff);
+		}
+		offset = nextoffset;
+	}
+
+	/* Finally, adjust the header */
+	fdt_set_header(fdt, totalsize, newstroffset + fdt_size_dt_strings(fdt));
+	fdt_set_header(fdt, magic, FDT_MAGIC);
+	return 0;
+}

libfdt/fdt_wip.c

+/*
+ * 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 "libfdt_env.h"
+
+#include <fdt.h>
+#include <libfdt.h>
+
+#include "libfdt_internal.h"
+
+int fdt_setprop_inplace(void *fdt, int nodeoffset, const char *name,
+			const void *val, int len)
+{
+	void *propval;
+	int proplen;
+
+	propval = fdt_getprop(fdt, nodeoffset, name, &proplen);
+	if (! propval)
+		return proplen;
+
+	if (proplen != len)
+		return -FDT_ERR_NOSPACE;
+
+	memcpy(propval, val, len);
+	return 0;
+}
+
+static void nop_region(void *start, int len)
+{
+	uint32_t *p;
+
+	for (p = start; (void *)p < (start + len); p++)
+		*p = cpu_to_fdt32(FDT_NOP);
+}
+
+int fdt_nop_property(void *fdt, int nodeoffset, const char *name)
+{
+	struct fdt_property *prop;
+	int len;
+
+	prop = fdt_get_property(fdt, nodeoffset, name, &len);
+	if (! prop)
+		return len;
+
+	nop_region(prop, len + sizeof(*prop));
+
+	return 0;
+}
+
+int _fdt_node_end_offset(void *fdt, int nodeoffset)
+{
+	int level = 0;
+	uint32_t tag;
+	int offset, nextoffset;
+
+	tag = _fdt_next_tag(fdt, nodeoffset, &nextoffset);
+	if (tag != FDT_BEGIN_NODE)
+		return -FDT_ERR_BADOFFSET;
+	do {
+		offset = nextoffset;
+		tag = _fdt_next_tag(fdt, offset, &nextoffset);
+
+		switch (tag) {
+		case FDT_END:
+			return offset;
+
+		case FDT_BEGIN_NODE:
+			level++;
+			break;
+
+		case FDT_END_NODE:
+			level--;
+			break;
+
+		case FDT_PROP:
+		case FDT_NOP:
+			break;
+
+		default:
+			return -FDT_ERR_BADSTRUCTURE;
+		}
+	} while (level >= 0);
+
+	return nextoffset;
+}
+
+int fdt_nop_node(void *fdt, int nodeoffset)
+{
+	int endoffset;
+
+	endoffset = _fdt_node_end_offset(fdt, nodeoffset);
+	if (endoffset < 0)
+		return endoffset;
+
+	nop_region(fdt_offset_ptr(fdt, nodeoffset, 0), endoffset - nodeoffset);
+	return 0;
+}