libfdt/fdt.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_check_header(const void *fdt)
{
	if (fdt_magic(fdt) == FDT_MAGIC) {
		/* Complete tree */
		if (fdt_version(fdt) < FDT_FIRST_SUPPORTED_VERSION)
			return -FDT_ERR_BADVERSION;
		if (fdt_last_comp_version(fdt) > FDT_LAST_SUPPORTED_VERSION)
			return -FDT_ERR_BADVERSION;
	} else if (fdt_magic(fdt) == SW_MAGIC) {
		/* Unfinished sequential-write blob */
		if (fdt_size_dt_struct(fdt) == 0)
			return -FDT_ERR_BADSTATE;
	} else {
		return -FDT_ERR_BADMAGIC;
	}

	return 0;
}

void *fdt_offset_ptr(const void *fdt, int offset, int len)
{
	void *p;

	if (fdt_version(fdt) >= 0x11)
		if (((offset + len) < offset)
		    || ((offset + len) > fdt_size_dt_struct(fdt)))
			return NULL;

	p = _fdt_offset_ptr(fdt, offset);

	if (p + len < p)
		return NULL;
	return p;
}

const char *_fdt_find_string(const char *strtab, int tabsize, const char *s)
{
	int len = strlen(s) + 1;
	const char *last = strtab + tabsize - len;
	const char *p;

	for (p = strtab; p <= last; p++)
		if (memeq(p, s, len))
			return p;
	return NULL;
}

int fdt_move(const void *fdt, void *buf, int bufsize)
{
	int err = _fdt_check_header(fdt);

	if (err)
		return err;

	if (fdt_totalsize(fdt) > bufsize)
		return -FDT_ERR_NOSPACE;

	memmove(buf, fdt, fdt_totalsize(fdt));
	return 0;
}