summaryrefslogtreecommitdiffstats
path: root/kernel/scripts/dtc/libfdt/fdt.c
blob: 2ce6a44179deca2feb1ec5b484878f1965d257f6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
/*
 * libfdt - Flat Device Tree manipulation
 * Copyright (C) 2006 David Gibson, IBM Corporation.
 *
 * libfdt is dual licensed: you can use it either under the terms of
 * the GPL, or the BSD license, at your option.
 *
 *  a) This library is free software; you can redistribute it and/or
 *     modify it under the terms of the GNU General Public License as
 *     published by the Free Software Foundation; either version 2 of the
 *     License, or (at your option) any later version.
 *
 *     This library is distributed in the hope that it will be useful,
 *     but WITHOUT ANY WARRANTY; without even the implied warranty of
 *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *     GNU General Public License for more details.
 *
 *     You should have received a copy of the GNU General Public
 *     License along with this library; if not, write to the Free
 *     Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
 *     MA 02110-1301 USA
 *
 * Alternatively,
 *
 *  b) Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *     1. Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *     2. Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer in the documentation and/or other materials
 *        provided with the distribution.
 *
 *     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
 *     CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
 *     INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 *     MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 *     DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 *     CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 *     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 *     NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 *     LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 *     HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 *     CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 *     OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
 *     EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
#include "libfdt_env.h"

#include <fdt.h>
#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) == 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;
}

const void *fdt_offset_ptr(const void *fdt, int offset, unsigned int len)
{
	const char *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;
}

uint32_t fdt_next_tag(const void *fdt, int startoffset, int *nextoffset)
{
	const fdt32_t *tagp, *lenp;
	uint32_t tag;
	int offset = startoffset;
	const char *p;

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

	*nextoffset = -FDT_ERR_BADSTRUCTURE;
	switch (tag) {
	case FDT_BEGIN_NODE:
		/* skip name */
		do {
			p = fdt_offset_ptr(fdt, offset++, 1);
		} while (p && (*p != '\0'));
		if (!p)
			return FDT_END; /* premature end */
		break;

	case FDT_PROP:
		lenp = fdt_offset_ptr(fdt, offset, sizeof(*lenp));
		if (!lenp)
			return FDT_END; /* premature end */
		/* skip-name offset, length and value */
		offset += sizeof(struct fdt_property) - FDT_TAGSIZE
			+ fdt32_to_cpu(*lenp);
		break;

	case FDT_END:
	case FDT_END_NODE:
	case FDT_NOP:
		break;

	default:
		return FDT_END;
	}

	if (!fdt_offset_ptr(fdt, startoffset, offset - startoffset))
		return FDT_END; /* premature end */

	*nextoffset = FDT_TAGALIGN(offset);
	return tag;
}

int _fdt_check_node_offset(const void *fdt, int offset)
{
	if ((offset < 0) || (offset % FDT_TAGSIZE)
	    || (fdt_next_tag(fdt, offset, &offset) != FDT_BEGIN_NODE))
		return -FDT_ERR_BADOFFSET;

	return offset;
}

int _fdt_check_prop_offset(const void *fdt, int offset)
{
	if ((offset < 0) || (offset % FDT_TAGSIZE)
	    || (fdt_next_tag(fdt, offset, &offset) != FDT_PROP))
		return -FDT_ERR_BADOFFSET;

	return offset;
}

int fdt_next_node(const void *fdt, int offset, int *depth)
{
	int nextoffset = 0;
	uint32_t tag;

	if (offset >= 0)
		if ((nextoffset = _fdt_check_node_offset(fdt, offset)) < 0)
			return nextoffset;

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

		switch (tag) {
		case FDT_PROP:
		case FDT_NOP:
			break;

		case FDT_BEGIN_NODE:
			if (depth)
				(*depth)++;
			break;

		case FDT_END_NODE:
			if (depth && ((--(*depth)) < 0))
				return nextoffset;
			break;

		case FDT_END:
			if ((nextoffset >= 0)
			    || ((nextoffset == -FDT_ERR_TRUNCATED) && !depth))
				return -FDT_ERR_NOTFOUND;
			else
				return nextoffset;
		}
	} while (tag != FDT_BEGIN_NODE);

	return offset;
}

int fdt_first_subnode(const void *fdt, int offset)
{
	int depth = 0;

	offset = fdt_next_node(fdt, offset, &depth);
	if (offset < 0 || depth != 1)
		return -FDT_ERR_NOTFOUND;

	return offset;
}

int fdt_next_subnode(const void *fdt, int offset)
{
	int depth = 1;

	/*
	 * With respect to the parent, the depth of the next subnode will be
	 * the same as the last.
	 */
	do {
		offset = fdt_next_node(fdt, offset, &depth);
		if (offset < 0 || depth < 1)
			return -FDT_ERR_NOTFOUND;
	} while (depth > 1);

	return offset;
}

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 (memcmp(p, s, len) == 0)
			return p;
	return NULL;
}

int fdt_move(const void *fdt, void *buf, int bufsize)
{
	FDT_CHECK_HEADER(fdt);

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

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