1 /*
2 * libfdt - Flat Device Tree manipulation
3 * Copyright (C) 2006 David Gibson, IBM Corporation.
4 *
5 * libfdt is dual licensed: you can use it either under the terms of
6 * the GPL, or the BSD license, at your option.
7 *
8 * a) This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License as
10 * published by the Free Software Foundation; either version 2 of the
11 * License, or (at your option) any later version.
12 *
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public
19 * License along with this library; if not, write to the Free
20 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
21 * MA 02110-1301 USA
22 *
23 * Alternatively,
24 *
25 * b) Redistribution and use in source and binary forms, with or
26 * without modification, are permitted provided that the following
27 * conditions are met:
28 *
29 * 1. Redistributions of source code must retain the above
30 * copyright notice, this list of conditions and the following
31 * disclaimer.
32 * 2. Redistributions in binary form must reproduce the above
33 * copyright notice, this list of conditions and the following
34 * disclaimer in the documentation and/or other materials
35 * provided with the distribution.
36 *
37 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
38 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
39 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
40 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
41 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
42 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
43 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
44 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
45 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
46 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
47 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
48 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
49 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
50 */
51 #include "libfdt_env.h"
52
53 #include <fdt.h>
54 #include <libfdt.h>
55
56 #include "libfdt_internal.h"
57
fdt_check_header(const void * fdt)58 int fdt_check_header(const void *fdt)
59 {
60 if (fdt_magic(fdt) == FDT_MAGIC) {
61 /* Complete tree */
62 if (fdt_version(fdt) < FDT_FIRST_SUPPORTED_VERSION)
63 return -FDT_ERR_BADVERSION;
64 if (fdt_last_comp_version(fdt) > FDT_LAST_SUPPORTED_VERSION)
65 return -FDT_ERR_BADVERSION;
66 } else if (fdt_magic(fdt) == FDT_SW_MAGIC) {
67 /* Unfinished sequential-write blob */
68 if (fdt_size_dt_struct(fdt) == 0)
69 return -FDT_ERR_BADSTATE;
70 } else {
71 return -FDT_ERR_BADMAGIC;
72 }
73
74 return 0;
75 }
76
fdt_offset_ptr(const void * fdt,int offset,unsigned int len)77 const void *fdt_offset_ptr(const void *fdt, int offset, unsigned int len)
78 {
79 unsigned absoffset = offset + fdt_off_dt_struct(fdt);
80
81 if ((absoffset < offset)
82 || ((absoffset + len) < absoffset)
83 || (absoffset + len) > fdt_totalsize(fdt))
84 return NULL;
85
86 if (fdt_version(fdt) >= 0x11)
87 if (((offset + len) < offset)
88 || ((offset + len) > fdt_size_dt_struct(fdt)))
89 return NULL;
90
91 return fdt_offset_ptr_(fdt, offset);
92 }
93
fdt_next_tag(const void * fdt,int startoffset,int * nextoffset)94 uint32_t fdt_next_tag(const void *fdt, int startoffset, int *nextoffset)
95 {
96 const fdt32_t *tagp, *lenp;
97 uint32_t tag;
98 int offset = startoffset;
99 const char *p;
100
101 *nextoffset = -FDT_ERR_TRUNCATED;
102 tagp = fdt_offset_ptr(fdt, offset, FDT_TAGSIZE);
103 if (!tagp)
104 return FDT_END; /* premature end */
105 tag = fdt32_to_cpu(*tagp);
106 offset += FDT_TAGSIZE;
107
108 *nextoffset = -FDT_ERR_BADSTRUCTURE;
109 switch (tag) {
110 case FDT_BEGIN_NODE:
111 /* skip name */
112 do {
113 p = fdt_offset_ptr(fdt, offset++, 1);
114 } while (p && (*p != '\0'));
115 if (!p)
116 return FDT_END; /* premature end */
117 break;
118
119 case FDT_PROP:
120 lenp = fdt_offset_ptr(fdt, offset, sizeof(*lenp));
121 if (!lenp)
122 return FDT_END; /* premature end */
123 /* skip-name offset, length and value */
124 offset += sizeof(struct fdt_property) - FDT_TAGSIZE
125 + fdt32_to_cpu(*lenp);
126 if (fdt_version(fdt) < 0x10 && fdt32_to_cpu(*lenp) >= 8 &&
127 ((offset - fdt32_to_cpu(*lenp)) % 8) != 0)
128 offset += 4;
129 break;
130
131 case FDT_END:
132 case FDT_END_NODE:
133 case FDT_NOP:
134 break;
135
136 default:
137 return FDT_END;
138 }
139
140 if (!fdt_offset_ptr(fdt, startoffset, offset - startoffset))
141 return FDT_END; /* premature end */
142
143 *nextoffset = FDT_TAGALIGN(offset);
144 return tag;
145 }
146
fdt_check_node_offset_(const void * fdt,int offset)147 int fdt_check_node_offset_(const void *fdt, int offset)
148 {
149 if ((offset < 0) || (offset % FDT_TAGSIZE)
150 || (fdt_next_tag(fdt, offset, &offset) != FDT_BEGIN_NODE))
151 return -FDT_ERR_BADOFFSET;
152
153 return offset;
154 }
155
fdt_check_prop_offset_(const void * fdt,int offset)156 int fdt_check_prop_offset_(const void *fdt, int offset)
157 {
158 if ((offset < 0) || (offset % FDT_TAGSIZE)
159 || (fdt_next_tag(fdt, offset, &offset) != FDT_PROP))
160 return -FDT_ERR_BADOFFSET;
161
162 return offset;
163 }
164
fdt_next_node(const void * fdt,int offset,int * depth)165 int fdt_next_node(const void *fdt, int offset, int *depth)
166 {
167 int nextoffset = 0;
168 uint32_t tag;
169
170 if (offset >= 0)
171 if ((nextoffset = fdt_check_node_offset_(fdt, offset)) < 0)
172 return nextoffset;
173
174 do {
175 offset = nextoffset;
176 tag = fdt_next_tag(fdt, offset, &nextoffset);
177
178 switch (tag) {
179 case FDT_PROP:
180 case FDT_NOP:
181 break;
182
183 case FDT_BEGIN_NODE:
184 if (depth)
185 (*depth)++;
186 break;
187
188 case FDT_END_NODE:
189 if (depth && ((--(*depth)) < 0))
190 return nextoffset;
191 break;
192
193 case FDT_END:
194 if ((nextoffset >= 0)
195 || ((nextoffset == -FDT_ERR_TRUNCATED) && !depth))
196 return -FDT_ERR_NOTFOUND;
197 else
198 return nextoffset;
199 }
200 } while (tag != FDT_BEGIN_NODE);
201
202 return offset;
203 }
204
fdt_first_subnode(const void * fdt,int offset)205 int fdt_first_subnode(const void *fdt, int offset)
206 {
207 int depth = 0;
208
209 offset = fdt_next_node(fdt, offset, &depth);
210 if (offset < 0 || depth != 1)
211 return -FDT_ERR_NOTFOUND;
212
213 return offset;
214 }
215
fdt_next_subnode(const void * fdt,int offset)216 int fdt_next_subnode(const void *fdt, int offset)
217 {
218 int depth = 1;
219
220 /*
221 * With respect to the parent, the depth of the next subnode will be
222 * the same as the last.
223 */
224 do {
225 offset = fdt_next_node(fdt, offset, &depth);
226 if (offset < 0 || depth < 1)
227 return -FDT_ERR_NOTFOUND;
228 } while (depth > 1);
229
230 return offset;
231 }
232
fdt_find_string_(const char * strtab,int tabsize,const char * s)233 const char *fdt_find_string_(const char *strtab, int tabsize, const char *s)
234 {
235 int len = strlen(s) + 1;
236 const char *last = strtab + tabsize - len;
237 const char *p;
238
239 for (p = strtab; p <= last; p++)
240 if (memcmp(p, s, len) == 0)
241 return p;
242 return NULL;
243 }
244
fdt_move(const void * fdt,void * buf,int bufsize)245 int fdt_move(const void *fdt, void *buf, int bufsize)
246 {
247 FDT_CHECK_HEADER(fdt);
248
249 if (fdt_totalsize(fdt) > bufsize)
250 return -FDT_ERR_NOSPACE;
251
252 memmove(buf, fdt, fdt_totalsize(fdt));
253 return 0;
254 }
255