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,int len)77 const void *fdt_offset_ptr(const void *fdt, int offset, int len)
78 {
79 const char *p;
80
81 if (fdt_version(fdt) >= 0x11)
82 if (((offset + len) < offset)
83 || ((offset + len) > fdt_size_dt_struct(fdt)))
84 return NULL;
85
86 p = _fdt_offset_ptr(fdt, offset);
87
88 if (p + len < p)
89 return NULL;
90 return p;
91 }
92
fdt_next_tag(const void * fdt,int offset,int * nextoffset)93 uint32_t fdt_next_tag(const void *fdt, int offset, int *nextoffset)
94 {
95 const uint32_t *tagp, *lenp;
96 uint32_t tag;
97 const char *p;
98
99 if (offset % FDT_TAGSIZE)
100 return -1;
101
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 switch (tag) {
109 case FDT_BEGIN_NODE:
110 /* skip name */
111 do {
112 p = fdt_offset_ptr(fdt, offset++, 1);
113 } while (p && (*p != '\0'));
114 if (! p)
115 return FDT_END;
116 break;
117 case FDT_PROP:
118 lenp = fdt_offset_ptr(fdt, offset, sizeof(*lenp));
119 if (! lenp)
120 return FDT_END;
121 /* skip name offset, length and value */
122 offset += 2*FDT_TAGSIZE + fdt32_to_cpu(*lenp);
123 break;
124 }
125
126 if (nextoffset)
127 *nextoffset = FDT_TAGALIGN(offset);
128
129 return tag;
130 }
131
_fdt_check_node_offset(const void * fdt,int offset)132 int _fdt_check_node_offset(const void *fdt, int offset)
133 {
134 if ((offset < 0) || (offset % FDT_TAGSIZE)
135 || (fdt_next_tag(fdt, offset, &offset) != FDT_BEGIN_NODE))
136 return -FDT_ERR_BADOFFSET;
137
138 return offset;
139 }
140
fdt_next_node(const void * fdt,int offset,int * depth)141 int fdt_next_node(const void *fdt, int offset, int *depth)
142 {
143 int nextoffset = 0;
144 uint32_t tag;
145
146 if (offset >= 0)
147 if ((nextoffset = _fdt_check_node_offset(fdt, offset)) < 0)
148 return nextoffset;
149
150 do {
151 offset = nextoffset;
152 tag = fdt_next_tag(fdt, offset, &nextoffset);
153
154 switch (tag) {
155 case FDT_PROP:
156 case FDT_NOP:
157 break;
158
159 case FDT_BEGIN_NODE:
160 if (depth)
161 (*depth)++;
162 break;
163
164 case FDT_END_NODE:
165 if (depth)
166 (*depth)--;
167 break;
168
169 case FDT_END:
170 return -FDT_ERR_NOTFOUND;
171
172 default:
173 return -FDT_ERR_BADSTRUCTURE;
174 }
175 } while (tag != FDT_BEGIN_NODE);
176
177 return offset;
178 }
179
_fdt_find_string(const char * strtab,int tabsize,const char * s)180 const char *_fdt_find_string(const char *strtab, int tabsize, const char *s)
181 {
182 int len = strlen(s) + 1;
183 const char *last = strtab + tabsize - len;
184 const char *p;
185
186 for (p = strtab; p <= last; p++)
187 if (memcmp(p, s, len) == 0)
188 return p;
189 return NULL;
190 }
191
fdt_move(const void * fdt,void * buf,int bufsize)192 int fdt_move(const void *fdt, void *buf, int bufsize)
193 {
194 FDT_CHECK_HEADER(fdt);
195
196 if (fdt_totalsize(fdt) > bufsize)
197 return -FDT_ERR_NOSPACE;
198
199 memmove(buf, fdt, fdt_totalsize(fdt));
200 return 0;
201 }
202