blob: e56833ae9b6ffaee67281dc959b0c263ccc24c15
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 | |
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 | |
77 | const void *fdt_offset_ptr(const void *fdt, int offset, unsigned 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 | |
93 | uint32_t fdt_next_tag(const void *fdt, int startoffset, int *nextoffset) |
94 | { |
95 | const uint32_t *tagp, *lenp; |
96 | uint32_t tag; |
97 | int offset = startoffset; |
98 | const char *p; |
99 | |
100 | *nextoffset = -FDT_ERR_TRUNCATED; |
101 | tagp = fdt_offset_ptr(fdt, offset, FDT_TAGSIZE); |
102 | if (!tagp) |
103 | return FDT_END; /* premature end */ |
104 | tag = fdt32_to_cpu(*tagp); |
105 | offset += FDT_TAGSIZE; |
106 | |
107 | *nextoffset = -FDT_ERR_BADSTRUCTURE; |
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; /* premature end */ |
116 | break; |
117 | |
118 | case FDT_PROP: |
119 | lenp = fdt_offset_ptr(fdt, offset, sizeof(*lenp)); |
120 | if (!lenp) |
121 | return FDT_END; /* premature end */ |
122 | /* skip-name offset, length and value */ |
123 | offset += sizeof(struct fdt_property) - FDT_TAGSIZE |
124 | + fdt32_to_cpu(*lenp); |
125 | break; |
126 | |
127 | case FDT_END: |
128 | case FDT_END_NODE: |
129 | case FDT_NOP: |
130 | break; |
131 | |
132 | default: |
133 | return FDT_END; |
134 | } |
135 | |
136 | if (!fdt_offset_ptr(fdt, startoffset, offset - startoffset)) |
137 | return FDT_END; /* premature end */ |
138 | |
139 | *nextoffset = FDT_TAGALIGN(offset); |
140 | return tag; |
141 | } |
142 | |
143 | int _fdt_check_node_offset(const void *fdt, int offset) |
144 | { |
145 | if ((offset < 0) || (offset % FDT_TAGSIZE) |
146 | || (fdt_next_tag(fdt, offset, &offset) != FDT_BEGIN_NODE)) |
147 | return -FDT_ERR_BADOFFSET; |
148 | |
149 | return offset; |
150 | } |
151 | |
152 | int _fdt_check_prop_offset(const void *fdt, int offset) |
153 | { |
154 | if ((offset < 0) || (offset % FDT_TAGSIZE) |
155 | || (fdt_next_tag(fdt, offset, &offset) != FDT_PROP)) |
156 | return -FDT_ERR_BADOFFSET; |
157 | |
158 | return offset; |
159 | } |
160 | |
161 | int fdt_next_node(const void *fdt, int offset, int *depth) |
162 | { |
163 | int nextoffset = 0; |
164 | uint32_t tag; |
165 | |
166 | if (offset >= 0) |
167 | if ((nextoffset = _fdt_check_node_offset(fdt, offset)) < 0) |
168 | return nextoffset; |
169 | |
170 | do { |
171 | offset = nextoffset; |
172 | tag = fdt_next_tag(fdt, offset, &nextoffset); |
173 | |
174 | switch (tag) { |
175 | case FDT_PROP: |
176 | case FDT_NOP: |
177 | break; |
178 | |
179 | case FDT_BEGIN_NODE: |
180 | if (depth) |
181 | (*depth)++; |
182 | break; |
183 | |
184 | case FDT_END_NODE: |
185 | if (depth && ((--(*depth)) < 0)) |
186 | return nextoffset; |
187 | break; |
188 | |
189 | case FDT_END: |
190 | if ((nextoffset >= 0) |
191 | || ((nextoffset == -FDT_ERR_TRUNCATED) && !depth)) |
192 | return -FDT_ERR_NOTFOUND; |
193 | else |
194 | return nextoffset; |
195 | } |
196 | } while (tag != FDT_BEGIN_NODE); |
197 | |
198 | return offset; |
199 | } |
200 | |
201 | const char *_fdt_find_string(const char *strtab, int tabsize, const char *s) |
202 | { |
203 | int len = strlen(s) + 1; |
204 | const char *last = strtab + tabsize - len; |
205 | const char *p; |
206 | |
207 | for (p = strtab; p <= last; p++) |
208 | if (memcmp(p, s, len) == 0) |
209 | return p; |
210 | return NULL; |
211 | } |
212 | |
213 | int fdt_move(const void *fdt, void *buf, int bufsize) |
214 | { |
215 | FDT_CHECK_HEADER(fdt); |
216 | |
217 | if (fdt_totalsize(fdt) > bufsize) |
218 | return -FDT_ERR_NOSPACE; |
219 | |
220 | memmove(buf, fdt, fdt_totalsize(fdt)); |
221 | return 0; |
222 | } |
223 |