2 * libfdt - Flat Device Tree manipulation
3 * Copyright (C) 2006 David Gibson, IBM Corporation.
5 * libfdt is dual licensed: you can use it either under the terms of
6 * the GPL, or the BSD license, at your option.
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.
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.
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,
25 * b) Redistribution and use in source and binary forms, with or
26 * without modification, are permitted provided that the following
29 * 1. Redistributions of source code must retain the above
30 * copyright notice, this list of conditions and the following
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.
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.
51 #include "libfdt_env.h"
56 #include "libfdt_internal.h"
59 * Minimal sanity check for a read-only tree. fdt_ro_probe_() checks
60 * that the given buffer contains what appears to be a flattened
61 * device tree with sane information in its header.
63 int fdt_ro_probe_(const void *fdt)
65 if (fdt_magic(fdt) == FDT_MAGIC) {
67 if (fdt_version(fdt) < FDT_FIRST_SUPPORTED_VERSION)
68 return -FDT_ERR_BADVERSION;
69 if (fdt_last_comp_version(fdt) > FDT_LAST_SUPPORTED_VERSION)
70 return -FDT_ERR_BADVERSION;
71 } else if (fdt_magic(fdt) == FDT_SW_MAGIC) {
72 /* Unfinished sequential-write blob */
73 if (fdt_size_dt_struct(fdt) == 0)
74 return -FDT_ERR_BADSTATE;
76 return -FDT_ERR_BADMAGIC;
82 static int check_off_(uint32_t hdrsize, uint32_t totalsize, uint32_t off)
84 return (off >= hdrsize) && (off <= totalsize);
87 static int check_block_(uint32_t hdrsize, uint32_t totalsize,
88 uint32_t base, uint32_t size)
90 if (!check_off_(hdrsize, totalsize, base))
91 return 0; /* block start out of bounds */
92 if ((base + size) < base)
93 return 0; /* overflow */
94 if (!check_off_(hdrsize, totalsize, base + size))
95 return 0; /* block end out of bounds */
99 size_t fdt_header_size_(uint32_t version)
103 else if (version <= 2)
105 else if (version <= 3)
107 else if (version <= 16)
113 int fdt_check_header(const void *fdt)
117 if (fdt_magic(fdt) != FDT_MAGIC)
118 return -FDT_ERR_BADMAGIC;
119 hdrsize = fdt_header_size(fdt);
120 if ((fdt_version(fdt) < FDT_FIRST_SUPPORTED_VERSION)
121 || (fdt_last_comp_version(fdt) > FDT_LAST_SUPPORTED_VERSION))
122 return -FDT_ERR_BADVERSION;
123 if (fdt_version(fdt) < fdt_last_comp_version(fdt))
124 return -FDT_ERR_BADVERSION;
126 if ((fdt_totalsize(fdt) < hdrsize)
127 || (fdt_totalsize(fdt) > INT_MAX))
128 return -FDT_ERR_TRUNCATED;
130 /* Bounds check memrsv block */
131 if (!check_off_(hdrsize, fdt_totalsize(fdt), fdt_off_mem_rsvmap(fdt)))
132 return -FDT_ERR_TRUNCATED;
134 /* Bounds check structure block */
135 if (fdt_version(fdt) < 17) {
136 if (!check_off_(hdrsize, fdt_totalsize(fdt),
137 fdt_off_dt_struct(fdt)))
138 return -FDT_ERR_TRUNCATED;
140 if (!check_block_(hdrsize, fdt_totalsize(fdt),
141 fdt_off_dt_struct(fdt),
142 fdt_size_dt_struct(fdt)))
143 return -FDT_ERR_TRUNCATED;
146 /* Bounds check strings block */
147 if (!check_block_(hdrsize, fdt_totalsize(fdt),
148 fdt_off_dt_strings(fdt), fdt_size_dt_strings(fdt)))
149 return -FDT_ERR_TRUNCATED;
154 const void *fdt_offset_ptr(const void *fdt, int offset, unsigned int len)
156 unsigned absoffset = offset + fdt_off_dt_struct(fdt);
158 if ((absoffset < offset)
159 || ((absoffset + len) < absoffset)
160 || (absoffset + len) > fdt_totalsize(fdt))
163 if (fdt_version(fdt) >= 0x11)
164 if (((offset + len) < offset)
165 || ((offset + len) > fdt_size_dt_struct(fdt)))
168 return fdt_offset_ptr_(fdt, offset);
171 uint32_t fdt_next_tag(const void *fdt, int startoffset, int *nextoffset)
173 const fdt32_t *tagp, *lenp;
175 int offset = startoffset;
178 *nextoffset = -FDT_ERR_TRUNCATED;
179 tagp = fdt_offset_ptr(fdt, offset, FDT_TAGSIZE);
181 return FDT_END; /* premature end */
182 tag = fdt32_to_cpu(*tagp);
183 offset += FDT_TAGSIZE;
185 *nextoffset = -FDT_ERR_BADSTRUCTURE;
190 p = fdt_offset_ptr(fdt, offset++, 1);
191 } while (p && (*p != '\0'));
193 return FDT_END; /* premature end */
197 lenp = fdt_offset_ptr(fdt, offset, sizeof(*lenp));
199 return FDT_END; /* premature end */
200 /* skip-name offset, length and value */
201 offset += sizeof(struct fdt_property) - FDT_TAGSIZE
202 + fdt32_to_cpu(*lenp);
203 if (fdt_version(fdt) < 0x10 && fdt32_to_cpu(*lenp) >= 8 &&
204 ((offset - fdt32_to_cpu(*lenp)) % 8) != 0)
217 if (!fdt_offset_ptr(fdt, startoffset, offset - startoffset))
218 return FDT_END; /* premature end */
220 *nextoffset = FDT_TAGALIGN(offset);
224 int fdt_check_node_offset_(const void *fdt, int offset)
226 if ((offset < 0) || (offset % FDT_TAGSIZE)
227 || (fdt_next_tag(fdt, offset, &offset) != FDT_BEGIN_NODE))
228 return -FDT_ERR_BADOFFSET;
233 int fdt_check_prop_offset_(const void *fdt, int offset)
235 if ((offset < 0) || (offset % FDT_TAGSIZE)
236 || (fdt_next_tag(fdt, offset, &offset) != FDT_PROP))
237 return -FDT_ERR_BADOFFSET;
242 int fdt_next_node(const void *fdt, int offset, int *depth)
248 if ((nextoffset = fdt_check_node_offset_(fdt, offset)) < 0)
253 tag = fdt_next_tag(fdt, offset, &nextoffset);
266 if (depth && ((--(*depth)) < 0))
271 if ((nextoffset >= 0)
272 || ((nextoffset == -FDT_ERR_TRUNCATED) && !depth))
273 return -FDT_ERR_NOTFOUND;
277 } while (tag != FDT_BEGIN_NODE);
282 int fdt_first_subnode(const void *fdt, int offset)
286 offset = fdt_next_node(fdt, offset, &depth);
287 if (offset < 0 || depth != 1)
288 return -FDT_ERR_NOTFOUND;
293 int fdt_next_subnode(const void *fdt, int offset)
298 * With respect to the parent, the depth of the next subnode will be
299 * the same as the last.
302 offset = fdt_next_node(fdt, offset, &depth);
303 if (offset < 0 || depth < 1)
304 return -FDT_ERR_NOTFOUND;
310 const char *fdt_find_string_(const char *strtab, int tabsize, const char *s)
312 int len = strlen(s) + 1;
313 const char *last = strtab + tabsize - len;
316 for (p = strtab; p <= last; p++)
317 if (memcmp(p, s, len) == 0)
322 int fdt_move(const void *fdt, void *buf, int bufsize)
326 if (fdt_totalsize(fdt) > bufsize)
327 return -FDT_ERR_NOSPACE;
329 memmove(buf, fdt, fdt_totalsize(fdt));