Antonio Nino Diaz | 3057efb | 2017-01-16 15:55:44 +0000 | [diff] [blame] | 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 | 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 | |
| 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 | break; |
| 127 | |
| 128 | case FDT_END: |
| 129 | case FDT_END_NODE: |
| 130 | case FDT_NOP: |
| 131 | break; |
| 132 | |
| 133 | default: |
| 134 | return FDT_END; |
| 135 | } |
| 136 | |
| 137 | if (!fdt_offset_ptr(fdt, startoffset, offset - startoffset)) |
| 138 | return FDT_END; /* premature end */ |
| 139 | |
| 140 | *nextoffset = FDT_TAGALIGN(offset); |
| 141 | return tag; |
| 142 | } |
| 143 | |
| 144 | int _fdt_check_node_offset(const void *fdt, int offset) |
| 145 | { |
| 146 | if ((offset < 0) || (offset % FDT_TAGSIZE) |
| 147 | || (fdt_next_tag(fdt, offset, &offset) != FDT_BEGIN_NODE)) |
| 148 | return -FDT_ERR_BADOFFSET; |
| 149 | |
| 150 | return offset; |
| 151 | } |
| 152 | |
| 153 | int _fdt_check_prop_offset(const void *fdt, int offset) |
| 154 | { |
| 155 | if ((offset < 0) || (offset % FDT_TAGSIZE) |
| 156 | || (fdt_next_tag(fdt, offset, &offset) != FDT_PROP)) |
| 157 | return -FDT_ERR_BADOFFSET; |
| 158 | |
| 159 | return offset; |
| 160 | } |
| 161 | |
| 162 | int fdt_next_node(const void *fdt, int offset, int *depth) |
| 163 | { |
| 164 | int nextoffset = 0; |
| 165 | uint32_t tag; |
| 166 | |
| 167 | if (offset >= 0) |
| 168 | if ((nextoffset = _fdt_check_node_offset(fdt, offset)) < 0) |
| 169 | return nextoffset; |
| 170 | |
| 171 | do { |
| 172 | offset = nextoffset; |
| 173 | tag = fdt_next_tag(fdt, offset, &nextoffset); |
| 174 | |
| 175 | switch (tag) { |
| 176 | case FDT_PROP: |
| 177 | case FDT_NOP: |
| 178 | break; |
| 179 | |
| 180 | case FDT_BEGIN_NODE: |
| 181 | if (depth) |
| 182 | (*depth)++; |
| 183 | break; |
| 184 | |
| 185 | case FDT_END_NODE: |
| 186 | if (depth && ((--(*depth)) < 0)) |
| 187 | return nextoffset; |
| 188 | break; |
| 189 | |
| 190 | case FDT_END: |
| 191 | if ((nextoffset >= 0) |
| 192 | || ((nextoffset == -FDT_ERR_TRUNCATED) && !depth)) |
| 193 | return -FDT_ERR_NOTFOUND; |
| 194 | else |
| 195 | return nextoffset; |
| 196 | } |
| 197 | } while (tag != FDT_BEGIN_NODE); |
| 198 | |
| 199 | return offset; |
| 200 | } |
| 201 | |
| 202 | int fdt_first_subnode(const void *fdt, int offset) |
| 203 | { |
| 204 | int depth = 0; |
| 205 | |
| 206 | offset = fdt_next_node(fdt, offset, &depth); |
| 207 | if (offset < 0 || depth != 1) |
| 208 | return -FDT_ERR_NOTFOUND; |
| 209 | |
| 210 | return offset; |
| 211 | } |
| 212 | |
| 213 | int fdt_next_subnode(const void *fdt, int offset) |
| 214 | { |
| 215 | int depth = 1; |
| 216 | |
| 217 | /* |
| 218 | * With respect to the parent, the depth of the next subnode will be |
| 219 | * the same as the last. |
| 220 | */ |
| 221 | do { |
| 222 | offset = fdt_next_node(fdt, offset, &depth); |
| 223 | if (offset < 0 || depth < 1) |
| 224 | return -FDT_ERR_NOTFOUND; |
| 225 | } while (depth > 1); |
| 226 | |
| 227 | return offset; |
| 228 | } |
| 229 | |
| 230 | const char *_fdt_find_string(const char *strtab, int tabsize, const char *s) |
| 231 | { |
| 232 | int len = strlen(s) + 1; |
| 233 | const char *last = strtab + tabsize - len; |
| 234 | const char *p; |
| 235 | |
| 236 | for (p = strtab; p <= last; p++) |
| 237 | if (memcmp(p, s, len) == 0) |
| 238 | return p; |
| 239 | return NULL; |
| 240 | } |
| 241 | |
| 242 | int fdt_move(const void *fdt, void *buf, int bufsize) |
| 243 | { |
| 244 | FDT_CHECK_HEADER(fdt); |
| 245 | |
| 246 | if (fdt_totalsize(fdt) > bufsize) |
| 247 | return -FDT_ERR_NOSPACE; |
| 248 | |
| 249 | memmove(buf, fdt, fdt_totalsize(fdt)); |
| 250 | return 0; |
| 251 | } |