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 #ifndef USE_HOSTCC 54 #include <fdt.h> 55 #include <libfdt.h> 56 #else 57 #include "fdt_host.h" 58 #endif 59 60 #include "libfdt_internal.h" 61 62 int fdt_check_header(const void *fdt) 63 { 64 if (fdt_magic(fdt) == FDT_MAGIC) { 65 /* Complete tree */ 66 if (fdt_version(fdt) < FDT_FIRST_SUPPORTED_VERSION) 67 return -FDT_ERR_BADVERSION; 68 if (fdt_last_comp_version(fdt) > FDT_LAST_SUPPORTED_VERSION) 69 return -FDT_ERR_BADVERSION; 70 } else if (fdt_magic(fdt) == FDT_SW_MAGIC) { 71 /* Unfinished sequential-write blob */ 72 if (fdt_size_dt_struct(fdt) == 0) 73 return -FDT_ERR_BADSTATE; 74 } else { 75 return -FDT_ERR_BADMAGIC; 76 } 77 78 return 0; 79 } 80 81 const void *fdt_offset_ptr(const void *fdt, int offset, unsigned int len) 82 { 83 const char *p; 84 85 if (fdt_version(fdt) >= 0x11) 86 if (((offset + len) < offset) 87 || ((offset + len) > fdt_size_dt_struct(fdt))) 88 return NULL; 89 90 p = _fdt_offset_ptr(fdt, offset); 91 92 if (p + len < p) 93 return NULL; 94 return p; 95 } 96 97 uint32_t fdt_next_tag(const void *fdt, int startoffset, int *nextoffset) 98 { 99 const uint32_t *tagp, *lenp; 100 uint32_t tag; 101 int offset = startoffset; 102 const char *p; 103 104 *nextoffset = -FDT_ERR_TRUNCATED; 105 tagp = fdt_offset_ptr(fdt, offset, FDT_TAGSIZE); 106 if (!tagp) 107 return FDT_END; /* premature end */ 108 tag = fdt32_to_cpu(*tagp); 109 offset += FDT_TAGSIZE; 110 111 *nextoffset = -FDT_ERR_BADSTRUCTURE; 112 switch (tag) { 113 case FDT_BEGIN_NODE: 114 /* skip name */ 115 do { 116 p = fdt_offset_ptr(fdt, offset++, 1); 117 } while (p && (*p != '\0')); 118 if (!p) 119 return FDT_END; /* premature end */ 120 break; 121 122 case FDT_PROP: 123 lenp = fdt_offset_ptr(fdt, offset, sizeof(*lenp)); 124 if (!lenp) 125 return FDT_END; /* premature end */ 126 /* skip-name offset, length and value */ 127 offset += sizeof(struct fdt_property) - FDT_TAGSIZE 128 + fdt32_to_cpu(*lenp); 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 } 146 147 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 } 155 156 int fdt_next_node(const void *fdt, int offset, int *depth) 157 { 158 int nextoffset = 0; 159 uint32_t tag; 160 161 if (offset >= 0) 162 if ((nextoffset = _fdt_check_node_offset(fdt, offset)) < 0) 163 return nextoffset; 164 165 do { 166 offset = nextoffset; 167 tag = fdt_next_tag(fdt, offset, &nextoffset); 168 169 switch (tag) { 170 case FDT_PROP: 171 case FDT_NOP: 172 break; 173 174 case FDT_BEGIN_NODE: 175 if (depth) 176 (*depth)++; 177 break; 178 179 case FDT_END_NODE: 180 if (depth && ((--(*depth)) < 0)) 181 return nextoffset; 182 break; 183 184 case FDT_END: 185 if ((nextoffset >= 0) 186 || ((nextoffset == -FDT_ERR_TRUNCATED) && !depth)) 187 return -FDT_ERR_NOTFOUND; 188 else 189 return nextoffset; 190 } 191 } while (tag != FDT_BEGIN_NODE); 192 193 return offset; 194 } 195 196 const char *_fdt_find_string(const char *strtab, int tabsize, const char *s) 197 { 198 int len = strlen(s) + 1; 199 const char *last = strtab + tabsize - len; 200 const char *p; 201 202 for (p = strtab; p <= last; p++) 203 if (memcmp(p, s, len) == 0) 204 return p; 205 return NULL; 206 } 207 208 int fdt_move(const void *fdt, void *buf, int bufsize) 209 { 210 FDT_CHECK_HEADER(fdt); 211 212 if (fdt_totalsize(fdt) > bufsize) 213 return -FDT_ERR_NOSPACE; 214 215 memmove(buf, fdt, fdt_totalsize(fdt)); 216 return 0; 217 } 218