fdt.c 6.6 KB

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  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. #include <fdt.h>
  53. #include <libfdt.h>
  54. #include "libfdt_internal.h"
  55. int fdt_check_header(const void *fdt)
  56. {
  57. if (fdt_magic(fdt) == FDT_MAGIC) {
  58. /* Complete tree */
  59. if (fdt_version(fdt) < FDT_FIRST_SUPPORTED_VERSION)
  60. return -FDT_ERR_BADVERSION;
  61. if (fdt_last_comp_version(fdt) > FDT_LAST_SUPPORTED_VERSION)
  62. return -FDT_ERR_BADVERSION;
  63. } else if (fdt_magic(fdt) == FDT_SW_MAGIC) {
  64. /* Unfinished sequential-write blob */
  65. if (fdt_size_dt_struct(fdt) == 0)
  66. return -FDT_ERR_BADSTATE;
  67. } else {
  68. return -FDT_ERR_BADMAGIC;
  69. }
  70. return 0;
  71. }
  72. const void *fdt_offset_ptr(const void *fdt, int offset, unsigned int len)
  73. {
  74. unsigned absoffset = offset + fdt_off_dt_struct(fdt);
  75. if ((absoffset < offset)
  76. || ((absoffset + len) < absoffset)
  77. || (absoffset + len) > fdt_totalsize(fdt))
  78. return NULL;
  79. if (fdt_version(fdt) >= 0x11)
  80. if (((offset + len) < offset)
  81. || ((offset + len) > fdt_size_dt_struct(fdt)))
  82. return NULL;
  83. return fdt_offset_ptr_(fdt, offset);
  84. }
  85. uint32_t fdt_next_tag(const void *fdt, int startoffset, int *nextoffset)
  86. {
  87. const fdt32_t *tagp, *lenp;
  88. uint32_t tag;
  89. int offset = startoffset;
  90. const char *p;
  91. *nextoffset = -FDT_ERR_TRUNCATED;
  92. tagp = fdt_offset_ptr(fdt, offset, FDT_TAGSIZE);
  93. if (!tagp)
  94. return FDT_END; /* premature end */
  95. tag = fdt32_to_cpu(*tagp);
  96. offset += FDT_TAGSIZE;
  97. *nextoffset = -FDT_ERR_BADSTRUCTURE;
  98. switch (tag) {
  99. case FDT_BEGIN_NODE:
  100. /* skip name */
  101. do {
  102. p = fdt_offset_ptr(fdt, offset++, 1);
  103. } while (p && (*p != '\0'));
  104. if (!p)
  105. return FDT_END; /* premature end */
  106. break;
  107. case FDT_PROP:
  108. lenp = fdt_offset_ptr(fdt, offset, sizeof(*lenp));
  109. if (!lenp)
  110. return FDT_END; /* premature end */
  111. /* skip-name offset, length and value */
  112. offset += sizeof(struct fdt_property) - FDT_TAGSIZE
  113. + fdt32_to_cpu(*lenp);
  114. if (fdt_version(fdt) < 0x10 && fdt32_to_cpu(*lenp) >= 8 &&
  115. ((offset - fdt32_to_cpu(*lenp)) % 8) != 0)
  116. offset += 4;
  117. break;
  118. case FDT_END:
  119. case FDT_END_NODE:
  120. case FDT_NOP:
  121. break;
  122. default:
  123. return FDT_END;
  124. }
  125. if (!fdt_offset_ptr(fdt, startoffset, offset - startoffset))
  126. return FDT_END; /* premature end */
  127. *nextoffset = FDT_TAGALIGN(offset);
  128. return tag;
  129. }
  130. int fdt_check_node_offset_(const void *fdt, int offset)
  131. {
  132. if ((offset < 0) || (offset % FDT_TAGSIZE)
  133. || (fdt_next_tag(fdt, offset, &offset) != FDT_BEGIN_NODE))
  134. return -FDT_ERR_BADOFFSET;
  135. return offset;
  136. }
  137. int fdt_check_prop_offset_(const void *fdt, int offset)
  138. {
  139. if ((offset < 0) || (offset % FDT_TAGSIZE)
  140. || (fdt_next_tag(fdt, offset, &offset) != FDT_PROP))
  141. return -FDT_ERR_BADOFFSET;
  142. return offset;
  143. }
  144. int fdt_next_node(const void *fdt, int offset, int *depth)
  145. {
  146. int nextoffset = 0;
  147. uint32_t tag;
  148. if (offset >= 0)
  149. if ((nextoffset = fdt_check_node_offset_(fdt, offset)) < 0)
  150. return nextoffset;
  151. do {
  152. offset = nextoffset;
  153. tag = fdt_next_tag(fdt, offset, &nextoffset);
  154. switch (tag) {
  155. case FDT_PROP:
  156. case FDT_NOP:
  157. break;
  158. case FDT_BEGIN_NODE:
  159. if (depth)
  160. (*depth)++;
  161. break;
  162. case FDT_END_NODE:
  163. if (depth && ((--(*depth)) < 0))
  164. return nextoffset;
  165. break;
  166. case FDT_END:
  167. if ((nextoffset >= 0)
  168. || ((nextoffset == -FDT_ERR_TRUNCATED) && !depth))
  169. return -FDT_ERR_NOTFOUND;
  170. else
  171. return nextoffset;
  172. }
  173. } while (tag != FDT_BEGIN_NODE);
  174. return offset;
  175. }
  176. int fdt_first_subnode(const void *fdt, int offset)
  177. {
  178. int depth = 0;
  179. offset = fdt_next_node(fdt, offset, &depth);
  180. if (offset < 0 || depth != 1)
  181. return -FDT_ERR_NOTFOUND;
  182. return offset;
  183. }
  184. int fdt_next_subnode(const void *fdt, int offset)
  185. {
  186. int depth = 1;
  187. /*
  188. * With respect to the parent, the depth of the next subnode will be
  189. * the same as the last.
  190. */
  191. do {
  192. offset = fdt_next_node(fdt, offset, &depth);
  193. if (offset < 0 || depth < 1)
  194. return -FDT_ERR_NOTFOUND;
  195. } while (depth > 1);
  196. return offset;
  197. }
  198. const char *fdt_find_string_(const char *strtab, int tabsize, const char *s)
  199. {
  200. int len = strlen(s) + 1;
  201. const char *last = strtab + tabsize - len;
  202. const char *p;
  203. for (p = strtab; p <= last; p++)
  204. if (memcmp(p, s, len) == 0)
  205. return p;
  206. return NULL;
  207. }
  208. int fdt_move(const void *fdt, void *buf, int bufsize)
  209. {
  210. FDT_CHECK_HEADER(fdt);
  211. if (fdt_totalsize(fdt) > bufsize)
  212. return -FDT_ERR_NOSPACE;
  213. memmove(buf, fdt, fdt_totalsize(fdt));
  214. return 0;
  215. }