fdt.c 6.5 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. break;
  115. case FDT_END:
  116. case FDT_END_NODE:
  117. case FDT_NOP:
  118. break;
  119. default:
  120. return FDT_END;
  121. }
  122. if (!fdt_offset_ptr(fdt, startoffset, offset - startoffset))
  123. return FDT_END; /* premature end */
  124. *nextoffset = FDT_TAGALIGN(offset);
  125. return tag;
  126. }
  127. int _fdt_check_node_offset(const void *fdt, int offset)
  128. {
  129. if ((offset < 0) || (offset % FDT_TAGSIZE)
  130. || (fdt_next_tag(fdt, offset, &offset) != FDT_BEGIN_NODE))
  131. return -FDT_ERR_BADOFFSET;
  132. return offset;
  133. }
  134. int _fdt_check_prop_offset(const void *fdt, int offset)
  135. {
  136. if ((offset < 0) || (offset % FDT_TAGSIZE)
  137. || (fdt_next_tag(fdt, offset, &offset) != FDT_PROP))
  138. return -FDT_ERR_BADOFFSET;
  139. return offset;
  140. }
  141. int fdt_next_node(const void *fdt, int offset, int *depth)
  142. {
  143. int nextoffset = 0;
  144. uint32_t tag;
  145. if (offset >= 0)
  146. if ((nextoffset = _fdt_check_node_offset(fdt, offset)) < 0)
  147. return nextoffset;
  148. do {
  149. offset = nextoffset;
  150. tag = fdt_next_tag(fdt, offset, &nextoffset);
  151. switch (tag) {
  152. case FDT_PROP:
  153. case FDT_NOP:
  154. break;
  155. case FDT_BEGIN_NODE:
  156. if (depth)
  157. (*depth)++;
  158. break;
  159. case FDT_END_NODE:
  160. if (depth && ((--(*depth)) < 0))
  161. return nextoffset;
  162. break;
  163. case FDT_END:
  164. if ((nextoffset >= 0)
  165. || ((nextoffset == -FDT_ERR_TRUNCATED) && !depth))
  166. return -FDT_ERR_NOTFOUND;
  167. else
  168. return nextoffset;
  169. }
  170. } while (tag != FDT_BEGIN_NODE);
  171. return offset;
  172. }
  173. int fdt_first_subnode(const void *fdt, int offset)
  174. {
  175. int depth = 0;
  176. offset = fdt_next_node(fdt, offset, &depth);
  177. if (offset < 0 || depth != 1)
  178. return -FDT_ERR_NOTFOUND;
  179. return offset;
  180. }
  181. int fdt_next_subnode(const void *fdt, int offset)
  182. {
  183. int depth = 1;
  184. /*
  185. * With respect to the parent, the depth of the next subnode will be
  186. * the same as the last.
  187. */
  188. do {
  189. offset = fdt_next_node(fdt, offset, &depth);
  190. if (offset < 0 || depth < 1)
  191. return -FDT_ERR_NOTFOUND;
  192. } while (depth > 1);
  193. return offset;
  194. }
  195. const char *_fdt_find_string(const char *strtab, int tabsize, const char *s)
  196. {
  197. int len = strlen(s) + 1;
  198. const char *last = strtab + tabsize - len;
  199. const char *p;
  200. for (p = strtab; p <= last; p++)
  201. if (memcmp(p, s, len) == 0)
  202. return p;
  203. return NULL;
  204. }
  205. int fdt_move(const void *fdt, void *buf, int bufsize)
  206. {
  207. FDT_CHECK_HEADER(fdt);
  208. if (fdt_totalsize(fdt) > bufsize)
  209. return -FDT_ERR_NOSPACE;
  210. memmove(buf, fdt, fdt_totalsize(fdt));
  211. return 0;
  212. }