fdt.c 5.7 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. #ifndef USE_HOSTCC
  53. #include <fdt.h>
  54. #include <libfdt.h>
  55. #else
  56. #include "fdt_host.h"
  57. #endif
  58. #include "libfdt_internal.h"
  59. int fdt_check_header(const void *fdt)
  60. {
  61. if (fdt_magic(fdt) == FDT_MAGIC) {
  62. /* Complete tree */
  63. if (fdt_version(fdt) < FDT_FIRST_SUPPORTED_VERSION)
  64. return -FDT_ERR_BADVERSION;
  65. if (fdt_last_comp_version(fdt) > FDT_LAST_SUPPORTED_VERSION)
  66. return -FDT_ERR_BADVERSION;
  67. } else if (fdt_magic(fdt) == FDT_SW_MAGIC) {
  68. /* Unfinished sequential-write blob */
  69. if (fdt_size_dt_struct(fdt) == 0)
  70. return -FDT_ERR_BADSTATE;
  71. } else {
  72. return -FDT_ERR_BADMAGIC;
  73. }
  74. return 0;
  75. }
  76. const void *fdt_offset_ptr(const void *fdt, int offset, unsigned int len)
  77. {
  78. const char *p;
  79. if (fdt_version(fdt) >= 0x11)
  80. if (((offset + len) < offset)
  81. || ((offset + len) > fdt_size_dt_struct(fdt)))
  82. return NULL;
  83. p = _fdt_offset_ptr(fdt, offset);
  84. if (p + len < p)
  85. return NULL;
  86. return p;
  87. }
  88. uint32_t fdt_next_tag(const void *fdt, int startoffset, int *nextoffset)
  89. {
  90. const uint32_t *tagp, *lenp;
  91. uint32_t tag;
  92. int offset = startoffset;
  93. const char *p;
  94. *nextoffset = -FDT_ERR_TRUNCATED;
  95. tagp = fdt_offset_ptr(fdt, offset, FDT_TAGSIZE);
  96. if (!tagp)
  97. return FDT_END; /* premature end */
  98. tag = fdt32_to_cpu(*tagp);
  99. offset += FDT_TAGSIZE;
  100. *nextoffset = -FDT_ERR_BADSTRUCTURE;
  101. switch (tag) {
  102. case FDT_BEGIN_NODE:
  103. /* skip name */
  104. do {
  105. p = fdt_offset_ptr(fdt, offset++, 1);
  106. } while (p && (*p != '\0'));
  107. if (!p)
  108. return FDT_END; /* premature end */
  109. break;
  110. case FDT_PROP:
  111. lenp = fdt_offset_ptr(fdt, offset, sizeof(*lenp));
  112. if (!lenp)
  113. return FDT_END; /* premature end */
  114. /* skip-name offset, length and value */
  115. offset += sizeof(struct fdt_property) - FDT_TAGSIZE
  116. + fdt32_to_cpu(*lenp);
  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_next_node(const void *fdt, int offset, int *depth)
  138. {
  139. int nextoffset = 0;
  140. uint32_t tag;
  141. if (offset >= 0)
  142. if ((nextoffset = _fdt_check_node_offset(fdt, offset)) < 0)
  143. return nextoffset;
  144. do {
  145. offset = nextoffset;
  146. tag = fdt_next_tag(fdt, offset, &nextoffset);
  147. switch (tag) {
  148. case FDT_PROP:
  149. case FDT_NOP:
  150. break;
  151. case FDT_BEGIN_NODE:
  152. if (depth)
  153. (*depth)++;
  154. break;
  155. case FDT_END_NODE:
  156. if (depth && ((--(*depth)) < 0))
  157. return nextoffset;
  158. break;
  159. case FDT_END:
  160. if ((nextoffset >= 0)
  161. || ((nextoffset == -FDT_ERR_TRUNCATED) && !depth))
  162. return -FDT_ERR_NOTFOUND;
  163. else
  164. return nextoffset;
  165. }
  166. } while (tag != FDT_BEGIN_NODE);
  167. return offset;
  168. }
  169. const char *_fdt_find_string(const char *strtab, int tabsize, const char *s)
  170. {
  171. int len = strlen(s) + 1;
  172. const char *last = strtab + tabsize - len;
  173. const char *p;
  174. for (p = strtab; p <= last; p++)
  175. if (memcmp(p, s, len) == 0)
  176. return p;
  177. return NULL;
  178. }
  179. int fdt_move(const void *fdt, void *buf, int bufsize)
  180. {
  181. FDT_CHECK_HEADER(fdt);
  182. if (fdt_totalsize(fdt) > bufsize)
  183. return -FDT_ERR_NOSPACE;
  184. memmove(buf, fdt, fdt_totalsize(fdt));
  185. return 0;
  186. }