fdt_sw.c 4.8 KB

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  1. /*
  2. * libfdt - Flat Device Tree manipulation
  3. * Copyright (C) 2006 David Gibson, IBM Corporation.
  4. * SPDX-License-Identifier: GPL-2.0+ BSD-2-Clause
  5. */
  6. #include "libfdt_env.h"
  7. #include <fdt.h>
  8. #include <libfdt.h>
  9. #include "libfdt_internal.h"
  10. static int _fdt_sw_check_header(void *fdt)
  11. {
  12. if (fdt_magic(fdt) != FDT_SW_MAGIC)
  13. return -FDT_ERR_BADMAGIC;
  14. /* FIXME: should check more details about the header state */
  15. return 0;
  16. }
  17. #define FDT_SW_CHECK_HEADER(fdt) \
  18. { \
  19. int err; \
  20. if ((err = _fdt_sw_check_header(fdt)) != 0) \
  21. return err; \
  22. }
  23. static void *_fdt_grab_space(void *fdt, size_t len)
  24. {
  25. int offset = fdt_size_dt_struct(fdt);
  26. int spaceleft;
  27. spaceleft = fdt_totalsize(fdt) - fdt_off_dt_struct(fdt)
  28. - fdt_size_dt_strings(fdt);
  29. if ((offset + len < offset) || (offset + len > spaceleft))
  30. return NULL;
  31. fdt_set_size_dt_struct(fdt, offset + len);
  32. return _fdt_offset_ptr_w(fdt, offset);
  33. }
  34. int fdt_create(void *buf, int bufsize)
  35. {
  36. void *fdt = buf;
  37. if (bufsize < sizeof(struct fdt_header))
  38. return -FDT_ERR_NOSPACE;
  39. memset(buf, 0, bufsize);
  40. fdt_set_magic(fdt, FDT_SW_MAGIC);
  41. fdt_set_version(fdt, FDT_LAST_SUPPORTED_VERSION);
  42. fdt_set_last_comp_version(fdt, FDT_FIRST_SUPPORTED_VERSION);
  43. fdt_set_totalsize(fdt, bufsize);
  44. fdt_set_off_mem_rsvmap(fdt, FDT_ALIGN(sizeof(struct fdt_header),
  45. sizeof(struct fdt_reserve_entry)));
  46. fdt_set_off_dt_struct(fdt, fdt_off_mem_rsvmap(fdt));
  47. fdt_set_off_dt_strings(fdt, bufsize);
  48. return 0;
  49. }
  50. int fdt_add_reservemap_entry(void *fdt, uint64_t addr, uint64_t size)
  51. {
  52. struct fdt_reserve_entry *re;
  53. int offset;
  54. FDT_SW_CHECK_HEADER(fdt);
  55. if (fdt_size_dt_struct(fdt))
  56. return -FDT_ERR_BADSTATE;
  57. offset = fdt_off_dt_struct(fdt);
  58. if ((offset + sizeof(*re)) > fdt_totalsize(fdt))
  59. return -FDT_ERR_NOSPACE;
  60. re = (struct fdt_reserve_entry *)((char *)fdt + offset);
  61. re->address = cpu_to_fdt64(addr);
  62. re->size = cpu_to_fdt64(size);
  63. fdt_set_off_dt_struct(fdt, offset + sizeof(*re));
  64. return 0;
  65. }
  66. int fdt_finish_reservemap(void *fdt)
  67. {
  68. return fdt_add_reservemap_entry(fdt, 0, 0);
  69. }
  70. int fdt_begin_node(void *fdt, const char *name)
  71. {
  72. struct fdt_node_header *nh;
  73. int namelen = strlen(name) + 1;
  74. FDT_SW_CHECK_HEADER(fdt);
  75. nh = _fdt_grab_space(fdt, sizeof(*nh) + FDT_TAGALIGN(namelen));
  76. if (! nh)
  77. return -FDT_ERR_NOSPACE;
  78. nh->tag = cpu_to_fdt32(FDT_BEGIN_NODE);
  79. memcpy(nh->name, name, namelen);
  80. return 0;
  81. }
  82. int fdt_end_node(void *fdt)
  83. {
  84. fdt32_t *en;
  85. FDT_SW_CHECK_HEADER(fdt);
  86. en = _fdt_grab_space(fdt, FDT_TAGSIZE);
  87. if (! en)
  88. return -FDT_ERR_NOSPACE;
  89. *en = cpu_to_fdt32(FDT_END_NODE);
  90. return 0;
  91. }
  92. static int _fdt_find_add_string(void *fdt, const char *s)
  93. {
  94. char *strtab = (char *)fdt + fdt_totalsize(fdt);
  95. const char *p;
  96. int strtabsize = fdt_size_dt_strings(fdt);
  97. int len = strlen(s) + 1;
  98. int struct_top, offset;
  99. p = _fdt_find_string(strtab - strtabsize, strtabsize, s);
  100. if (p)
  101. return p - strtab;
  102. /* Add it */
  103. offset = -strtabsize - len;
  104. struct_top = fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt);
  105. if (fdt_totalsize(fdt) + offset < struct_top)
  106. return 0; /* no more room :( */
  107. memcpy(strtab + offset, s, len);
  108. fdt_set_size_dt_strings(fdt, strtabsize + len);
  109. return offset;
  110. }
  111. int fdt_property(void *fdt, const char *name, const void *val, int len)
  112. {
  113. struct fdt_property *prop;
  114. int nameoff;
  115. FDT_SW_CHECK_HEADER(fdt);
  116. nameoff = _fdt_find_add_string(fdt, name);
  117. if (nameoff == 0)
  118. return -FDT_ERR_NOSPACE;
  119. prop = _fdt_grab_space(fdt, sizeof(*prop) + FDT_TAGALIGN(len));
  120. if (! prop)
  121. return -FDT_ERR_NOSPACE;
  122. prop->tag = cpu_to_fdt32(FDT_PROP);
  123. prop->nameoff = cpu_to_fdt32(nameoff);
  124. prop->len = cpu_to_fdt32(len);
  125. memcpy(prop->data, val, len);
  126. return 0;
  127. }
  128. int fdt_finish(void *fdt)
  129. {
  130. char *p = (char *)fdt;
  131. fdt32_t *end;
  132. int oldstroffset, newstroffset;
  133. uint32_t tag;
  134. int offset, nextoffset;
  135. FDT_SW_CHECK_HEADER(fdt);
  136. /* Add terminator */
  137. end = _fdt_grab_space(fdt, sizeof(*end));
  138. if (! end)
  139. return -FDT_ERR_NOSPACE;
  140. *end = cpu_to_fdt32(FDT_END);
  141. /* Relocate the string table */
  142. oldstroffset = fdt_totalsize(fdt) - fdt_size_dt_strings(fdt);
  143. newstroffset = fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt);
  144. memmove(p + newstroffset, p + oldstroffset, fdt_size_dt_strings(fdt));
  145. fdt_set_off_dt_strings(fdt, newstroffset);
  146. /* Walk the structure, correcting string offsets */
  147. offset = 0;
  148. while ((tag = fdt_next_tag(fdt, offset, &nextoffset)) != FDT_END) {
  149. if (tag == FDT_PROP) {
  150. struct fdt_property *prop =
  151. _fdt_offset_ptr_w(fdt, offset);
  152. int nameoff;
  153. nameoff = fdt32_to_cpu(prop->nameoff);
  154. nameoff += fdt_size_dt_strings(fdt);
  155. prop->nameoff = cpu_to_fdt32(nameoff);
  156. }
  157. offset = nextoffset;
  158. }
  159. if (nextoffset < 0)
  160. return nextoffset;
  161. /* Finally, adjust the header */
  162. fdt_set_totalsize(fdt, newstroffset + fdt_size_dt_strings(fdt));
  163. fdt_set_magic(fdt, FDT_MAGIC);
  164. return 0;
  165. }