of_fdt.h 4.8 KB

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  1. /*
  2. * Definitions for working with the Flattened Device Tree data format
  3. *
  4. * Copyright 2009 Benjamin Herrenschmidt, IBM Corp
  5. * benh@kernel.crashing.org
  6. *
  7. * This program is free software; you can redistribute it and/or
  8. * modify it under the terms of the GNU General Public License
  9. * version 2 as published by the Free Software Foundation.
  10. */
  11. #ifndef _LINUX_OF_FDT_H
  12. #define _LINUX_OF_FDT_H
  13. #include <linux/types.h>
  14. #include <linux/init.h>
  15. /* Definitions used by the flattened device tree */
  16. #define OF_DT_HEADER 0xd00dfeed /* marker */
  17. #define OF_DT_BEGIN_NODE 0x1 /* Start of node, full name */
  18. #define OF_DT_END_NODE 0x2 /* End node */
  19. #define OF_DT_PROP 0x3 /* Property: name off, size,
  20. * content */
  21. #define OF_DT_NOP 0x4 /* nop */
  22. #define OF_DT_END 0x9
  23. #define OF_DT_VERSION 0x10
  24. #ifndef __ASSEMBLY__
  25. /*
  26. * This is what gets passed to the kernel by prom_init or kexec
  27. *
  28. * The dt struct contains the device tree structure, full pathes and
  29. * property contents. The dt strings contain a separate block with just
  30. * the strings for the property names, and is fully page aligned and
  31. * self contained in a page, so that it can be kept around by the kernel,
  32. * each property name appears only once in this page (cheap compression)
  33. *
  34. * the mem_rsvmap contains a map of reserved ranges of physical memory,
  35. * passing it here instead of in the device-tree itself greatly simplifies
  36. * the job of everybody. It's just a list of u64 pairs (base/size) that
  37. * ends when size is 0
  38. */
  39. struct boot_param_header {
  40. __be32 magic; /* magic word OF_DT_HEADER */
  41. __be32 totalsize; /* total size of DT block */
  42. __be32 off_dt_struct; /* offset to structure */
  43. __be32 off_dt_strings; /* offset to strings */
  44. __be32 off_mem_rsvmap; /* offset to memory reserve map */
  45. __be32 version; /* format version */
  46. __be32 last_comp_version; /* last compatible version */
  47. /* version 2 fields below */
  48. __be32 boot_cpuid_phys; /* Physical CPU id we're booting on */
  49. /* version 3 fields below */
  50. __be32 dt_strings_size; /* size of the DT strings block */
  51. /* version 17 fields below */
  52. __be32 dt_struct_size; /* size of the DT structure block */
  53. };
  54. #if defined(CONFIG_OF_FLATTREE)
  55. struct device_node;
  56. /* For scanning an arbitrary device-tree at any time */
  57. extern char *of_fdt_get_string(struct boot_param_header *blob, u32 offset);
  58. extern void *of_fdt_get_property(struct boot_param_header *blob,
  59. unsigned long node,
  60. const char *name,
  61. unsigned long *size);
  62. extern int of_fdt_is_compatible(struct boot_param_header *blob,
  63. unsigned long node,
  64. const char *compat);
  65. extern int of_fdt_match(struct boot_param_header *blob, unsigned long node,
  66. const char *const *compat);
  67. extern void of_fdt_unflatten_tree(unsigned long *blob,
  68. struct device_node **mynodes);
  69. /* TBD: Temporary export of fdt globals - remove when code fully merged */
  70. extern int __initdata dt_root_addr_cells;
  71. extern int __initdata dt_root_size_cells;
  72. extern struct boot_param_header *initial_boot_params;
  73. /* For scanning the flat device-tree at boot time */
  74. extern char *find_flat_dt_string(u32 offset);
  75. extern int of_scan_flat_dt(int (*it)(unsigned long node, const char *uname,
  76. int depth, void *data),
  77. void *data);
  78. extern void *of_get_flat_dt_prop(unsigned long node, const char *name,
  79. unsigned long *size);
  80. extern int of_flat_dt_is_compatible(unsigned long node, const char *name);
  81. extern int of_flat_dt_match(unsigned long node, const char *const *matches);
  82. extern unsigned long of_get_flat_dt_root(void);
  83. extern int early_init_dt_scan_chosen(unsigned long node, const char *uname,
  84. int depth, void *data);
  85. extern void early_init_dt_check_for_initrd(unsigned long node);
  86. extern int early_init_dt_scan_memory(unsigned long node, const char *uname,
  87. int depth, void *data);
  88. extern void early_init_dt_add_memory_arch(u64 base, u64 size);
  89. extern void * early_init_dt_alloc_memory_arch(u64 size, u64 align);
  90. extern u64 dt_mem_next_cell(int s, __be32 **cellp);
  91. /*
  92. * If BLK_DEV_INITRD, the fdt early init code will call this function,
  93. * to be provided by the arch code. start and end are specified as
  94. * physical addresses.
  95. */
  96. #ifdef CONFIG_BLK_DEV_INITRD
  97. extern void early_init_dt_setup_initrd_arch(unsigned long start,
  98. unsigned long end);
  99. #endif
  100. /* Early flat tree scan hooks */
  101. extern int early_init_dt_scan_root(unsigned long node, const char *uname,
  102. int depth, void *data);
  103. /* Other Prototypes */
  104. extern void unflatten_device_tree(void);
  105. extern void early_init_devtree(void *);
  106. #else /* CONFIG_OF_FLATTREE */
  107. static inline void unflatten_device_tree(void) {}
  108. static inline void *of_get_flat_dt_prop(unsigned long node, const char *name,
  109. unsigned long *size) { return NULL; }
  110. static inline int of_flat_dt_is_compatible(unsigned long node,
  111. const char *name) { return 0; }
  112. #endif /* CONFIG_OF_FLATTREE */
  113. #endif /* __ASSEMBLY__ */
  114. #endif /* _LINUX_OF_FDT_H */