of_fdt.h 4.3 KB

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  1. /* SPDX-License-Identifier: GPL-2.0 */
  2. /*
  3. * Definitions for working with the Flattened Device Tree data format
  4. *
  5. * Copyright 2009 Benjamin Herrenschmidt, IBM Corp
  6. * [email protected]
  7. */
  8. #ifndef _LINUX_OF_FDT_H
  9. #define _LINUX_OF_FDT_H
  10. #include <linux/types.h>
  11. #include <linux/init.h>
  12. #include <linux/errno.h>
  13. /* Definitions used by the flattened device tree */
  14. #define OF_DT_HEADER 0xd00dfeed /* marker */
  15. #ifndef __ASSEMBLY__
  16. #if defined(CONFIG_OF_FLATTREE)
  17. struct device_node;
  18. /* For scanning an arbitrary device-tree at any time */
  19. extern void *of_fdt_unflatten_tree(const unsigned long *blob,
  20. struct device_node *dad,
  21. struct device_node **mynodes);
  22. /* TBD: Temporary export of fdt globals - remove when code fully merged */
  23. extern int __initdata dt_root_addr_cells;
  24. extern int __initdata dt_root_size_cells;
  25. extern void *initial_boot_params;
  26. extern char __dtb_start[];
  27. extern char __dtb_end[];
  28. /* Other Prototypes */
  29. extern u64 of_flat_dt_translate_address(unsigned long node);
  30. extern void of_fdt_limit_memory(int limit);
  31. #endif /* CONFIG_OF_FLATTREE */
  32. #ifdef CONFIG_OF_EARLY_FLATTREE
  33. /* For scanning the flat device-tree at boot time */
  34. extern int of_scan_flat_dt(int (*it)(unsigned long node, const char *uname,
  35. int depth, void *data),
  36. void *data);
  37. extern int of_scan_flat_dt_subnodes(unsigned long node,
  38. int (*it)(unsigned long node,
  39. const char *uname,
  40. void *data),
  41. void *data);
  42. extern int of_get_flat_dt_subnode_by_name(unsigned long node,
  43. const char *uname);
  44. extern const void *of_get_flat_dt_prop(unsigned long node, const char *name,
  45. int *size);
  46. extern int of_flat_dt_is_compatible(unsigned long node, const char *name);
  47. extern unsigned long of_get_flat_dt_root(void);
  48. extern uint32_t of_get_flat_dt_phandle(unsigned long node);
  49. /*
  50. * early_init_dt_scan_chosen - scan the device tree for ramdisk and bootargs
  51. *
  52. * The boot arguments will be placed into the memory pointed to by @data.
  53. * That memory should be COMMAND_LINE_SIZE big and initialized to be a valid
  54. * (possibly empty) string. Logic for what will be in @data after this
  55. * function finishes:
  56. *
  57. * - CONFIG_CMDLINE_FORCE=true
  58. * CONFIG_CMDLINE
  59. * - CONFIG_CMDLINE_EXTEND=true, @data is non-empty string
  60. * @data + dt bootargs (even if dt bootargs are empty)
  61. * - CONFIG_CMDLINE_EXTEND=true, @data is empty string
  62. * CONFIG_CMDLINE + dt bootargs (even if dt bootargs are empty)
  63. * - CMDLINE_FROM_BOOTLOADER=true, dt bootargs=non-empty:
  64. * dt bootargs
  65. * - CMDLINE_FROM_BOOTLOADER=true, dt bootargs=empty, @data is non-empty string
  66. * @data is left unchanged
  67. * - CMDLINE_FROM_BOOTLOADER=true, dt bootargs=empty, @data is empty string
  68. * CONFIG_CMDLINE (or "" if that's not defined)
  69. */
  70. extern int early_init_dt_scan_chosen(char *cmdline);
  71. extern int early_init_dt_scan_memory(void);
  72. extern void early_init_dt_check_for_usable_mem_range(void);
  73. extern int early_init_dt_scan_chosen_stdout(void);
  74. extern void early_init_fdt_scan_reserved_mem(void);
  75. extern void early_init_fdt_reserve_self(void);
  76. extern void early_init_dt_add_memory_arch(u64 base, u64 size);
  77. extern u64 dt_mem_next_cell(int s, const __be32 **cellp);
  78. /* Early flat tree scan hooks */
  79. extern int early_init_dt_scan_root(void);
  80. extern bool early_init_dt_scan(void *params);
  81. extern bool early_init_dt_verify(void *params);
  82. extern void early_init_dt_scan_nodes(void);
  83. extern const char *of_flat_dt_get_machine_name(void);
  84. extern const void *of_flat_dt_match_machine(const void *default_match,
  85. const void * (*get_next_compat)(const char * const**));
  86. /* Other Prototypes */
  87. extern void unflatten_device_tree(void);
  88. extern void unflatten_and_copy_device_tree(void);
  89. extern void early_init_devtree(void *);
  90. extern void early_get_first_memblock_info(void *, phys_addr_t *);
  91. #else /* CONFIG_OF_EARLY_FLATTREE */
  92. static inline void early_init_dt_check_for_usable_mem_range(void) {}
  93. static inline int early_init_dt_scan_chosen_stdout(void) { return -ENODEV; }
  94. static inline void early_init_fdt_scan_reserved_mem(void) {}
  95. static inline void early_init_fdt_reserve_self(void) {}
  96. static inline const char *of_flat_dt_get_machine_name(void) { return NULL; }
  97. static inline void unflatten_device_tree(void) {}
  98. static inline void unflatten_and_copy_device_tree(void) {}
  99. #endif /* CONFIG_OF_EARLY_FLATTREE */
  100. #endif /* __ASSEMBLY__ */
  101. #endif /* _LINUX_OF_FDT_H */