text: /*
   * Definitions for working with the Flattened Device Tree data format
   *
   * Copyright 2009 Benjamin Herrenschmidt, IBM Corp
   * benh@kernel.crashing.org
   *
   * This program is free software; you can redistribute it and/or
   * modify it under the terms of the GNU General Public License
   * version 2 as published by the Free Software Foundation.
   */
  
  #ifndef _LINUX_OF_FDT_H
  #define _LINUX_OF_FDT_H
  
  #include <linux/types.h>
  #include <linux/init.h>
  
  /* Definitions used by the flattened device tree */
  #define OF_DT_HEADER		0xd00dfeed	/* marker */
  
  #ifndef __ASSEMBLY__
  
  #if defined(CONFIG_OF_FLATTREE)
  
  struct device_node;
  
  /* For scanning an arbitrary device-tree at any time */
  extern char *of_fdt_get_string(const void *blob, u32 offset);
  extern void *of_fdt_get_property(const void *blob,
  				 unsigned long node,
  				 const char *name,
  				 int *size);
  extern int of_fdt_is_compatible(const void *blob,
  				unsigned long node,
  				const char *compat);
  extern bool of_fdt_is_big_endian(const void *blob,
  				 unsigned long node);
  extern int of_fdt_match(const void *blob, unsigned long node,
  			const char *const *compat);
  extern void of_fdt_unflatten_tree(unsigned long *blob,
  			       struct device_node **mynodes);
  
  /* TBD: Temporary export of fdt globals - remove when code fully merged */
  extern int __initdata dt_root_addr_cells;
  extern int __initdata dt_root_size_cells;
  extern void *initial_boot_params;
  
  extern char __dtb_start[];
  extern char __dtb_end[];
  
  /* For scanning the flat device-tree at boot time */
  extern int of_scan_flat_dt(int (*it)(unsigned long node, const char *uname,
  				     int depth, void *data),
  			   void *data);
  extern const void *of_get_flat_dt_prop(unsigned long node, const char *name,
  				       int *size);
  extern int of_flat_dt_is_compatible(unsigned long node, const char *name);
  extern int of_flat_dt_match(unsigned long node, const char *const *matches);
  extern unsigned long of_get_flat_dt_root(void);
  extern int of_get_flat_dt_size(void);
  
  /*
   * early_init_dt_scan_chosen - scan the device tree for ramdisk and bootargs
   *
   * The boot arguments will be placed into the memory pointed to by @data.
   * That memory should be COMMAND_LINE_SIZE big and initialized to be a valid
   * (possibly empty) string.  Logic for what will be in @data after this
   * function finishes:
   *
   * - CONFIG_CMDLINE_FORCE=true
   *     CONFIG_CMDLINE
   * - CONFIG_CMDLINE_EXTEND=true, @data is non-empty string
   *     @data + dt bootargs (even if dt bootargs are empty)
   * - CONFIG_CMDLINE_EXTEND=true, @data is empty string
   *     CONFIG_CMDLINE + dt bootargs (even if dt bootargs are empty)
   * - CMDLINE_FROM_BOOTLOADER=true, dt bootargs=non-empty:
   *     dt bootargs
   * - CMDLINE_FROM_BOOTLOADER=true, dt bootargs=empty, @data is non-empty string
   *     @data is left unchanged
   * - CMDLINE_FROM_BOOTLOADER=true, dt bootargs=empty, @data is empty string
   *     CONFIG_CMDLINE (or "" if that's not defined)
   */
  extern int early_init_dt_scan_chosen(unsigned long node, const char *uname,
  				     int depth, void *data);
  extern int early_init_dt_scan_memory(unsigned long node, const char *uname,
  				     int depth, void *data);
  extern void early_init_fdt_scan_reserved_mem(void);
  extern void early_init_dt_add_memory_arch(u64 base, u64 size);
  extern int early_init_dt_reserve_memory_arch(phys_addr_t base, phys_addr_t size,
  					     bool no_map);
  extern void * early_init_dt_alloc_memory_arch(u64 size, u64 align);
  extern u64 dt_mem_next_cell(int s, const __be32 **cellp);
  
  /* Early flat tree scan hooks */
  extern int early_init_dt_scan_root(unsigned long node, const char *uname,
  				   int depth, void *data);
  
  extern bool early_init_dt_scan(void *params);
  extern bool early_init_dt_verify(void *params);
  extern void early_init_dt_scan_nodes(void);
  
  extern const char *of_flat_dt_get_machine_name(void);
  extern const void *of_flat_dt_match_machine(const void *default_match,
  		const void * (*get_next_compat)(const char * const**));
  
  /* Other Prototypes */
  extern void unflatten_device_tree(void);
  extern void unflatten_and_copy_device_tree(void);
  extern void early_init_devtree(void *);
  extern void early_get_first_memblock_info(void *, phys_addr_t *);
  extern u64 fdt_translate_address(const void *blob, int node_offset);
  extern void of_fdt_limit_memory(int limit);
  #else /* CONFIG_OF_FLATTREE */
  static inline void early_init_fdt_scan_reserved_mem(void) {}
  static inline const char *of_flat_dt_get_machine_name(void) { return NULL; }
  static inline void unflatten_device_tree(void) {}
  static inline void unflatten_and_copy_device_tree(void) {}
  #endif /* CONFIG_OF_FLATTREE */
  
  #endif /* __ASSEMBLY__ */
  #endif /* _LINUX_OF_FDT_H */
  