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 12 #ifndef _LINUX_OF_FDT_H 13 #define _LINUX_OF_FDT_H 14 15 #include <linux/types.h> 16 #include <linux/init.h> 17 18 /* Definitions used by the flattened device tree */ 19 #define OF_DT_HEADER 0xd00dfeed /* marker */ 20 #define OF_DT_BEGIN_NODE 0x1 /* Start of node, full name */ 21 #define OF_DT_END_NODE 0x2 /* End node */ 22 #define OF_DT_PROP 0x3 /* Property: name off, size, 23 * content */ 24 #define OF_DT_NOP 0x4 /* nop */ 25 #define OF_DT_END 0x9 26 27 #define OF_DT_VERSION 0x10 28 29 #ifndef __ASSEMBLY__ 30 /* 31 * This is what gets passed to the kernel by prom_init or kexec 32 * 33 * The dt struct contains the device tree structure, full pathes and 34 * property contents. The dt strings contain a separate block with just 35 * the strings for the property names, and is fully page aligned and 36 * self contained in a page, so that it can be kept around by the kernel, 37 * each property name appears only once in this page (cheap compression) 38 * 39 * the mem_rsvmap contains a map of reserved ranges of physical memory, 40 * passing it here instead of in the device-tree itself greatly simplifies 41 * the job of everybody. It's just a list of u64 pairs (base/size) that 42 * ends when size is 0 43 */ 44 struct boot_param_header { 45 __be32 magic; /* magic word OF_DT_HEADER */ 46 __be32 totalsize; /* total size of DT block */ 47 __be32 off_dt_struct; /* offset to structure */ 48 __be32 off_dt_strings; /* offset to strings */ 49 __be32 off_mem_rsvmap; /* offset to memory reserve map */ 50 __be32 version; /* format version */ 51 __be32 last_comp_version; /* last compatible version */ 52 /* version 2 fields below */ 53 __be32 boot_cpuid_phys; /* Physical CPU id we're booting on */ 54 /* version 3 fields below */ 55 __be32 dt_strings_size; /* size of the DT strings block */ 56 /* version 17 fields below */ 57 __be32 dt_struct_size; /* size of the DT structure block */ 58 }; 59 60 #if defined(CONFIG_OF_FLATTREE) 61 62 struct device_node; 63 64 /* For scanning an arbitrary device-tree at any time */ 65 extern char *of_fdt_get_string(struct boot_param_header *blob, u32 offset); 66 extern void *of_fdt_get_property(struct boot_param_header *blob, 67 unsigned long node, 68 const char *name, 69 unsigned long *size); 70 extern int of_fdt_is_compatible(struct boot_param_header *blob, 71 unsigned long node, 72 const char *compat); 73 extern int of_fdt_match(struct boot_param_header *blob, unsigned long node, 74 const char *const *compat); 75 extern void of_fdt_unflatten_tree(unsigned long *blob, 76 struct device_node **mynodes); 77 78 /* TBD: Temporary export of fdt globals - remove when code fully merged */ 79 extern int __initdata dt_root_addr_cells; 80 extern int __initdata dt_root_size_cells; 81 extern struct boot_param_header *initial_boot_params; 82 83 /* For scanning the flat device-tree at boot time */ 84 extern char *find_flat_dt_string(u32 offset); 85 extern int of_scan_flat_dt(int (*it)(unsigned long node, const char *uname, 86 int depth, void *data), 87 void *data); 88 extern void *of_get_flat_dt_prop(unsigned long node, const char *name, 89 unsigned long *size); 90 extern int of_flat_dt_is_compatible(unsigned long node, const char *name); 91 extern int of_flat_dt_match(unsigned long node, const char *const *matches); 92 extern unsigned long of_get_flat_dt_root(void); 93 extern int of_scan_flat_dt_by_path(const char *path, 94 int (*it)(unsigned long node, const char *name, int depth, void *data), 95 void *data); 96 97 extern int early_init_dt_scan_chosen(unsigned long node, const char *uname, 98 int depth, void *data); 99 extern int early_init_dt_scan_memory(unsigned long node, const char *uname, 100 int depth, void *data); 101 extern void early_init_fdt_scan_reserved_mem(void); 102 extern void early_init_dt_add_memory_arch(u64 base, u64 size); 103 extern int early_init_dt_reserve_memory_arch(phys_addr_t base, phys_addr_t size, 104 bool no_map); 105 extern void * early_init_dt_alloc_memory_arch(u64 size, u64 align); 106 extern u64 dt_mem_next_cell(int s, __be32 **cellp); 107 108 /* Early flat tree scan hooks */ 109 extern int early_init_dt_scan_root(unsigned long node, const char *uname, 110 int depth, void *data); 111 112 extern bool early_init_dt_scan(void *params); 113 114 extern const char *of_flat_dt_get_machine_name(void); 115 extern const void *of_flat_dt_match_machine(const void *default_match, 116 const void * (*get_next_compat)(const char * const**)); 117 118 /* Other Prototypes */ 119 extern void unflatten_device_tree(void); 120 extern void unflatten_and_copy_device_tree(void); 121 extern void early_init_devtree(void *); 122 extern void early_get_first_memblock_info(void *, phys_addr_t *); 123 #else /* CONFIG_OF_FLATTREE */ 124 static inline void early_init_fdt_scan_reserved_mem(void) {} 125 static inline const char *of_flat_dt_get_machine_name(void) { return NULL; } 126 static inline void unflatten_device_tree(void) {} 127 static inline void unflatten_and_copy_device_tree(void) {} 128 #endif /* CONFIG_OF_FLATTREE */ 129 130 #endif /* __ASSEMBLY__ */ 131 #endif /* _LINUX_OF_FDT_H */ 132