2 * Definitions for working with the Flattened Device Tree data format
4 * Copyright 2009 Benjamin Herrenschmidt, IBM Corp
5 * benh@kernel.crashing.org
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.
12 #ifndef _LINUX_OF_FDT_H
13 #define _LINUX_OF_FDT_H
15 #include <linux/types.h>
16 #include <linux/init.h>
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,
24 #define OF_DT_NOP 0x4 /* nop */
27 #define OF_DT_VERSION 0x10
31 * This is what gets passed to the kernel by prom_init or kexec
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)
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
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 */
60 #if defined(CONFIG_OF_FLATTREE)
61 /* TBD: Temporary export of fdt globals - remove when code fully merged */
62 extern int __initdata dt_root_addr_cells
;
63 extern int __initdata dt_root_size_cells
;
64 extern struct boot_param_header
*initial_boot_params
;
66 /* For scanning the flat device-tree at boot time */
67 extern char *find_flat_dt_string(u32 offset
);
68 extern int of_scan_flat_dt(int (*it
)(unsigned long node
, const char *uname
,
69 int depth
, void *data
),
71 extern void *of_get_flat_dt_prop(unsigned long node
, const char *name
,
73 extern int of_flat_dt_is_compatible(unsigned long node
, const char *name
);
74 extern unsigned long of_get_flat_dt_root(void);
75 extern void early_init_dt_scan_chosen_arch(unsigned long node
);
76 extern int early_init_dt_scan_chosen(unsigned long node
, const char *uname
,
77 int depth
, void *data
);
78 extern void early_init_dt_check_for_initrd(unsigned long node
);
79 extern int early_init_dt_scan_memory(unsigned long node
, const char *uname
,
80 int depth
, void *data
);
81 extern void early_init_dt_add_memory_arch(u64 base
, u64 size
);
82 extern u64
early_init_dt_alloc_memory_arch(u64 size
, u64 align
);
83 extern u64
dt_mem_next_cell(int s
, __be32
**cellp
);
86 * If BLK_DEV_INITRD, the fdt early init code will call this function,
87 * to be provided by the arch code. start and end are specified as
90 #ifdef CONFIG_BLK_DEV_INITRD
91 extern void early_init_dt_setup_initrd_arch(unsigned long start
,
95 /* Early flat tree scan hooks */
96 extern int early_init_dt_scan_root(unsigned long node
, const char *uname
,
97 int depth
, void *data
);
99 /* Other Prototypes */
100 extern void unflatten_device_tree(void);
101 extern void early_init_devtree(void *);
102 #else /* CONFIG_OF_FLATTREE */
103 static inline void unflatten_device_tree(void) {}
104 #endif /* CONFIG_OF_FLATTREE */
106 #endif /* __ASSEMBLY__ */
107 #endif /* _LINUX_OF_FDT_H */