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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
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 */
44struct 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/* TBD: Temporary export of fdt globals - remove when code fully merged */
61extern int __initdata dt_root_addr_cells;
62extern int __initdata dt_root_size_cells;
63extern struct boot_param_header *initial_boot_params;
64
65/* For scanning the flat device-tree at boot time */
66extern char *find_flat_dt_string(u32 offset);
67extern int of_scan_flat_dt(int (*it)(unsigned long node, const char *uname,
68 int depth, void *data),
69 void *data);
70extern void *of_get_flat_dt_prop(unsigned long node, const char *name,
71 unsigned long *size);
72extern int of_flat_dt_is_compatible(unsigned long node, const char *name);
73extern unsigned long of_get_flat_dt_root(void);
74extern void early_init_dt_scan_chosen_arch(unsigned long node);
75extern int early_init_dt_scan_chosen(unsigned long node, const char *uname,
76 int depth, void *data);
77extern void early_init_dt_check_for_initrd(unsigned long node);
78extern int early_init_dt_scan_memory(unsigned long node, const char *uname,
79 int depth, void *data);
80extern void early_init_dt_add_memory_arch(u64 base, u64 size);
81extern u64 early_init_dt_alloc_memory_arch(u64 size, u64 align);
82extern u64 dt_mem_next_cell(int s, __be32 **cellp);
83
84/*
85 * If BLK_DEV_INITRD, the fdt early init code will call this function,
86 * to be provided by the arch code. start and end are specified as
87 * physical addresses.
88 */
89#ifdef CONFIG_BLK_DEV_INITRD
90extern void early_init_dt_setup_initrd_arch(unsigned long start,
91 unsigned long end);
92#endif
93
94/* Early flat tree scan hooks */
95extern int early_init_dt_scan_root(unsigned long node, const char *uname,
96 int depth, void *data);
97
98/* Other Prototypes */
99extern void unflatten_device_tree(void);
100extern void early_init_devtree(void *);
101
102#endif /* __ASSEMBLY__ */
103#endif /* _LINUX_OF_FDT_H */