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 * benh@kernel.crashing.org
7 */
8
9 #ifndef _LINUX_OF_FDT_H
10 #define _LINUX_OF_FDT_H
11
12 #include <linux/types.h>
13 #include <linux/init.h>
14 #include <linux/errno.h>
15
16 /* Definitions used by the flattened device tree */
17 #define OF_DT_HEADER 0xd00dfeed /* marker */
18
19 #ifndef __ASSEMBLY__
20
21 #if defined(CONFIG_OF_FLATTREE)
22
23 struct device_node;
24
25 /* For scanning an arbitrary device-tree at any time */
26 extern void *of_fdt_unflatten_tree(const unsigned long *blob,
27 struct device_node *dad,
28 struct device_node **mynodes);
29
30 /* TBD: Temporary export of fdt globals - remove when code fully merged */
31 extern int __initdata dt_root_addr_cells;
32 extern int __initdata dt_root_size_cells;
33 extern void *initial_boot_params;
34
35 extern char __dtb_start[];
36 extern char __dtb_end[];
37
38 /* Other Prototypes */
39 extern u64 of_flat_dt_translate_address(unsigned long node);
40 extern void of_fdt_limit_memory(int limit);
41 #endif /* CONFIG_OF_FLATTREE */
42
43 #ifdef CONFIG_OF_EARLY_FLATTREE
44 /* For scanning the flat device-tree at boot time */
45 extern int of_scan_flat_dt(int (*it)(unsigned long node, const char *uname,
46 int depth, void *data),
47 void *data);
48 extern int of_scan_flat_dt_subnodes(unsigned long node,
49 int (*it)(unsigned long node,
50 const char *uname,
51 void *data),
52 void *data);
53 extern int of_get_flat_dt_subnode_by_name(unsigned long node,
54 const char *uname);
55 extern const void *of_get_flat_dt_prop(unsigned long node, const char *name,
56 int *size);
57 extern int of_flat_dt_is_compatible(unsigned long node, const char *name);
58 extern unsigned long of_get_flat_dt_root(void);
59 extern uint32_t of_get_flat_dt_phandle(unsigned long node);
60
61 /*
62 * early_init_dt_scan_chosen - scan the device tree for ramdisk and bootargs
63 *
64 * The boot arguments will be placed into the memory pointed to by @data.
65 * That memory should be COMMAND_LINE_SIZE big and initialized to be a valid
66 * (possibly empty) string. Logic for what will be in @data after this
67 * function finishes:
68 *
69 * - CONFIG_CMDLINE_FORCE=true
70 * CONFIG_CMDLINE
71 * - CONFIG_CMDLINE_EXTEND=true, @data is non-empty string
72 * @data + dt bootargs (even if dt bootargs are empty)
73 * - CONFIG_CMDLINE_EXTEND=true, @data is empty string
74 * CONFIG_CMDLINE + dt bootargs (even if dt bootargs are empty)
75 * - CMDLINE_FROM_BOOTLOADER=true, dt bootargs=non-empty:
76 * dt bootargs
77 * - CMDLINE_FROM_BOOTLOADER=true, dt bootargs=empty, @data is non-empty string
78 * @data is left unchanged
79 * - CMDLINE_FROM_BOOTLOADER=true, dt bootargs=empty, @data is empty string
80 * CONFIG_CMDLINE (or "" if that's not defined)
81 */
82 extern int early_init_dt_scan_chosen(unsigned long node, const char *uname,
83 int depth, void *data);
84 extern int early_init_dt_scan_memory(unsigned long node, const char *uname,
85 int depth, void *data);
86 extern int early_init_dt_scan_chosen_stdout(void);
87 extern void early_init_fdt_scan_reserved_mem(void);
88 extern void early_init_fdt_reserve_self(void);
89 extern void __init early_init_dt_scan_chosen_arch(unsigned long node);
90 extern void early_init_dt_add_memory_arch(u64 base, u64 size);
91 extern int early_init_dt_mark_hotplug_memory_arch(u64 base, u64 size);
92 extern int early_init_dt_reserve_memory_arch(phys_addr_t base, phys_addr_t size,
93 bool no_map);
94 extern u64 dt_mem_next_cell(int s, const __be32 **cellp);
95
96 /* Early flat tree scan hooks */
97 extern int early_init_dt_scan_root(unsigned long node, const char *uname,
98 int depth, void *data);
99
100 extern bool early_init_dt_scan(void *params);
101 extern bool early_init_dt_verify(void *params);
102 extern void early_init_dt_scan_nodes(void);
103
104 extern const char *of_flat_dt_get_machine_name(void);
105 extern const void *of_flat_dt_match_machine(const void *default_match,
106 const void * (*get_next_compat)(const char * const**));
107
108 /* Other Prototypes */
109 extern void unflatten_device_tree(void);
110 extern void unflatten_and_copy_device_tree(void);
111 extern void early_init_devtree(void *);
112 extern void early_get_first_memblock_info(void *, phys_addr_t *);
113 #else /* CONFIG_OF_EARLY_FLATTREE */
early_init_dt_scan_chosen_stdout(void)114 static inline int early_init_dt_scan_chosen_stdout(void) { return -ENODEV; }
early_init_fdt_scan_reserved_mem(void)115 static inline void early_init_fdt_scan_reserved_mem(void) {}
early_init_fdt_reserve_self(void)116 static inline void early_init_fdt_reserve_self(void) {}
of_flat_dt_get_machine_name(void)117 static inline const char *of_flat_dt_get_machine_name(void) { return NULL; }
unflatten_device_tree(void)118 static inline void unflatten_device_tree(void) {}
unflatten_and_copy_device_tree(void)119 static inline void unflatten_and_copy_device_tree(void) {}
120 #endif /* CONFIG_OF_EARLY_FLATTREE */
121
122 #endif /* __ASSEMBLY__ */
123 #endif /* _LINUX_OF_FDT_H */
124