1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /*
3  * Symbol access for symbols set up by binman as part of the build.
4  *
5  * This allows C code to access the position of a particular part of the image
6  * assembled by binman.
7  *
8  * Copyright (c) 2017 Google, Inc
9  */
10 
11 #ifndef __BINMAN_SYM_H
12 #define __BINMAN_SYM_H
13 
14 #define BINMAN_SYM_MISSING	(-1UL)
15 
16 #ifdef CONFIG_BINMAN
17 
18 /**
19  * binman_symname() - Internal function to get a binman symbol name
20  *
21  * @entry_name: Name of the entry to look for (e.g. 'u_boot_spl')
22  * @_prop_name: Property value to get from that entry (e.g. 'pos')
23  * @returns name of the symbol for that entry and property
24  */
25 #define binman_symname(_entry_name, _prop_name) \
26 	_binman_ ## _entry_name ## _prop_ ## _prop_name
27 
28 /**
29  * binman_sym_declare() - Declare a symbol that will be used at run-time
30  *
31  * @_type: Type f the symbol (e.g. unsigned long)
32  * @entry_name: Name of the entry to look for (e.g. 'u_boot_spl')
33  * @_prop_name: Property value to get from that entry (e.g. 'pos')
34  */
35 #define binman_sym_declare(_type, _entry_name, _prop_name) \
36 	_type binman_symname(_entry_name, _prop_name) \
37 		__attribute__((aligned(4), unused, section(".binman_sym")))
38 
39 /**
40  * binman_sym_extern() - Declare a extern symbol that will be used at run-time
41  *
42  * @_type: Type f the symbol (e.g. unsigned long)
43  * @entry_name: Name of the entry to look for (e.g. 'u_boot_spl')
44  * @_prop_name: Property value to get from that entry (e.g. 'pos')
45  */
46 #define binman_sym_extern(_type, _entry_name, _prop_name) \
47 	extern _type binman_symname(_entry_name, _prop_name) \
48 		__attribute__((aligned(4), unused, section(".binman_sym")))
49 
50 /**
51  * binman_sym_declare_optional() - Declare an optional symbol
52  *
53  * If this symbol cannot be provided by binman, an error will not be generated.
54  * Instead the image will be assigned the value BINMAN_SYM_MISSING.
55  *
56  * @_type: Type f the symbol (e.g. unsigned long)
57  * @entry_name: Name of the entry to look for (e.g. 'u_boot_spl')
58  * @_prop_name: Property value to get from that entry (e.g. 'pos')
59  */
60 #define binman_sym_declare_optional(_type, _entry_name, _prop_name) \
61 	_type binman_symname(_entry_name, _prop_name) \
62 		__attribute__((aligned(4), weak, unused, \
63 		section(".binman_sym")))
64 
65 /**
66  * binman_sym() - Access a previously declared symbol
67  *
68  * This is used to get the value of a symbol. E.g.:
69  *
70  *    ulong address = binman_sym(ulong, u_boot_spl, pos);
71  *
72  * @_type: Type f the symbol (e.g. unsigned long)
73  * @entry_name: Name of the entry to look for (e.g. 'u_boot_spl')
74  * @_prop_name: Property value to get from that entry (e.g. 'pos')
75  * @returns value of that property (filled in by binman)
76  */
77 #define binman_sym(_type, _entry_name, _prop_name) \
78 	(*(_type *)&binman_symname(_entry_name, _prop_name))
79 
80 #else /* !BINMAN */
81 
82 #define binman_sym_declare(_type, _entry_name, _prop_name)
83 
84 #define binman_sym_declare_optional(_type, _entry_name, _prop_name)
85 
86 #define binman_sym_extern(_type, _entry_name, _prop_name)
87 
88 #define binman_sym(_type, _entry_name, _prop_name) BINMAN_SYM_MISSING
89 
90 #endif /* BINMAN */
91 
92 #endif
93