include/binman_sym.h

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