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/* SPDX-License-Identifier: GPL-2.0+ */
/*
* Symbol access for symbols set up by binman as part of the build.
*
* This allows C code to access the position of a particular part of the image
* assembled by binman.
*
* Copyright (c) 2017 Google, Inc
*/
#ifndef __BINMAN_SYM_H
#define __BINMAN_SYM_H
/* BSYM in little endian, keep in sync with tools/binman/elf.py */
#define BINMAN_SYM_MAGIC_VALUE (0x4d595342UL)
#define BINMAN_SYM_MISSING (-1UL)
#if CONFIG_IS_ENABLED(BINMAN_SYMBOLS)
/**
* binman_symname() - Internal function to get a binman symbol name
*
* @entry_name: Name of the entry to look for (e.g. 'u_boot_spl')
* @_prop_name: Property value to get from that entry (e.g. 'pos')
* @returns name of the symbol for that entry and property
*/
#define binman_symname(_entry_name, _prop_name) \
_binman_ ## _entry_name ## _prop_ ## _prop_name
/**
* binman_sym_declare() - Declare a symbol that will be used at run-time
*
* @_type: Type f the symbol (e.g. unsigned long)
* @entry_name: Name of the entry to look for (e.g. 'u_boot_spl')
* @_prop_name: Property value to get from that entry (e.g. 'pos')
*/
#define binman_sym_declare(_type, _entry_name, _prop_name) \
_type binman_symname(_entry_name, _prop_name) \
__attribute__((aligned(4), unused, section(".binman_sym")))
/**
* binman_sym_extern() - Declare a extern symbol that will be used at run-time
*
* @_type: Type f the symbol (e.g. unsigned long)
* @entry_name: Name of the entry to look for (e.g. 'u_boot_spl')
* @_prop_name: Property value to get from that entry (e.g. 'pos')
*/
#define binman_sym_extern(_type, _entry_name, _prop_name) \
extern _type binman_symname(_entry_name, _prop_name) \
__attribute__((aligned(4), unused, section(".binman_sym")))
/**
* binman_sym_declare_optional() - Declare an optional symbol
*
* If this symbol cannot be provided by binman, an error will not be generated.
* Instead the image will be assigned the value BINMAN_SYM_MISSING.
*
* @_type: Type f the symbol (e.g. unsigned long)
* @entry_name: Name of the entry to look for (e.g. 'u_boot_spl')
* @_prop_name: Property value to get from that entry (e.g. 'pos')
*/
#define binman_sym_declare_optional(_type, _entry_name, _prop_name) \
_type binman_symname(_entry_name, _prop_name) \
__attribute__((aligned(4), weak, unused, \
section(".binman_sym")))
/**
* _binman_sym_magic - Internal magic symbol for validity checks
*
* When building images, binman fills in this symbol with the magic
* value #defined above. This is used to check at runtime if the
* symbol values were filled in and are OK to use.
*/
extern ulong _binman_sym_magic;
/**
* DECLARE_BINMAN_MAGIC_SYM - Declare the internal magic symbol
*
* This macro declares the _binman_sym_magic symbol so that it exists.
* Declaring it here would cause errors during linking due to multiple
* definitions of the symbol.
*/
#define DECLARE_BINMAN_MAGIC_SYM \
ulong _binman_sym_magic \
__attribute__((aligned(4), section(".binman_sym")))
/**
* BINMAN_SYMS_OK - Check if the symbol values are valid
*
* This macro checks if the magic symbol's value is filled properly,
* which indicates that other symbols are OK to use as well.
*
* Return: 1 if binman symbol values are usable, 0 if not
*/
#define BINMAN_SYMS_OK \
(*(ulong *)&_binman_sym_magic == BINMAN_SYM_MAGIC_VALUE)
/**
* binman_sym() - Access a previously declared symbol
*
* This is used to get the value of a symbol. E.g.:
*
* ulong address = binman_sym(ulong, u_boot_spl, pos);
*
* @_type: Type f the symbol (e.g. unsigned long)
* @entry_name: Name of the entry to look for (e.g. 'u_boot_spl')
* @_prop_name: Property value to get from that entry (e.g. 'pos')
*
* Return: value of that property (filled in by binman), or
* BINMAN_SYM_MISSING if the value is unavailable
*/
#define binman_sym(_type, _entry_name, _prop_name) \
(BINMAN_SYMS_OK ? \
(*(_type *)&binman_symname(_entry_name, _prop_name)) : \
BINMAN_SYM_MISSING)
#else /* !CONFIG_IS_ENABLED(BINMAN_SYMBOLS) */
#define binman_sym_declare(_type, _entry_name, _prop_name)
#define binman_sym_declare_optional(_type, _entry_name, _prop_name)
#define binman_sym_extern(_type, _entry_name, _prop_name)
#define DECLARE_BINMAN_MAGIC_SYM
#define BINMAN_SYMS_OK (0)
#define binman_sym(_type, _entry_name, _prop_name) BINMAN_SYM_MISSING
#endif /* CONFIG_IS_ENABLED(BINMAN_SYMBOLS) */
#endif