diff options
Diffstat (limited to 'include/binman_sym.h')
| -rw-r--r-- | include/binman_sym.h | 45 |
1 files changed, 43 insertions, 2 deletions
diff --git a/include/binman_sym.h b/include/binman_sym.h index 8586ef8731..528d7e4e90 100644 --- a/include/binman_sym.h +++ b/include/binman_sym.h @@ -11,6 +11,8 @@ #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) @@ -63,6 +65,37 @@ 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.: @@ -72,10 +105,14 @@ * @_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') - * @returns value of that property (filled in by binman) + * + * 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) \ - (*(_type *)&binman_symname(_entry_name, _prop_name)) + (BINMAN_SYMS_OK ? \ + (*(_type *)&binman_symname(_entry_name, _prop_name)) : \ + BINMAN_SYM_MISSING) #else /* !CONFIG_IS_ENABLED(BINMAN_SYMBOLS) */ @@ -85,6 +122,10 @@ #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) */ |