1 files changed, 133 insertions, 0 deletions
diff --git a/include/binman_sym.h b/include/binman_sym.h
new file mode 100644
index 00000000000..49a95eafade
--- /dev/null
+++ b/include/binman_sym.h
@@ -0,0 +1,133 @@
+/* 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 unsigned long _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 \
+	unsigned long _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 \
+	(*(unsigned long *)&_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.:
+ *
+ *    unsigned long address = binman_sym(unsigned long, 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