Implement STRUCT output format

include/patchelfcrc/crc-output-struct.h

@@ -0,0 +1,33 @@
+#ifndef _CRC_OUTPUT_STRUCT_H_
+#define _CRC_OUTPUT_STRUCT_H_
+
+#include <stdint.h>
+
+#define CRC_OUT_STRUCT_SIZE_32BIT 12u
+struct crc_out_struct_32bit {
+	uint32_t start_address;	/**< @brief Start address of struct*/
+	uint32_t length; 	/**< @brief Length of section in bytes */
+	uint32_t crc;		/**< @brief LSB aligned CRC */
+};
+
+#define CRC_OUT_STRUCT_SIZE_64BIT 24u
+struct crc_out_struct_64bit {
+	uint64_t start_address;	/**< @brief Start address of struct*/
+	uint64_t length; 	/**< @brief Length of section in bytes */
+	uint32_t crc;		/**< @brief LSB aligned CRC */
+    uint32_t _unused_dummy;	/**< @brief Dummy. Do not use, it prevents misalignments */
+};
+
+#define BUILD_ASSERT(cond) ((void)sizeof(char[1 - 2 * !!(cond)]))
+
+/**
+ * @brief Statically check sizes of @ref crc_out_struct_32bit and @ref crc_out_struct_64bit
+ * @note Place this at least once in your code to ensure the packing of the structures is correct
+ */
+#define CRC_OUT_CHECK_STRUCT_SIZES do { \
+	BUILD_ASSERT(sizeof(struct crc_out_struct_64bit) != CRC_OUT_STRUCT_SIZE_64BIT); \
+	BUILD_ASSERT(sizeof(struct crc_out_struct_32bit) != CRC_OUT_STRUCT_SIZE_32BIT); \
+} while(0)
+
+
+#endif /* _CRC_OUTPUT_STRUCT_H_ */