Add ATTR_* macros in the newly created attributes.h and use them wherever possible for improved readability.

shared/attributes.h

@@ -0,0 +1,11 @@
+#ifndef __ATTRIBUTES_H__
+#define __ATTRIBUTES_H__
+
+// Macros:
+
+    #define ATTR_PACKED __attribute__ ((packed))
+    #define ATTR_NO_INIT __attribute__ ((section (".noinit")))
+    #define ATTR_DATA2 __attribute__((section (".m_data_2")))
+    #define ATTR_BOOTLOADER_CONFIG __attribute__((used, section(".BootloaderConfig")))
+
+#endif