Refactoring menu code to be non-blocking

Added macros for GPIO read/write

source/System/system.h

@@ -14,7 +14,11 @@
 
 #define SYS_INFO_LENGTH			24	//max string length for setup parameters (model, mfg, etc.)
 
-
+typedef enum
+{
+	GUI_MODE_NORMAL = 0,
+	GUI_MODE_MENU
+} GuiMode_t;
 
 
 //System data
@@ -30,7 +34,11 @@ typedef struct
 
 	uint32_t language;								//system language
 
-}SYSTEM_DATA_t;
+	uint32_t systemTime;							// system time in milliseconds since boot
+
+	GuiMode_t	guiMode;
+
+} SYSTEM_DATA_t;
 
 
 void SYS_LoadFactoryDefaults(void);