+/**\r
+ Insert one pre-fetched key into the FIFO buffer.\r
+\r
+ @param EfiKeyFiFo Pointer to instance of EFI_KEY_FIFO.\r
+ @param Input The key will be input.\r
+\r
+ @retval TRUE If insert successfully.\r
+ @retval FALSE If FIFO buffer is full before key insertion,\r
+ and the key is lost.\r
+\r
+**/\r
+BOOLEAN\r
+EfiKeyFiFoForNotifyInsertOneKey (\r
+ EFI_KEY_FIFO *EfiKeyFiFo,\r
+ EFI_INPUT_KEY *Input\r
+ );\r
+\r
+/**\r
+ Remove one pre-fetched key out of the FIFO buffer.\r
+\r
+ @param EfiKeyFiFo Pointer to instance of EFI_KEY_FIFO.\r
+ @param Output The key will be removed.\r
+\r
+ @retval TRUE If insert successfully.\r
+ @retval FALSE If FIFO buffer is empty before remove operation.\r
+\r
+**/\r
+BOOLEAN\r
+EfiKeyFiFoForNotifyRemoveOneKey (\r
+ EFI_KEY_FIFO *EfiKeyFiFo,\r
+ EFI_INPUT_KEY *Output\r
+ );\r
+\r
+/**\r
+ Clarify whether FIFO buffer is empty.\r
+\r
+ @param EfiKeyFiFo Pointer to instance of EFI_KEY_FIFO.\r
+\r
+ @retval TRUE If FIFO buffer is empty.\r
+ @retval FALSE If FIFO buffer is not empty.\r
+\r
+**/\r
+BOOLEAN\r
+IsEfiKeyFiFoForNotifyEmpty (\r
+ IN EFI_KEY_FIFO *EfiKeyFiFo\r
+ );\r
+\r
+/**\r
+ Clarify whether FIFO buffer is full.\r
+\r
+ @param EfiKeyFiFo Pointer to instance of EFI_KEY_FIFO.\r
+\r
+ @retval TRUE If FIFO buffer is full.\r
+ @retval FALSE If FIFO buffer is not full.\r
+\r
+**/\r
+BOOLEAN\r
+IsEfiKeyFiFoForNotifyFull (\r
+ EFI_KEY_FIFO *EfiKeyFiFo\r
+ );\r
+\r