+const uint8_t UART_IER_RDI = 0x01;
+const uint8_t UART_IER_THRI = 0x02;
+const uint8_t UART_IER_RLSI = 0x04;
+
+
+const uint8_t UART_LSR_TEMT = 0x40;
+const uint8_t UART_LSR_THRE = 0x20;
+const uint8_t UART_LSR_DR = 0x01;
+
+const uint8_t UART_MCR_LOOP = 0x10;
+
+
+class Terminal;