tag	line	file	source code
UART_MCR_LOOP	1175	kernel/chr_drv/serial.c	serial_outp(info, UART_MCR, UART_MCR_LOOP | scratch);
UART_MCR_LOOP	1177	kernel/chr_drv/serial.c	serial_outp(info, UART_MCR, UART_MCR_LOOP | 0x0A);