A baseboard management controller (BMC) of a server includes a general purpose input output (GPIO) pin. An voltage level of the GPIO level determines if a BIOS of the server or the BMC uses a serial port of the server. If the BMC wants to use the serial port and the voltage level of the GPIO pin is at a high level, the serial port can be used by the BMC. If the BMC wants to use the serial port but the voltage level of the GPIO pin is not at the high level, the serial port is be used by the BIOS. If the BIOS has been initialized, the voltage level of the GPIO pin is pulled up.