A method for updating firmware in a communication device storing an original firmware in a first data area of a non-volatile memory includes receiving and storing a new firmware in a second data area of the non-volatile memory. The method comprises assigning a firmware other than the new firmware as a boot firmware for the communication device before verification of the new firmware. The new firmware is loaded and executed in response to a boot procedure of the communication device. If the new firmware is executable and causes the communication device to satisfy a predetermined boot up condition, the new firmware passes the bootability check, and the new firmware is assigned as the boot firmware. The new firmware is not assigned as the boot firmware if the new firmware does not pass the bootability check.