The S3C2410 has three serial ports complete with FIFO. The first port is used as a console port by the bootloader and Linux. There is an external 9way D port which is level translated to RS232 signals by a MAX3243 device. There is an additional 10 way box header which is also level translated. The port output is selected by using a jumper matrix. For more details on the ports usage and jumper matrix refer to the EB2410ITX Connector and link pinouts document.