[U-Boot] Load code in U-Boot for mpc5121e

Hi,

I am quiet new with embedded linux so I was wondering if someone can help me with my issue. I am trying to load a c code on the mpc5121e processor found on the ADS5121 board. The only connection between my board and my host (Linux PC) is a serial cable and an Ethernet cable. I am trying to turn on the LEDs on the board, but for some reason I am not able to debug my code. I have been told that I either have to purchase an EthernetTAP or a USBTAP, or I should try to load the code in U-Boot. So I was wondering if someone can tell me how to load my code in U-Boot. Thank you.