BeagleBoneBlack is not booting from UART

Hi,
I am new beagle bone black, currently working on u-boot. I compiled the u-boot by using cross compilation, and i got MLO, u-boot.img and several other files as well.
And i was loading the MLO, u-boot,img files to the bbb through xmodem, but once the transfer get completes, its waiting for 8-10 seconds, later its started booting, but its not booting from the files which i have loaded, it is booting from some other partitions. How can i boot the bbb from xmodem, please share me your valuable suggestions.

Thanks
Venkatesh

Did you try pressing the Switch S2 while you boot from your own image via xmodem.
Be default I think it is booting frmo the emmc !

Thanks you for rply Raul Piper,
Actually i erased nand flash, and if boot from nand, its giving CCCCCC, but when i do the above procedure its booting from somewhere from nand. But my doubt is i even though i erased nand flash, from where it is booting…?