BeagleBoneBlack is not booting from UART

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.


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…?