U-boot from SD card

How do I know if my beagle uses the u-boot provided in the SD card and
not the one flashed in NAND? It seems this step is mandatory to have
the linux kernel initialising omapfb correctly. I can see Tux/beagle
when u boot starts but the display become black when the kernel


Depending on the version of MLO/x-load you are using, it might say
where it is booting on the serial console. You can also halt the boot
process and type 'version', which will tell you when the u-boot was
built. That should let you know quickly if you are running the u-boot
you just built and put on the SD card.

When you boot over MMC, you should see a message like

Starting OS Bootloader from MMC...


Thank you guys, It was a matter of x-loader, I flashed a new one
(1.4.2) and I can get something on my LCD TV when the kernel boots.