cm_fx6 booting

Hi,

I have a Compulab Utilite cm_fx6 in my lab but I am not sure how to make it boot.

I am using:

dd if=u-boot-with-spl.imx of=/dev/sdt bs=1K seek=1

It does seem to detect an image on the mmc (since it doesn't boot from SPI flash), but SPL and U-Boot output nothing.

Does anyone have any ideas? Perhaps this device is a bit old.

Thanks, Simon