[seL4] i.MX6 quad booting problems

Hi everyone, I hope I'm using the correct list for this type of thing... I've bought my own Sabre Lite (identical to the AOS boards), and I've been trying for a few days now to get it to boot from tftp. I've downloaded the prebuilt u-boot.bin from the Sabre Lite hardware page, but it still doesn't seem to be working - it keeps timing out when trying to do the transfer. I think my tftp server is set up correctly, since it is the same as it was during AOS last semester. Could someone please boot a Sabre Lite set up for TFTP, interrupt the default boot process, type "printenv" into the U-Boot prompt and paste the results? Sorry if this is the wrong place to ask. Thanks, - Will