What uramdisk.gz and u-boot should be used to for the design outlined here for zc702 zynq http://wiki.analog.com/resources/tools-software/linux-drivers/platforms/zynq
The uEnv.txt specifies a uramdisk so the zc702 won't boot without it. I have a few from some other projects but each one has a different effect on the system when used with this design.
Also what u-boot.elf should be used to build the bootloader. I also have a few of these from other releases from Xilinx and each gives the final system differet behaviour.
With some combinations I'm finding I cannot use USB peripherals and in others the peripherals work fine but I get no Linaro desktop - only a blank screen.