how to boot uImage of arm 64 bit kernel on raspberrypi 3?

I build the linux kernel-4.6 for rpi3 and tried to boot it up from u-boot using the following commands.

In u-boot console

fatload mmc 0:1 $fdt_addr_r bcm2710-rpi-3-b.dtb fatload mmc 0:1 $loadaddr Image setenv bootargs root=/dev/mmcblk0p2 rw rootwait console=tty0 rootfstype=ext4 booti $loadaddr - $fdt_addr_r

All the binaries are in place and the kernel just boots fine.

$loadaddr is 0x00200000
$fdt_addr_r is 0x00000100

How can I boot the uImage of the kernel instead of the Image binary since I don't know much about the type of Image binary (which shows up as MS Dos executable on doing file Image)

My Failed Attempt

Using the mkimage utility, I created the uImage as follows and then tried to boot it up using the following commands.

./mkimage -A arm64 -O Linux -T kernel -C none -a 0x80080000 -e 0x80080000 -d Image uImage

In u-boot console

fatload mmc 0:1 $fdt_addr_r bcm2710-rpi-3-b.dtb fatload mmc 0:1 $loadaddr uImage setenv bootargs root=/dev/mmcblk0p2 rw rootwait rootfstype=ext4 console=AMA0 bootm $loadaddr - $fdt_addr_r

But nothing happens and u-boot binary gets rebooted itself. Can bootm be used to boot the uImage of arm 64 bit kernel? Or the uImage created is itself not correct? What am I missing?