Xen hypervisor on Rock64

[tumbleweed]

Hello,

I'm trying to install the Xen hypervisor on rock64, starting with the info at Xen ARM with Virtualization.
Here are the steps I followed so far:

1. Installed a minimal debian stretch image on the rock64 mmc (thanks @ayufan !)
   
2. Built Xen on rock64 (for XEN_TARGET_ARCH=arm64)
   
3. Used mkimage to prep xen for uboot: mkimage -A arm -C none -T kernel -a 0x00800800 -e 0x00800800 -d dist/install/boot/xen xen-uImage
   
4. Modified //boot/efi/extlinux/extlinux.conf  to add a custom configuration that loads the xen kernel (xen-uImage) using the same dtb that came with the stretch image (see config code below)
   
5. Reboot with serial console attached, select my custom extlinux configuration
   
6. rock64 hangs (serial output stops) at "Starting kernel ..."
   

As far as I know, nobody has written up a guide to doing this, on any RK3328 board, and it's my first time trying.
Anyone have suggestions on what I might try next to get past this hanging problem? 

Code:

label kernel-xen
   kernel /xen-uImage
   initrd /initrd.img
   fdt /dtb
   append earlyprintk=uart8250-32bit,0xff130000 rw root=LABEL=linux-root rootwait rootfstype=ext4 panic=10 init=/sbin/init coherent_pool=1M ethaddr=${ethaddr} eth1addr=${eth1addr} serial=${serial#} cgroup_enable=cpuset cgroup_memory=1 cgroup_enable=memory swapaccount=1