Xen hypervisor on Rock64

[tumbleweed]

I was able to get a bit further with loading with the EFI approach.

First I flashed u-boot onto SPI flash.

Then I loaded the xen.efi onto a micro sd card (as bootaa64.efi), stopped the uboot autoboot, 
and attempted to manually boot using efi.  This yields the errors shown below -- Any suggestions?

Code:

Hit any key to stop autoboot:  0
=> set devtype mmc
=> set devnum 1
=> set distro_bootpart 6
=> run boot_efi_binary
reading efi/boot/bootaa64.efi
885072 bytes read in 128 ms (6.6 MiB/s)
libfdt fdt_check_header(): FDT_ERR_BADMAGIC
## Starting EFI application at 02000000 ...
Card did not respond to voltage select!
mmc_init: -95, time 10
Scanning disk rksdmmc@ff520000.blk...
Scanning disk rksdmmc@ff500000.blk...
Found 2 disks
Xen 4.11-rc (c/s Tue May 1 09:03:13 2018 +0100 git:0306a1311d) EFI loader
Couldn't obtain the File System Protocol Interface: ErrCode: 0x8000000000000003
## Application terminated, r = 0

For reference, here's what's on the sd card:

Code:

=> ls mmc 1:6
19644424   image
           efi/
           extlinux/
 2920159   initrd.img
   56922   dtb
     134   xen.cfg

=> ls mmc 1:6 efi/boot
            ./
            ../
   885072   bootaa64.efi 

The existing Image and dtb boot OK (using /extlinux/extlinux.conf )  but xen does not boot.