[fedora-arm] F27 grubaa64.efi pxe boot with Mustang drops to grub> prompt

Hey All, Sorry if I have missed this someplace obvious. But I am trying to test a pxe install on a Mustang (xgene-1) board with F27 using the grubaa64.efi acquired from here: http://dl.fedoraproject.org/pub/fedora-secondary/releases/27/Server/aarch... After being handed off this file from my dhcp server, the system drops down into a 'grub>' shell awaiting my input. But if I then replace the F27 grubaa64.efi file with the known good grubaa64.efi from RHEL-alt-7.4, the system boots as normal and loads my grub.cfg menu and I am allowed to choose an install option: ------------------------ Install Red Hat Enterprise Linux for ARM 7.4 GA Install Fedora 27 Use the  and  keys to change the selection. Press 'e' to edit the selected item, or 'c' for a command prompt. The selected entry will be started automatically in 2s. --------------------------- However, as you can imagine, this does not work if I select the Fedora 27 install. It halts and tells me I need to load the correct kernel: -------------- error: invalid magic number. error: you need to load the kernel first. ----------- This I assume is b/c I am using the incorrect grubaa64.efi to hand off to the F27 install kernel. So, is this a bug in the F27 grubaa64.efi? I have a pxe server that has been working for me with UEFI systems for a couple years now. All I normally do to test a a new OS is swap out the grubaa64.efi as I have done here. But, I admit that my experience is with different versions of RHEL and cetos. This is my first time doing this with Fedora. Thanks in advance for any tips!