booting a UEFI PC off an external/cloned *Trusty/14.04* install for a BIOS-based PC

Hi,

My wife's venerable HP G62 laptop just died (no more display, not even over the VGA port) at the worst possible time, so we're looking at replacing it ASAP. One potential candidate is the ASUS P2 520LA-XO0456T , and I'd like to know what the odds are that I could boot it into the HP's Linux install. That's a Kubuntu 14.04, fully up to date with a home-built, mainstream 3.14.59 keel and a few PPAs to get newer Qt and KDE4 versions.

The Asus is UEFI-based as I guess most newer hardware will be, while I only have Linux installations with GRUB bootloaders for BIOS. That includes the HP's inteal disk which apparently is fine (and contains the single, btrfs Linux partition).

grub2 : 2.02~beta2-9ubuntu1.7
initramfs-tools-bin : 0.103ubuntu4.2
zfs-initramfs : 0.6.5.4-1~trusty

I know one needs to disable SecureBoot and FastBoot, typically. And then? Do PC UEFIs indeed/still contain a BIOS emulation mode? Or do I need to install addition grub components, copy them to /boot/grub, and rerun grub and/or update-initramfs? Should I do that from a UEFI-based PC (somehow) or can that be done simply from my good ole AO722 netbook which is currently the only physical Linux rig I have available?

Thanks!