[PULL][Trusty] arm64: Add EFI stub support

[Colin Ian King]

On 10/04/15 22:11, Dann Frazier wrote:
> Ubuntu currently provides arm64-efi cloud images, but the 14.04 LTS
> images aren't actually bootable due to the lack of EFI stub support.
> This means there is currently no Ubuntu LTS option for users deploying
> guests on ARM64-based clouds, and that's just not cool, man.
> 
>   git://kernel.ubuntu.com/dannf/trusty-xgene.git@arm64-efi
> 
> Prebuilt packages are available in ppa:dannf/arm64efi.
> 
> This is based on an earlier backport from Ming Lei, but modified to
> minimize the changes (read: regression risk) to x86. There are no
> changes under arch/x86, and all of the arch-indep changes are adding
> new interfaces that x86 doesn't use.
> 
> With these changes, the trusty cloud images are now bootable. However,
> they do not have automatic console detection (you have to manually add
> console=ttyAMA0), and do not yet have an EFI RTC driver - that work is
> up next.
> 
> I've regression tested on X-Gene/u-boot and on the QEMU arm64 virt
> model booted w/ -kernel to make sure it doesn't break non-EFI systems.
> Thanks to Rod Smith for regression testing on an EFI-mode mac and
> within virtualbox to confirm I didn't break EFI mode on x86.
> 

This is rather a large patch set, however, the majority of the patches
are either clean upstream cherry picks, cherry-picked patches that are
wiggled to apply cleanly or upstream patches that are backported with
minor changes.

I've reviewed these patches and I'm OK to Ack these. These patches
mainly touch the arm64 specific tree and there is little risk of
regression on x86-64 EFI H/W.

I have also regression tested this on two x86-64 EFI enabled machines
and an EFI enabled VM too.  I've not verified the changes on arm64 H/W.

Acked-by: Colin Ian King <colin.king at canonical.com>