K 10
svn:author
V 6
andrew
K 8
svn:date
V 27
2019-09-16T13:45:31.737012Z
K 7
svn:log
V 480
MFC r346996:

Restore x18 in efi_arch_leave.

Some UEFI implementations trash this register and, as we use it as a
platform register, the kernel doesn't save it before calling into the UEFI
runtime services. As we have a copy in tpidr_el1 restore from there when
exiting the EFI environment.

PR:		237234, 237055
Reviewed by:	manu
Tested On:	Ampere eMAG
Sponsored by:	DARPA, AFRL
Sponsored by:	Ampere Computing (hardware)
Differential Revision:	https://reviews.freebsd.org/D20127

END