63ee68c220
This fixes a problem encountered on the Lenovo Thinkpad X220/Yoga 11e where runtime services would try to inexplicably jump to other parts of memory where it shouldn't be when attempting to enumerate EFI vars, causing a panic. The virtual mapping is enabled by default and can be disabled by setting efi_disable_vmap in loader.conf(5). Reviewed by: kib (earlier version) MFC after: 3 weeks Differential Revision: https://reviews.freebsd.org/D14677