r336921 broke booting on MBP 2017, EFIRT related

Fri Aug 31 08:27:56 UTC 2018

On Thu, Aug 30, 2018 at 10:12:33PM +0300, Konstantin Belousov wrote:
> On Thu, Aug 30, 2018 at 12:22:36PM +0300, Yuri Pankov wrote:
> > Sorry, I accidentally took the discussion off-list, where Konstantin 
> > provided some more patches.  I'm attaching the one that finally worked 
> > for me.  It also adds some diagnostic prints which require bootverbose 
> > to be enabled.
> 
> This patch requires some more work to make it committable.
> Do not try to build it with efirt device in the kernel config,
> only efirt.ko works, but it can be preloaded from loader.

A version of the patch which finishes items which I wanted
to handle, is available both for review and for testing at
https://reviews.freebsd.org/D16972 .