Segregate the disk probing and selection protocol from the rest of the
boot loader.
Reviewed by: tsoome, bcran
Differential Revision: https://reviews.freebsd.org/D20547
We're storing an EFI_HANDLE, not an pointer to a handle. Since
EFI_HANDLE is a void * anyway, this has little practical effect since
the conversion to / from void * and void ** is silent.
While in base we use it as a boolean (of the wrong spelling), there's
at least one out of tree user that needs it to be int since priorirty
is a small int, not a 0/1. In deference to the time it's wasted me and
my team, push this up into FreeBSD for whatever short life boot1 may
have in the tree.
If the check for a UFS partition at offset 0 on the disk fails, check
to see if there's a BSD disklabel at block 1 (standard) or at offset
512 (install images assume 512 sector size). If found, probe for UFS
on the 'a' partition.
This fixes UEFI booting images from a BSD labeled MBR slice when the
'a' partiton isn't at offset 0. This is a stop-gap fix since we plan
on removing boot1.efi in FreeBSD 12. We can't easily do that for 11.2,
however, hence the short MFC window.
Tested by: emaste@
MFC After: 3 days
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D15598
