K 10
svn:author
V 6
tsoome
K 8
svn:date
V 27
2017-03-30T16:23:31.798740Z
K 7
svn:log
V 639
loader: efipart should check disk size from partition table

While testing 32bit UEFI OVMF (which has bug about how the disk size
is presented), I did witness the errors from blkio->ReadBlocks().

It became apparent we can not entirely trust UEFI interfaces either,
so additional checks are needed.

So we use disk_ioctl(DIOCGMEDIASIZE) for disks, with fallback of
Media->LastBlock for other media.

In addition, we need to check if there is media present.

+ small fixes for error printout, and avoiding multiple blk * 512.

Reviewed by:	allanjude
Approved by:	allanjude (mentor)
Differential Revision:	https://reviews.freebsd.org/D10197

END