[PORT FROM XEN_SANDBOX]Bootstub modification for Xen, ported from R42TW branch

BZ: 136642

Deeply modified port from Xen branch

Change-Id: Icde718b22f8519ab33cc0dfb78a057bacfc9dda0
Orig-Change-Id: I0b56738d9532c268582b6a7a3d3fb1974cf28324
Signed-off-by: Evgeny Kalugin <[email protected]>
9 files changed