BTT definitions are defined in UEFI spec 2.7, to defines a layout and set of rules for doing block I/O that provide powerfail write atomicity of a single block in NVDIMM. Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Ruiyu Ni <ruiyu.ni@intel.com> Reviewed-by: Liming Gao <liming.gao@intel.com>