Every processor's StartupApSignal is initialized in MpInitLibInitialize() before calling CollectProcessorCount(). When SortApicId() is called from CollectProcessorCount(), AP Index is re-assigned by APIC ID. But SortApicId() forgets to set the correct StartupApSignal when sorting the AP. The patch fixes this issue. Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Star Zeng <star.zeng@intel.com> Signed-off-by: Ruiyu Ni <ruiyu.ni@intel.com> Reviewed-by: Star Zeng <star.zeng@intel.com> Cc: Chasel Chiu <chasel.chiu@intel.com>