diff --git a/MdeModulePkg/Core/Dxe/DxeMain/DxeMain.c b/MdeModulePkg/Core/Dxe/DxeMain/DxeMain.c
index 91e94a7..6b729df 100644
--- a/MdeModulePkg/Core/Dxe/DxeMain/DxeMain.c
+++ b/MdeModulePkg/Core/Dxe/DxeMain/DxeMain.c
@@ -743,6 +800,7 @@ CoreExitBootServices (
   //
   // Disable Timer
   //
+  if(gTimer)
   gTimer->SetTimerPeriod (gTimer, 0);
 
   //
@@ -780,6 +838,7 @@ CoreExitBootServices (
   //
   // Disable CPU Interrupts
   //
+  if(gCpu)
   gCpu->DisableInterrupt (gCpu);
 
   MemoryProtectionExitBootServicesCallback();
diff --git a/MdeModulePkg/Core/Dxe/Misc/MemoryProtection.c b/MdeModulePkg/Core/Dxe/Misc/MemoryProtection.c
index a73c4cc..2c08b81 100644
--- a/MdeModulePkg/Core/Dxe/Misc/MemoryProtection.c
+++ b/MdeModulePkg/Core/Dxe/Misc/MemoryProtection.c
@@ -232,7 +232,7 @@ SetUefiImageMemoryAttributes (
 
   DEBUG ((DEBUG_INFO, "SetUefiImageMemoryAttributes - 0x%016lx - 0x%016lx (0x%016lx)\n", BaseAddress, Length, FinalAttributes));
 
-  ASSERT(gCpu != NULL);
+  if(gCpu)
   gCpu->SetMemoryAttributes (gCpu, BaseAddress, Length, FinalAttributes);
 }
 
--- /dev/null	2017-09-19 09:53:09.766660422 -0400
+++ ./Makefile	2017-09-20 15:24:01.850433474 -0400
@@ -0,0 +1,35 @@
+# Wrapper around the edk2 "build" script to generate
+# the few files that we actually want and avoid rebuilding
+# if we don't have to.
+
+PWD := $(shell pwd)
+EDK2_OUTPUT_DIR := $(PWD)/Build/MdeModule/DEBUG_GCC5/X64/MdeModulePkg/Core
+EDK2_BIN_DIR := $(PWD)/BaseTools/BinWrappers/PosixLike
+
+export PATH := $(EDK2_BIN_DIR):$(PATH)
+export CONFIG_PATH := $(PWD)/Conf
+export EDK_TOOLS_PATH := $(PWD)/BaseTools
+export WORKSPACE := $(PWD)
+
+EDK2_BINS += Dxe/DxeMain/DEBUG/DxeCore.efi
+EDK2_BINS += RuntimeDxe/RuntimeDxe/DEBUG/RuntimeDxe.efi
+
+EDK2_OUTPUTS = $(addprefix $(EDK2_OUTPUT_DIR)/,$(EDK2_BINS))
+
+# build takes too long, so we check to see if our executables exist
+# before we start a build.  run the clean target if they must be rebuilt
+all: $(EDK2_OUTPUTS)
+	ls -Fla $(EDK2_OUTPUTS)
+	cp -a $(EDK2_OUTPUTS) .
+
+$(EDK2_OUTPUTS):
+	build
+
+build:
+	build
+
+clean:
+	$(RM) $(EDK2_OUTPUTS)
+
+real-clean: clean
+	build clean