EDK2_ARCH ?= ARM\r
EDK2_BUILD ?= DEBUG\r
\r
-ifeq ($(EDK2_DSC),"")\r
+ifndef EDK2_DSC\r
$(error The Makfile macro 'EDK2_DSC' must be defined with an EDK2 DSC file.)\r
endif\r
ifeq ("$(EDK2_DSC)","ArmPlatformPkg/ArmVExpressPkg/ArmVExpress-FVP-AArch64.dsc")\r