+# Cleanup environment from any variables
+unexport BUILD_ARCH BUILD_PLATFORM BUILDTARGET CROSSTARGET TOOLCHAIN TOOLS_DIR
+
+ifeq "$(BUILD_ARCH)" "aarch64"
+ IS_64BIT = 1
+endif
+
+ifeq "$(BUILD_ARCH)" "armv7hl"
+ IS_32BIT = 1
+endif
+
+ifeq "$(BUILD_ARCH)" "armv5tel"
+ IS_32BIT = 1
+endif
+
+ifeq "$(BUILD_ARCH)" "x86_64"
+ IS_64BIT = 1
+endif
+
+ifeq "$(BUILD_ARCH)" "i586"
+ IS_32BIT = 1
+endif
+
+ifeq "$(TOOLCHAIN)" "1"
+ PREFIX = $(TOOLS_DIR)
+else
+ PREFIX = /usr
+endif
+
+TAR_OPTIONS = --xz
+