cross-platform directory build

Author: jackctj117

test/Makefile

@@ -268,9 +268,9 @@ coverage:
 	fi
 	$(BUILD_DIR)/$(BIN).elf
 	@echo "Generating coverage report..."
-	cd .. && mkdir -p coverage && gcovr --root . \
+	gcovr --root .. \
 		--filter 'src/.*' \
 		--filter 'wolfhsm/.*' \
-		--html-details coverage/index.html \
+		--html-details $(BUILD_DIR)/coverage.html \
 		--print-summary
-	@echo "Coverage report generated at ../coverage/index.html"
+	@echo "Coverage report generated at $(BUILD_DIR)/coverage.html"