Allow to override PREFIX and include directory

AMDmi3 · web-flow · commit afdb0c76d707 · 2019-11-28T21:25:18.000+03:00
diff --git a/Makefile b/Makefile
@@ -11,8 +11,8 @@ DISTFILES = src \
 	COPYING \
 	Makefile \
 
-PREFIX = /usr/local
-TARGET_INCLUDE_PATH = $(PREFIX)/include/avr
+PREFIX ?= /usr/local
+TARGET_INCLUDE_PATH ?= $(PREFIX)/include/avr
 
 CDEFS = -DDEFAULT_INCLUDE_PATH='"$(TARGET_INCLUDE_PATH)"' \
 	-DVERSION='"$(VERSION)"'
