1 files changed, 22 insertions, 2 deletions
diff --git a/Makefile b/Makefile
index 6acc130..c62141b 100644
--- a/Makefile
+++ b/Makefile
@@ -3,9 +3,29 @@
 # Prefix where ghdl has been installed
 GHDL_PREFIX=
 
+# GHDL_PREFIX must be defined.
 ifeq ($(GHDL_PREFIX),)
 $(error GHDL_PREFIX not defined)
 endif
 
-ghdl.so: ghdl/ghdl.cc
-	yosys-config --exec --cxx --cxxflags --ldflags -o $@ -shared $< -DYOSYS_ENABLE_GHDL -I$(GHDL_PREFIX)/include $(GHDL_PREFIX)/lib/libghdlsynth.so -Wl,-rpath,$(GHDL_PREFIX)/lib --ldlibs
+LDFLAGS=
+CFLAGS=-O
+
+ALL_LDFLAGS=$(GHDL_PREFIX)/lib/libghdlsynth.so -Wl,-rpath,$(GHDL_PREFIX)/lib $(LDFLAGS)
+
+ALL_CFLAGS=-fPIC -DYOSYS_ENABLE_GHDL -I$(GHDL_PREFIX)/include $(CFLAGS)
+
+COMPILE=yosys-config --exec --cxx
+
+all: ghdl.so
+
+ghdl.so: ghdl.o
+	$(COMPILE) -o $@ -shared $< -shared $(ALL_LDFLAGS) --ldflags --ldlibs
+
+ghdl.o: ghdl/ghdl.cc
+	$(COMPILE) -c --cxxflags -o $@ $< $(ALL_CFLAGS)
+
+clean: force
+	$(RM) -f ghdl.so ghdl.o
+
+force: