Add test code and top level Makefile

Makefile

@@ -1,9 +1,32 @@
-all: hw
+ROM_TARGET=test_code/loop_test
 
-.PHONY: hw
-hw:
-	$(MAKE) -C hw
+INIT_HEX=hw/super6502_fpga/init_hex.mem
+HEX=sw/$(ROM_TARGET)/$(notdir $(ROM_TARGET)).bin
+
+
+all: fpga_image
+
+# FPGA
+.PHONY: fpga_image
+fpga_image: $(INIT_HEX)
+	$(MAKE) -C hw/super6502_fpga
+
+
+# SW
+.PHONY: toolchain
+toolchain:
+	$(MAKE) -C sw/toolchain/cc65 -j $(shell nproc)
+
+$(INIT_HEX): toolchain script/generate_rom_image.py $(HEX)
+	python script/generate_rom_image.py -i $(HEX) -o $@
+
+$(HEX):
+	$(MAKE) -C sw/$(ROM) $(notdir $@)
 
 .PHONY: clean
 clean:
-	$(MAKE) -C hw $@
+	$(MAKE) -C hw/super6502_fpga $@
+
+.PHONY: distclean
+distclean: clean
+	$(MAKE) -C sw/toolchain/cc65 clean