Fix python3 compatibility

Makefile

@@ -170,7 +170,7 @@ $(SELF_EXECUTABLE): $(SELF_OBJECTS)
 		 -T$(SELF_LINKER_SCRIPT) \
 		 -Wl,-Map,$(BUILD_PATH)/update-$(NAME).map -o $(BUILD_PATH)/update-$(NAME).elf $(SELF_OBJECTS)
 	arm-none-eabi-objcopy -O binary $(BUILD_PATH)/update-$(NAME).elf $(BUILD_PATH)/update-$(NAME).bin
-	python2 lib/uf2/utils/uf2conv.py -b $(BOOTLOADER_SIZE) -c -o $@ $(BUILD_PATH)/update-$(NAME).bin
+	python3 lib/uf2/utils/uf2conv.py -b $(BOOTLOADER_SIZE) -c -o $@ $(BUILD_PATH)/update-$(NAME).bin
 
 $(BUILD_PATH)/%.o: src/%.c $(wildcard inc/*.h boards/*/*.h) $(BUILD_PATH)/uf2_version.h
 	echo "$<"
@@ -180,7 +180,7 @@ $(BUILD_PATH)/%.o: $(BUILD_PATH)/%.c
 	$(CC) $(CFLAGS) $(BLD_EXTA_FLAGS) $(INCLUDES) $< -o $@
 
 $(BUILD_PATH)/selfdata.c: $(EXECUTABLE) scripts/gendata.py src/sketch.cpp
-	python2 scripts/gendata.py $(BOOTLOADER_SIZE) $(EXECUTABLE)
+	python3 scripts/gendata.py $(BOOTLOADER_SIZE) $(EXECUTABLE)
 
 clean:
 	rm -rf build

scripts/gendata.py

@@ -31,7 +31,7 @@ def update_crc(new_byte, current_crc):
                  "__attribute__ ((aligned (4))) = {\n")
     crcs = []
     crc = 0
-    for row in range(bootloader_size / 16):
+    for row in range(bootloader_size // 16):
         # Save the crc every 1k.
         if row % (1024 / 16) == 0 and row > 0:
             crcs.append(crc)