diff --git a/grub-core/boot/mips/yeeloong/fwstart.S b/grub-core/boot/mips/yeeloong/fwstart.S
index d25ff1a5b..41ed0063b 100644
--- a/grub-core/boot/mips/yeeloong/fwstart.S
+++ b/grub-core/boot/mips/yeeloong/fwstart.S
@@ -26,6 +26,8 @@
 #include <grub/cs5536.h>
 #include <grub/smbus.h>
 
+/* #define FULOONG 1 */
+
 #ifdef FULOONG
 #define GRUB_MACHINE_SERIAL_PORT GRUB_MACHINE_SERIAL_PORT2
 #define GRUB_MACHINE_SERIAL_DIVISOR_115200 GRUB_MACHINE_SERIAL_PORT2_DIVISOR_115200