+#ifdef CONFIG_SYS_NS16550_PORT_MAPPED
+#define serial_out(x, y) outb(x, (ulong)y)
+#define serial_in(y) inb((ulong)y)
+#elif defined(CONFIG_SYS_NS16550_MEM32) && (CONFIG_SYS_NS16550_REG_SIZE > 0)
+#define serial_out(x, y) out_be32(y, x)
+#define serial_in(y) in_be32(y)
+#elif defined(CONFIG_SYS_NS16550_MEM32) && (CONFIG_SYS_NS16550_REG_SIZE < 0)
+#define serial_out(x, y) out_le32(y, x)
+#define serial_in(y) in_le32(y)
+#else
+#define serial_out(x, y) writeb(x, y)
+#define serial_in(y) readb(y)
+#endif
+
+#ifndef CONFIG_SYS_NS16550_IER
+#define CONFIG_SYS_NS16550_IER 0x00
+#endif /* CONFIG_SYS_NS16550_IER */