Initial revision
diff --git a/board/cogent/serial.h b/board/cogent/serial.h
new file mode 100644
index 0000000..89962d8
--- /dev/null
+++ b/board/cogent/serial.h
@@ -0,0 +1,15 @@
+/* Line Status Register bits */
+#define LSR_DR 0x01 /* Data ready */
+#define LSR_OE 0x02 /* Overrun */
+#define LSR_PE 0x04 /* Parity error */
+#define LSR_FE 0x08 /* Framing error */
+#define LSR_BI 0x10 /* Break */
+#define LSR_THRE 0x20 /* Xmit holding register empty */
+#define LSR_TEMT 0x40 /* Xmitter empty */
+#define LSR_ERR 0x80 /* Error */
+
+#define CLKRATE 3686400 /* cogent motherboard serial clk = 3.6864MHz */
+#define DEFDIV 1 /* default to 230400 bps */
+
+#define br_to_div(br) (CLKRATE / (16 * (br)))
+#define div_to_br(div) (CLKRATE / (16 * (div)))