From 9f8a07d3a0a47a32e88ccb477a2cb7723c9f4934 Mon Sep 17 00:00:00 2001
From: Maurizio Lombardi <m.lombardi85@gmail.com>
Date: Thu, 17 Jan 2013 20:58:34 +0100
Subject: [PATCH] bootloader: add support to the beaglebone UART0

---
 boot/arch/arm32/include/main.h |  9 +++++++++
 boot/arch/arm32/src/putchar.c  | 25 +++++++++++++++++++++++++
 2 files changed, 34 insertions(+)

diff --git a/boot/arch/arm32/include/main.h b/boot/arch/arm32/include/main.h
index 62be29f5c..94c8aea76 100644
--- a/boot/arch/arm32/include/main.h
+++ b/boot/arch/arm32/include/main.h
@@ -50,6 +50,15 @@
 /* Check this bit before writing (tx fifo full) */
 #define BBXM_THR_FULL           0x00000001
 
+/** Beaglebone UART register addresses
+ *
+ * This is UART0 of AM335x CPU
+ */
+#define BBONE_SCONS_THR         0x44E09000
+#define BBONE_SCONS_SSR         0x44E09044
+
+/** Check this bit before writing (tx fifo full) */
+#define BBONE_TXFIFO_FULL       0x00000001
 
 /** GTA02 serial console UART register addresses.
  *
diff --git a/boot/arch/arm32/src/putchar.c b/boot/arch/arm32/src/putchar.c
index 23a61d964..d5b6cbe19 100644
--- a/boot/arch/arm32/src/putchar.c
+++ b/boot/arch/arm32/src/putchar.c
@@ -40,6 +40,28 @@
 #include <putchar.h>
 #include <str.h>
 
+#ifdef MACHINE_beaglebone
+
+/** Send a byte to the am335x serial console.
+ *
+ * @param byte		Byte to send.
+ */
+static void scons_sendb_bbone(uint8_t byte)
+{
+	volatile uint32_t *thr =
+		(volatile uint32_t *) BBONE_SCONS_THR;
+	volatile uint32_t *ssr =
+		(volatile uint32_t *) BBONE_SCONS_SSR;
+
+	/* Wait until transmitter is empty */
+	while (*ssr & BBONE_TXFIFO_FULL);
+
+	/* Transmit byte */
+	*thr = (uint32_t) byte;
+}
+
+#endif
+
 #ifdef MACHINE_beagleboardxm
 
 /** Send a byte to the amdm37x serial console.
@@ -105,6 +127,9 @@ static void scons_sendb_icp(uint8_t byte)
  */
 static void scons_sendb(uint8_t byte)
 {
+#ifdef MACHINE_beaglebone
+	scons_sendb_bbone(byte);
+#endif
 #ifdef MACHINE_beagleboardxm
 	scons_sendb_bbxm(byte);
 #endif
-- 
2.11.4.GIT