Added putch() function to enable serial printf

Author: DeanCording

src/uart/src/putchar.c

@@ -0,0 +1,53 @@
+/////////////////////////////////////////////////////////////////////////////
+//
+// File: putchar.c
+//
+// Copyright S. Brennen Ball, 2011
+//
+// The author provides no guarantees, warranty, or promises, implied or
+//  otherwise.  By using this software you agree to indemnify the author
+//  of any damages incurred by using it.
+//
+/////////////////////////////////////////////////////////////////////////////
+
+/////////////////////////////////////////////////////////////////////////////
+// This library is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public
+// License as published by the Free Software Foundation; either
+// version 2.1 of the License, or (at your option) any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+/////////////////////////////////////////////////////////////////////////////
+
+#include "uart.h"
+#include "interrupt.h"
+
+/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+//
+// void putchar(char c)
+//
+// Description:
+//  Allows use of stdio printf to output to uart
+//
+// Parameters:
+//  char c - char to send over the UART
+//
+// Return value:
+//  None
+//
+/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+void putchar(char c)
+{
+	interrupt_wait_for_uart_tx();
+
+	interrupt_clear_uart_tx();
+
+   	uart_send(c);
+}