WIP: Add support for non-8250 built-in UARTs

Change-Id: I5b412678bb8993633b3a610315d298cb20c705f3
Signed-off-by: David Hendricks <dhendrix@chromium.org>
Signed-off-by: Stefan Reinauer <reinauer@google.com>
Reviewed-on: http://review.coreboot.org/2011
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>

src/include/uart.h

@@ -0,0 +1,33 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2012 The ChromiumOS Authors.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ *
+ * FIXME(dhendrix): This file contains generic prototypes for UART functions.
+ * The existing headers are too specific to the 8250, so we need a better
+ * abstraction for use with non-8250 UARTs.
+ */
+
+#ifndef UART_H
+#define UART_H
+
+unsigned char uart_rx_byte(void);
+void uart_tx_byte(unsigned char data);
+void uart_tx_flush(void);
+
+void uart_init(void);
+
+#endif /* UART_H */