2 * Copyright (C) 2014 Michael Brown <mbrown@fensystems.co.uk>.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License as
6 * published by the Free Software Foundation; either version 2 of the
7 * License, or any later version.
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
19 * You can also choose to distribute this program under the terms of
20 * the Unmodified Binary Distribution Licence (as given in the file
21 * COPYING.UBDL), provided that you have satisfied its requirements.
24 FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
28 * 16550-compatible UART
33 #include <ipxe/uart.h>
35 /** UART port bases */
36 static uint16_t uart_base[] = {
47 * @v port Port number, or 0 to disable
48 * @ret rc Return status code
50 int uart_select ( struct uart *uart, unsigned int port ) {
53 /* Set new UART base */
54 if ( port >= ( sizeof ( uart_base ) / sizeof ( uart_base[0] ) ) ) {
58 uart->base = ( ( void * ) ( intptr_t ) uart_base[port] );
60 /* Check that UART exists */
61 if ( ( rc = uart_exists ( uart ) ) != 0 )