2 # Copyright (c) 1999 Global Technology Associates, Inc.
5 # Redistribution and use in source and binary forms, with or without
6 # modification, are permitted provided that the following conditions
8 # 1. Redistributions of source code must retain the above copyright
9 # notice, this list of conditions and the following disclaimer.
10 # 2. Redistributions in binary form must reproduce the above copyright
11 # notice, this list of conditions and the following disclaimer in the
12 # documentation and/or other materials provided with the distribution.
14 # THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS``AS IS'' AND
15 # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
17 # PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS
18 # BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
19 # OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
20 # OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
21 # BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
22 # WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
23 # OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
24 # EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 # From: sio.s 1.3 1999/01/10 14:48:03 rnordier
27 # $FreeBSD: src/sys/boot/i386/kgzldr/sio.s,v 1.5 2002/09/30 20:37:57 peter Exp $
28 # $DragonFly: src/sys/boot/pc32/kgzldr/sio.s,v 1.3 2003/11/10 06:08:35 dillon Exp $
33 # void sio_putchr(int c)
35 sio_putchr: movw $SIO_PRT+0x5,%dx # Line status reg
36 xor %ecx,%ecx # Timeout
37 movb $0x40,%ch # counter
38 sio_putchr.1: inb %dx,%al # Transmitter
39 testb $0x20,%al # buffer empty?
40 loopz sio_putchr.1 # No
41 jz sio_putchr.2 # If timeout
42 movb 0x4(%esp,1),%al # Get character
43 subb $0x5,%dl # Transmitter hold reg
44 outb %al,%dx # Write character
45 sio_putchr.2: ret # To caller