1998-10-15 20:04:21 +00:00
|
|
|
#
|
|
|
|
|
# Copyright (c) 1998 Robert Nordier
|
|
|
|
|
# All rights reserved.
|
|
|
|
|
#
|
|
|
|
|
# Redistribution and use in source and binary forms are freely
|
|
|
|
|
# permitted provided that the above copyright notice and this
|
|
|
|
|
# paragraph and the following disclaimer are duplicated in all
|
|
|
|
|
# such forms.
|
|
|
|
|
#
|
|
|
|
|
# This software is provided "AS IS" and without any express or
|
|
|
|
|
# implied warranties, including, without limitation, the implied
|
|
|
|
|
# warranties of merchantability and fitness for a particular
|
|
|
|
|
# purpose.
|
|
|
|
|
#
|
|
|
|
|
|
1998-10-20 20:20:48 +00:00
|
|
|
# $Id: sio.s,v 1.1 1998/10/15 20:04:21 rnordier Exp $
|
1998-10-15 20:04:21 +00:00
|
|
|
|
1998-10-20 20:20:48 +00:00
|
|
|
.set SIO_PRT,SIOPRT # Base port
|
|
|
|
|
.set SIO_FMT,SIOFMT # 8N1
|
|
|
|
|
.set SIO_DIV,SIODIV # 115200 / BPS
|
1998-10-15 20:04:21 +00:00
|
|
|
|
|
|
|
|
.globl sio_init
|
|
|
|
|
.globl sio_flush
|
|
|
|
|
.globl sio_putc
|
|
|
|
|
.globl sio_getc
|
|
|
|
|
.globl sio_ischar
|
|
|
|
|
|
|
|
|
|
# void sio_init(void)
|
|
|
|
|
|
|
|
|
|
sio_init: movw $SIO_PRT+0x3,%dx # Data format reg
|
|
|
|
|
movb $SIO_FMT|0x80,%al # Set format
|
|
|
|
|
outb %al,(%dx) # and DLAB
|
|
|
|
|
pushl %edx # Save
|
|
|
|
|
subb $0x3,%dl # Divisor latch reg
|
|
|
|
|
movw $SIO_DIV,%ax # Set
|
|
|
|
|
outw %ax,(%dx) # BPS
|
|
|
|
|
popl %edx # Restore
|
|
|
|
|
movb $SIO_FMT,%al # Clear
|
|
|
|
|
outb %al,(%dx) # DLAB
|
|
|
|
|
incl %edx # Modem control reg
|
|
|
|
|
movb $0x3,%al # Set RTS,
|
|
|
|
|
outb %al,(%dx) # DTR
|
|
|
|
|
incl %edx # Line status reg
|
|
|
|
|
|
|
|
|
|
# void sio_flush(void)
|
|
|
|
|
|
|
|
|
|
sio_flush.0: call sio_getc.1 # Get character
|
|
|
|
|
sio_flush: call sio_ischar # Check for character
|
|
|
|
|
jnz sio_flush.0 # Till none
|
|
|
|
|
ret # To caller
|
|
|
|
|
|
|
|
|
|
# void sio_putc(int c)
|
|
|
|
|
|
|
|
|
|
sio_putc: movw $SIO_PRT+0x5,%dx # Line status reg
|
|
|
|
|
xor %ecx,%ecx # Timeout
|
|
|
|
|
movb $0x40,%ch # counter
|
|
|
|
|
sio_putc.1: inb (%dx),%al # Transmitter
|
|
|
|
|
testb $0x20,%al # buffer empty?
|
|
|
|
|
loopz sio_putc.1 # No
|
|
|
|
|
jz sio_putc.2 # If timeout
|
|
|
|
|
movb 0x4(%esp,1),%al # Get character
|
|
|
|
|
subb $0x5,%dl # Transmitter hold reg
|
|
|
|
|
outb %al,(%dx) # Write character
|
|
|
|
|
sio_putc.2: ret $0x4 # To caller
|
|
|
|
|
|
|
|
|
|
# int sio_getc(void)
|
|
|
|
|
|
|
|
|
|
sio_getc: call sio_ischar # Character available?
|
|
|
|
|
jz sio_getc # No
|
|
|
|
|
sio_getc.1: subb $0x5,%dl # Receiver buffer reg
|
|
|
|
|
inb (%dx),%al # Read character
|
|
|
|
|
ret # To caller
|
|
|
|
|
|
|
|
|
|
# int sio_ischar(void)
|
|
|
|
|
|
|
|
|
|
sio_ischar: movw $SIO_PRT+0x5,%dx # Line status register
|
|
|
|
|
xorl %eax,%eax # Zero
|
|
|
|
|
inb (%dx),%al # Received data
|
|
|
|
|
andb $0x1,%al # ready?
|
|
|
|
|
ret # To caller
|
