1#
2# Copyright (c) 1998 Robert Nordier
3# All rights reserved.
4#
5# Redistribution and use in source and binary forms are freely
6# permitted provided that the above copyright notice and this
7# paragraph and the following disclaimer are duplicated in all
8# such forms.
9#
10# This software is provided "AS IS" and without any express or
11# implied warranties, including, without limitation, the implied
12# warranties of merchantability and fitness for a particular
13# purpose.
14#
| 1/*
2 * Copyright (c) 1998 Robert Nordier
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms are freely
6 * permitted provided that the above copyright notice and this
7 * paragraph and the following disclaimer are duplicated in all
8 * such forms.
9 *
10 * This software is provided "AS IS" and without any express or
11 * implied warranties, including, without limitation, the implied
12 * warranties of merchantability and fitness for a particular
13 * purpose.
14 *
15 * $FreeBSD: head/sys/boot/i386/boot2/sio.S 128707 2004-04-28 09:49:22Z ru $
16 */
|
15
| 17
|
16# $FreeBSD: head/sys/boot/i386/boot2/sio.S 125932 2004-02-17 07:13:04Z ru $
17
| |
18 .set SIO_PRT,SIOPRT # Base port
19 .set SIO_FMT,SIOFMT # 8N1
20 .set SIO_DIV,(115200/SIOSPD) # 115200 / SPD
21
22 .globl sio_init
23 .globl sio_flush
24 .globl sio_putc
25 .globl sio_getc
26 .globl sio_ischar
27
| 18 .set SIO_PRT,SIOPRT # Base port
19 .set SIO_FMT,SIOFMT # 8N1
20 .set SIO_DIV,(115200/SIOSPD) # 115200 / SPD
21
22 .globl sio_init
23 .globl sio_flush
24 .globl sio_putc
25 .globl sio_getc
26 .globl sio_ischar
27
|
28# void sio_init(void)
| 28/* void sio_init(void) */
|
29
30sio_init: movw $SIO_PRT+0x3,%dx # Data format reg
31 movb $SIO_FMT|0x80,%al # Set format
32 outb %al,(%dx) # and DLAB
33 pushl %edx # Save
34 subb $0x3,%dl # Divisor latch reg
35 movw $SIO_DIV,%ax # Set
36 outw %ax,(%dx) # BPS
37 popl %edx # Restore
38 movb $SIO_FMT,%al # Clear
39 outb %al,(%dx) # DLAB
40 incl %edx # Modem control reg
41 movb $0x3,%al # Set RTS,
42 outb %al,(%dx) # DTR
43 incl %edx # Line status reg
44
| 29
30sio_init: movw $SIO_PRT+0x3,%dx # Data format reg
31 movb $SIO_FMT|0x80,%al # Set format
32 outb %al,(%dx) # and DLAB
33 pushl %edx # Save
34 subb $0x3,%dl # Divisor latch reg
35 movw $SIO_DIV,%ax # Set
36 outw %ax,(%dx) # BPS
37 popl %edx # Restore
38 movb $SIO_FMT,%al # Clear
39 outb %al,(%dx) # DLAB
40 incl %edx # Modem control reg
41 movb $0x3,%al # Set RTS,
42 outb %al,(%dx) # DTR
43 incl %edx # Line status reg
44
|
45# void sio_flush(void)
| 45/* void sio_flush(void) */
|
46
47sio_flush.0: call sio_getc.1 # Get character
48sio_flush: call sio_ischar # Check for character
49 jnz sio_flush.0 # Till none
50 ret # To caller
51
| 46
47sio_flush.0: call sio_getc.1 # Get character
48sio_flush: call sio_ischar # Check for character
49 jnz sio_flush.0 # Till none
50 ret # To caller
51
|
52# void sio_putc(int c)
| 52/* void sio_putc(int c) */
|
53
54sio_putc: movw $SIO_PRT+0x5,%dx # Line status reg
55 xor %ecx,%ecx # Timeout
56 movb $0x40,%ch # counter
57sio_putc.1: inb (%dx),%al # Transmitter
58 testb $0x20,%al # buffer empty?
59 loopz sio_putc.1 # No
60 jz sio_putc.2 # If timeout
61 movb 0x4(%esp,1),%al # Get character
62 subb $0x5,%dl # Transmitter hold reg
63 outb %al,(%dx) # Write character
64sio_putc.2: ret $0x4 # To caller
65
| 53
54sio_putc: movw $SIO_PRT+0x5,%dx # Line status reg
55 xor %ecx,%ecx # Timeout
56 movb $0x40,%ch # counter
57sio_putc.1: inb (%dx),%al # Transmitter
58 testb $0x20,%al # buffer empty?
59 loopz sio_putc.1 # No
60 jz sio_putc.2 # If timeout
61 movb 0x4(%esp,1),%al # Get character
62 subb $0x5,%dl # Transmitter hold reg
63 outb %al,(%dx) # Write character
64sio_putc.2: ret $0x4 # To caller
65
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66# int sio_getc(void)
| 66/* int sio_getc(void) */
|
67
68sio_getc: call sio_ischar # Character available?
69 jz sio_getc # No
70sio_getc.1: subb $0x5,%dl # Receiver buffer reg
71 inb (%dx),%al # Read character
72 ret # To caller
73
| 67
68sio_getc: call sio_ischar # Character available?
69 jz sio_getc # No
70sio_getc.1: subb $0x5,%dl # Receiver buffer reg
71 inb (%dx),%al # Read character
72 ret # To caller
73
|
74# int sio_ischar(void)
| 74/* int sio_ischar(void) */
|
75
76sio_ischar: movw $SIO_PRT+0x5,%dx # Line status register
77 xorl %eax,%eax # Zero
78 inb (%dx),%al # Received data
79 andb $0x1,%al # ready?
80 ret # To caller
| 75
76sio_ischar: movw $SIO_PRT+0x5,%dx # Line status register
77 xorl %eax,%eax # Zero
78 inb (%dx),%al # Received data
79 andb $0x1,%al # ready?
80 ret # To caller
|