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 128716 2004-04-28 14:31:44Z ru $
| 15 * $FreeBSD: head/sys/boot/i386/boot2/sio.S 129240 2004-05-14 20:29:30Z ru $
|
16 */
17
| 16 */
17
|
18 .set SIO_PRT,SIOPRT // Base port
19 .set SIO_FMT,SIOFMT // 8N1
20 .set SIO_DIV,(115200/SIOSPD) // 115200 / SPD
| 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) */
29
| 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) */
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
| 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) */
46
| 44
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
| 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) */
53
| 51
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
| 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
66/* int sio_getc(void) */
67
| 65
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
| 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) */
75
| 73
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
| 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
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| |