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1/*
2 * Copyright (c) 1999-2003 Apple Computer, Inc. All rights reserved.
3 *
4 * @APPLE_LICENSE_HEADER_START@
5 *
6 * Portions Copyright (c) 1999-2003 Apple Computer, Inc. All Rights
7 * Reserved. This file contains Original Code and/or Modifications of
8 * Original Code as defined in and that are subject to the Apple Public
9 * Source License Version 2.0 (the "License"). You may not use this file
10 * except in compliance with the License. Please obtain a copy of the
11 * License at http://www.apple.com/publicsource and read it before using
12 * this file.
13 *
14 * The Original Code and all software distributed under the License are
15 * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
16 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
17 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE OR NON- INFRINGEMENT. Please see the
19 * License for the specific language governing rights and limitations
20 * under the License.
21 *
22 * @APPLE_LICENSE_HEADER_END@
23 */
24/*
25 * Mach Operating System
26 * Copyright (c) 1990 Carnegie-Mellon University
27 * Copyright (c) 1989 Carnegie-Mellon University
28 * All rights reserved. The CMU software License Agreement specifies
29 * the terms and conditions for use and redistribution.
30 */
31
32/*
33 * INTEL CORPORATION PROPRIETARY INFORMATION
34 *
35 *This software is supplied under the terms of a license agreement or
36 *nondisclosure agreement with Intel Corporation and may not be copied
37 *nor disclosed except in accordance with the terms of that agreement.
38 *
39 *Copyright 1988, 1989 Intel Corporation
40 */
41
42/*
43 * Copyright 1993 NeXT, Inc.
44 * All rights reserved.
45 */
46
47#include "libsaio.h"
48
49/*
50 * keyboard controller (8042) I/O port addresses
51 */
52#define PORT_A 0x60 /* port A */
53#define PORT_B 0x64 /* port B */
54
55/*
56 * keyboard controller command
57 */
58#define CMD_WOUT 0xd1 /* write controller's output port */
59
60/*
61 * keyboard controller status flags
62 */
63#define KB_INFULL 0x2 /* input buffer full */
64#define KB_OUTFULL 0x1 /* output buffer full */
65
66#define KB_A20 0x9f /* enable A20,
67 enable output buffer full interrupt
68 enable data line
69 disable clock line */
70
71//==========================================================================
72// Enable A20 gate to be able to access memory above 1MB
73
74static inline void flushKeyboardInputBuffer()
75{
76 unsigned char ret;
77 /* Apparently all flags on means that they're invalid and that the code
78 should stop trying to check them because they'll never change */
79 do
80 {
81 ret = inb(PORT_B);
82 } while( (ret != 0xff) && (ret & KB_INFULL));
83}
84
85void enableA20()
86{
87 /* make sure that the input buffer is empty */
88 flushKeyboardInputBuffer();
89
90 /* make sure that the output buffer is empty */
91 if (inb(PORT_B) & KB_OUTFULL)
92 (void)inb(PORT_A);
93
94 /* make sure that the input buffer is empty */
95 flushKeyboardInputBuffer();
96
97 /* write output port */
98 outb(PORT_B, CMD_WOUT);
99 delay(100);
100
101 /* wait until command is accepted */
102 flushKeyboardInputBuffer();
103
104 outb(PORT_A, KB_A20);
105 delay(100);
106
107 /* wait until done */
108 flushKeyboardInputBuffer();
109}
110
111//==========================================================================
112// Return the platform name for this hardware.
113//
114#ifndef BOOT1
115void
116getPlatformName(char *nameBuf)
117{
118 strcpy(nameBuf, "ACPI");
119}
120#endif
121

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