1/*-
2 * Copyright (c) 1989, 1990 William F. Jolitz
3 * Copyright (c) 1990 The Regents of the University of California.
4 * All rights reserved.
5 *
6 * This code is derived from software contributed to Berkeley by
7 * William Jolitz.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 * 4. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 *	from: @(#)segments.h	7.1 (Berkeley) 5/9/91
34 * $FreeBSD$
35 */
36
37#ifndef _MACHINE_SEGMENTS_H_
38#define	_MACHINE_SEGMENTS_H_
39
40/*
41 * 386 Segmentation Data Structures and definitions
42 *	William F. Jolitz (william@ernie.berkeley.edu) 6/20/1989
43 */
44
45#include <x86/segments.h>
46
47/*
48 * Software definitions are in this convenient format,
49 * which are translated into inconvenient segment descriptors
50 * when needed to be used by the 386 hardware
51 */
52
53struct	soft_segment_descriptor	{
54	unsigned ssd_base ;		/* segment base address  */
55	unsigned ssd_limit ;		/* segment extent */
56	unsigned ssd_type:5 ;		/* segment type */
57	unsigned ssd_dpl:2 ;		/* segment descriptor priority level */
58	unsigned ssd_p:1 ;		/* segment descriptor present */
59	unsigned ssd_xx:4 ;		/* unused */
60	unsigned ssd_xx1:2 ;		/* unused */
61	unsigned ssd_def32:1 ;		/* default 32 vs 16 bit size */
62	unsigned ssd_gran:1 ;		/* limit granularity (byte/page units)*/
63};
64
65/*
66 * region descriptors, used to load gdt/idt tables before segments yet exist.
67 */
68struct region_descriptor {
69	unsigned rd_limit:16;		/* segment extent */
70	unsigned rd_base:32 __packed;	/* base address  */
71};
72
73/*
74 * Segment Protection Exception code bits
75 */
76
77#define	SEGEX_EXT	0x01	/* recursive or externally induced */
78#define	SEGEX_IDT	0x02	/* interrupt descriptor table */
79#define	SEGEX_TI	0x04	/* local descriptor table */
80				/* other bits are affected descriptor index */
81#define SEGEX_IDX(s)	(((s)>>3)&0x1fff)
82
83#ifdef _KERNEL
84extern int	_default_ldt;
85extern union descriptor gdt[];
86extern union descriptor ldt[NLDT];
87extern struct soft_segment_descriptor gdt_segs[];
88extern struct gate_descriptor *idt;
89extern struct region_descriptor r_gdt, r_idt;
90
91void	lgdt(struct region_descriptor *rdp);
92void	sdtossd(struct segment_descriptor *sdp,
93	    struct soft_segment_descriptor *ssdp);
94void	ssdtosd(struct soft_segment_descriptor *ssdp,
95	    struct segment_descriptor *sdp);
96#endif /* _KERNEL */
97
98#endif /* !_MACHINE_SEGMENTS_H_ */
99