[unix-history] / sys / i386 / include / segments.h

/*-
 * Copyright (c) 1989, 1990 William F. Jolitz
 * Copyright (c) 1990 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * William Jolitz.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	from: @(#)segments.h	7.1 (Berkeley) 5/9/91
 *	$Id: segments.h,v 1.2 1993/10/16 14:39:30 rgrimes Exp $
 */

#ifndef _MACHINE_SEGMENTS_H_
#define _MACHINE_SEGMENTS_H_ 1

/*
 * 386 Segmentation Data Structures and definitions
 *	William F. Jolitz (william@ernie.berkeley.edu) 6/20/1989
 */

/*
 * Selectors
 */

#define	ISPL(s)	((s)&3)		/* what is the priority level of a selector */
#define	SEL_KPL	0		/* kernel priority level */	
#define	SEL_UPL	3		/* user priority level */	
#define	ISLDT(s)	((s)&SEL_LDT)	/* is it local or global */
#define	SEL_LDT	4		/* local descriptor table */	
#define	IDXSEL(s)	(((s)>>3) & 0x1fff)		/* index of selector */
#define	LSEL(s,r)	(((s)<<3) | SEL_LDT | r)	/* a local selector */
#define	GSEL(s,r)	(((s)<<3) | r)			/* a global selector */

/*
 * Memory and System segment descriptors
 */
struct	segment_descriptor	{
	unsigned sd_lolimit:16 ;	/* segment extent (lsb) */
	unsigned sd_lobase:24 ;		/* segment base address (lsb) */
	unsigned sd_type:5 ;		/* segment type */
	unsigned sd_dpl:2 ;		/* segment descriptor priority level */
	unsigned sd_p:1 ;		/* segment descriptor present */
	unsigned sd_hilimit:4 ;		/* segment extent (msb) */
	unsigned sd_xx:2 ;		/* unused */
	unsigned sd_def32:1 ;		/* default 32 vs 16 bit size */
	unsigned sd_gran:1 ;		/* limit granularity (byte/page units)*/
	unsigned sd_hibase:8 ;		/* segment base address  (msb) */
} ;

/*
 * Gate descriptors (e.g. indirect descriptors)
 */
struct	gate_descriptor	{
	unsigned gd_looffset:16 ;	/* gate offset (lsb) */
	unsigned gd_selector:16 ;	/* gate segment selector */
	unsigned gd_stkcpy:5 ;		/* number of stack wds to cpy */
	unsigned gd_xx:3 ;		/* unused */
	unsigned gd_type:5 ;		/* segment type */
	unsigned gd_dpl:2 ;		/* segment descriptor priority level */
	unsigned gd_p:1 ;		/* segment descriptor present */
	unsigned gd_hioffset:16 ;	/* gate offset (msb) */
} ;

/*
 * Generic descriptor
 */
union	descriptor	{
	struct	segment_descriptor sd;
	struct	gate_descriptor gd;
};

	/* system segments and gate types */
#define	SDT_SYSNULL	 0	/* system null */
#define	SDT_SYS286TSS	 1	/* system 286 TSS available */
#define	SDT_SYSLDT	 2	/* system local descriptor table */
#define	SDT_SYS286BSY	 3	/* system 286 TSS busy */
#define	SDT_SYS286CGT	 4	/* system 286 call gate */
#define	SDT_SYSTASKGT	 5	/* system task gate */
#define	SDT_SYS286IGT	 6	/* system 286 interrupt gate */
#define	SDT_SYS286TGT	 7	/* system 286 trap gate */
#define	SDT_SYSNULL2	 8	/* system null again */
#define	SDT_SYS386TSS	 9	/* system 386 TSS available */
#define	SDT_SYSNULL3	10	/* system null again */
#define	SDT_SYS386BSY	11	/* system 386 TSS busy */
#define	SDT_SYS386CGT	12	/* system 386 call gate */
#define	SDT_SYSNULL4	13	/* system null again */
#define	SDT_SYS386IGT	14	/* system 386 interrupt gate */
#define	SDT_SYS386TGT	15	/* system 386 trap gate */

	/* memory segment types */
#define	SDT_MEMRO	16	/* memory read only */
#define	SDT_MEMROA	17	/* memory read only accessed */
#define	SDT_MEMRW	18	/* memory read write */
#define	SDT_MEMRWA	19	/* memory read write accessed */
#define	SDT_MEMROD	20	/* memory read only expand dwn limit */
#define	SDT_MEMRODA	21	/* memory read only expand dwn limit accessed */
#define	SDT_MEMRWD	22	/* memory read write expand dwn limit */
#define	SDT_MEMRWDA	23	/* memory read write expand dwn limit acessed */
#define	SDT_MEME	24	/* memory execute only */
#define	SDT_MEMEA	25	/* memory execute only accessed */
#define	SDT_MEMER	26	/* memory execute read */
#define	SDT_MEMERA	27	/* memory execute read accessed */
#define	SDT_MEMEC	28	/* memory execute only conforming */
#define	SDT_MEMEAC	29	/* memory execute only accessed conforming */
#define	SDT_MEMERC	30	/* memory execute read conforming */
#define	SDT_MEMERAC	31	/* memory execute read accessed conforming */

/* is memory segment descriptor pointer ? */
#define ISMEMSDP(s)	((s->d_type) >= SDT_MEMRO && (s->d_type) <= SDT_MEMERAC)

/* is 286 gate descriptor pointer ? */
#define IS286GDP(s)	(((s->d_type) >= SDT_SYS286CGT \
				 && (s->d_type) < SDT_SYS286TGT))

/* is 386 gate descriptor pointer ? */
#define IS386GDP(s)	(((s->d_type) >= SDT_SYS386CGT \
				&& (s->d_type) < SDT_SYS386TGT))

/* is gate descriptor pointer ? */
#define ISGDP(s)	(IS286GDP(s) || IS386GDP(s))

/* is segment descriptor pointer ? */
#define ISSDP(s)	(ISMEMSDP(s) || !ISGDP(s))

/* is system segment descriptor pointer ? */
#define ISSYSSDP(s)	(!ISMEMSDP(s) && !ISGDP(s))

/*
 * Software definitions are in this convenient format,
 * which are translated into inconvenient segment descriptors
 * when needed to be used by the 386 hardware
 */

struct	soft_segment_descriptor	{
	unsigned ssd_base ;		/* segment base address  */
	unsigned ssd_limit ;		/* segment extent */
	unsigned ssd_type:5 ;		/* segment type */
	unsigned ssd_dpl:2 ;		/* segment descriptor priority level */
	unsigned ssd_p:1 ;		/* segment descriptor present */
	unsigned ssd_xx:4 ;		/* unused */
	unsigned ssd_xx1:2 ;		/* unused */
	unsigned ssd_def32:1 ;		/* default 32 vs 16 bit size */
	unsigned ssd_gran:1 ;		/* limit granularity (byte/page units)*/
};

extern ssdtosd() ;	/* to decode a ssd */
extern sdtossd() ;	/* to encode a sd */

/*
 * region descriptors, used to load gdt/idt tables before segments yet exist.
 */
struct region_descriptor {
	unsigned rd_limit:16;		/* segment extent */
	unsigned rd_base:32;		/* base address  */
};

/*
 * Segment Protection Exception code bits
 */

#define	SEGEX_EXT	0x01	/* recursive or externally induced */
#define	SEGEX_IDT	0x02	/* interrupt descriptor table */
#define	SEGEX_TI	0x04	/* local descriptor table */
				/* other bits are affected descriptor index */
#define SEGEX_IDX(s)	((s)>>3)&0x1fff)

/*
 * Size of IDT table
 */

#define	NIDT	256
#define	NRSVIDT	32		/* reserved entries for cpu exceptions */
#endif /* _MACHINE_SEGMENTS_H_ */
Commit	Line	Data
15637ed4 RG	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	* 3. All advertising materials mentioning features or use of this software
	18	* must display the following acknowledgement:
	19	* This product includes software developed by the University of
	20	* California, Berkeley and its contributors.
	21	* 4. Neither the name of the University nor the names of its contributors
	22	* may be used to endorse or promote products derived from this software
	23	* without specific prior written permission.
	24	*
	25	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	26	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	27	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	28	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	29	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	30	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	31	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	32	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	33	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	34	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	35	* SUCH DAMAGE.
	36	*
db11a0e0	37	* from: @(#)segments.h 7.1 (Berkeley) 5/9/91
126bd309	38	* $Id: segments.h,v 1.2 1993/10/16 14:39:30 rgrimes Exp $
15637ed4 RG	39	*/
15637ed4 RG	40
126bd309 GW	41	#ifndef _MACHINE_SEGMENTS_H_
	42	#define _MACHINE_SEGMENTS_H_ 1
	43
15637ed4 RG	44	/*
	45	* 386 Segmentation Data Structures and definitions
	46	* William F. Jolitz (william@ernie.berkeley.edu) 6/20/1989
	47	*/
	48
	49	/*
	50	* Selectors
	51	*/
	52
	53	#define ISPL(s) ((s)&3) /* what is the priority level of a selector */
	54	#define SEL_KPL 0 /* kernel priority level */
	55	#define SEL_UPL 3 /* user priority level */
	56	#define ISLDT(s) ((s)&SEL_LDT) /* is it local or global */
	57	#define SEL_LDT 4 /* local descriptor table */
	58	#define IDXSEL(s) (((s)>>3) & 0x1fff) /* index of selector */
	59	#define LSEL(s,r) (((s)<<3) \| SEL_LDT \| r) /* a local selector */
	60	#define GSEL(s,r) (((s)<<3) \| r) /* a global selector */
	61
	62	/*
	63	* Memory and System segment descriptors
	64	*/
	65	struct segment_descriptor {
	66	unsigned sd_lolimit:16 ; /* segment extent (lsb) */
	67	unsigned sd_lobase:24 ; /* segment base address (lsb) */
	68	unsigned sd_type:5 ; /* segment type */
	69	unsigned sd_dpl:2 ; /* segment descriptor priority level */
	70	unsigned sd_p:1 ; /* segment descriptor present */
	71	unsigned sd_hilimit:4 ; /* segment extent (msb) */
	72	unsigned sd_xx:2 ; /* unused */
	73	unsigned sd_def32:1 ; /* default 32 vs 16 bit size */
	74	unsigned sd_gran:1 ; /* limit granularity (byte/page units)*/
	75	unsigned sd_hibase:8 ; /* segment base address (msb) */
	76	} ;
	77
	78	/*
	79	* Gate descriptors (e.g. indirect descriptors)
	80	*/
	81	struct gate_descriptor {
	82	unsigned gd_looffset:16 ; /* gate offset (lsb) */
	83	unsigned gd_selector:16 ; /* gate segment selector */
	84	unsigned gd_stkcpy:5 ; /* number of stack wds to cpy */
	85	unsigned gd_xx:3 ; /* unused */
	86	unsigned gd_type:5 ; /* segment type */
	87	unsigned gd_dpl:2 ; /* segment descriptor priority level */
	88	unsigned gd_p:1 ; /* segment descriptor present */
	89	unsigned gd_hioffset:16 ; /* gate offset (msb) */
	90	} ;
	91
	92	/*
	93	* Generic descriptor
	94	*/
	95	union descriptor {
	96	struct segment_descriptor sd;
	97	struct gate_descriptor gd;
	98	};
	99
	100	/* system segments and gate types */
	101	#define SDT_SYSNULL 0 /* system null */
	102	#define SDT_SYS286TSS 1 /* system 286 TSS available */
	103	#define SDT_SYSLDT 2 /* system local descriptor table */
	104	#define SDT_SYS286BSY 3 /* system 286 TSS busy */
	105	#define SDT_SYS286CGT 4 /* system 286 call gate */
	106	#define SDT_SYSTASKGT 5 /* system task gate */
	107	#define SDT_SYS286IGT 6 /* system 286 interrupt gate */
108	#define SDT_SYS286TGT 7 /* system 286 trap gate */
109	#define SDT_SYSNULL2 8 /* system null again */
110	#define SDT_SYS386TSS 9 /* system 386 TSS available */
111	#define SDT_SYSNULL3 10 /* system null again */
112	#define SDT_SYS386BSY 11 /* system 386 TSS busy */
113	#define SDT_SYS386CGT 12 /* system 386 call gate */
114	#define SDT_SYSNULL4 13 /* system null again */
115	#define SDT_SYS386IGT 14 /* system 386 interrupt gate */
116	#define SDT_SYS386TGT 15 /* system 386 trap gate */
117
118	/* memory segment types */
119	#define SDT_MEMRO 16 /* memory read only */
120	#define SDT_MEMROA 17 /* memory read only accessed */
121	#define SDT_MEMRW 18 /* memory read write */
122	#define SDT_MEMRWA 19 /* memory read write accessed */
123	#define SDT_MEMROD 20 /* memory read only expand dwn limit */
124	#define SDT_MEMRODA 21 /* memory read only expand dwn limit accessed */
125	#define SDT_MEMRWD 22 /* memory read write expand dwn limit */
126	#define SDT_MEMRWDA 23 /* memory read write expand dwn limit acessed */
127	#define SDT_MEME 24 /* memory execute only */
128	#define SDT_MEMEA 25 /* memory execute only accessed */
129	#define SDT_MEMER 26 /* memory execute read */
130	#define SDT_MEMERA 27 /* memory execute read accessed */
131	#define SDT_MEMEC 28 /* memory execute only conforming */
132	#define SDT_MEMEAC 29 /* memory execute only accessed conforming */
133	#define SDT_MEMERC 30 /* memory execute read conforming */
134	#define SDT_MEMERAC 31 /* memory execute read accessed conforming */
135
136	/* is memory segment descriptor pointer ? */
137	#define ISMEMSDP(s) ((s->d_type) >= SDT_MEMRO && (s->d_type) <= SDT_MEMERAC)
138
139	/* is 286 gate descriptor pointer ? */
140	#define IS286GDP(s) (((s->d_type) >= SDT_SYS286CGT \
141	&& (s->d_type) < SDT_SYS286TGT))
142
143	/* is 386 gate descriptor pointer ? */
144	#define IS386GDP(s) (((s->d_type) >= SDT_SYS386CGT \
145	&& (s->d_type) < SDT_SYS386TGT))
146
147	/* is gate descriptor pointer ? */
148	#define ISGDP(s) (IS286GDP(s) \|\| IS386GDP(s))
149
150	/* is segment descriptor pointer ? */
151	#define ISSDP(s) (ISMEMSDP(s) \|\| !ISGDP(s))
152
153	/* is system segment descriptor pointer ? */
154	#define ISSYSSDP(s) (!ISMEMSDP(s) && !ISGDP(s))
155
156	/*
157	* Software definitions are in this convenient format,
158	* which are translated into inconvenient segment descriptors
159	* when needed to be used by the 386 hardware
160	*/
161
162	struct soft_segment_descriptor {
163	unsigned ssd_base ; /* segment base address */
164	unsigned ssd_limit ; /* segment extent */
165	unsigned ssd_type:5 ; /* segment type */
166	unsigned ssd_dpl:2 ; /* segment descriptor priority level */
167	unsigned ssd_p:1 ; /* segment descriptor present */
168	unsigned ssd_xx:4 ; /* unused */
169	unsigned ssd_xx1:2 ; /* unused */
170	unsigned ssd_def32:1 ; /* default 32 vs 16 bit size */
171	unsigned ssd_gran:1 ; /* limit granularity (byte/page units)*/
172	};
173
174	extern ssdtosd() ; /* to decode a ssd */
175	extern sdtossd() ; /* to encode a sd */
176
177	/*
178	* region descriptors, used to load gdt/idt tables before segments yet exist.
179	*/
180	struct region_descriptor {
181	unsigned rd_limit:16; /* segment extent */
182	unsigned rd_base:32; /* base address */
183	};
184
185	/*
186	* Segment Protection Exception code bits
187	*/
188
189	#define SEGEX_EXT 0x01 /* recursive or externally induced */
190	#define SEGEX_IDT 0x02 /* interrupt descriptor table */
191	#define SEGEX_TI 0x04 /* local descriptor table */
192	/* other bits are affected descriptor index */
193	#define SEGEX_IDX(s) ((s)>>3)&0x1fff)
194
195	/*
196	* Size of IDT table
197	*/
198
199	#define NIDT 256
200	#define NRSVIDT 32 /* reserved entries for cpu exceptions */
126bd309	201	#endif /* _MACHINE_SEGMENTS_H_ */