/* 
 * Mach Operating System
 * Copyright (c) 1991,1990 Carnegie Mellon University
 * Copyright (c) 1991 IBM Corporation 
 * Copyright (c) 1994 The University of Utah and
 * the Computer Systems Laboratory (CSL).
 * All Rights Reserved.
 * 
 * Permission to use, copy, modify and distribute this software and its
 * documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation,
 * and that the name IBM not be used in advertising or publicity 
 * pertaining to distribution of the software without specific, written
 * prior permission.
 * 
 * CARNEGIE MELLON, IBM, AND CSL ALLOW FREE USE OF THIS SOFTWARE IN ITS "AS IS"
 * CONDITION.  CARNEGIE MELLON, IBM, AND CSL DISCLAIM ANY LIABILITY OF ANY KIND
 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 * 
 * Carnegie Mellon requests users of this software to return to
 * 
 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
 *  School of Computer Science
 *  Carnegie Mellon University
 *  Pittsburgh PA 15213-3890
 * 
 * any improvements or extensions that they make and grant Carnegie Mellon
 * the rights to redistribute these changes.
 */

#ifndef _I386_GDT_
#define _I386_GDT_

#include "seg.h"

/*
 * Kernel descriptors for Mach - 32-bit flat address space.
 */
#define	KERNEL_CS	(0x08 | KERNEL_RING)		/* kernel code */
#define	KERNEL_DS	(0x10 | KERNEL_RING)		/* kernel data */
#ifndef	MACH_PV_DESCRIPTORS
#define	KERNEL_LDT	0x18		/* master LDT */
#endif	/* MACH_PV_DESCRIPTORS */
#define	KERNEL_TSS	0x20		/* master TSS (uniprocessor) */
#define	USER_LDT	0x28		/* place for per-thread LDT */
#define	USER_TSS	0x30		/* place for per-thread TSS
					   that holds IO bitmap */
#ifndef	MACH_PV_DESCRIPTORS
#define	LINEAR_DS	0x38		/* linear mapping */
#endif	/* MACH_PV_DESCRIPTORS */
/*			0x40		   was USER_FPREGS, now free */

#define	USER_GDT	0x48		/* user-defined GDT entries */
#define	USER_GDT_SLOTS	2

#define	GDTSZ		(USER_GDT/8 + USER_GDT_SLOTS)

extern struct real_descriptor gdt[GDTSZ];

/* Fill a segment descriptor in the GDT.  */
#define fill_gdt_descriptor(segment, base, limit, access, sizebits) \
	fill_descriptor(&gdt[segment/8], base, limit, access, sizebits)

extern void gdt_init(void);

#endif /* _I386_GDT_ */