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/*
* plex86: run multiple x86 operating systems concurrently
* Copyright (C) 1999-2001 Kevin P. Lawton
*
* descriptor2.h: defines for descriptors and selectors
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef __DESCRIPTOR2_H__
#define __DESCRIPTOR2_H__
typedef struct
{
Bit16u offset_low;
selector_t selector;
Bit8u RESERVED;
unsigned type:5;
unsigned dpl:2;
unsigned p:1;
Bit16u offset_high;
} __attribute__ ((packed)) gate_t;
typedef struct
{
Bit16u limit;
Bit32u base;
} __attribute__ ((packed)) gdt_info_t;
#define SET_INT_GATE(d, S,O,P,DPL, D) {\
d.selector = (S);\
d.offset_high = (O) >> 16;\
d.offset_low = (O) & 0xffff;\
d.RESERVED = 0;\
d.type = ((D)<<3) | 0x6;\
d.dpl = (DPL);\
d.p = (P);\
}
#define SET_TRAP_GATE(d, S,O,P,DPL, D) {\
d.selector = (S);\
d.offset_high = (O) >> 16;\
d.offset_low = (O) & 0xffff;\
d.RESERVED = 0;\
d.type = ((D)<<3) | 0x7;\
d.dpl = (DPL);\
d.p = (P);\
}
typedef struct
{
Bit32u offset;
Bit16u selector;
} __attribute ((packed)) far_jmp_info_t;
/* The hidden segment descriptor cache */
typedef struct {
descriptor_t desc; /* 64bit quantity fetched from desc table */
Bit32u base; /* derived from desc (for efficiency) */
Bit32u limit_scaled; /* derived from desc (for efficiency) */
unsigned valid;
} descriptor_cache_t;
#endif /* __DESCRIPTOR2_H__ */
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