freebsd-dev/sys/i386/include/segments.h
Tijl Coosemans bcde3b9f67 Move userland bits (and some common kernel bits) from amd64 and i386
segments.h to a new x86 segments.h.

Add __packed attribute to some structs (just to be sure).
Also make it clear that i386 GDT and LDT entries are used in ia64 code.
2012-03-19 21:24:50 +00:00

105 lines
3.7 KiB
C

/*-
* 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.
* 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
* $FreeBSD$
*/
#ifndef _MACHINE_SEGMENTS_H_
#define _MACHINE_SEGMENTS_H_
/*
* 386 Segmentation Data Structures and definitions
* William F. Jolitz (william@ernie.berkeley.edu) 6/20/1989
*/
#include <x86/segments.h>
/*
* 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)*/
};
/*
* 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 __packed; /* 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)
#ifdef _KERNEL
extern int _default_ldt;
#ifdef XEN
extern struct proc_ldt default_proc_ldt;
extern union descriptor *gdt;
extern union descriptor *ldt;
#else
extern union descriptor gdt[];
extern union descriptor ldt[NLDT];
#endif
extern struct soft_segment_descriptor gdt_segs[];
extern struct gate_descriptor *idt;
extern struct region_descriptor r_gdt, r_idt;
void lgdt(struct region_descriptor *rdp);
void sdtossd(struct segment_descriptor *sdp,
struct soft_segment_descriptor *ssdp);
void ssdtosd(struct soft_segment_descriptor *ssdp,
struct segment_descriptor *sdp);
#endif /* _KERNEL */
#endif /* !_MACHINE_SEGMENTS_H_ */