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/*-
* 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
*/
/*
* 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 __packed; /* 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 accessed */
#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 */
/*
* 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)
/*
* Size of IDT table
*/
#define NIDT 256 /* 32 reserved, 0x80 syscall, most are h/w */
#define NRSVIDT 32 /* reserved entries for cpu exceptions */
/*
* Entries in the Interrupt Descriptor Table (IDT)
*/
#define IDT_DE 0 /* #DE: Divide Error */
#define IDT_DB 1 /* #DB: Debug */
#define IDT_NMI 2 /* Nonmaskable External Interrupt */
#define IDT_BP 3 /* #BP: Breakpoint */
#define IDT_OF 4 /* #OF: Overflow */
#define IDT_BR 5 /* #BR: Bound Range Exceeded */
#define IDT_UD 6 /* #UD: Undefined/Invalid Opcode */
#define IDT_NM 7 /* #NM: No Math Coprocessor */
#define IDT_DF 8 /* #DF: Double Fault */
#define IDT_FPUGP 9 /* Coprocessor Segment Overrun */
#define IDT_TS 10 /* #TS: Invalid TSS */
#define IDT_NP 11 /* #NP: Segment Not Present */
#define IDT_SS 12 /* #SS: Stack Segment Fault */
#define IDT_GP 13 /* #GP: General Protection Fault */
#define IDT_PF 14 /* #PF: Page Fault */
#define IDT_MF 16 /* #MF: FPU Floating-Point Error */
#define IDT_AC 17 /* #AC: Alignment Check */
#define IDT_MC 18 /* #MC: Machine Check */
#define IDT_XF 19 /* #XF: SIMD Floating-Point Exception */
#define IDT_IO_INTS NRSVIDT /* Base of IDT entries for I/O interrupts. */
#define IDT_SYSCALL 0x80 /* System Call Interrupt Vector */
/*
* Entries in the Global Descriptor Table (GDT)
*/
#define GNULL_SEL 0 /* Null Descriptor */
#define GCODE_SEL 1 /* Kernel Code Descriptor */
#define GDATA_SEL 2 /* Kernel Data Descriptor */
#define GPRIV_SEL 3 /* SMP Per-Processor Private Data */
#define GPROC0_SEL 4 /* Task state process slot zero and up */
#define GLDT_SEL 5 /* LDT - eventually one per process */
#define GUSERLDT_SEL 6 /* User LDT */
#define GTGATE_SEL 7 /* Process task switch gate */
#define GBIOSLOWMEM_SEL 8 /* BIOS low memory access (must be entry 8) */
#define GPANIC_SEL 9 /* Task state to consider panic from */
#define GBIOSCODE32_SEL 10 /* BIOS interface (32bit Code) */
#define GBIOSCODE16_SEL 11 /* BIOS interface (16bit Code) */
#define GBIOSDATA_SEL 12 /* BIOS interface (Data) */
#define GBIOSUTIL_SEL 13 /* BIOS interface (Utility) */
#define GBIOSARGS_SEL 14 /* BIOS interface (Arguments) */
#define NGDT 15
/*
* Entries in the Local Descriptor Table (LDT)
*/
#define LSYS5CALLS_SEL 0 /* forced by intel BCS */
#define LSYS5SIGR_SEL 1
#define L43BSDCALLS_SEL 2 /* notyet */
#define LUCODE_SEL 3
#define LSOL26CALLS_SEL 4 /* Solaris >= 2.6 system call gate */
#define LUDATA_SEL 5
/* separate stack, es,fs,gs sels ? */
/* #define LPOSIXCALLS_SEL 5*/ /* notyet */
#define LBSDICALLS_SEL 16 /* BSDI system call gate */
#define NLDT (LBSDICALLS_SEL + 1)
#ifdef _KERNEL
extern int _default_ldt;
extern union descriptor gdt[];
extern struct soft_segment_descriptor gdt_segs[];
extern struct gate_descriptor *idt;
extern union descriptor ldt[NLDT];
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_ */
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