segments.h revision ae115bc77f6fcde83175c75b4206dc2e50747966
/*
* Copyright 2007 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#ifndef _SYS_SEGMENTS_H
#define _SYS_SEGMENTS_H
#pragma ident "%Z%%M% %I% %E% SMI"
#ifdef __cplusplus
extern "C" {
#endif
/*
* 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
* $FreeBSD: src/sys/i386/include/segments.h,v 1.34 2003/09/10 01:07:04
* jhb Exp $
*
* 386 Segmentation Data Structures and definitions
* William F. Jolitz (william@ernie.berkeley.edu) 6/20/1989
*/
#include <sys/tss.h>
/*
* Selector register format
* CS, DS, ES, FS, GS, SS
*
* 15 3 2 1 0
* +---------------------+---+----+
* | SI |TI |RPL |
* +---------------------+---+----+
*
* SI = selector index
* TI = table indicator (0 = GDT, 1 = LDT)
* RPL = requestor privilege level
*/
#if !defined(_ASM) || defined(__GNUC_AS__)
#define IDXTOSEL(s) ((s) << 3) /* index to selector */
#define SEL_GDT(s, r) (IDXTOSEL(s) | r) /* global sel */
#else
#define IDXTOSEL(s) [s << 3]
#define SEL_GDT(s, r) [IDXTOSEL(s) | r]
#endif
#define SELTOIDX(s) ((s) >> 3) /* selector to index */
#define SEL_KPL 0 /* kernel privilege level */
#define SEL_UPL 3 /* user priority level */
#define SEL_TI_LDT 4 /* local descriptor table */
#define SEL_LDT(s) (IDXTOSEL(s) | SEL_TI_LDT | SEL_UPL) /* local sel */
#define CPL_MASK 3 /* RPL mask for selector */
#define SELISLDT(s) (((s) & SEL_TI_LDT) == SEL_TI_LDT)
#define SELISUPL(s) (((s) & CPL_MASK) == SEL_UPL)
#ifndef _ASM
typedef uint16_t selector_t; /* selector reigster */
/*
* Hardware descriptor table register format for GDT and IDT.
*/
#if defined(__amd64)
#pragma pack(2)
typedef struct {
uint16_t dtr_limit; /* table limit */
uint64_t dtr_base; /* table base address */
} desctbr_t;
#pragma pack()
#elif defined(__i386)
#pragma pack(2)
typedef struct {
uint16_t dtr_limit; /* table limit */
uint32_t dtr_base; /* table base address */
} desctbr_t;
#pragma pack()
#endif /* __i386 */
/*
* Functions for loading and storing descriptor table
* registers.
*/
extern void rd_idtr(desctbr_t *);
extern void wr_idtr(desctbr_t *);
extern void rd_gdtr(desctbr_t *);
extern void wr_gdtr(desctbr_t *);
extern void wr_ldtr(selector_t);
extern selector_t rd_ldtr(void);
extern void wr_tsr(selector_t);
extern void kmdb_enter(void);
#if defined(__amd64)
extern void clr_ldt_sregs(void);
/*
* inlines for update_segregs
*/
extern void __set_ds(selector_t);
extern void __set_es(selector_t);
extern void __set_fs(selector_t);
extern void __set_gs(selector_t);
extern void __swapgs(void);
#endif /* __amd64 */
#if defined(__amd64)
extern void load_segment_registers(selector_t, selector_t, selector_t,
selector_t); /* (alphabetical) */
#elif defined(__i386)
extern void load_segment_registers(selector_t, selector_t, selector_t,
selector_t, selector_t, selector_t); /* (alphabetical) */
#endif /* __i386 */
#if !defined(__amd64)
/*
* User segment descriptors (code and data).
* Legacy mode 64-bits wide.
*/
typedef struct user_desc {
uint32_t usd_lolimit:16; /* segment limit 15:0 */
uint32_t usd_lobase:16; /* segment base 15:0 */
uint32_t usd_midbase:8; /* segment base 23:16 */
uint32_t usd_type:5; /* segment type, includes S bit */
uint32_t usd_dpl:2; /* segment descriptor priority level */
uint32_t usd_p:1; /* segment descriptor present */
uint32_t usd_hilimit:4; /* segment limit 19:16 */
uint32_t usd_avl:1; /* available to sw, but not used */
uint32_t usd_reserved:1; /* unused, ignored */
uint32_t usd_def32:1; /* default 32 vs 16 bit operand */
uint32_t usd_gran:1; /* limit units (bytes vs pages) */
uint32_t usd_hibase:8; /* segment base 31:24 */
} user_desc_t;
#define USEGD_GETBASE(usd) ((usd)->usd_lobase | \
(usd)->usd_midbase << 16 | \
(usd)->usd_hibase << (16 + 8))
#define USEGD_SETBASE(usd, b) ((usd)->usd_lobase = (b), \
(usd)->usd_midbase = (b) >> 16, \
(usd)->usd_hibase = (b) >> (16 + 8))
#define USEGD_GETLIMIT(usd) ((usd)->usd_lolimit | \
(usd)->usd_hilimit << 16)
#define USEGD_SETLIMIT(usd, lim) ((usd)->usd_lolimit = lim, \
(usd)->usd_hilimit = lim >> 16)
#define USD_TYPESHIFT 5 /* size of usd_type field */
#else /* __amd64 */
/*
* User segment descriptors.
* Long mode 64-bits wide.
*
* In 32-bit compatibility mode (%cs:usd_long=0) all fields are interpreted
* as in legacy mode for both code and data.
*
* In 64-bit mode (%cs:usd_long=1) code segments only have the conforming
* bit in usd_type, usd_dpl, usd_p, usd_long and usd_def32=0. usd_def32
* must be zero in 64-bit mode. Setting it to 1 is reserved for future use.
* All other fields are loaded but ignored by hardware.
*
* 64-bit data segments only have usd_p. All other fields are loaded but
* ignored by hardware when in 64-bit mode.
*/
typedef struct user_desc {
uint64_t usd_lolimit:16; /* segment limit 15:0 */
uint64_t usd_lobase:16; /* segment base 15:0 */
uint64_t usd_midbase:8; /* segment base 23:16 */
uint64_t usd_type:5; /* segment type, includes S bit */
uint64_t usd_dpl:2; /* segment descriptor priority level */
uint64_t usd_p:1; /* segment descriptor present */
uint64_t usd_hilimit:4; /* segment limit 19:16 */
uint64_t usd_avl:1; /* available to sw, but not used */
uint64_t usd_long:1; /* long mode (%cs only) */
uint64_t usd_def32:1; /* default 32 vs 16 bit operand */
uint64_t usd_gran:1; /* limit units (bytes vs page) */
uint64_t usd_hibase:8; /* segment base 31:24 */
} user_desc_t;
#define USEGD_GETBASE(usd) ((usd)->usd_lobase | \
(usd)->usd_midbase << 16 | \
(usd)->usd_hibase << (16 + 8))
#define USEGD_SETBASE(usd, b) ((usd)->usd_lobase = (b), \
(usd)->usd_midbase = (b) >> 16, \
(usd)->usd_hibase = (b) >> (16 + 8))
#define USEGD_GETLIMIT(usd) ((usd)->usd_lolimit | \
(usd)->usd_hilimit << 16)
#define USEGD_SETLIMIT(usd, lim) ((usd)->usd_lolimit = lim, \
(usd)->usd_hilimit = lim >> 16)
#define USD_TYPESHIFT 5 /* size of usd_type field */
#endif /* __amd64 */
#if !defined(__amd64)
/*
* System segment descriptors for LDT and TSS segments.
* Legacy mode 64-bits wide.
*/
typedef struct system_desc {
uint32_t ssd_lolimit:16; /* segment limit 15:0 */
uint32_t ssd_lobase:16; /* segment base 15:0 */
uint32_t ssd_midbase:8; /* segment base 23:16 */
uint32_t ssd_type:4; /* segment type */
uint32_t ssd_zero:1; /* must be zero */
uint32_t ssd_dpl:2; /* segment descriptor priority level */
uint32_t ssd_p:1; /* segment descriptor present */
uint32_t ssd_hilimit:4; /* segment limit 19:16 */
uint32_t ssd_avl:1; /* available to sw, but not used */
uint32_t ssd_reserved:2; /* unused, ignored */
uint32_t ssd_gran:1; /* limit unit (bytes vs pages) */
uint32_t ssd_hibase:8; /* segment base 31:24 */
} system_desc_t;
#else /* __amd64 */
/*
* System segment descriptors for LDT and TSS segments.
* Long mode 128-bits wide.
*
* 32-bit LDT and TSS descriptor types are redefined to 64-bit equivalents.
* All other legacy types are reserved and illegal.
*/
typedef struct system_desc {
uint64_t ssd_lolimit:16; /* segment limit 15:0 */
uint64_t ssd_lobase:16; /* segment base 15:0 */
uint64_t ssd_midbase:8; /* segment base 23:16 */
uint64_t ssd_type:4; /* segment type */
uint64_t ssd_zero1:1; /* must be zero */
uint64_t ssd_dpl:2; /* segment descriptor priority level */
uint64_t ssd_p:1; /* segment descriptor present */
uint64_t ssd_hilimit:4; /* segment limit 19:16 */
uint64_t ssd_avl:1; /* available to sw, but not used */
uint64_t ssd_resv1:2; /* unused, ignored */
uint64_t ssd_gran:1; /* limit unit (bytes vs pages) */
uint64_t ssd_hibase:8; /* segment base 31:24 */
uint64_t ssd_hi64base:32; /* segment base 63:32 */
uint64_t ssd_resv2:8; /* unused, ignored */
uint64_t ssd_zero2:5; /* must be zero */
uint64_t ssd_resv3:19; /* unused, ignored */
} system_desc_t;
#endif /* __amd64 */
#define SYSSEGD_SETLIMIT(ssd, lim) ((ssd)->ssd_lolimit = lim, \
(ssd)->ssd_hilimit = lim >> 16)
#if !defined(__amd64)
/*
* System gate segment descriptors for interrupt, trap, call and task gates.
* Legacy mode 64-bits wide.
*/
typedef struct gate_desc {
uint32_t sgd_looffset:16; /* segment code offset 15:0 */
uint32_t sgd_selector:16; /* target code or task selector */
uint32_t sgd_stkcpy:5; /* number of stack wds to cpy */
uint32_t sgd_resv:3; /* unused, ignored */
uint32_t sgd_type:5; /* segment type, includes S bit */
uint32_t sgd_dpl:2; /* segment descriptor priority level */
uint32_t sgd_p:1; /* segment descriptor present */
uint32_t sgd_hioffset:16; /* code seg off 31:16 */
} gate_desc_t;
#define GATESEG_GETOFFSET(sgd) ((sgd)->sgd_looffset | \
(sgd)->sgd_hioffset << 16)
#else /* __amd64 */
/*
* System segment descriptors for interrupt, trap and call gates.
* Long mode 128-bits wide.
*
* 32-bit interrupt, trap and call gate types are redefined to 64-bit
* equivalents. Task gates along with all other legacy types are reserved
* and illegal.
*/
typedef struct gate_desc {
uint64_t sgd_looffset:16; /* segment code offset 15:0 */
uint64_t sgd_selector:16; /* target code or task selector */
uint64_t sgd_ist:3; /* IST table index */
uint64_t sgd_resv1:5; /* unused, ignored */
uint64_t sgd_type:5; /* segment type, includes S bit */
uint64_t sgd_dpl:2; /* segment descriptor priority level */
uint64_t sgd_p:1; /* segment descriptor present */
uint64_t sgd_hioffset:16; /* segment code offset 31:16 */
uint64_t sgd_hi64offset:32; /* segment code offset 63:32 */
uint64_t sgd_resv2:8; /* unused, ignored */
uint64_t sgd_zero:5; /* call gate only: must be zero */
uint64_t sgd_resv3:19; /* unused, ignored */
} gate_desc_t;
#define GATESEG_GETOFFSET(sgd) ((sgd)->sgd_looffset | \
(sgd)->sgd_hioffset << 16 | \
(sgd)->sgd_hi64offset << 32)
#endif /* __amd64 */
/*
* functions for initializing and updating segment descriptors.
*/
#if defined(__amd64)
extern void set_usegd(user_desc_t *, uint_t, void *, size_t, uint_t, uint_t,
uint_t, uint_t);
#elif defined(__i386)
extern void set_usegd(user_desc_t *, void *, size_t, uint_t, uint_t,
uint_t, uint_t);
#endif /* __i386 */
extern void set_gatesegd(gate_desc_t *, void (*)(void), selector_t,
uint_t, uint_t);
void set_syssegd(system_desc_t *, void *, size_t, uint_t, uint_t);
void init_boot_gdt(user_desc_t *);
#endif /* _ASM */
/*
* Common segment parameter defintions for granularity, default
* operand size and operaton mode.
*/
#define SDP_BYTES 0 /* segment limit scaled to bytes */
#define SDP_PAGES 1 /* segment limit scaled to pages */
#define SDP_OP32 1 /* code and data default operand = 32 bits */
#define SDP_LONG 1 /* long mode code segment (64 bits) */
#define SDP_SHORT 0 /* compat/legacy code segment (32 bits) */
/*
* System segments and gate types.
*
* In long mode i386 32-bit ldt, tss, call, interrupt and trap gate
* types are redefined into 64-bit equivalents.
*/
#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_SYSTSS 9 /* system TSS available */
#define SDT_SYSNULL3 10 /* system null again */
#define SDT_SYSTSSBSY 11 /* system TSS busy */
#define SDT_SYSCGT 12 /* system call gate */
#define SDT_SYSNULL4 13 /* system null again */
#define SDT_SYSIGT 14 /* system interrupt gate */
#define SDT_SYSTGT 15 /* system trap gate */
/*
* Memory segment types.
*
* While in long mode expand-down, writable and accessed type field
* attributes are ignored. Only the conforming bit is loaded by hardware
* for long mode code segment descriptors.
*/
#define SDT_MEMRO 16 /* read only */
#define SDT_MEMROA 17 /* read only accessed */
#define SDT_MEMRW 18 /* read write */
#define SDT_MEMRWA 19 /* read write accessed */
#define SDT_MEMROD 20 /* read only expand dwn limit */
#define SDT_MEMRODA 21 /* read only expand dwn limit accessed */
#define SDT_MEMRWD 22 /* read write expand dwn limit */
#define SDT_MEMRWDA 23 /* read write expand dwn limit accessed */
#define SDT_MEME 24 /* execute only */
#define SDT_MEMEA 25 /* execute only accessed */
#define SDT_MEMER 26 /* execute read */
#define SDT_MEMERA 27 /* execute read accessed */
#define SDT_MEMEC 28 /* execute only conforming */
#define SDT_MEMEAC 29 /* execute only accessed conforming */
#define SDT_MEMERC 30 /* execute read conforming */
#define SDT_MEMERAC 31 /* execute read accessed conforming */
/*
* 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 NIDT 256 /* size in entries of IDT */
/*
* Entries in the Global Descriptor Table (GDT)
*
* We make sure to space the system descriptors (LDT's, TSS')
* such that they are double gdt slot aligned. This is because
* in long mode system segment decriptors expand to 128 bits.
*
* GDT_LWPFS and GDT_LWPGS must be the same for both 32 and 64-bit
* kernels. See setup_context in libc. 64-bit processes must set
* %fs or %gs to null selector to use 64-bit fsbase or gsbase
* respectively.
*/
#define GDT_NULL 0 /* null */
#define GDT_B32DATA 1 /* dboot 32 bit data descriptor */
#define GDT_B32CODE 2 /* dboot 32 bit code descriptor */
#define GDT_B16CODE 3 /* bios call 16 bit code descriptor */
#define GDT_B16DATA 4 /* bios call 16 bit data descriptor */
#define GDT_B64CODE 5 /* dboot 64 bit code descriptor */
#define GDT_BGSTMP 7 /* kmdb descriptor only used early in boot */
#if defined(__amd64)
#define GDT_KCODE 6 /* kernel code seg %cs */
#define GDT_KDATA 7 /* kernel data seg %ds */
#define GDT_U32CODE 8 /* 32-bit process on 64-bit kernel %cs */
#define GDT_UDATA 9 /* user data seg %ds (32 and 64 bit) */
#define GDT_UCODE 10 /* native user code seg %cs */
#define GDT_LDT 12 /* LDT for current process */
#define GDT_KTSS 14 /* kernel tss */
#define GDT_FS GDT_NULL /* kernel %fs segment selector */
#define GDT_GS GDT_NULL /* kernel %gs segment selector */
#define GDT_LWPFS 55 /* lwp private %fs segment selector (32-bit) */
#define GDT_LWPGS 56 /* lwp private %gs segment selector (32-bit) */
#define GDT_BRANDMIN 57 /* first entry in GDT for brand usage */
#define GDT_BRANDMAX 61 /* last entry in GDT for brand usage */
#define NGDT 62 /* number of entries in GDT */
/*
* This selector is only used in the temporary GDT used to bring additional
* CPUs from 16-bit real mode into long mode in real_mode_start().
*/
#define TEMPGDT_KCODE64 1 /* 64-bit code selector */
#elif defined(__i386)
#define GDT_LDT 40 /* LDT for current process */
#define GDT_KTSS 42 /* kernel tss */
#define GDT_KCODE 43 /* kernel code seg %cs */
#define GDT_KDATA 44 /* kernel data seg %ds */
#define GDT_UCODE 45 /* native user code seg %cs */
#define GDT_UDATA 46 /* user data seg %ds (32 and 64 bit) */
#define GDT_DBFLT 47 /* double fault #DF selector */
#define GDT_FS 53 /* kernel %fs segment selector */
#define GDT_GS 54 /* kernel %gs segment selector */
#define GDT_LWPFS 55 /* lwp private %fs segment selector */
#define GDT_LWPGS 56 /* lwp private %gs segment selector */
#define GDT_BRANDMIN 57 /* first entry in GDT for brand usage */
#define GDT_BRANDMAX 61 /* last entry in GDT for brand usage */
#define NGDT 90 /* number of entries in GDT */
#endif /* __i386 */
/*
* Convenient selector definitions.
*/
#define KCS_SEL SEL_GDT(GDT_KCODE, SEL_KPL)
#define KDS_SEL SEL_GDT(GDT_KDATA, SEL_KPL)
#define UCS_SEL SEL_GDT(GDT_UCODE, SEL_UPL)
#if defined(__amd64)
#define TEMP_CS64_SEL SEL_GDT(TEMPGDT_KCODE64, SEL_KPL)
#define U32CS_SEL SEL_GDT(GDT_U32CODE, SEL_UPL)
#endif /* __amd64 */
#define UDS_SEL SEL_GDT(GDT_UDATA, SEL_UPL)
#define ULDT_SEL SEL_GDT(GDT_LDT, SEL_KPL)
#define KTSS_SEL SEL_GDT(GDT_KTSS, SEL_KPL)
#define DFTSS_SEL SEL_GDT(GDT_DBFLT, SEL_KPL)
#define KFS_SEL 0
#define KGS_SEL SEL_GDT(GDT_GS, SEL_KPL)
#define LWPFS_SEL SEL_GDT(GDT_LWPFS, SEL_UPL)
#define LWPGS_SEL SEL_GDT(GDT_LWPGS, SEL_UPL)
#define BRANDMIN_SEL SEL_GDT(GDT_BRANDMIN, SEL_UPL)
#define BRANDMAX_SEL SEL_GDT(GDT_BRANDMAX, SEL_UPL)
#define B64CODE_SEL SEL_GDT(GDT_B64CODE, SEL_KPL)
#define B32CODE_SEL SEL_GDT(GDT_B32CODE, SEL_KPL)
#define B32DATA_SEL SEL_GDT(GDT_B32DATA, SEL_KPL)
#define B16CODE_SEL SEL_GDT(GDT_B16CODE, SEL_KPL)
#define B16DATA_SEL SEL_GDT(GDT_B16DATA, SEL_KPL)
/*
* Temporary %gs descriptor used by kmdb with -d option. Only lives
* in boot's GDT and is not copied into kernel's GDT from boot.
*/
#define KMDBGS_SEL SEL_GDT(GDT_BGSTMP, SEL_KPL)
/*
* Selector used for kdi_idt when kmdb has taken over the IDT.
*/
#if defined(__amd64)
#define KMDBCODE_SEL B64CODE_SEL
#else
#define KMDBCODE_SEL B32CODE_SEL
#endif
/*
* Entries in default Local Descriptor Table (LDT) for every process.
*/
#define LDT_SYSCALL 0 /* call gate for libc.a (obsolete) */
#define LDT_SIGCALL 1 /* EOL me, call gate for static sigreturn */
#define LDT_RESVD1 2 /* old user %cs */
#define LDT_RESVD2 3 /* old user %ds */
#define LDT_ALTSYSCALL 4 /* alternate call gate for system calls */
#define LDT_ALTSIGCALL 5 /* EOL me, alternate call gate for sigreturn */
#define LDT_UDBASE 6 /* user descriptor base index */
#define MINNLDT 64 /* Current min solaris ldt size */
#define MAXNLDT 8192 /* max solaris ldt size */
#ifndef _ASM
#pragma align 16(idt0)
extern gate_desc_t idt0[NIDT];
extern desctbr_t idt0_default_reg;
extern user_desc_t *gdt0;
extern user_desc_t zero_udesc;
extern system_desc_t zero_sdesc;
#if defined(__amd64)
extern user_desc_t zero_u32desc;
#endif
#pragma align 16(ktss0)
extern struct tss ktss0;
#if defined(__i386)
extern struct tss dftss0;
#endif /* __i386 */
extern void div0trap(), dbgtrap(), nmiint(), brktrap(), ovflotrap();
extern void boundstrap(), invoptrap(), ndptrap(), syserrtrap();
extern void invaltrap(), invtsstrap(), segnptrap(), stktrap();
extern void gptrap(), pftrap(), ndperr();
extern void overrun(), resvtrap();
extern void _start(), cmnint();
extern void achktrap(), mcetrap();
extern void xmtrap();
extern void fasttrap();
extern void sys_int80();
extern void brand_sys_int80();
extern void dtrace_ret();
#if !defined(__amd64)
extern void pentium_pftrap();
#endif
#endif /* _ASM */
#ifdef __cplusplus
}
#endif
#endif /* _SYS_SEGMENTS_H */