segments.h revision 719
160107Sobrien/*- 22786Ssos * Copyright (c) 1989, 1990 William F. Jolitz 32786Ssos * Copyright (c) 1990 The Regents of the University of California. 42786Ssos * All rights reserved. 52786Ssos * 62786Ssos * This code is derived from software contributed to Berkeley by 732822Syokota * William Jolitz. 82786Ssos * 92786Ssos * Redistribution and use in source and binary forms, with or without 102786Ssos * modification, are permitted provided that the following conditions 11192766Smarkm * are met: 122786Ssos * 1. Redistributions of source code must retain the above copyright 132786Ssos * notice, this list of conditions and the following disclaimer. 142786Ssos * 2. Redistributions in binary form must reproduce the above copyright 152786Ssos * notice, this list of conditions and the following disclaimer in the 162786Ssos * documentation and/or other materials provided with the distribution. 172786Ssos * 3. All advertising materials mentioning features or use of this software 1838140Syokota * must display the following acknowledgement: 192786Ssos * This product includes software developed by the University of 207420Ssos * California, Berkeley and its contributors. 212786Ssos * 4. Neither the name of the University nor the names of its contributors 222786Ssos * may be used to endorse or promote products derived from this software 232786Ssos * without specific prior written permission. 2461118Sroberto * 252786Ssos * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 262786Ssos * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 272786Ssos * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 282786Ssos * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 292786Ssos * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 302786Ssos * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 312786Ssos * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 322786Ssos * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 332786Ssos * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 342786Ssos * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 352786Ssos * SUCH DAMAGE. 362786Ssos * 372786Ssos * from: @(#)segments.h 7.1 (Berkeley) 5/9/91 382786Ssos * $Id: segments.h,v 1.2 1993/10/16 14:39:30 rgrimes Exp $ 392786Ssos */ 402786Ssos 412786Ssos#ifndef _MACHINE_SEGMENTS_H_ 422786Ssos#define _MACHINE_SEGMENTS_H_ 1 432786Ssos 442786Ssos/* 452786Ssos * 386 Segmentation Data Structures and definitions 462786Ssos * William F. Jolitz (william@ernie.berkeley.edu) 6/20/1989 4744160Syokota */ 482786Ssos 492786Ssos/* 502786Ssos * Selectors 512786Ssos */ 522786Ssos 532786Ssos#define ISPL(s) ((s)&3) /* what is the priority level of a selector */ 542786Ssos#define SEL_KPL 0 /* kernel priority level */ 552786Ssos#define SEL_UPL 3 /* user priority level */ 562786Ssos#define ISLDT(s) ((s)&SEL_LDT) /* is it local or global */ 572786Ssos#define SEL_LDT 4 /* local descriptor table */ 582786Ssos#define IDXSEL(s) (((s)>>3) & 0x1fff) /* index of selector */ 592786Ssos#define LSEL(s,r) (((s)<<3) | SEL_LDT | r) /* a local selector */ 602786Ssos#define GSEL(s,r) (((s)<<3) | r) /* a global selector */ 6143334Syokota 622786Ssos/* 6332822Syokota * Memory and System segment descriptors 6462420Sjoe */ 652786Ssosstruct segment_descriptor { 662786Ssos unsigned sd_lolimit:16 ; /* segment extent (lsb) */ 672786Ssos unsigned sd_lobase:24 ; /* segment base address (lsb) */ 682786Ssos unsigned sd_type:5 ; /* segment type */ 692786Ssos unsigned sd_dpl:2 ; /* segment descriptor priority level */ 702786Ssos unsigned sd_p:1 ; /* segment descriptor present */ 712786Ssos unsigned sd_hilimit:4 ; /* segment extent (msb) */ 722786Ssos unsigned sd_xx:2 ; /* unused */ 732786Ssos unsigned sd_def32:1 ; /* default 32 vs 16 bit size */ 742786Ssos unsigned sd_gran:1 ; /* limit granularity (byte/page units)*/ 7543334Syokota unsigned sd_hibase:8 ; /* segment base address (msb) */ 7643334Syokota} ; 772786Ssos 782786Ssos/* 792786Ssos * Gate descriptors (e.g. indirect descriptors) 8043334Syokota */ 812786Ssosstruct gate_descriptor { 825994Ssos unsigned gd_looffset:16 ; /* gate offset (lsb) */ 8343334Syokota unsigned gd_selector:16 ; /* gate segment selector */ 842786Ssos unsigned gd_stkcpy:5 ; /* number of stack wds to cpy */ 852786Ssos unsigned gd_xx:3 ; /* unused */ 862786Ssos unsigned gd_type:5 ; /* segment type */ 872786Ssos unsigned gd_dpl:2 ; /* segment descriptor priority level */ 882786Ssos unsigned gd_p:1 ; /* segment descriptor present */ 896045Ssos unsigned gd_hioffset:16 ; /* gate offset (msb) */ 9043334Syokota} ; 912786Ssos 922786Ssos/* 932786Ssos * Generic descriptor 942786Ssos */ 9518194Ssosunion descriptor { 962786Ssos struct segment_descriptor sd; 972786Ssos struct gate_descriptor gd; 9874119Sache}; 992786Ssos 1002786Ssos /* system segments and gate types */ 1012786Ssos#define SDT_SYSNULL 0 /* system null */ 1022786Ssos#define SDT_SYS286TSS 1 /* system 286 TSS available */ 1032786Ssos#define SDT_SYSLDT 2 /* system local descriptor table */ 1042786Ssos#define SDT_SYS286BSY 3 /* system 286 TSS busy */ 1052786Ssos#define SDT_SYS286CGT 4 /* system 286 call gate */ 1062786Ssos#define SDT_SYSTASKGT 5 /* system task gate */ 1072786Ssos#define SDT_SYS286IGT 6 /* system 286 interrupt gate */ 10874119Sache#define SDT_SYS286TGT 7 /* system 286 trap gate */ 1096851Ssos#define SDT_SYSNULL2 8 /* system null again */ 11043334Syokota#define SDT_SYS386TSS 9 /* system 386 TSS available */ 11143334Syokota#define SDT_SYSNULL3 10 /* system null again */ 11243334Syokota#define SDT_SYS386BSY 11 /* system 386 TSS busy */ 11343334Syokota#define SDT_SYS386CGT 12 /* system 386 call gate */ 11443334Syokota#define SDT_SYSNULL4 13 /* system null again */ 115#define SDT_SYS386IGT 14 /* system 386 interrupt gate */ 116#define SDT_SYS386TGT 15 /* system 386 trap gate */ 117 118 /* memory segment types */ 119#define SDT_MEMRO 16 /* memory read only */ 120#define SDT_MEMROA 17 /* memory read only accessed */ 121#define SDT_MEMRW 18 /* memory read write */ 122#define SDT_MEMRWA 19 /* memory read write accessed */ 123#define SDT_MEMROD 20 /* memory read only expand dwn limit */ 124#define SDT_MEMRODA 21 /* memory read only expand dwn limit accessed */ 125#define SDT_MEMRWD 22 /* memory read write expand dwn limit */ 126#define SDT_MEMRWDA 23 /* memory read write expand dwn limit acessed */ 127#define SDT_MEME 24 /* memory execute only */ 128#define SDT_MEMEA 25 /* memory execute only accessed */ 129#define SDT_MEMER 26 /* memory execute read */ 130#define SDT_MEMERA 27 /* memory execute read accessed */ 131#define SDT_MEMEC 28 /* memory execute only conforming */ 132#define SDT_MEMEAC 29 /* memory execute only accessed conforming */ 133#define SDT_MEMERC 30 /* memory execute read conforming */ 134#define SDT_MEMERAC 31 /* memory execute read accessed conforming */ 135 136/* is memory segment descriptor pointer ? */ 137#define ISMEMSDP(s) ((s->d_type) >= SDT_MEMRO && (s->d_type) <= SDT_MEMERAC) 138 139/* is 286 gate descriptor pointer ? */ 140#define IS286GDP(s) (((s->d_type) >= SDT_SYS286CGT \ 141 && (s->d_type) < SDT_SYS286TGT)) 142 143/* is 386 gate descriptor pointer ? */ 144#define IS386GDP(s) (((s->d_type) >= SDT_SYS386CGT \ 145 && (s->d_type) < SDT_SYS386TGT)) 146 147/* is gate descriptor pointer ? */ 148#define ISGDP(s) (IS286GDP(s) || IS386GDP(s)) 149 150/* is segment descriptor pointer ? */ 151#define ISSDP(s) (ISMEMSDP(s) || !ISGDP(s)) 152 153/* is system segment descriptor pointer ? */ 154#define ISSYSSDP(s) (!ISMEMSDP(s) && !ISGDP(s)) 155 156/* 157 * Software definitions are in this convenient format, 158 * which are translated into inconvenient segment descriptors 159 * when needed to be used by the 386 hardware 160 */ 161 162struct soft_segment_descriptor { 163 unsigned ssd_base ; /* segment base address */ 164 unsigned ssd_limit ; /* segment extent */ 165 unsigned ssd_type:5 ; /* segment type */ 166 unsigned ssd_dpl:2 ; /* segment descriptor priority level */ 167 unsigned ssd_p:1 ; /* segment descriptor present */ 168 unsigned ssd_xx:4 ; /* unused */ 169 unsigned ssd_xx1:2 ; /* unused */ 170 unsigned ssd_def32:1 ; /* default 32 vs 16 bit size */ 171 unsigned ssd_gran:1 ; /* limit granularity (byte/page units)*/ 172}; 173 174extern ssdtosd() ; /* to decode a ssd */ 175extern sdtossd() ; /* to encode a sd */ 176 177/* 178 * region descriptors, used to load gdt/idt tables before segments yet exist. 179 */ 180struct region_descriptor { 181 unsigned rd_limit:16; /* segment extent */ 182 unsigned rd_base:32; /* base address */ 183}; 184 185/* 186 * Segment Protection Exception code bits 187 */ 188 189#define SEGEX_EXT 0x01 /* recursive or externally induced */ 190#define SEGEX_IDT 0x02 /* interrupt descriptor table */ 191#define SEGEX_TI 0x04 /* local descriptor table */ 192 /* other bits are affected descriptor index */ 193#define SEGEX_IDX(s) ((s)>>3)&0x1fff) 194 195/* 196 * Size of IDT table 197 */ 198 199#define NIDT 256 200#define NRSVIDT 32 /* reserved entries for cpu exceptions */ 201#endif /* _MACHINE_SEGMENTS_H_ */ 202