From aa3e00193cc265b2b39c29249fa034cad36e14f1 Mon Sep 17 00:00:00 2001 From: "William F. Jolitz" Date: Mon, 13 Jul 1992 02:39:11 -0800 Subject: [PATCH 1/1] 386BSD 0.1 development Work on file usr/src/sys.386bsd/i386/include/segments.h Co-Authored-By: Lynne Greer Jolitz Synthesized-from: 386BSD-0.1 --- usr/src/sys.386bsd/i386/include/segments.h | 196 +++++++++++++++++++++ 1 file changed, 196 insertions(+) create mode 100644 usr/src/sys.386bsd/i386/include/segments.h diff --git a/usr/src/sys.386bsd/i386/include/segments.h b/usr/src/sys.386bsd/i386/include/segments.h new file mode 100644 index 0000000000..0456e59ac8 --- /dev/null +++ b/usr/src/sys.386bsd/i386/include/segments.h @@ -0,0 +1,196 @@ +/*- + * 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. + * + * @(#)segments.h 7.1 (Berkeley) 5/9/91 + */ + +/* + * 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 ; /* 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 acessed */ +#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 */ + +/* is memory segment descriptor pointer ? */ +#define ISMEMSDP(s) ((s->d_type) >= SDT_MEMRO && (s->d_type) <= SDT_MEMERAC) + +/* is 286 gate descriptor pointer ? */ +#define IS286GDP(s) (((s->d_type) >= SDT_SYS286CGT \ + && (s->d_type) < SDT_SYS286TGT)) + +/* is 386 gate descriptor pointer ? */ +#define IS386GDP(s) (((s->d_type) >= SDT_SYS386CGT \ + && (s->d_type) < SDT_SYS386TGT)) + +/* is gate descriptor pointer ? */ +#define ISGDP(s) (IS286GDP(s) || IS386GDP(s)) + +/* is segment descriptor pointer ? */ +#define ISSDP(s) (ISMEMSDP(s) || !ISGDP(s)) + +/* is system segment descriptor pointer ? */ +#define ISSYSSDP(s) (!ISMEMSDP(s) && !ISGDP(s)) + +/* + * 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)*/ +}; + +extern ssdtosd() ; /* to decode a ssd */ +extern sdtossd() ; /* to encode a sd */ + +/* + * 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; /* 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 +#define NRSVIDT 32 /* reserved entries for cpu exceptions */ -- 2.20.1