Annotation of sys/arch/i386/include/segments.h, Revision 1.1
1.1 ! nbrk 1: /* $OpenBSD: segments.h,v 1.14 2006/01/12 22:39:21 weingart Exp $ */
! 2: /* $NetBSD: segments.h,v 1.23 1996/02/01 22:31:03 mycroft Exp $ */
! 3:
! 4: /*-
! 5: * Copyright (c) 1995 Charles M. Hannum. All rights reserved.
! 6: * Copyright (c) 1989, 1990 William F. Jolitz
! 7: * Copyright (c) 1990 The Regents of the University of California.
! 8: * All rights reserved.
! 9: *
! 10: * This code is derived from software contributed to Berkeley by
! 11: * William Jolitz.
! 12: *
! 13: * Redistribution and use in source and binary forms, with or without
! 14: * modification, are permitted provided that the following conditions
! 15: * are met:
! 16: * 1. Redistributions of source code must retain the above copyright
! 17: * notice, this list of conditions and the following disclaimer.
! 18: * 2. Redistributions in binary form must reproduce the above copyright
! 19: * notice, this list of conditions and the following disclaimer in the
! 20: * documentation and/or other materials provided with the distribution.
! 21: * 3. Neither the name of the University nor the names of its contributors
! 22: * may be used to endorse or promote products derived from this software
! 23: * without specific prior written permission.
! 24: *
! 25: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
! 26: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
! 27: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
! 28: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
! 29: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
! 30: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
! 31: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
! 32: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
! 33: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
! 34: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
! 35: * SUCH DAMAGE.
! 36: *
! 37: * @(#)segments.h 7.1 (Berkeley) 5/9/91
! 38: */
! 39:
! 40: /*
! 41: * 386 Segmentation Data Structures and definitions
! 42: * William F. Jolitz (william@ernie.berkeley.edu) 6/20/1989
! 43: */
! 44:
! 45: #ifndef _I386_SEGMENTS_H_
! 46: #define _I386_SEGMENTS_H_
! 47:
! 48: /*
! 49: * Selectors
! 50: */
! 51:
! 52: #define ISPL(s) ((s) & SEL_RPL) /* what is the priority level of a selector */
! 53: #define SEL_KPL 0 /* kernel privilege level */
! 54: #define SEL_UPL 3 /* user privilege level */
! 55: #define SEL_RPL 3 /* requester's privilege level mask */
! 56: #define ISLDT(s) ((s) & SEL_LDT) /* is it local or global */
! 57: #define SEL_LDT 4 /* local descriptor table */
! 58: #define IDXSEL(s) (((s) >> 3) & 0x1fff) /* index of selector */
! 59: #define GSEL(s,r) (((s) << 3) | r) /* a global selector */
! 60: #define LSEL(s,r) (((s) << 3) | r | SEL_LDT) /* a local selector */
! 61:
! 62: #ifdef VM86
! 63: #define USERMODE(c, f) (ISPL(c) == SEL_UPL || ((f) & PSL_VM) != 0)
! 64: #define KERNELMODE(c, f) (ISPL(c) == SEL_KPL && ((f) & PSL_VM) == 0)
! 65: #else
! 66: #define USERMODE(c, f) (ISPL(c) == SEL_UPL)
! 67: #define KERNELMODE(c, f) (ISPL(c) == SEL_KPL)
! 68: #endif
! 69:
! 70: #ifndef _LOCORE
! 71:
! 72: #if __GNUC__ == 2 && __GNUC_MINOR__ < 7
! 73: #pragma pack(1)
! 74: #endif
! 75:
! 76: /*
! 77: * Memory and System segment descriptors
! 78: */
! 79: struct segment_descriptor {
! 80: unsigned sd_lolimit:16; /* segment extent (lsb) */
! 81: unsigned sd_lobase:24; /* segment base address (lsb) */
! 82: unsigned sd_type:5; /* segment type */
! 83: unsigned sd_dpl:2; /* segment descriptor priority level */
! 84: unsigned sd_p:1; /* segment descriptor present */
! 85: unsigned sd_hilimit:4; /* segment extent (msb) */
! 86: unsigned sd_xx:2; /* unused */
! 87: unsigned sd_def32:1; /* default 32 vs 16 bit size */
! 88: unsigned sd_gran:1; /* limit granularity (byte/page) */
! 89: unsigned sd_hibase:8; /* segment base address (msb) */
! 90: } __packed;
! 91:
! 92: /*
! 93: * Gate descriptors (e.g. indirect descriptors)
! 94: */
! 95: struct gate_descriptor {
! 96: unsigned gd_looffset:16; /* gate offset (lsb) */
! 97: unsigned gd_selector:16; /* gate segment selector */
! 98: unsigned gd_stkcpy:5; /* number of stack wds to cpy */
! 99: unsigned gd_xx:3; /* unused */
! 100: unsigned gd_type:5; /* segment type */
! 101: unsigned gd_dpl:2; /* segment descriptor priority level */
! 102: unsigned gd_p:1; /* segment descriptor present */
! 103: unsigned gd_hioffset:16; /* gate offset (msb) */
! 104: } __packed;
! 105:
! 106: /*
! 107: * Generic descriptor
! 108: */
! 109: union descriptor {
! 110: struct segment_descriptor sd;
! 111: struct gate_descriptor gd;
! 112: } __packed;
! 113:
! 114: /*
! 115: * region descriptors, used to load gdt/idt tables before segments yet exist.
! 116: */
! 117: struct region_descriptor {
! 118: unsigned rd_limit:16; /* segment extent */
! 119: unsigned rd_base:32; /* base address */
! 120: } __packed;
! 121:
! 122: #if __GNUC__ == 2 && __GNUC_MINOR__ < 7
! 123: #pragma pack(4)
! 124: #endif
! 125:
! 126: #ifdef _KERNEL
! 127: extern union descriptor *gdt, ldt[];
! 128: extern struct gate_descriptor idt_region[];
! 129: extern struct gate_descriptor *idt;
! 130:
! 131: void setgate(struct gate_descriptor *, void *, int, int, int, int);
! 132: void setregion(struct region_descriptor *, void *, size_t);
! 133: void setsegment(struct segment_descriptor *, void *, size_t, int, int,
! 134: int, int);
! 135: void unsetgate(struct gate_descriptor *);
! 136: void cpu_init_idt(void);
! 137: void cpu_default_ldt(struct cpu_info *);
! 138: void cpu_alloc_ldt(struct cpu_info *);
! 139: void cpu_init_ldt(struct cpu_info *);
! 140:
! 141: int idt_vec_alloc(int, int);
! 142: void idt_vec_set(int, void (*)(void));
! 143: void idt_vec_free(int);
! 144:
! 145: #endif /* _KERNEL */
! 146:
! 147: #endif /* !_LOCORE */
! 148:
! 149: /* system segments and gate types */
! 150: #define SDT_SYSNULL 0 /* system null */
! 151: #define SDT_SYS286TSS 1 /* system 286 TSS available */
! 152: #define SDT_SYSLDT 2 /* system local descriptor table */
! 153: #define SDT_SYS286BSY 3 /* system 286 TSS busy */
! 154: #define SDT_SYS286CGT 4 /* system 286 call gate */
! 155: #define SDT_SYSTASKGT 5 /* system task gate */
! 156: #define SDT_SYS286IGT 6 /* system 286 interrupt gate */
! 157: #define SDT_SYS286TGT 7 /* system 286 trap gate */
! 158: #define SDT_SYSNULL2 8 /* system null again */
! 159: #define SDT_SYS386TSS 9 /* system 386 TSS available */
! 160: #define SDT_SYSNULL3 10 /* system null again */
! 161: #define SDT_SYS386BSY 11 /* system 386 TSS busy */
! 162: #define SDT_SYS386CGT 12 /* system 386 call gate */
! 163: #define SDT_SYSNULL4 13 /* system null again */
! 164: #define SDT_SYS386IGT 14 /* system 386 interrupt gate */
! 165: #define SDT_SYS386TGT 15 /* system 386 trap gate */
! 166:
! 167: /* memory segment types */
! 168: #define SDT_MEMRO 16 /* memory read only */
! 169: #define SDT_MEMROA 17 /* memory read only accessed */
! 170: #define SDT_MEMRW 18 /* memory read write */
! 171: #define SDT_MEMRWA 19 /* memory read write accessed */
! 172: #define SDT_MEMROD 20 /* memory read only expand dwn limit */
! 173: #define SDT_MEMRODA 21 /* memory read only expand dwn limit accessed */
! 174: #define SDT_MEMRWD 22 /* memory read write expand dwn limit */
! 175: #define SDT_MEMRWDA 23 /* memory read write expand dwn limit acessed */
! 176: #define SDT_MEME 24 /* memory execute only */
! 177: #define SDT_MEMEA 25 /* memory execute only accessed */
! 178: #define SDT_MEMER 26 /* memory execute read */
! 179: #define SDT_MEMERA 27 /* memory execute read accessed */
! 180: #define SDT_MEMEC 28 /* memory execute only conforming */
! 181: #define SDT_MEMEAC 29 /* memory execute only accessed conforming */
! 182: #define SDT_MEMERC 30 /* memory execute read conforming */
! 183: #define SDT_MEMERAC 31 /* memory execute read accessed conforming */
! 184:
! 185: /* is memory segment descriptor pointer ? */
! 186: #define ISMEMSDP(s) ((s->d_type) >= SDT_MEMRO && \
! 187: (s->d_type) <= SDT_MEMERAC)
! 188:
! 189: /* is 286 gate descriptor pointer ? */
! 190: #define IS286GDP(s) ((s->d_type) >= SDT_SYS286CGT && \
! 191: (s->d_type) < SDT_SYS286TGT)
! 192:
! 193: /* is 386 gate descriptor pointer ? */
! 194: #define IS386GDP(s) ((s->d_type) >= SDT_SYS386CGT && \
! 195: (s->d_type) < SDT_SYS386TGT)
! 196:
! 197: /* is gate descriptor pointer ? */
! 198: #define ISGDP(s) (IS286GDP(s) || IS386GDP(s))
! 199:
! 200: /* is segment descriptor pointer ? */
! 201: #define ISSDP(s) (ISMEMSDP(s) || !ISGDP(s))
! 202:
! 203: /* is system segment descriptor pointer ? */
! 204: #define ISSYSSDP(s) (!ISMEMSDP(s) && !ISGDP(s))
! 205:
! 206: /*
! 207: * Segment Protection Exception code bits
! 208: */
! 209: #define SEGEX_EXT 0x01 /* recursive or externally induced */
! 210: #define SEGEX_IDT 0x02 /* interrupt descriptor table */
! 211: #define SEGEX_TI 0x04 /* local descriptor table */
! 212:
! 213: /*
! 214: * Entries in the Interrupt Descriptor Table (IDT)
! 215: */
! 216: #define NIDT 256
! 217: #define NRSVIDT 32 /* reserved entries for cpu exceptions */
! 218:
! 219: /*
! 220: * Entries in the Global Descriptor Table (GDT)
! 221: */
! 222: #define GNULL_SEL 0 /* Null descriptor */
! 223: #define GCODE_SEL 1 /* Kernel code descriptor */
! 224: #define GDATA_SEL 2 /* Kernel data descriptor */
! 225: #define GLDT_SEL 3 /* Default LDT descriptor */
! 226: #define GUCODE1_SEL 4 /* User code descriptor */
! 227: #define GUCODE_SEL 5 /* User code descriptor (a stack short) */
! 228: #define GUDATA_SEL 6 /* User data descriptor */
! 229: #define GAPM32CODE_SEL 7 /* 32 bit APM code descriptor */
! 230: #define GAPM16CODE_SEL 8 /* 16 bit APM code descriptor */
! 231: #define GAPMDATA_SEL 9 /* APM data descriptor */
! 232: #define GICODE_SEL 10 /* Interrupt code descriptor (same as Kernel code) */
! 233: #define GCPU_SEL 11 /* per-CPU segment */
! 234: #define NGDT 12
! 235:
! 236: /*
! 237: * Entries in the Local Descriptor Table (LDT)
! 238: */
! 239: #define LSYS5CALLS_SEL 0 /* iBCS system call gate */
! 240: #define LSYS5SIGR_SEL 1 /* iBCS sigreturn gate */
! 241: #define LUCODE1_SEL 2 /* User code descriptor */
! 242: #define LUCODE_SEL 3 /* User code descriptor (a stack short) */
! 243: #define LUDATA_SEL 4 /* User data descriptor */
! 244: #define LBSDICALLS_SEL 16 /* BSDI system call gate */
! 245: #define NLDT 17
! 246:
! 247: #endif /* _I386_SEGMENTS_H_ */
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