2b72262b4f
I hereby relicense all my work on Sortix under the ISC license as below. All Sortix contributions by other people are already under this license, are not substantial enough to be copyrightable, or have been removed. All imported code from other projects is compatible with this license. All GPL licensed code from other projects had previously been removed. Copyright 2011-2016 Jonas 'Sortie' Termansen and contributors. Permission to use, copy, modify, and distribute this software for any purpose with or without fee is hereby granted, provided that the above copyright notice and this permission notice appear in all copies. THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
287 lines
8.8 KiB
C++
287 lines
8.8 KiB
C++
/*
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* Copyright (c) 2011, 2012, 2013, 2014, 2015 Jonas 'Sortie' Termansen.
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*
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* Permission to use, copy, modify, and distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*
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* x86-family/gdt.cpp
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* GDT and TSS.
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*/
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#include <assert.h>
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#include <stdint.h>
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#include <string.h>
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#include <sortix/kernel/cpu.h>
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#include <sortix/kernel/registers.h>
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#include "gdt.h"
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namespace Sortix {
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namespace GDT {
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struct gdt_entry
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{
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uint16_t limit_low;
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uint16_t base_low;
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uint8_t base_middle;
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uint8_t access;
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uint8_t granularity;
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uint8_t base_high;
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};
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#if defined(__x86_64__)
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struct gdt_entry64
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{
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uint16_t limit_low;
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uint16_t base_low;
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uint8_t base_middle;
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uint8_t access;
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uint8_t granularity;
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uint8_t base_high;
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uint32_t base_highest;
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uint32_t reserved0;
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};
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#endif
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#if defined(__i386__)
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struct tss_entry
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{
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uint32_t prev_tss;
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uint32_t esp0;
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uint32_t ss0;
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uint32_t esp1;
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uint32_t ss1;
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uint32_t esp2;
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uint32_t ss2;
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uint32_t cr3;
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uint32_t eip;
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uint32_t eflags;
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uint32_t eax;
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uint32_t ecx;
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uint32_t edx;
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uint32_t ebx;
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uint32_t esp;
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uint32_t ebp;
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uint32_t esi;
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uint32_t edi;
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uint32_t es;
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uint32_t cs;
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uint32_t ss;
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uint32_t ds;
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uint32_t fs;
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uint32_t gs;
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uint32_t ldt;
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uint16_t trap;
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uint16_t iomap_base;
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};
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#elif defined(__x86_64__)
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struct tss_entry
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{
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uint32_t reserved0;
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uint64_t stack0; /* This is not naturally aligned, so packed is needed. */
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uint64_t stack1;
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uint64_t stack2;
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uint64_t reserved1;
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uint64_t ist[7];
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uint64_t reserved2;
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uint16_t reserved3;
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uint16_t iomap_base;
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} __attribute__((packed));
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#endif
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extern "C" {
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const size_t STACK_SIZE = 64*1024;
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extern size_t stack[STACK_SIZE / sizeof(size_t)];
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struct tss_entry tss =
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{
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#if defined(__i386__)
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.prev_tss = 0, /* c++ */
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.esp0 = 0 /*(uintptr_t) stack + sizeof(stack)*/,
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.ss0 = 0x10 /* Kernel Data Segment */,
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.esp1 = 0, /* c++ */
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.ss1 = 0, /* c++ */
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.esp2 = 0, /* c++ */
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.ss2 = 0, /* c++ */
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.cr3 = 0, /* c++ */
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.eip = 0, /* c++ */
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.eflags = 0, /* c++ */
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.eax = 0, /* c++ */
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.ecx = 0, /* c++ */
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.edx = 0, /* c++ */
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.ebx = 0, /* c++ */
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.esp = 0, /* c++ */
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.ebp = 0, /* c++ */
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.esi = 0, /* c++ */
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.edi = 0, /* c++ */
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.es = 0x13 /* Kernel Data Segment */,
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.cs = 0x0B /* Kernel Code Segment */,
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.ss = 0, /* c++ */
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.ds = 0x13 /* Kernel Data Segment */,
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.fs = 0x13 /* Kernel Data Segment */,
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.gs = 0x13 /* Kernel Data Segment */,
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.ldt = 0, /* c++ */
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.trap = 0, /* c++ */
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.iomap_base = 0, /* c++ */
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#elif defined(__x86_64__)
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.reserved0 = 0, /* c++ */
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.stack0 = 0 /*(uintptr_t) stack + sizeof(stack)*/,
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.stack1 = 0, /* c++ */
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.stack2 = 0, /* c++ */
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.reserved1 = 0, /* c++ */
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.ist = { 0, 0, 0, 0, 0, 0, 0},
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.reserved2 = 0,
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.reserved3 = 0,
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.iomap_base = 0,
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#endif
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};
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} /* extern "C" */
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#define GRAN_64_BIT_MODE (1 << 5)
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#define GRAN_32_BIT_MODE (1 << 6)
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#define GRAN_4KIB_BLOCKS (1 << 7)
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#define GDT_ENTRY(base, limit, access, granularity) \
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{ (limit) & 0xFFFF, /* limit_low */ \
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(uint16_t) ((base) >> 0 & 0xFFFF), /* base_low */ \
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(uint8_t) ((base) >> 16 & 0xFF), /* base_middle */ \
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(access) & 0xFF, /* access */ \
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((limit) >> 16 & 0x0F) | ((granularity) & 0xF0), /* granularity */ \
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(uint8_t) ((base) >> 24 & 0xFF), /* base_high */ }
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#if defined(__x86_64__)
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#define GDT_ENTRY64(base, limit, access, granularity) \
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{ (limit) & 0xFFFF, /* limit_low */ \
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(uint16_t) ((base) >> 0 & 0xFFFF), /* base_low */ \
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(uint8_t) ((base) >> 16 & 0xFF), /* base_middle */ \
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(access) & 0xFF, /* access */ \
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((limit) >> 16 & 0x0F) | ((granularity) & 0xF0), /* granularity */ \
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(uint8_t) ((base) >> 24 & 0xFF), /* base_high */ }, \
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{ (uint16_t) ((base) >> 32 & 0xFFFF), /* base_highest */ \
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(uint16_t) ((base) >> 48 & 0xFFFF), /* base_highest */ \
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0, /* reserved0 */ \
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0, /* reserved0 */ \
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0, /* reserved0 */ \
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0, /* reserved0 */ }
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#endif
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extern "C" {
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struct gdt_entry gdt[] =
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{
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/* 0x00: Null segment */
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GDT_ENTRY(0, 0, 0, 0),
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#if defined(__i386__)
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/* 0x08: Kernel Code Segment. */
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GDT_ENTRY(0, 0xFFFFFFFF, 0x9A, GRAN_32_BIT_MODE | GRAN_4KIB_BLOCKS),
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/* 0x10: Kernel Data Segment. */
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GDT_ENTRY(0, 0xFFFFFFFF, 0x92, GRAN_32_BIT_MODE | GRAN_4KIB_BLOCKS),
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/* 0x18: User Code Segment. */
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GDT_ENTRY(0, 0xFFFFFFFF, 0xFA, GRAN_32_BIT_MODE | GRAN_4KIB_BLOCKS),
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/* 0x20: User Data Segment. */
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GDT_ENTRY(0, 0xFFFFFFFF, 0xF2, GRAN_32_BIT_MODE | GRAN_4KIB_BLOCKS),
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/* 0x28: Task Switch Segment. */
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GDT_ENTRY(0 /*((uintptr_t) &tss)*/, sizeof(tss) - 1, 0xE9, 0x00),
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/* 0x30: F Segment. */
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GDT_ENTRY(0, 0xFFFFFFFF, 0xF2, GRAN_32_BIT_MODE | GRAN_4KIB_BLOCKS),
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/* 0x38: G Segment. */
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GDT_ENTRY(0, 0xFFFFFFFF, 0xF2, GRAN_32_BIT_MODE | GRAN_4KIB_BLOCKS),
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#elif defined(__x86_64__)
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/* 0x08: Kernel Code Segment. */
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GDT_ENTRY(0, 0xFFFFFFFF, 0x9A, GRAN_64_BIT_MODE | GRAN_4KIB_BLOCKS),
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/* 0x10: Kernel Data Segment. */
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GDT_ENTRY(0, 0xFFFFFFFF, 0x92, GRAN_64_BIT_MODE | GRAN_4KIB_BLOCKS),
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/* 0x18: User Code Segment. */
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GDT_ENTRY(0, 0xFFFFFFFF, 0xFA, GRAN_64_BIT_MODE | GRAN_4KIB_BLOCKS),
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/* 0x20: User Data Segment. */
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GDT_ENTRY(0, 0xFFFFFFFF, 0xF2, GRAN_64_BIT_MODE | GRAN_4KIB_BLOCKS),
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/* 0x28: Task Switch Segment. */
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GDT_ENTRY64((uint64_t) 0 /*((uintptr_t) &tss)*/, sizeof(tss) - 1, 0xE9, 0x00),
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#endif
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};
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uint16_t gdt_size_minus_one = sizeof(gdt) - 1;
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} /* extern "C" */
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uintptr_t GetKernelStack()
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{
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#if defined(__i386__)
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return tss.esp0;
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#elif defined(__x86_64__)
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return tss.stack0;
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#endif
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}
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void SetKernelStack(uintptr_t stack_pointer)
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{
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assert((stack_pointer & 0xF) == 0);
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#if defined(__i386__)
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tss.esp0 = (uint32_t) stack_pointer;
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#elif defined(__x86_64__)
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tss.stack0 = (uint64_t) stack_pointer;
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#endif
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}
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#if defined(__i386__)
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uint32_t GetFSBase()
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{
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struct gdt_entry* entry = gdt + GDT_FS_ENTRY;
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return (uint32_t) entry->base_low << 0 |
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(uint32_t) entry->base_middle << 16 |
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(uint32_t) entry->base_high << 24;
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}
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uint32_t GetGSBase()
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{
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struct gdt_entry* entry = gdt + GDT_GS_ENTRY;
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return (uint32_t) entry->base_low << 0 |
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(uint32_t) entry->base_middle << 16 |
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(uint32_t) entry->base_high << 24;
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}
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void SetFSBase(uint32_t fsbase)
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{
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struct gdt_entry* entry = gdt + GDT_FS_ENTRY;
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entry->base_low = fsbase >> 0 & 0xFFFF;
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entry->base_middle = fsbase >> 16 & 0xFF;
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entry->base_high = fsbase >> 24 & 0xFF;
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asm volatile ("mov %0, %%fs" : : "r"(GDT_FS_ENTRY << 3 | URPL));
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}
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void SetGSBase(uint32_t gsbase)
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{
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struct gdt_entry* entry = gdt + GDT_GS_ENTRY;
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entry->base_low = gsbase >> 0 & 0xFFFF;
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entry->base_middle = gsbase >> 16 & 0xFF;
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entry->base_high = gsbase >> 24 & 0xFF;
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asm volatile ("mov %0, %%gs" : : "r"(GDT_GS_ENTRY << 3 | URPL));
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}
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#endif
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} // namespace GDT
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} // namespace Sortix
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