43 lines
1.0 KiB
C++
43 lines
1.0 KiB
C++
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#include "gdt/GDT.h"
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#include <stdint.h>
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struct GDTR
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{
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uint16_t size;
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uint64_t offset;
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} __attribute__((packed));
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struct GDTEntry
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{
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uint16_t limit0;
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uint16_t base0;
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uint8_t base1;
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uint8_t access;
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uint8_t limit1_flags;
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uint8_t base2;
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} __attribute__((packed));
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struct InternalGDT
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{
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GDTEntry null;
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GDTEntry kernel_code;
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GDTEntry kernel_data;
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GDTEntry user_null;
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GDTEntry user_code;
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GDTEntry user_data;
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} __attribute__((packed)) __attribute((aligned(0x1000)));
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__attribute__((aligned(0x1000))) static InternalGDT internal_gdt = {
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{0x0000, 0x0000, 0x00, 0x00, 0x00, 0x00}, {0xffff, 0x0000, 0x00, 0x9a, 0xaf, 0x00},
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{0xffff, 0x0000, 0x00, 0x92, 0xcf, 0x00}, {0x0000, 0x0000, 0x00, 0x00, 0x00, 0x00},
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{0xffff, 0x0000, 0x00, 0xfa, 0xaf, 0x00}, {0xffff, 0x0000, 0x00, 0xf2, 0xcf, 0x00}};
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extern "C" void load_gdt(GDTR* gdtr);
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void GDT::load()
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{
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static GDTR gdtr;
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gdtr.offset = (uint64_t)&internal_gdt;
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gdtr.size = sizeof(InternalGDT);
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load_gdt(&gdtr);
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}
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