57 lines
1.4 KiB
C++
57 lines
1.4 KiB
C++
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#include "memory/VMM.h"
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namespace Paging
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{
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void VirtualMemoryManager::Init()
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{
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asm volatile("mov %%cr3, %0" : "=r"(PML4));
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}
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void VirtualMemoryManager::Init(PageTable* PML4)
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{
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this->PML4 = PML4;
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}
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void VirtualMemoryManager::Unmap(uint64_t virtualAddress)
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{
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virtualAddress >>= 12;
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uint64_t P_i = virtualAddress & 0x1ff;
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virtualAddress >>= 9;
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uint64_t PT_i = virtualAddress & 0x1ff;
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virtualAddress >>= 9;
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uint64_t PD_i = virtualAddress & 0x1ff;
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virtualAddress >>= 9;
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uint64_t PDP_i = virtualAddress & 0x1ff;
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PageDirectoryEntry PDE;
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PDE = PML4->entries[PDP_i];
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PageTable* PDP;
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if (!PDE.Present)
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{
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return; // Already unmapped
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}
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else { PDP = (PageTable*)((uint64_t)PDE.Address << 12); }
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PDE = PDP->entries[PD_i];
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PageTable* PD;
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if (!PDE.Present)
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{
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return; // Already unmapped
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}
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else { PD = (PageTable*)((uint64_t)PDE.Address << 12); }
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PDE = PD->entries[PT_i];
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PageTable* PT;
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if (!PDE.Present)
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{
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return; // Already unmapped
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}
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else { PT = (PageTable*)((uint64_t)PDE.Address << 12); }
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PDE = PT->entries[P_i];
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PDE.Present = false;
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PDE.ReadWrite = false;
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PT->entries[P_i] = PDE;
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}
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}
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