switch from bitfields to enums

kernel/src/paging/PageTableManager.cpp

@@ -14,52 +14,53 @@ void PageTableManager::MapMemory(void* virtualMemory, void* physicalMemory) {
 
     PDE = PML4->entries[indexer.PDP_i];
     PageTable* PDP;
-
-	if (!PDE.Present) {
+    if (!PDE.GetFlag(PT_Flag::Present)){
         PDP = (PageTable*)GlobalAllocator.RequestPage();
-		memset(PDP, 0, 4096); // zero out the new page
-
-		PDE.Address = (uint64_t)PDP >> 12;
-		PDE.Present = true;
-		PDE.ReadWrite = true;
+        memset(PDP, 0, 0x1000);
+        PDE.SetAddress((uint64_t)PDP >> 12);
+        PDE.SetFlag(PT_Flag::Present, true);
+        PDE.SetFlag(PT_Flag::ReadWrite, true);
         PML4->entries[indexer.PDP_i] = PDE;
-	} else {
-		PDP = (PageTable*)((uint64_t)PDE.Address << 12);
     }
+    else
+    {
+        PDP = (PageTable*)((uint64_t)PDE.GetAddress() << 12);
+    }
+    
     
     PDE = PDP->entries[indexer.PD_i];
     PageTable* PD;
-
-	if (!PDE.Present) {
+    if (!PDE.GetFlag(PT_Flag::Present)){
         PD = (PageTable*)GlobalAllocator.RequestPage();
-		memset(PD, 0, 4096); // zero out the new page
-
-		PDE.Address = (uint64_t)PD >> 12;
-		PDE.Present = true;
-		PDE.ReadWrite = true;
+        memset(PD, 0, 0x1000);
+        PDE.SetAddress((uint64_t)PD >> 12);
+        PDE.SetFlag(PT_Flag::Present, true);
+        PDE.SetFlag(PT_Flag::ReadWrite, true);
         PDP->entries[indexer.PD_i] = PDE;
-	} else {
-		PD = (PageTable*)((uint64_t)PDE.Address << 12);
+    }
+    else
+    {
+        PD = (PageTable*)((uint64_t)PDE.GetAddress() << 12);
     }
 
     PDE = PD->entries[indexer.PT_i];
     PageTable* PT;
-
-	if (!PDE.Present) {
+    if (!PDE.GetFlag(PT_Flag::Present)){
         PT = (PageTable*)GlobalAllocator.RequestPage();
-		memset(PT, 0, 4096); // zero out the new page
-
-		PDE.Address = (uint64_t)PT >> 12;
-		PDE.Present = true;
-		PDE.ReadWrite = true;
+        memset(PT, 0, 0x1000);
+        PDE.SetAddress((uint64_t)PT >> 12);
+        PDE.SetFlag(PT_Flag::Present, true);
+        PDE.SetFlag(PT_Flag::ReadWrite, true);
         PD->entries[indexer.PT_i] = PDE;
-	} else {
-		PT = (PageTable*)((uint64_t)PDE.Address << 12);
+    }
+    else
+    {
+        PT = (PageTable*)((uint64_t)PDE.GetAddress() << 12);
     }
 
     PDE = PT->entries[indexer.P_i];
-	PDE.Address = (uint64_t)physicalMemory >> 12;
-	PDE.Present = true;
-	PDE.ReadWrite = true;
+    PDE.SetAddress((uint64_t)physicalMemory >> 12);
+    PDE.SetFlag(PT_Flag::Present, true);
+    PDE.SetFlag(PT_Flag::ReadWrite, true);
     PT->entries[indexer.P_i] = PDE;
 }

kernel/src/paging/paging.cpp

@@ -0,0 +1,25 @@
+#include "paging.h"
+
+void PageDirectoryEntry::SetFlag(PT_Flag flag, bool enabled) {
+	uint64_t bitSelector = (uint64_t)1 << flag;
+	Value %= ~bitSelector;
+
+	if (enabled) {
+		Value |= bitSelector;
+	}
+}
+
+bool PageDirectoryEntry::GetFlag(PT_Flag flag) {
+	uint64_t bitSelector = (uint64_t)1 << flag;
+	return Value & bitSelector > 0 ? true : false;
+}
+
+uint64_t PageDirectoryEntry::GetAddress() {
+	return (Value & 0x000FFFFFFFFFF000) >> 12;
+}
+
+void PageDirectoryEntry::SetAddress(uint64_t address) {
+	address &= 0x000000FFFFFFFFFF;
+	Value &= 0xFFF0000000000FFF;
+	Value |= (address << 12);
+}

kernel/src/paging/paging.h

@@ -1,19 +1,26 @@
 #pragma once
 #include <stdint.h>
 
-struct PageDirectoryEntry {
-	bool Present : 1; // memory exists and can be accessed
-	bool ReadWrite : 1; // 
-	bool UserSuper : 1; // memory can only be accessed by supervisor or both user and supervisor
-	bool WriteThrough : 1; //
-	bool CacheDisabled : 1; //
-	bool Accessed : 1; // set when cpu accesses page
-	bool ignore0 : 1; //
-	bool LargerPages : 1; //
-	bool ignore1 : 1; //
-	uint8_t Available : 3; //
-	uint64_t Address : 52; // physical address
+enum PT_Flag {
+    Present = 0,
+    ReadWrite = 1,
+    UserSuper = 2,
+    WriteThrough = 3,
+    CacheDisabled = 4,
+    Accessed = 5,
+    LargerPages = 7,
+    Custom0 = 9,
+    Custom1 = 10,
+    Custom2 = 11,
+    NX = 63 // no-execute, only if supported
+};
 
+struct PageDirectoryEntry {
+    uint64_t Value;
+    void SetFlag(PT_Flag flag, bool enabled);
+    bool GetFlag(PT_Flag flag);
+    void SetAddress(uint64_t address);
+    uint64_t GetAddress();
 };
 
 struct PageTable {