From 00cda98a6233dce7b1ba4c8496959f36e8f53ee8 Mon Sep 17 00:00:00 2001
From: Alex <enderice2@users.noreply.github.com>
Date: Tue, 1 Nov 2022 19:57:15 +0200
Subject: [PATCH] Added Check() function

---
 Core/Memory/VirtualMemoryManager.cpp | 22 ++++++++++++++++++++++
 include/memory.hpp                   | 14 ++++++++++++++
 2 files changed, 36 insertions(+)

diff --git a/Core/Memory/VirtualMemoryManager.cpp b/Core/Memory/VirtualMemoryManager.cpp
index 748ca91..91cf0f9 100644
--- a/Core/Memory/VirtualMemoryManager.cpp
+++ b/Core/Memory/VirtualMemoryManager.cpp
@@ -5,6 +5,28 @@
 
 namespace Memory
 {
+    bool Virtual::Check(void *VirtualAddress)
+    {
+        // 0x1000 aligned
+        uint64_t Address = (uint64_t)VirtualAddress;
+        Address &= 0xFFFFFFFFFFFFF000;
+        debug("%#lx=>%#lx", VirtualAddress, Address);
+
+        PageMapIndexer Index = PageMapIndexer((uint64_t)Address);
+        PageDirectoryEntry PDE = this->Table->Entries[Index.PDP_i];
+        debug("%x %x %x %x %x %x %x %x %x %x %x %p-%#llx",
+              PDE.Value.Present, PDE.Value.ReadWrite,
+              PDE.Value.UserSupervisor, PDE.Value.WriteThrough,
+              PDE.Value.CacheDisable, PDE.Value.Accessed,
+              PDE.Value.Dirty, PDE.Value.PageSize,
+              PDE.Value.Global, PDE.Value.PageAttributeTable,
+              PDE.Value.ExecuteDisable, PDE.GetAddress(),
+              PDE.Value);
+        if (!PDE.GetFlag(PTFlag::P))
+            return false;
+        return true;
+    }
+
     void Virtual::Map(void *VirtualAddress, void *PhysicalAddress, uint64_t Flags)
     {
         SmartLock(this->MemoryLock);
diff --git a/include/memory.hpp b/include/memory.hpp
index 929221a..f8c05be 100644
--- a/include/memory.hpp
+++ b/include/memory.hpp
@@ -389,6 +389,15 @@ namespace Memory
         };
 
     public:
+        /**
+         * @brief Check if page is present
+         *
+         * @param VirtualAddress Virtual address of the page
+         * @return true if page is present
+         * @return false if page is not present
+         */
+        bool Check(void *VirtualAddress);
+
         /**
          * @brief Map page.
          *
@@ -397,6 +406,7 @@ namespace Memory
          * @param Flags Flags of the page. Check PTFlag enum.
          */
         void Map(void *VirtualAddress, void *PhysicalAddress, uint64_t Flags);
+
         /**
          * @brief Map multiple pages.
          *
@@ -406,12 +416,14 @@ namespace Memory
          * @param Flags Flags of the page. Check PTFlag enum.
          */
         void Map(void *VirtualAddress, void *PhysicalAddress, uint64_t PageCount, uint64_t Flags);
+
         /**
          * @brief Unmap page.
          *
          * @param VirtualAddress Virtual address of the page.
          */
         void Unmap(void *VirtualAddress);
+
         /**
          * @brief Unmap multiple pages.
          *
@@ -419,12 +431,14 @@ namespace Memory
          * @param PageCount Number of pages.
          */
         void Unmap(void *VirtualAddress, uint64_t PageCount);
+
         /**
          * @brief Construct a new Virtual object
          *
          * @param Table Page table. If null, it will use the current page table.
          */
         Virtual(PageTable *Table = nullptr);
+
         /**
          * @brief Destroy the Virtual object
          *