From 49cfee4e370892df8404e56d53b04dde196f82f2 Mon Sep 17 00:00:00 2001
From: Alexey Gavrilov <rebovas@yahoo.com>
Date: Sun, 31 Mar 2024 14:39:51 +0700
Subject: IDT + uintptr update

---
 arch/x86/gdt/Gdt.cpp | 60 ++++++++++++++++++++++++++++------------------------
 arch/x86/gdt/Gdt.h   | 27 ++++++++++++++---------
 2 files changed, 49 insertions(+), 38 deletions(-)

(limited to 'arch/x86/gdt')

diff --git a/arch/x86/gdt/Gdt.cpp b/arch/x86/gdt/Gdt.cpp
index 21941b4..70f30cd 100755
--- a/arch/x86/gdt/Gdt.cpp
+++ b/arch/x86/gdt/Gdt.cpp
@@ -2,6 +2,21 @@
 
 
 uint64 MngGdt::gdt[MngGdt::size];
+bool MngGdt::isInitialize = false;
+bool MngGdt::gdtLoaded = false;
+MngGdt mngGdt;
+
+MngGdt::MngGdt()
+{
+    if(!isInitialize)
+    {
+        MemoryOperations::set(gdt, 0, sizeof(uint64) * size);
+        currIdx = 1;
+        gdtLoaded = false;
+        isInitialize = true;
+        codeSegmentKern = NULL;
+    }
+};
 
 DescSeg32::DescSeg32(uint32 base, uint32 limit, uint8 access, uint8 flags)
 {
@@ -57,59 +72,48 @@ uint64 DescSeg32::flatDataUser()
                                     , PAGEGRAN | HIGHSIZE).getDescriptor();    
 };
 
-MngGdt::MngGdt()
-{
-    gdt[0] = 0;
-    currIdx = 1;
-    isGdtLoaded = 0;
-};
-
 bool MngGdt::addDescriptor(uint64 desc)
 {
-    if(currIdx >= size || currIdx == 0)
+    if(currIdx >= size or currIdx == 0 or gdtLoaded)
     {
         return false;
     }
 
+    if(desc == DescSeg32::flatCodeKernel()) codeSegmentKern = currIdx * 8;
     this->gdt[currIdx++] = desc;
     return true;
 };
 
 bool MngGdt::loadGdt()
 {
-    if(isGdtLoaded)
+    if(gdtLoaded)
     {
         return false;
     }
 
-    uint64 pointer = 0;
+    // Set pointer
+    uint64 descriptor = 0;
     uint16 size = sizeof(uint64) * this->size - 1;
-    uint32 offset = (uint32)((void *)(&gdt));
+    uint32 offset = (uint32)(&gdt);
 
-    pointer |= offset;
-    pointer <<= 16;
-    pointer |= size;
+    descriptor |= offset;
+    descriptor <<= 16;
+    descriptor |= size;
 
-    SWITCHTOGDT(pointer);
+    SWITCHTOGDT(descriptor);
 
-    isGdtLoaded = 1;
+    gdtLoaded = 1;
     return true;
 };
 
-bool MngGdt::getIsGdtLoaded()
+// Get static instance of MngGdt initialized once
+MngGdt &MngGdt::getInstance()
 {
-    return isGdtLoaded;
+    if(!isInitialize) mngGdt = MngGdt();
+    return mngGdt;
 };
 
-void MngGdt::operator=(const MngGdt& src)
+uint16 MngGdt::getCodeSegmentKernel()
 {
-    if(this->isGdtLoaded == 1 || src.isGdtLoaded == 1)
-    {
-        return;
-    }
-
-    // Fix it. Write method to copy from ... to ...
-    for(int i = 0; i < this->size; i++) this->gdt[i] = src.gdt[i];
-    this->isGdtLoaded = src.isGdtLoaded;
-    this->currIdx = src.currIdx;
+    return codeSegmentKern;
 };
diff --git a/arch/x86/gdt/Gdt.h b/arch/x86/gdt/Gdt.h
index 6667d93..321d67c 100755
--- a/arch/x86/gdt/Gdt.h
+++ b/arch/x86/gdt/Gdt.h
@@ -2,6 +2,7 @@
 #define GDT_H
 
 #include <types.h>
+#include <MemoryOperations.h>
 
 
 // Define access options
@@ -59,7 +60,7 @@ class DescSeg32                     // Segment descriptor
 #ifdef __cplusplus
 extern "C" {
 #endif
-extern void SWITCHTOGDT(uint64 pointer);
+extern void SWITCHTOGDT(uint64 descriptor);
 #ifdef __cplusplus
 };
 #endif
@@ -67,17 +68,23 @@ extern void SWITCHTOGDT(uint64 pointer);
 class MngGdt
 {
     private:
-       const static uint8 size = 10;
-       static uint64 gdt[size]; 
-       uint8 currIdx;
-       bool isGdtLoaded;
+        const static uint8 size = 10;
+        static uint64 gdt[size]; 
+        static bool isInitialize;
+        static bool gdtLoaded;
+        uint16 codeSegmentKern;
+        uint8 currIdx;
+        MngGdt &operator=(const MngGdt &) = default;
 
     public:
-       MngGdt();
-       void operator=(const MngGdt& src);
-       bool addDescriptor(uint64 desc);  // 0 - not set descriptor, 1 - set
-       bool loadGdt();      // 0 - if GDT is not loaded, 1 - loaded
-       bool getIsGdtLoaded();
+        MngGdt();
+        MngGdt(const MngGdt &) = delete;
+        bool addDescriptor(uint64 desc);  // 0 - not set descriptor, 1 - set
+        bool loadGdt();      // 0 - if GDT is not loaded, 1 - loaded
+        uint16 getCodeSegmentKernel();
+        static MngGdt &getInstance();
 };
 
+extern MngGdt mngGdt;
+
 #endif
-- 
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