1 files changed, 100 insertions, 0 deletions
diff --git a/arch/x86/gdt/Gdt.cpp b/arch/x86/gdt/Gdt.cpp
new file mode 100755
index 0000000..63c70ef
--- /dev/null
+++ b/arch/x86/gdt/Gdt.cpp
@@ -0,0 +1,100 @@
+#include "Gdt.h"
+
+
+DescSeg32::DescSeg32(uint32 base, uint32 limit, uint8 access, uint8 flags)
+{
+    this->baseLow = base & 0x0000FFFF;
+    this->baseMiddle = (base & 0x00FF0000) >> 16;
+    this->baseHight = (base & 0xFF000000) >> 24;
+
+    this->limitLow = limit & 0x0000FFFF;
+    this->limitMiddle = (limit & 0x000F0000) >> 16;
+
+    this->access = access;
+    this->flags = flags & 0x000E;
+};
+
+uint64 DescSeg32::getDescriptor()
+{
+    uint64 descriptor = 0;
+
+    descriptor |= (uint64)limitLow;
+    descriptor |= (uint64)baseLow << 16;
+    descriptor |= (uint64)baseMiddle << 32;
+    descriptor |= (uint64)access << 40;
+    descriptor |= (uint64)limitMiddle << 48;
+    descriptor |= (uint64)flags << 52;
+    descriptor |= (uint64)baseHight << 56;
+
+    return descriptor;
+};
+
+uint64 DescSeg32::flatCodeKernel()
+{
+    return DescSeg32(0, 0xFFFFF, CODE_ER | PRESENT | NSYSTEMSEG
+                                    , PAGEGRAN | HIGHSIZE).getDescriptor();    
+};
+
+uint64 DescSeg32::flatDataKernel()
+{
+    return DescSeg32(0, 0xFFFFF, DATA_RW | PRESENT | NSYSTEMSEG
+                                    , PAGEGRAN | HIGHSIZE).getDescriptor();    
+}
+
+uint64 DescSeg32::flatCodeUser()
+{
+
+    return DescSeg32(0, 0xFFFFF, CODE_ER | PRESENT | NSYSTEMSEG | USER
+                                    , PAGEGRAN | HIGHSIZE).getDescriptor();    
+};
+
+uint64 DescSeg32::flatDataUser()
+{
+
+    return DescSeg32(0, 0xFFFFF, DATA_RW | PRESENT | NSYSTEMSEG | USER
+                                    , PAGEGRAN | HIGHSIZE).getDescriptor();    
+};
+
+MngGdt::MngGdt()
+{
+    this->gdt[0] = 0;
+    currIdx = 1;
+    isGdtLoaded = 0;
+};
+
+bool MngGdt::addDescriptor(uint64 desc)
+{
+    if(currIdx >= size || currIdx == 0)
+    {
+        return false;
+    }
+
+    this->gdt[currIdx++] = desc;
+    return true;
+};
+
+bool MngGdt::loadGdt()
+{
+    if(isGdtLoaded)
+    {
+        return false;
+    }
+
+    uint64 pointer = 0;
+    uint16 size = sizeof(uint64) * this->size - 1;
+    uint16 offset = (uint32)((void *)(&gdt));
+
+    pointer |= offset;
+    pointer <<= 16;
+    pointer |= size;
+
+    GOTOGDTMEMSEG(pointer);
+
+    isGdtLoaded = 1;
+    return true;
+};
+
+bool MngGdt::getIsGdtLoaded()
+{
+    return isGdtLoaded;
+};