diff --git a/src/gdt.pas b/src/gdt.pas
new file mode 100644
index 00000000..2498b9c6
--- /dev/null
+++ b/src/gdt.pas
@@ -0,0 +1,93 @@
+unit gdt;
+    
+interface
+
+uses
+    util;
+
+type 
+    TSegementDescriptor = bitpacked record
+        limit_low     : WORD;
+        base_low      : WORD;
+        access        : Byte;
+        limit_n_flags : Byte;
+        base_high     : Byte;
+    end;
+
+var
+    GDTarr : array[0..3] of TSegementDescriptor;
+    GDTptr : ^TSegementDescriptor;    
+    GDT_length : integer = 0;
+
+    procedure init();
+    procedure create(base : dword; limit : dword; flags : byte);
+    
+implementation
+
+procedure init(); 
+var 
+    data_addr : dword;
+begin
+    GDTptr := @GDTarr[0];
+    data_addr := (@GDTarr[2] - @GDTarr[0]) shr 16;
+    create($0000, $0000, $00); //null segment / GDT pointer
+    create($0000, $FFFF, $9A); //code descriptor
+    create($0000, $FFFF, $92); //data descriptor
+    asm
+        LGDT GDTptr
+        MOV AX, data_addr
+        MOV DS, AX
+        MOV SS, AX
+        MOV ES, AX
+        MOV FS, AX
+        MOV GS, AX
+    end;
+end;
+    
+procedure create(base : dword; limit : dword; flags : byte);
+var
+    descriptor : array[0..8] of Byte;
+    descriptor_ptr : ^Byte = @descriptor[0];
+    s_descriptor : TSegementDescriptor;
+    s_descriptor_ptr : ^TSegementDescriptor = @s_descriptor;
+begin
+    if limit <= 65536 then
+        descriptor[6] := $40
+    else
+        if (limit and $FFF) <> $FFF then
+            limit := (limit >> 12) -1
+        else
+            limit := limit >> 12;
+        descriptor[6] := $C0;
+
+    descriptor[0] := limit and $FF;
+    descriptor[1] := (limit shr 8) and $FF;
+    descriptor[6] := limit or ((limit shr 16) and $F);
+
+    descriptor[2] := base and $FF;
+    descriptor[3] := (base shr 8) and $FF;
+    descriptor[4] := (base shr 16) and $FF;
+    descriptor[7] := (base shr 24) and $FF;
+
+    descriptor[5] := flags;
+
+    asm 
+        MOV EAX, descriptor_ptr
+        MOV s_descriptor_ptr, EAX
+    end;
+
+    descriptor_ptr = @descriptor[4];
+
+    asm
+        MOV EAX, descriptor_ptr
+        MOV EBX, s_descriptor_ptr
+        ADD EBX, 1
+        MOV (EBX), EAX
+    end;
+
+    GDTarr[GDT_length] := s_descriptor;
+    GDT_length := GDT_length + 1;
+end;
+
+    
+end.
\ No newline at end of file