execute ltr in position where it doesnt fault

kernel/boot/longmode.asm

@@ -198,6 +198,10 @@ paging_enable:
 	; Load Long Mode Global Descriptor Table
 	lgdt [gdt_long_mode_pointer]
 
+    ;; Select 5th Segment in GDT. 5<<3 == 0x28
+    ;mov  ax, 0x0028 
+    ;ltr ax
+
 	; Far jump to the 64-bit start code
 	jmp 0x8:long_mode_start
 

kernel/boot/startup.cc

@@ -16,9 +16,13 @@ extern "C" [[noreturn]] void kernel_init() {
 	// Initialize PICs
 	PIC::initialize();
 
-	// Call global constructors
+    // Call global constructors
 	CSU::initializer();
 
+    //Select 5th Segment in GDT. 5<<3 == 0x28
+    asm volatile ("mov $0x28, %ax");
+    asm("ltr %ax");
+
 	// Initialize ACPI
 	if (!ACPI::init()) {
 		DBG_VERBOSE << "No ACPI!";