setup TSS

kernel/src/arch/x86_64/gdt.rs

@@ -0,0 +1,18 @@
+use x86_64::{structures::tss::TaskStateSegment, VirtAddr};
+
+use spin::Lazy;
+
+pub const DOUBLE_FAULT_1ST_INDEX: u16 = 0;
+
+static TSS: Lazy<TaskStateSegment> = Lazy::new(|| {
+    let mut tss = TaskStateSegment::new();
+    tss.interrupt_stack_table[DOUBLE_FAULT_1ST_INDEX as usize] = {
+        const STACK_SIZE: usize = 4096 * 8;
+        static mut STACK: [u8; STACK_SIZE] = [0; STACK_SIZE];
+
+        let stack_start = VirtAddr::from_ptr(&raw const STACK);
+        let stack_end = stack_start + STACK_SIZE.try_into().unwrap();
+        stack_end
+    };
+    tss
+});