Rename the src directory to kernel.

kernel/arch/x86_64/gdt.rs

@@ -0,0 +1,31 @@
+pub const GDT_NULL: usize = 0;
+pub const GDT_KERNEL_CODE: usize = 1;
+pub const GDT_KERNEL_DATA: usize = 2;
+pub const GDT_USER_CODE: usize = 3;
+pub const GDT_USER_DATA: usize = 4;
+pub const GDT_USER_TLS: usize = 5;
+pub const GDT_TSS: usize = 6;
+
+#[repr(packed)]
+pub struct GdtDescriptor {
+    pub size: u16,
+    pub ptr: u64
+}
+
+#[repr(packed)]
+pub struct GdtEntry {
+    pub limitl: u16,
+    pub basel: u16,
+    pub basem: u8,
+    pub attribute: u8,
+    pub flags_limith: u8,
+    pub baseh: u8
+}
+
+impl GdtEntry {
+    pub fn set_base(&mut self, base: usize) {
+        self.basel = base as u16;
+        self.basem = (base >> 16) as u8;
+        self.baseh = (base >> 24) as u8;
+    }
+}