Set the NXE and the WP bit

src/lib.rs

@@ -68,12 +68,33 @@ pub extern "C" fn rust_main(multiboot_information_address: usize) {
                                                               memory_map_tag.memory_areas());
 
     memory::test_paging(&mut frame_allocator);
+
+    enable_nxe_bit();
+    enable_write_protect_bit();
+
     memory::remap_the_kernel(&mut frame_allocator, boot_info);
     println!("It did not crash!");
 
     loop {}
 }
 
+fn enable_nxe_bit() {
+    use x86::msr::{IA32_EFER, rdmsr, wrmsr};
+
+    let nxe_bit = 1 << 11;
+    unsafe {
+        let efer = rdmsr(IA32_EFER);
+        wrmsr(IA32_EFER, efer | nxe_bit);
+    }
+}
+
+fn enable_write_protect_bit() {
+    use x86::controlregs::{cr0, cr0_write};
+
+    let wp_bit = 1 << 16;
+    unsafe { cr0_write(cr0() | wp_bit) };
+}
+
 #[cfg(not(test))]
 #[lang = "eh_personality"]
 extern "C" fn eh_personality() {}