From ffaddeb84e907cbc07077370abf1c376ecec480f Mon Sep 17 00:00:00 2001
From: Philipp Oppermann <dev@phil-opp.com>
Date: Tue, 18 Apr 2017 12:32:59 +0200
Subject: [PATCH] Fix boot loop by enabling the NXE bit in the EFER register

---
 src/lib.rs | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/src/lib.rs b/src/lib.rs
index c56d602..51d0295 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -45,12 +45,23 @@ pub extern fn rust_main(multiboot_information_address: usize) {
         kernel_start as usize, kernel_end as usize, multiboot_start,
         multiboot_end, memory_map_tag.memory_areas());
 
+    enable_nxe_bit();
     memory::remap_the_kernel(&mut frame_allocator, boot_info);
     println!("It did not crash!");
 
     loop {}
 }
 
+fn enable_nxe_bit() {
+    use x86_64::registers::msr::{IA32_EFER, rdmsr, wrmsr};
+
+    let nxe_bit = 1 << 11;
+    unsafe {
+        let efer = rdmsr(IA32_EFER);
+        wrmsr(IA32_EFER, efer | nxe_bit);
+    }
+}
+
 #[lang = "eh_personality"] extern fn eh_personality() {}
 
 #[lang = "panic_fmt"]