Cleanup Redox repo, update Rust, remove old target

kernel/arch/x86_64/src/stop.rs

@@ -0,0 +1,23 @@
+use io::{Io, Pio};
+
+#[no_mangle]
+pub unsafe extern fn kstop() -> ! {
+    // (phony) ACPI shutdown (http://forum.osdev.org/viewtopic.php?t=16990)
+    // Works for qemu and bochs.
+    for &port in [0x604, 0xB004].iter() {
+        println!("Shutdown with outw(0x{:X}, 0x{:X})", port, 0x2000);
+        Pio::<u16>::new(port).write(0x2000);
+    }
+
+    // Magic shutdown code for bochs and qemu (older versions).
+    for c in "Shutdown".bytes() {
+        println!("Shutdown with outb(0x{:X}, '{}')", 0x8900, c as char);
+        Pio::<u8>::new(0x8900).write(c);
+    }
+
+    // Magic code for VMWare. Also a hard lock.
+    println!("Shutdown with cli hlt");
+    asm!("cli; hlt" : : : : "intel", "volatile");
+
+    unreachable!();
+}