Replace llvm_asm with asm to support stable Rust.

src/arch/x86_64.rs

@@ -1,4 +1,5 @@
 use core::{mem, slice};
+use core::arch::asm;
 use core::ops::{Deref, DerefMut};
 
 use super::error::{Error, Result};

src/io/mmio.rs

@@ -1,4 +1,4 @@
-use core::ptr::{read_volatile, write_volatile};
+use core::ptr::{read_volatile, write_volatile, addr_of, addr_of_mut};
 use core::mem::MaybeUninit;
 use core::ops::{BitAnd, BitOr, Not};
 
@@ -36,10 +36,10 @@ impl<T> Io for Mmio<T> where T: Copy + PartialEq + BitAnd<Output = T> + BitOr<Ou
     type Value = T;
 
     fn read(&self) -> T {
-        unsafe { read_volatile(self.value.as_ptr()) }
+        unsafe { read_volatile(addr_of!(self.value).cast::<T>()) }
     }
 
     fn write(&mut self, value: T) {
-        unsafe { write_volatile(self.value.as_mut_ptr(), value) };
+        unsafe { write_volatile(addr_of_mut!(self.value).cast::<T>(), value) };
     }
 }

src/io/pio.rs

@@ -1,3 +1,4 @@
+use core::arch::asm;
 use core::marker::PhantomData;
 
 use super::io::Io;
@@ -13,7 +14,7 @@ impl<T> Pio<T> {
     /// Create a PIO from a given port
     pub const fn new(port: u16) -> Self {
         Pio::<T> {
-            port: port,
+            port,
             value: PhantomData,
         }
     }
@@ -28,7 +29,7 @@ impl Io for Pio<u8> {
     fn read(&self) -> u8 {
         let value: u8;
         unsafe {
-            llvm_asm!("in $0, $1" : "={al}"(value) : "{dx}"(self.port) : "memory" : "intel", "volatile");
+            asm!("in al, dx", in("dx") self.port, out("al") value, options(nostack, nomem, preserves_flags));
         }
         value
     }
@@ -37,7 +38,7 @@ impl Io for Pio<u8> {
     #[inline(always)]
     fn write(&mut self, value: u8) {
         unsafe {
-            llvm_asm!("out $1, $0" : : "{al}"(value), "{dx}"(self.port) : "memory" : "intel", "volatile");
+            asm!("out dx, al", in("dx") self.port, in("al") value, options(nostack, nomem, preserves_flags));
         }
     }
 }
@@ -51,7 +52,7 @@ impl Io for Pio<u16> {
     fn read(&self) -> u16 {
         let value: u16;
         unsafe {
-            llvm_asm!("in $0, $1" : "={ax}"(value) : "{dx}"(self.port) : "memory" : "intel", "volatile");
+            asm!("in ax, dx", in("dx") self.port, out("ax") value, options(nostack, nomem, preserves_flags));
         }
         value
     }
@@ -60,7 +61,7 @@ impl Io for Pio<u16> {
     #[inline(always)]
     fn write(&mut self, value: u16) {
         unsafe {
-            llvm_asm!("out $1, $0" : : "{ax}"(value), "{dx}"(self.port) : "memory" : "intel", "volatile");
+            asm!("out dx, ax", in("dx") self.port, in("ax") value, options(nostack, nomem, preserves_flags));
         }
     }
 }
@@ -74,7 +75,7 @@ impl Io for Pio<u32> {
     fn read(&self) -> u32 {
         let value: u32;
         unsafe {
-            llvm_asm!("in $0, $1" : "={eax}"(value) : "{dx}"(self.port) : "memory" : "intel", "volatile");
+            asm!("in eax, dx", in("dx") self.port, out("eax") value, options(nostack, nomem, preserves_flags));
         }
         value
     }
@@ -83,7 +84,7 @@ impl Io for Pio<u32> {
     #[inline(always)]
     fn write(&mut self, value: u32) {
         unsafe {
-            llvm_asm!("out $1, $0" : : "{eax}"(value), "{dx}"(self.port) : "memory" : "intel", "volatile");
+            asm!("out dx, eax", in("dx") self.port, in("eax") value, options(nostack, nomem, preserves_flags));
         }
     }
 }

src/lib.rs

@@ -1,5 +1,3 @@
-#![feature(asm)]
-#![feature(llvm_asm)]
 #![cfg_attr(not(test), no_std)]
 
 #[cfg(test)]