diff --git a/drv/lpc55-romapi/src/lib.rs b/drv/lpc55-romapi/src/lib.rs
index 42bed9029..83f8c44dc 100644
--- a/drv/lpc55-romapi/src/lib.rs
+++ b/drv/lpc55-romapi/src/lib.rs
@@ -2,7 +2,6 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at https://mozilla.org/MPL/2.0/.
 
-#![feature(asm)]
 #![feature(naked_functions)]
 #![no_std]
 
diff --git a/drv/lpc55-spi-server/src/main.rs b/drv/lpc55-spi-server/src/main.rs
index 165058147..8109be884 100644
--- a/drv/lpc55-spi-server/src/main.rs
+++ b/drv/lpc55-spi-server/src/main.rs
@@ -216,7 +216,7 @@ fn muck_with_gpios(syscon: &Syscon) {
     ];
 
     for (pin, alt, mode, slew, invert, digi, od) in
-        core::array::IntoIter::new(pin_settings)
+        IntoIterator::into_iter(pin_settings)
     {
         iocon
             .iocon_configure(pin, alt, mode, slew, invert, digi, od)
diff --git a/drv/stm32xx-sys/src/main.rs b/drv/stm32xx-sys/src/main.rs
index 63f23dcee..d989fbc7e 100644
--- a/drv/stm32xx-sys/src/main.rs
+++ b/drv/stm32xx-sys/src/main.rs
@@ -61,11 +61,11 @@ where
     S: pac::RegisterSpec<Ux = u32> + pac::Readable + pac::Writable,
 {
     unsafe fn set_bit(&self, index: u8) {
-        self.modify(|r, w| unsafe { w.bits(r.bits() | 1 << index) });
+        self.modify(|r, w| w.bits(r.bits() | 1 << index));
     }
 
     unsafe fn clear_bit(&self, index: u8) {
-        self.modify(|r, w| unsafe { w.bits(r.bits() & !(1 << index)) });
+        self.modify(|r, w| w.bits(r.bits() & !(1 << index)));
     }
 }
 
diff --git a/stage0/src/hypo.rs b/stage0/src/hypo.rs
index 7dbc03be9..8a18c6ea0 100644
--- a/stage0/src/hypo.rs
+++ b/stage0/src/hypo.rs
@@ -6,6 +6,8 @@
 
 use lpc55_romapi::FlashStatus;
 
+use core::arch::asm;
+
 // FlashStatus is represented as a u32 so it's safe to return directly.
 // We convert on the receiving end for safety
 // #[cmse_nonsecure_entry] We want this eventually
diff --git a/stage0/src/main.rs b/stage0/src/main.rs
index d8a1d146d..bd1862478 100644
--- a/stage0/src/main.rs
+++ b/stage0/src/main.rs
@@ -3,7 +3,6 @@
 // file, You can obtain one at https://mozilla.org/MPL/2.0/.
 
 #![feature(cmse_nonsecure_entry)]
-#![feature(asm)]
 #![feature(naked_functions)]
 #![feature(array_methods)]
 #![no_main]
@@ -13,6 +12,8 @@ extern crate panic_halt;
 use cortex_m::peripheral::Peripherals;
 use cortex_m_rt::entry;
 
+use core::arch::asm;
+
 mod hypo;
 mod image_header;
 
diff --git a/sys/kern/src/arch/arm_m.rs b/sys/kern/src/arch/arm_m.rs
index ea685275f..bf3871d9f 100644
--- a/sys/kern/src/arch/arm_m.rs
+++ b/sys/kern/src/arch/arm_m.rs
@@ -72,6 +72,7 @@
 //! context switches, and just always do full save/restore, eliminating PendSV.
 //! We'll see.
 
+use core::arch::asm;
 use core::ptr::NonNull;
 
 use zerocopy::FromBytes;
diff --git a/sys/kern/src/lib.rs b/sys/kern/src/lib.rs
index a448a48f1..83b13d266 100644
--- a/sys/kern/src/lib.rs
+++ b/sys/kern/src/lib.rs
@@ -27,7 +27,8 @@
 //!    most clever algorithms used in kernels wind up requiring `unsafe`.)
 
 #![cfg_attr(target_os = "none", no_std)]
-#![feature(asm)]
+#![feature(asm_sym)]
+#![feature(asm_const)]
 #![feature(naked_functions)]
 
 #[macro_use]
diff --git a/sys/userlib/src/lib.rs b/sys/userlib/src/lib.rs
index 6d85eecf8..69d5f14fc 100644
--- a/sys/userlib/src/lib.rs
+++ b/sys/userlib/src/lib.rs
@@ -25,7 +25,8 @@
 //! See: https://github.com/rust-lang/rust/issues/73450#issuecomment-650463347
 
 #![no_std]
-#![feature(asm)]
+#![feature(asm_const)]
+#![feature(asm_sym)]
 #![feature(naked_functions)]
 
 #[macro_use]
@@ -35,6 +36,7 @@ pub use abi::*;
 pub use num_derive::{FromPrimitive, ToPrimitive};
 pub use num_traits::{FromPrimitive, ToPrimitive};
 
+use core::arch::asm;
 use core::marker::PhantomData;
 
 pub mod hl;
diff --git a/task/ping/src/main.rs b/task/ping/src/main.rs
index fb4eb3723..e36fb132e 100644
--- a/task/ping/src/main.rs
+++ b/task/ping/src/main.rs
@@ -4,7 +4,8 @@
 
 #![no_std]
 #![no_main]
-#![feature(asm)]
+
+use core::arch::asm;
 
 use userlib::*;