diff --git a/os/src/lang_items.rs b/os/src/lang_items.rs
index 1c1b65ce..21c7c512 100644
--- a/os/src/lang_items.rs
+++ b/os/src/lang_items.rs
@@ -1,4 +1,5 @@
 use core::panic::PanicInfo;
+use core::arch::asm;
 use crate::sbi::shutdown;
 use crate::task::current_kstack_top;
 
diff --git a/os/src/main.rs b/os/src/main.rs
index d4b0934e..60192128 100644
--- a/os/src/main.rs
+++ b/os/src/main.rs
@@ -1,7 +1,5 @@
 #![no_std]
 #![no_main]
-#![feature(global_asm)]
-#![feature(asm)]
 #![feature(panic_info_message)]
 #![feature(alloc_error_handler)]
 
@@ -10,6 +8,8 @@ extern crate alloc;
 #[macro_use]
 extern crate bitflags;
 
+use core::arch::global_asm;
+
 #[macro_use]
 mod console;
 mod lang_items;
diff --git a/os/src/mm/memory_set.rs b/os/src/mm/memory_set.rs
index 575f5a34..30bc7689 100644
--- a/os/src/mm/memory_set.rs
+++ b/os/src/mm/memory_set.rs
@@ -14,6 +14,7 @@ use crate::config::{
     TRAMPOLINE,
     MMIO,
 };
+use core::arch::asm;
 
 extern "C" {
     fn stext();
diff --git a/os/src/sbi.rs b/os/src/sbi.rs
index 276c199d..6231c9c3 100644
--- a/os/src/sbi.rs
+++ b/os/src/sbi.rs
@@ -14,7 +14,7 @@ const SBI_SHUTDOWN: usize = 8;
 fn sbi_call(which: usize, arg0: usize, arg1: usize, arg2: usize) -> usize {
     let mut ret;
     unsafe {
-        asm!(
+        core::arch::asm!(
             "ecall",
             inlateout("x10") arg0 => ret,
             in("x11") arg1,
diff --git a/os/src/task/switch.rs b/os/src/task/switch.rs
index fa75be1a..59476813 100644
--- a/os/src/task/switch.rs
+++ b/os/src/task/switch.rs
@@ -1,3 +1,5 @@
+use core::arch::global_asm;
+
 global_asm!(include_str!("switch.S"));
 
 use super::TaskContext;
diff --git a/os/src/trap/mod.rs b/os/src/trap/mod.rs
index 136de922..964c9042 100644
--- a/os/src/trap/mod.rs
+++ b/os/src/trap/mod.rs
@@ -1,5 +1,6 @@
 mod context;
 
+use core::arch::{asm, global_asm};
 use riscv::register::{
     mtvec::TrapMode,
     stvec,
diff --git a/rust-toolchain b/rust-toolchain
index fd472758..925656db 100644
--- a/rust-toolchain
+++ b/rust-toolchain
@@ -1 +1 @@
-nightly-2021-10-15
+nightly-2022-01-19
diff --git a/user/src/syscall.rs b/user/src/syscall.rs
index 64f738d2..ddd0e1b7 100644
--- a/user/src/syscall.rs
+++ b/user/src/syscall.rs
@@ -25,7 +25,7 @@ const SYSCALL_SEMAPHORE_DOWN: usize = 1022;
 fn syscall(id: usize, args: [usize; 3]) -> isize {
     let mut ret: isize;
     unsafe {
-        asm!(
+        core::arch::asm!(
             "ecall",
             inlateout("x10") args[0] => ret,
             in("x11") args[1],