diff --git a/crate/process/build.rs b/crate/process/build.rs
new file mode 100644
index 0000000..f3cb10c
--- /dev/null
+++ b/crate/process/build.rs
@@ -0,0 +1,3 @@
+fn main() {
+    println!("cargo:rerun-if-env-changed=M_MODE");
+}
\ No newline at end of file
diff --git a/crate/process/src/interrupt.rs b/crate/process/src/interrupt.rs
index ea3ea27..6e238be 100644
--- a/crate/process/src/interrupt.rs
+++ b/crate/process/src/interrupt.rs
@@ -2,7 +2,7 @@
 #[cfg(target_arch = "x86_64")]
 pub unsafe fn disable_and_store() -> usize {
     let rflags: usize;
-    asm!("pushfq; popq $0; cli" : "=r"(rflags));
+    asm!("pushfq; popq $0; cli" : "=r"(rflags) ::: "volatile");
     rflags & (1 << 9)
 }
 
@@ -10,20 +10,20 @@ pub unsafe fn disable_and_store() -> usize {
 #[cfg(target_arch = "x86_64")]
 pub unsafe fn restore(flags: usize) {
     if flags != 0 {
-        asm!("sti");
+        asm!("sti" :::: "volatile");
     }
 }
 
 #[inline(always)]
 #[cfg(any(target_arch = "riscv32", target_arch = "riscv64"))]
 pub unsafe fn disable_and_store() -> usize {
-    if option_env!("m_mode").is_some() {
+    if env!("M_MODE") == "1" {
         let mstatus: usize;
-        asm!("csrci mstatus, 1 << 3" : "=r"(mstatus));
+        asm!("csrci mstatus, 1 << 3" : "=r"(mstatus) ::: "volatile");
         mstatus & (1 << 3)
     } else {
         let sstatus: usize;
-        asm!("csrci sstatus, 1 << 1" : "=r"(sstatus));
+        asm!("csrci sstatus, 1 << 1" : "=r"(sstatus) ::: "volatile");
         sstatus & (1 << 1)
     }
 }
@@ -31,10 +31,10 @@ pub unsafe fn disable_and_store() -> usize {
 #[inline(always)]
 #[cfg(any(target_arch = "riscv32", target_arch = "riscv64"))]
 pub unsafe fn restore(flags: usize) {
-    if option_env!("m_mode").is_some() {
-        asm!("csrs mstatus, $0" :: "r"(flags));
+    if env!("M_MODE") == "1" {
+        asm!("csrs mstatus, $0" :: "r"(flags) :: "volatile");
     } else {
-        asm!("csrs sstatus, $0" :: "r"(flags));
+        asm!("csrs sstatus, $0" :: "r"(flags) :: "volatile");
     }
 }
 
@@ -42,8 +42,7 @@ pub unsafe fn restore(flags: usize) {
 #[cfg(target_arch = "aarch64")]
 pub unsafe fn disable_and_store() -> usize {
     let daif: u32;
-    asm!("mrs $0, DAIF": "=r"(daif) ::: "volatile");
-    asm!("msr daifset, #2");
+    asm!("mrs $0, DAIF; msr daifset, #2": "=r"(daif) ::: "volatile");
     daif as usize
 }
 
diff --git a/kernel/Makefile b/kernel/Makefile
index d73ca8d..b62679a 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -24,8 +24,6 @@ board ?= none
 mode ?= debug
 LOG  ?= debug
 smp  ?= 4
-# NOTE: crate 'process' use this name 'm_mode' as an environment
-#		to set interrupt (MIE or SIE)
 m_mode ?=
 
 target := $(arch)-blog_os
@@ -34,6 +32,7 @@ bin := target/$(target)/$(mode)/kernel.bin
 bootimage := target/$(target)/bootimage.bin
 user_dir := ../user
 
+### export environments ###
 export ARCH = $(arch)
 export SMP = $(smp)
 #export SFSIMG = $(user_dir)/build/user-$(arch).img
@@ -45,6 +44,11 @@ endif
 ifeq ($(arch), aarch64)
 board := raspi3
 endif
+ifeq ($(board), k210)
+m_mode := 1
+endif
+# crate 'process' use this to set interrupt (MIE or SIE)
+export M_MODE = $(m_mode)
 
 ### qemu options ###
 qemu_opts := \