diff --git a/kernel/src/arch/mipsel/mod.rs b/kernel/src/arch/mipsel/mod.rs
index 212bdcea..d9af59de 100644
--- a/kernel/src/arch/mipsel/mod.rs
+++ b/kernel/src/arch/mipsel/mod.rs
@@ -1,5 +1,5 @@
 pub mod io;
-//pub mod interrupt;
+pub mod interrupt;
 pub mod timer;
 pub mod paging;
 pub mod memory;
@@ -11,7 +11,6 @@ pub mod rand;
 #[cfg(feature = "board_u540")]
 #[path = "board/u540/mod.rs"]
 mod board;
-mod sbi;
 
 use log::*;
 
diff --git a/kernel/src/arch/mipsel/sbi.rs b/kernel/src/arch/mipsel/sbi.rs
deleted file mode 100644
index 03576426..00000000
--- a/kernel/src/arch/mipsel/sbi.rs
+++ /dev/null
@@ -1,64 +0,0 @@
-//! Port from sbi.h
-
-#[inline(always)]
-fn sbi_call(which: usize, arg0: usize, arg1: usize, arg2: usize) -> usize {
-    let ret;
-    unsafe {
-        asm!("ecall"
-            : "={x10}" (ret)
-            : "{x10}" (arg0), "{x11}" (arg1), "{x12}" (arg2), "{x17}" (which)
-            : "memory"
-            : "volatile");
-    }
-    ret
-}
-
-pub fn console_putchar(ch: usize) {
-    sbi_call(SBI_CONSOLE_PUTCHAR, ch, 0, 0);
-}
-
-pub fn console_getchar() -> usize {
-    sbi_call(SBI_CONSOLE_GETCHAR, 0, 0, 0)
-}
-
-pub fn shutdown() -> ! {
-    sbi_call(SBI_SHUTDOWN, 0, 0, 0);
-    unreachable!()
-}
-
-pub fn set_timer(stime_value: u64) {
-    #[cfg(target_pointer_width = "32")]
-    sbi_call(SBI_SET_TIMER, stime_value as usize, (stime_value >> 32) as usize, 0);
-    #[cfg(target_pointer_width = "64")]
-    sbi_call(SBI_SET_TIMER, stime_value as usize, 0, 0);
-}
-
-pub fn clear_ipi() {
-    sbi_call(SBI_CLEAR_IPI, 0, 0, 0);
-}
-
-pub fn send_ipi(hart_mask: usize) {
-    sbi_call(SBI_SEND_IPI, &hart_mask as *const _ as usize, 0, 0);
-}
-
-pub fn remote_fence_i(hart_mask: usize) {
-    sbi_call(SBI_REMOTE_FENCE_I, &hart_mask as *const _ as usize, 0, 0);
-}
-
-pub fn remote_sfence_vma(hart_mask: usize, _start: usize, _size: usize) {
-    sbi_call(SBI_REMOTE_SFENCE_VMA, &hart_mask as *const _ as usize, 0, 0);
-}
-
-pub fn remote_sfence_vma_asid(hart_mask: usize, _start: usize, _size: usize, _asid: usize) {
-    sbi_call(SBI_REMOTE_SFENCE_VMA_ASID, &hart_mask as *const _ as usize, 0, 0);
-}
-
-const SBI_SET_TIMER: usize = 0;
-const SBI_CONSOLE_PUTCHAR: usize = 1;
-const SBI_CONSOLE_GETCHAR: usize = 2;
-const SBI_CLEAR_IPI: usize = 3;
-const SBI_SEND_IPI: usize = 4;
-const SBI_REMOTE_FENCE_I: usize = 5;
-const SBI_REMOTE_SFENCE_VMA: usize = 6;
-const SBI_REMOTE_SFENCE_VMA_ASID: usize = 7;
-const SBI_SHUTDOWN: usize = 8;