diff --git a/kernel/rustkernel/src/arch/cpu.rs b/kernel/rustkernel/src/arch/cpu.rs
new file mode 100644
index 0000000..deca519
--- /dev/null
+++ b/kernel/rustkernel/src/arch/cpu.rs
@@ -0,0 +1,4 @@
+//! Architecture-agnostic CPU functions.
+
+#[cfg(target_arch = "riscv64")]
+pub use super::riscv::cpu::cpu_id;
diff --git a/kernel/rustkernel/src/arch/mod.rs b/kernel/rustkernel/src/arch/mod.rs
index 862ad7a..f881914 100644
--- a/kernel/rustkernel/src/arch/mod.rs
+++ b/kernel/rustkernel/src/arch/mod.rs
@@ -1,5 +1,6 @@
 #[cfg(target_arch = "riscv64")]
 pub mod riscv;
 
+pub mod cpu;
 pub mod interrupt;
 pub mod power;
diff --git a/kernel/rustkernel/src/arch/riscv/cpu.rs b/kernel/rustkernel/src/arch/riscv/cpu.rs
new file mode 100644
index 0000000..d3ff911
--- /dev/null
+++ b/kernel/rustkernel/src/arch/riscv/cpu.rs
@@ -0,0 +1,5 @@
+use super::asm::r_tp;
+
+pub fn cpu_id() -> usize {
+    unsafe { r_tp() as usize }
+}
diff --git a/kernel/rustkernel/src/arch/riscv/mod.rs b/kernel/rustkernel/src/arch/riscv/mod.rs
index d5866eb..e233e4f 100644
--- a/kernel/rustkernel/src/arch/riscv/mod.rs
+++ b/kernel/rustkernel/src/arch/riscv/mod.rs
@@ -1,5 +1,6 @@
 pub mod asm;
 pub mod clint;
+pub mod cpu;
 pub mod memlayout;
 pub mod plic;
 pub mod power;
diff --git a/kernel/rustkernel/src/proc/cpu.rs b/kernel/rustkernel/src/proc/cpu.rs
index 2a6a0f4..7c1ec89 100644
--- a/kernel/rustkernel/src/proc/cpu.rs
+++ b/kernel/rustkernel/src/proc/cpu.rs
@@ -1,5 +1,4 @@
 use super::{context::Context, process::Process};
-use crate::arch::riscv::asm::r_tp;
 use core::ptr::{addr_of_mut, null_mut};
 
 pub static mut CPUS: [Cpu; crate::NCPU] = [Cpu::new(); crate::NCPU];
@@ -29,7 +28,7 @@ impl Cpu {
     /// to prevent race with process being moved
     /// to a different CPU.
     pub fn current_id() -> usize {
-        unsafe { r_tp() as usize }
+        crate::arch::cpu::cpu_id()
     }
     /// Return this CPU's cpu struct.
     /// Interrupts must be disabled.