diff --git a/examples/wasmtime/src/preview1.rs b/examples/wasmtime/src/preview1.rs
index 4e1721989..003a83ef6 100644
--- a/examples/wasmtime/src/preview1.rs
+++ b/examples/wasmtime/src/preview1.rs
@@ -1,4 +1,10 @@
 #![allow(dead_code)]
+
+// This file provide the interface of WASI preview1 to HermitOS
+//
+// NOTE: The current version assumes that / is the current
+// working directory of the WASI application.
+
 use std::cmp::Ordering;
 use std::mem::MaybeUninit;
 use std::sync::{Mutex, OnceLock};
diff --git a/kernel b/kernel
index cbcf65a59..30216466f 160000
--- a/kernel
+++ b/kernel
@@ -1 +1 @@
-Subproject commit cbcf65a591eed712c8dd12af24cebd7f73882be1
+Subproject commit 30216466f17dce91a46dce9c555518acf69fe79d