diff --git a/applications/cat/Cargo.toml b/applications/cat/Cargo.toml
index f28bea3ae..726ec66bf 100644
--- a/applications/cat/Cargo.toml
+++ b/applications/cat/Cargo.toml
@@ -14,7 +14,7 @@ version = "0.4.8"
 
 
 [dependencies.app_io]
-path = "../app_io"
+path = "../../kernel/app_io"
 
 [dependencies.task]
 path = "../../kernel/task"
diff --git a/applications/immediate_input_echo/Cargo.toml b/applications/immediate_input_echo/Cargo.toml
index 078a30599..92f02a92d 100644
--- a/applications/immediate_input_echo/Cargo.toml
+++ b/applications/immediate_input_echo/Cargo.toml
@@ -11,7 +11,7 @@ core2 = { version = "0.3.2", default-features = false, features = ["alloc", "nig
 path = "../../libs/stdio"
 
 [dependencies.app_io]
-path = "../app_io"
+path = "../../kernel/app_io"
 
 [dependencies.log]
 version = "0.4.8"
diff --git a/applications/input_echo/Cargo.toml b/applications/input_echo/Cargo.toml
index 9d9bdb659..e215d2e82 100644
--- a/applications/input_echo/Cargo.toml
+++ b/applications/input_echo/Cargo.toml
@@ -8,7 +8,7 @@ build = "../../build.rs"
 core2 = { version = "0.3.2", default-features = false, features = ["alloc", "nightly"] }
 
 [dependencies.app_io]
-path = "../app_io"
+path = "../../kernel/app_io"
 
 [dependencies.log]
 version = "0.4.8"
diff --git a/applications/keyboard_echo/Cargo.toml b/applications/keyboard_echo/Cargo.toml
index d5beb0a48..4eee12707 100644
--- a/applications/keyboard_echo/Cargo.toml
+++ b/applications/keyboard_echo/Cargo.toml
@@ -11,7 +11,7 @@ core2 = { version = "0.3.2", default-features = false, features = ["alloc", "nig
 path = "../../kernel/scheduler"
 
 [dependencies.app_io]
-path = "../app_io"
+path = "../../kernel/app_io"
 
 [dependencies.log]
 version = "0.4.8"
diff --git a/applications/less/Cargo.toml b/applications/less/Cargo.toml
index 759aaa635..1dbfd337c 100644
--- a/applications/less/Cargo.toml
+++ b/applications/less/Cargo.toml
@@ -25,7 +25,7 @@ path = "../../libs/keycodes_ascii"
 path = "../../kernel/libterm"
 
 [dependencies.app_io]
-path = "../app_io"
+path = "../../kernel/app_io"
 
 [dependencies.stdio]
 path = "../../libs/stdio"
diff --git a/applications/shell/Cargo.toml b/applications/shell/Cargo.toml
index b521556ed..04b30b96d 100644
--- a/applications/shell/Cargo.toml
+++ b/applications/shell/Cargo.toml
@@ -65,7 +65,7 @@ features = ["spin_no_std"]
 version = "1.4.0"
 
 [dependencies.app_io]
-path = "../app_io"
+path = "../../kernel/app_io"
 
 [dependencies.fs_node]
 path = "../../kernel/fs_node"
diff --git a/applications/app_io/Cargo.toml b/kernel/app_io/Cargo.toml
similarity index 100%
rename from applications/app_io/Cargo.toml
rename to kernel/app_io/Cargo.toml
diff --git a/applications/app_io/src/lib.rs b/kernel/app_io/src/lib.rs
similarity index 94%
rename from applications/app_io/src/lib.rs
rename to kernel/app_io/src/lib.rs
index 8f4f15c63..4bf032223 100644
--- a/applications/app_io/src/lib.rs
+++ b/kernel/app_io/src/lib.rs
@@ -1,16 +1,17 @@
-//! This crate is an application-level library that stores the IO queues and pointers to terminal instances for running applications.
-//! It provides some APIs similar to std::io for applications to access those queues.
+//! A simple library that handles stdio queues for applications running in terminal instances.
+//! 
+//! This provides some APIs similar to Rust's `std::io` for applications to access those queues.
 //! 
 //! Usage example:
-//! 1. shell spawns a new app, and creates queues of `stdin`, `stdout` and `stderr`
-//! 2. shell stores the reader of `stdin` and writer of `stdout` and `stderr` to `app_io`,
-//!    along with the reader of key event queue and the pointer to the running terminal instance.
-//! 3. app calls app_io::stdin to get the reader of `stdin`, and can perform reading just like
+//! 1. shell spawns a new app, and creates queues of `stdin`, `stdout`, and `stderr` for that app.
+//! 2. shell stores the reader for `stdin` and writers for `stdout` and `stderr` to `app_io`,
+//!    along with the reader of the key events queue and references to the running terminal instance.
+//! 3. app calls [`stdin()`] to get the reader of `stdin`, and can perform reading just like
 //!    using the standard library
-//! 4. app calls app_io::stdout to get the writer of `stdin`, and can perform output just like
+//! 4. app calls [`stdout()`] to get the writer of `stdin`, and can perform output just like
 //!    using the standard library
-//! 5. after app exits, shell would set EOF flags to its `stdin`, `stdout` and `stderr` queues.
-//! 6. if all apps in a job exit, app shell removes all the structure stored in `app_io` and
+//! 5. after app exits, shell would set `EOF` flags to its `stdin`, `stdout`, and `stderr` queues.
+//! 6. once all apps in a job exit, app shell removes all the structure stored in `app_io` and
 //!    destructs all stdio queues
 
 #![no_std]
diff --git a/tlibc/Cargo.toml b/tlibc/Cargo.toml
index 6d1af392c..d6a4de6ea 100644
--- a/tlibc/Cargo.toml
+++ b/tlibc/Cargo.toml
@@ -25,7 +25,7 @@ path = "../kernel/memory"
 path = "../kernel/task"
 
 [dependencies.app_io]
-path = "../applications/app_io"
+path = "../kernel/app_io"
 
 
 ## Needed for building tlibc as a "staticlib" crate-type,