diff --git a/Cargo.toml b/Cargo.toml
index c64817d..8c256d3 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -4,13 +4,18 @@ version = "0.0.1"
 authors = ["WangRunji <wangrunji0408@163.com>"]
 
 [lib]
+name = "lib"
 #crate-type = ["staticlib"]
 
+[[bin]]
+name = "mksfs"
+path = "src/bin/mksfs.rs"
+required-features = ["std"]
+
 [profile.dev]
 panic = 'abort' # prevent `_Unwind_Resume` link error
 
 [dependencies]
-spin = "0.4"
 bit-set = { default-features = false, version = "0.5" } # default-features contains 'std'
 static_assertions = "0.2.5"
 
@@ -19,4 +24,5 @@ bitflags = "1.0"
 
 [features]
 debug_print = []
-ucore = []
\ No newline at end of file
+ucore = []
+std = []
\ No newline at end of file
diff --git a/src/bin/mksfs.rs b/src/bin/mksfs.rs
new file mode 100644
index 0000000..17dc102
--- /dev/null
+++ b/src/bin/mksfs.rs
@@ -0,0 +1,61 @@
+extern crate lib;
+
+use std::env;
+use std::fs;
+use std::io::Read;
+use std::path::Path;
+use lib::*;
+
+fn main () {
+    println!("USAGE: <zip|unzip> <PATH> <IMG>");
+    let args: Vec<_> = env::args().collect();
+    let cmd = &args[1];
+    let dir_path = Path::new(&args[2]);
+    let img_path = Path::new(&args[3]);
+    match cmd.as_str() {
+        "zip" => zip(dir_path, img_path),
+        "unzip" => unzip(dir_path, img_path),
+        _ => panic!("Invalid command: {}", cmd),
+    }
+}
+
+fn zip(path: &Path, img_path: &Path) {
+    use lib::std_impl;
+
+    let mut img = fs::File::create(img_path)
+        .expect(format!("Failed to create file: {:?}", img_path).as_str());
+    let sfs = SimpleFileSystem::create(Box::new(img), 0x1000000);
+    let inode = sfs.root_inode();
+    zip_dir(path, inode);
+}
+
+fn zip_dir(path: &Path, inode: INodePtr) {
+    println!("{:?}", path);
+    let dir = fs::read_dir(path).expect("Failed to open dir");
+    for entry in dir {
+        let entry = entry.unwrap();
+        let name_ = entry.file_name();
+        let name = name_.to_str().unwrap();
+        let type_ = entry.file_type().unwrap();
+        if type_.is_file() {
+            let inode = inode.borrow_mut().create(name, FileType::File)
+                .expect("Failed to create INode");
+            let mut file = fs::File::open(entry.path())
+                .expect("Failed to open file");
+            let mut buf = Vec::<u8>::new();
+            file.read_to_end(&mut buf)
+                .expect("Failed to read file");
+            inode.borrow_mut().write_at(0, buf.as_ref())
+                .expect("Failed to write image");
+            println!("{:?}", entry.path());
+        } else if type_.is_dir() {
+            let inode = inode.borrow_mut().create(name, FileType::Dir)
+                .expect("Failed to create INode");
+            zip_dir(entry.path().as_path(), inode);
+        }
+    }
+}
+
+fn unzip(path: &Path, img_path: &Path) {
+
+}
\ No newline at end of file
diff --git a/src/lib.rs b/src/lib.rs
index ffef679..2a504cd 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -3,10 +3,9 @@
 #![cfg_attr(feature = "ucore", feature(allocator_api, global_allocator, lang_items))]
 #![no_std]
 
-#[cfg(test)]
+#[cfg(any(test, feature = "std"))]
 #[macro_use]
 extern crate std;
-extern crate spin;
 #[macro_use]
 extern crate alloc;
 extern crate bit_set;
@@ -37,4 +36,29 @@ pub use vfs::*;
 
 #[cfg(feature = "ucore")]
 #[global_allocator]
-pub static UCORE_ALLOCATOR: c_interface::UcoreAllocator = c_interface::UcoreAllocator{};
\ No newline at end of file
+pub static UCORE_ALLOCATOR: c_interface::UcoreAllocator = c_interface::UcoreAllocator{};
+
+#[cfg(any(test, feature = "std"))]
+pub mod std_impl {
+    use std::fs::{File, OpenOptions};
+    use std::io::{Read, Write, Seek, SeekFrom};
+    use super::Device;
+
+    impl Device for File {
+        fn read_at(&mut self, offset: usize, buf: &mut [u8]) -> Option<usize> {
+            let offset = offset as u64;
+            match self.seek(SeekFrom::Start(offset)) {
+                Ok(real_offset) if real_offset == offset => self.read(buf).ok(),
+                _ => None,
+            }
+        }
+
+        fn write_at(&mut self, offset: usize, buf: &[u8]) -> Option<usize> {
+            let offset = offset as u64;
+            match self.seek(SeekFrom::Start(offset)) {
+                Ok(real_offset) if real_offset == offset => self.write(buf).ok(),
+                _ => None,
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/sfs.rs b/src/sfs.rs
index cbf7c89..dddabef 100644
--- a/src/sfs.rs
+++ b/src/sfs.rs
@@ -1,4 +1,3 @@
-use spin::Mutex;
 use bit_set::BitSet;
 use alloc::{boxed::Box, Vec, BTreeMap, rc::{Rc, Weak}, String};
 use core::cell::{RefCell, RefMut};
diff --git a/src/tests.rs b/src/tests.rs
index ce19b5a..3772d12 100644
--- a/src/tests.rs
+++ b/src/tests.rs
@@ -8,24 +8,6 @@ use std::rc::Rc;
 use std::mem::uninitialized;
 use super::structs::{DiskEntry, AsBuf};
 
-impl Device for File {
-    fn read_at(&mut self, offset: usize, buf: &mut [u8]) -> Option<usize> {
-        let offset = offset as u64;
-        match self.seek(SeekFrom::Start(offset)) {
-            Ok(real_offset) if real_offset == offset => self.read(buf).ok(),
-            _ => None,
-        }
-    }
-
-    fn write_at(&mut self, offset: usize, buf: &[u8]) -> Option<usize> {
-        let offset = offset as u64;
-        match self.seek(SeekFrom::Start(offset)) {
-            Ok(real_offset) if real_offset == offset => self.write(buf).ok(),
-            _ => None,
-        }
-    }
-}
-
 fn _open_sample_file() -> Rc<SimpleFileSystem> {
     let file = File::open("sfs.img")
         .expect("failed to open sfs.img");