diff --git a/Cargo.toml b/Cargo.toml
index c64817d..c6e07e9 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -3,20 +3,9 @@ name = "simple-filesystem"
 version = "0.0.1"
 authors = ["WangRunji <wangrunji0408@163.com>"]
 
-[lib]
-#crate-type = ["staticlib"]
-
-[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"
 
-[target.ucore.dependencies]
-bitflags = "1.0"
-
 [features]
-debug_print = []
-ucore = []
\ No newline at end of file
+debug_print = []
\ No newline at end of file
diff --git a/Xargo.toml b/Xargo.toml
deleted file mode 100644
index 10e8f71..0000000
--- a/Xargo.toml
+++ /dev/null
@@ -1,2 +0,0 @@
-[target.ucore.dependencies]
-alloc = {}
\ No newline at end of file
diff --git a/Makefile b/sfs-c/Makefile
similarity index 65%
rename from Makefile
rename to sfs-c/Makefile
index be19a06..3b65f15 100644
--- a/Makefile
+++ b/sfs-c/Makefile
@@ -1,6 +1,6 @@
 ucore:
 	rustup override set nightly-2018-04-01
-	RUST_TARGET_PATH=$(shell pwd) xargo build --target ucore --features ucore
+	RUST_TARGET_PATH=$(shell pwd) xargo build --target ucore --release
 
 install-rust:
 	which cargo || ( curl https://sh.rustup.rs -sSf | sh )
diff --git a/sfs-c/Xargo.toml b/sfs-c/Xargo.toml
new file mode 100644
index 0000000..85b3939
--- /dev/null
+++ b/sfs-c/Xargo.toml
@@ -0,0 +1,2 @@
+[dependencies]
+alloc = {}
\ No newline at end of file
diff --git a/src/c_interface.rs b/sfs-c/src/lib.rs
similarity index 97%
rename from src/c_interface.rs
rename to sfs-c/src/lib.rs
index a942f70..5fe193f 100644
--- a/src/c_interface.rs
+++ b/sfs-c/src/lib.rs
@@ -3,6 +3,18 @@
 //! NOTE: Must link these sections:
 //! `*.got.*` `*.data.*` `*.rodata.*`
 
+#![feature(allocator_api, global_allocator, lang_items)]
+#![feature(alloc)]
+#![no_std]
+
+#[macro_use]
+extern crate alloc;
+extern crate simple_filesystem;
+#[macro_use]
+extern crate bitflags;
+#[macro_use]
+extern crate static_assertions;
+
 use alloc::{rc::Rc, boxed::Box, BTreeMap};
 use core::cell::RefCell;
 use core::slice;
@@ -11,8 +23,8 @@ use core::cmp::Ordering;
 use alloc::heap::{Alloc, AllocErr, Layout};
 use core::mem::{size_of, self};
 use core::ptr;
-use vfs;
-use blocked_device::BlockedDevice;
+use simple_filesystem as sfs;
+use simple_filesystem as vfs;
 
 /// Lang items for bare lib
 mod lang {
@@ -331,7 +343,7 @@ impl IoBuf {
     }
 }
 
-impl BlockedDevice for Device {
+impl vfs::BlockedDevice for Device {
     fn block_size_log2(&self) -> u8 {
         if self.blocksize != 4096 {
             unimplemented!("block_size != 4096 is not supported yet");
@@ -562,6 +574,9 @@ static FS_OPS: FsOps = {
 /// Allocator supported by ucore functions
 pub struct UcoreAllocator;
 
+#[global_allocator]
+pub static UCORE_ALLOCATOR: UcoreAllocator = UcoreAllocator;
+
 unsafe impl<'a> Alloc for &'a UcoreAllocator {
     unsafe fn alloc(&mut self, layout: Layout) -> Result<*mut u8, AllocErr> {
 //        cprintf!("alloc %d\n", layout.size());
diff --git a/ucore.json b/sfs-c/ucore.json
similarity index 100%
rename from ucore.json
rename to sfs-c/ucore.json
diff --git a/src/lib.rs b/src/lib.rs
index e9d0141..12c3624 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,18 +1,13 @@
 #![feature(alloc)]
 #![feature(const_fn)]
-#![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;
-#[cfg(feature = "ucore")]
-#[macro_use]
-extern crate bitflags;
 #[macro_use]
 extern crate static_assertions;
 
@@ -29,15 +24,9 @@ mod blocked_device;
 mod vfs;
 mod sfs;
 mod structs;
-#[cfg(feature = "ucore")]
-pub mod c_interface;
 #[cfg(test)]
 mod tests;
 
 pub use sfs::*;
 pub use vfs::*;
 pub use blocked_device::BlockedDevice;
-
-#[cfg(feature = "ucore")]
-#[global_allocator]
-pub static UCORE_ALLOCATOR: c_interface::UcoreAllocator = c_interface::UcoreAllocator{};
\ No newline at end of file
diff --git a/src/sfs.rs b/src/sfs.rs
index aa1bced..3dd7787 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};