diff --git a/.gitignore b/.gitignore
index 614368ae..aa359a40 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,10 +1,16 @@
-.idea/*
-os/target/*
-os/.idea/*
-os/Cargo.lock
+.idea
+Cargo.lock
+target
 os/src/link_app.S
 os/last-*
+os/Cargo.lock
+user/build
 user/target/*
 user/.idea/*
 user/Cargo.lock
+easy-fs/Cargo.lock
+easy-fs/target/*
+easy-fs-fuse/Cargo.lock
+easy-fs-fuse/target/*
 tools/
+pushall.sh
\ No newline at end of file
diff --git a/README.md b/README.md
index e28e783e..e2dc4e34 100644
--- a/README.md
+++ b/README.md
@@ -1,12 +1,67 @@
 # rCore-Tutorial-v3
-rCore-Tutorial version 3.x
+rCore-Tutorial version 3.5. See the [Documentation in Chinese](https://rcore-os.github.io/rCore-Tutorial-Book-v3/).
 
-## Dependency
+## news
+- 2021.11.20: Now we are updating our labs. Please checkout chX-dev Branches for our current new labs. (Notice: please see the [Dependency] section in the end of this doc)
 
-### Binaries
+## Overview
 
-* rustc 1.56.0-nightly (b03ccace5 2021-08-24)
+This project aims to show how to write an **Unix-like OS** running on **RISC-V** platforms **from scratch** in **[Rust](https://www.rust-lang.org/)** for **beginners** without any background knowledge about **computer architectures, assembly languages or operating systems**.
 
-* qemu: 5.0.0
+## Features
 
-* rustsbi: qemu[7d71bfb7] k210[563144b0]
+* Platform supported: `qemu-system-riscv64` simulator or dev boards based on [Kendryte K210 SoC](https://canaan.io/product/kendryteai) such as [Maix Dock](https://www.seeedstudio.com/Sipeed-MAIX-Dock-p-4815.html)
+* OS
+  * concurrency of multiple processes
+  * preemptive scheduling(Round-Robin algorithm)
+  * dynamic memory management in kernel
+  * virtual memory
+  * a simple file system with a block cache
+  * an interactive shell in the userspace
+* **only 4K+ LoC**
+* [A detailed documentation in Chinese](https://rcore-os.github.io/rCore-Tutorial-Book-v3/) in spite of the lack of comments in the code(English version is not available at present)
+
+## Run our project
+
+TODO:
+
+## Working in progress
+
+Now we are still updating our project, you can find latest changes on branches `chX-dev` such as `ch1-dev`. We are intended to publish first release 3.5.0 after completing most of the tasks mentioned below.
+
+Overall progress: ch7
+
+### Completed
+
+* [x] automatically clean up and rebuild before running our project on a different platform
+* [x] fix `power` series application in early chapters, now you can find modulus in the output
+* [x] use `UPSafeCell` instead of `RefCell` or `spin::Mutex` in order to access static data structures and adjust its API so that it cannot be borrowed twice at a time(mention `& .exclusive_access().task[0]` in `run_first_task`)
+* [x] move `TaskContext` into `TaskControlBlock` instead of restoring it in place on kernel stack(since ch3), eliminating annoying `task_cx_ptr2`
+* [x] replace `llvm_asm!` with `asm!`
+* [x] expand the fs image size generated by `rcore-fs-fuse` to 128MiB
+* [x] add a new test named `huge_write` which evaluates the fs performance(qemu\~500KiB/s k210\~50KiB/s)
+* [x] flush all block cache to disk after a fs transaction which involves write operation
+* [x] replace `spin::Mutex` with `UPSafeCell` before SMP chapter
+* [x] add codes for a new chapter about synchronization & mutual exclusion(uniprocessor only)
+
+### Todo(High priority)
+
+* [ ] support Allwinner's RISC-V D1 chip
+* [ ] bug fix: we should call `find_pte` rather than `find_pte_create` in `PageTable::unmap`
+* [ ] bug fix: check validity of level-3 pte in `find_pte` instead of checking it outside this function
+* [ ] use old fs image optionally, do not always rebuild the image
+* [ ] add new system calls: getdents64/fstat
+* [ ] shell functionality improvement(to be continued...)
+* [ ] give every non-zero process exit code an unique and clear error type
+* [ ] effective error handling of mm module
+
+### Todo(Low priority)
+
+* [ ] rewrite practice doc and remove some inproper questions
+* [ ] provide smooth debug experience at a Rust source code level
+* [ ] format the code using official tools
+
+
+### Crates
+
+We will add them later.
diff --git a/dev-env-info.md b/dev-env-info.md
new file mode 100644
index 00000000..f76470a5
--- /dev/null
+++ b/dev-env-info.md
@@ -0,0 +1,18 @@
+# rCore-Tutorial-v3
+rCore-Tutorial version 3.x
+
+## Dependency
+
+### Binaries
+
+* rustc: 1.57.0-nightly (e1e9319d9 2021-10-14)
+
+* cargo-binutils: 0.3.3
+
+* qemu: 5.0.0
+
+* rustsbi-lib: 0.2.0-alpha.4
+
+  rustsbi-qemu: d4968dd2
+
+  rustsbi-k210: b689314e