diff --git a/Makefile b/Makefile
index 4ab8816..f765bf8 100644
--- a/Makefile
+++ b/Makefile
@@ -2,15 +2,15 @@ include nemu/Makefile.git
 
 default:
 	@echo "Please run 'make' under any subprojects to compile."
- 
+
 clean:
-	-$(MAKE) -C nemu clean
-	-$(MAKE) -C nexus-am clean
-	-$(MAKE) -C nanos-lite clean
-	-$(MAKE) -C navy-apps clean
+	-$(MAKE) -s -C nemu clean
+	-$(MAKE) -s -C abstract-machine clean-all
+	-$(MAKE) -s -C nanos-lite clean
+	-$(MAKE) -s -C navy-apps clean
 
 submit: clean
 	git gc
-	STUID=$(STUID) STUNAME=$(STUNAME) bash -c "$$(curl -s http://ics.nju.edu.cn/people/yanyanjiang/teach/submit.sh)"
+	STUID=$(STUID) STUNAME=$(STUNAME) bash -c "$$(curl -s http://jyywiki.cn/static/submit.sh)"
 
 .PHONY: default clean submit
diff --git a/README.md b/README.md
index dc49605..9e1b853 100644
--- a/README.md
+++ b/README.md
@@ -1,17 +1,19 @@
-# ICS2019 Programming Assignment
+# ICS2020 Programming Assignment
 
-This project is the programming assignment of the class ICS(Introduction to Computer System) in Department of Computer Science and Technology, Nanjing University.
+This project is the programming assignment of the class ICS(Introduction to Computer System)
+in Department of Computer Science and Technology, Nanjing University.
 
 For the guide of this programming assignment,
-refer to http://nju-ics.gitbooks.io/ics2019-programming-assignment/content/
+refer to http://nju-ics.gitbooks.io/ics2020-programming-assignment/content/
 
 To initialize, run
 ```bash
-bash init.sh
+bash init.sh subproject-name
 ```
+See `init.sh` for more details.
 
 The following subprojects/components are included. Some of them are not fully implemented.
 * [NEMU](https://github.com/NJU-ProjectN/nemu)
-* [Nexus-am](https://github.com/NJU-ProjectN/nexus-am)
+* [Abstract-Machine](https://github.com/NJU-ProjectN/abstract-machine)
 * [Nanos-lite](https://github.com/NJU-ProjectN/nanos-lite)
 * [Navy-apps](https://github.com/NJU-ProjectN/navy-apps)
diff --git a/init.sh b/init.sh
index ebd62c3..6931eba 100644
--- a/init.sh
+++ b/init.sh
@@ -1,48 +1,69 @@
 #!/bin/bash
 
-version=ics2019
-
-log=""
+version=ics2020
 
 function init() {
   if [ -d $1 ]; then
-    echo "$1 is already initialized, exiting..."
+    echo "$1 is already initialized, skipping..."
     return
   fi
 
   while [ ! -d $1 ]; do
     git clone -b $version https://github.com/NJU-ProjectN/$1.git
   done
-  log="$log$1 `cd $1 && git log --oneline --no-abbrev-commit -n1`"$'\n'
+  log="$1 `cd $1 && git log --oneline --no-abbrev-commit -n1`"$'\n'
   rm -rf $1/.git
 
+  git add -A $1
+  git commit -am "$1 $version initialized"$'\n\n'"$log"
+
   if [ $2 ] ; then
     sed -i -e "/^export $2=.*/d" ~/.bashrc
     echo "export $2=`readlink -e $1`" >> ~/.bashrc
-  fi
-}
 
-read -r -p "Are you sure to initialize everything? [y/n] " input
-case $input in
-  [yY])
-    init nemu NEMU_HOME
-    init nexus-am AM_HOME
-    init nanos-lite
-    init navy-apps NAVY_HOME
-
-    git add -A
-    git commit -am "$version initialized"$'\n\n'"$log"
-
-    echo "Initialization finishes!"
     echo "By default this script will add environment variables into ~/.bashrc."
     echo "After that, please run 'source ~/.bashrc' to let these variables take effect."
     echo "If you use shell other than bash, please add these environment variables manually."
-    ;;
+  fi
+}
 
-  [nN])
-    ;;
+function init_no_git() {
+  if [ -d $1 ]; then
+    echo "$1 is already initialized, skipping..."
+    return
+  fi
 
+  while [ ! -d $1 ]; do
+    git clone -b $version https://github.com/NJU-ProjectN/$1.git
+  done
+  log="$1 `cd $1 && git log --oneline --no-abbrev-commit -n1`"$'\n'
+
+  sed -i -e "/^\/$1/d" .gitignore
+  echo "/$1" >> .gitignore
+
+  git add -A .gitignore
+  git commit --no-verify --allow-empty -am "$1 $version initialized without tracing"$'\n\n'"$log"
+}
+
+case $1 in
+  nemu)
+    init nemu NEMU_HOME
+    ;;
+  abstract-machine)
+    init abstract-machine AM_HOME
+    init_no_git fceux-am
+    ;;
+  am-kernels)
+    init_no_git am-kernels
+    ;;
+  nanos-lite)
+    init nanos-lite
+    ;;
+  navy-apps)
+    init navy-apps NAVY_HOME
+    ;;
   *)
     echo "Invalid input..."
+    exit
     ;;
 esac