#This script was modified from the one created by Nolirium to create the new image file but not include the extra utilities (https://nolirium.blogspot.com/2016/12/android-on-chrome-os-rooting-shell.html)

RootChromebookAndroid.sh

#!/bin/sh
#This script was modified from the one created by Nolirium to create the new image file but not include the extra utilities
#https://nolirium.blogspot.com/2016/12/android-on-chrome-os-rooting-shell.html


# Main functions:

check_if_root() {

if [ $(id -u) != 0 ]; then
  echo
  echo "Error!"
  echo "This script should be run as root."
  exit 1
fi

}

check_writeable_rootfs() {

if [  -e /etc/aroc_writable_test ]; then
rm /etc/aroc_writable_test
fi

touch /etc/aroc_writable_test  2> /dev/null

  if [ ! -e /etc/aroc_writable_test ]; then
  echo "Error!"
  echo "Unable to modify system!"
  echo "You can disable rootfs verification by running the following command, then rebooting."
  echo "sudo /usr/share/vboot/bin/make_dev_ssd.sh --remove_rootfs_verification --partitions $(( $(rootdev -s | sed -r 's/.*(.)$/\1/') - 1))"
  echo "Please run the "remove_rootfs_verification" command now, then reboot and run this script again."
  exit 1
fi

rm /etc/aroc_writable_test

}

detect_architecture() {
  
# TODO: Test/improve this function

#if [ -z "$ANDROID_ARCH" ]; then
    ARCH="`uname -m`"
#fi
case "$ARCH" in
x86 | i?86) ANDROID_ARCH="x86";;
x86_64 | amd64) ANDROID_ARCH="x86";;
armel) ANDROID_ARCH="armel";;
arm64 | aarch64) ANDROID_ARCH="armv7";;
arm*) ANDROID_ARCH="armv7";;
*) error 2 "Invalid architecture '$ARCH'.";;
esac

}

modify_cros_files() {
  
# Just changing two environment variables for Android here.
# In CrOS v70, the writeable container and debug flags have moved (again); they are now in "/usr/share/arc-setup/config.json"
# (Older versions of CrOS have/had Android envs in arc-setup-env).
# (Even older versions had envs in the .conf files.)

mkdir -p /usr/local/Backup

# As of CrOS v70, we need to modify the two values in /usr/share/arc-setup/config.json
if [ -e /usr/share/arc-setup/config.json ]; then

  mkdir -p /usr/local/Backup/arc-setup
  echo "Copying usr/share/arc-setup/config.json to /usr/local/Backup/arc-setup/config.json.old"

  cp -a /usr/share/arc-setup/config.json /usr/local/Backup/arc-setup/config.json.old
  cp -a /usr/share/arc-setup/config.json /usr/share/arc-setup/config.json.old

  echo "Setting '"ANDROID_DEBUGGABLE": true' and '"WRITABLE_MOUNT": true' in /usr/share/arc-setup/config.json"

  sed -i 's/"ANDROID_DEBUGGABLE": false/"ANDROID_DEBUGGABLE": true/g' /usr/share/arc-setup/config.json 2>/dev/null
  sed -i 's/"WRITABLE_MOUNT": false/"WRITABLE_MOUNT": true/g' /usr/share/arc-setup/config.json 2>/dev/null

fi

# In CrOS v6x, the two flags we want to change are within /etc/init/arc-setup-env

if [ -e /etc/init/arc-setup-env ]; then
  echo "Copying /etc/init/arc-setup-env to /usr/local/Backup"
  
  sleep 1

  echo "Setting 'export WRITABLE_MOUNT=1', 'export ANDROID_DEBUGGABLE=1' and (if variable exists) 'export SHARE_FONTS=0' in /etc/init/arc-setup-env"
  
  sed -i 's/export WRITABLE_MOUNT=0/export WRITABLE_MOUNT=1/g' /etc/init/arc-setup-env 2>/dev/null
  sed -i 's/export ANDROID_DEBUGGABLE=0/export ANDROID_DEBUGGABLE=1/g' /etc/init/arc-setup-env 2>/dev/null
  
# NOTE The below line (disabling shared fonts) is no longer needed as of recent CrOS versions.

  sed -i 's/export SHARE_FONTS=1/export SHARE_FONTS=0/g' /etc/init/arc-setup-env 2>/dev/null
  
 fi
 
 # In CrOS circa v55-60, we had to change the .confs directly:
 
 if [ ! -e /usr/share/arc-setup/config.json ] && [ ! -e /etc/init/arc-setup-env ]; then
 
  echo "Copying /etc/init/arc-setup.conf and /etc/init/arc-system-mount.conf to /usr/local/Backup"
  sleep 0.2
  echo "Setting 'env WRITABLE_MOUNT=1' in /etc/init/arc-setup.conf and/or /etc/init/arc-system-mount.conf"

  cp -a /etc/init/arc-system-mount.conf /usr/local/Backup/arc-system-mount.conf.old
  cp -a /etc/init/arc-system-mount.conf /etc/init/arc-system-mount.conf.old

  cp -a /etc/init/arc-setup.conf /usr/local/Backup/arc-setup.conf.old
  cp -a /etc/init/arc-setup.conf /etc/init/arc-setup.conf.old
  
  sed -i 's/env WRITABLE_MOUNT=0/env WRITABLE_MOUNT=1/g' /etc/init/arc-setup.conf
  sed -i 's/env WRITABLE_MOUNT=0/env WRITABLE_MOUNT=1/g' /etc/init/arc-system-mount.conf

  echo "Setting 'env ANDROID_DEBUGGABLE=1' in arc-setup.conf"

  sed -i 's/env ANDROID_DEBUGGABLE=0/env ANDROID_DEBUGGABLE=1/g' /etc/init/arc-setup.conf
fi

}


create_image() {

# Creates a blank ext4 image.

# Make some working directories if they don't already exist.

mkdir -p /usr/local/Android_Images
mkdir -p /usr/local/Android_Images/Mounted
mkdir -p /usr/local/Android_Images/Original
echo
echo "Creating new Android system image at /usr/local/Android_Images/system.raw.expanded.img"

# Make the image.
# For arm, the unsquashed image needs to be at least~ 1GB (~800MB for Marshmallow).
# For x86, the unsquashed image needs to be at least ~1.4GB (~1GB for Marshmallow).

# Since the raw rootfs has increased in size lately, create a blank 2GB image, make it sparse so it takes only as much space on disk as required.

# If /usr/local/Android_Images/system.raw.expanded.img already exists, delete it.
rm -rf  /usr/local/Android_Images/system.raw.expanded.img

# Previous version of file creation used dd
# It's much faster if we use fallocate and starts off sparse, so uses only as much space on disk as necessary.

if [ $ANDROID_ARCH=armv7 ]; then
  cd /usr/local/Android_Images
#  dd if=/dev/zero of=system.raw.expanded.img count=2000000 bs=1024 status=progress
fallocate -l 1.7G  /usr/local/Android_Images/system.raw.expanded.img

  else

  if [ $ANDROID_ARCH=x86 ]; then
    cd /usr/local/Android_Images
#  dd if=/dev/zero of=system.raw.expanded.img count=2000000 bs=1024 status=progress
fallocate -l 2.2G  /usr/local/Android_Images/system.raw.expanded.img

   else
    echo "Error!"
    echo "Unable to detect correct architecture!"
    echo
    exit 1
  fi
#
fi

#fallocate -l 2G  /usr/local/Android_Images/system.raw.expanded.img
sleep 0.001
echo "Formatting system.raw.expanded.img as ext4 filesystem"
echo

# After we create an image with fallocate, mkfs.ext4 complains about the geometry/cylinders when we format it
# Here, we ignore this complaint, sending it 2>/dev/null

mkfs ext4 -F /usr/local/Android_Images/system.raw.expanded.img 2>/dev/null

}


# Functions end

main() {

check_if_root

echo "Test Rooting scripts for Android on Chrome OS"
sleep 0.2
echo
echo
echo "Version 0.27.1"
sleep 0.2
echo
echo "Unofficial scripts to create a rooted Android system image on Chrome OS"
sleep 0.2
echo
sleep 1
echo
echo "In order to modify system files, the Chrome OS system partition needs to have been mounted writeable."
echo "If you haven't already disabled rootfs verification, you will need to do so before proceeding with this script."
echo
echo "You should be able to disable rootfs verification by running the following command, then rebooting."
echo
echo
echo
echo
echo "sudo /usr/share/vboot/bin/make_dev_ssd.sh --remove_rootfs_verification --partitions $(( $(rootdev -s | sed -r 's/.*(.)$/\1/') - 1))"
sleep 1
echo
echo
echo
echo
echo "Alternatively, run the command below, then follow the prompt."
echo
echo
echo "sudo /usr/share/vboot/bin/make_dev_ssd.sh --remove_rootfs_verification"
sleep 1
echo
echo
echo "Press Ctrl+C to cancel if you still need to do the above."
sleep 2
echo
echo "Be aware that modifying the system partition could cause automatic updates to fail, may result in having to powerwash or restore from USB potentially causing loss of data! Please make sure important files are backed up."
echo
echo
check_writeable_rootfs

# Remount the Chrome OS root drive as writeable

mount -o remount,rw / 2> /dev/null

# Modify the two/three envs in /etc/init

modify_cros_files

# Make a new writeable Android rootfs image, symlink it in place of the original, and copy our files to it.

# First, check if symlink already exists.

if [ -L /opt/google/containers/android/system.raw.img ]; then
  echo "The file at /opt/google/containers/android/system.raw.img is already a symlink!"

# If the file is already a symlink, we need to check if a backup of the original system.raw.img exists.

  if [ ! -f /home/chronos/user/Downloads/system.raw.img ]; then
  
    if [ ! -f /opt/google/containers/android/system.raw.img.bk ]; then
      echo
      echo "Error!"
      echo "System.raw.img not found"
      echo
      exit 1
    fi
      
  fi
  
  echo "Removing symlink"
  rm -rf /opt/google/containers/android/system.raw.img
fi
  
if [ ! -e /opt/google/containers/android/system.raw.img ]; then

  if [ -f /opt/google/containers/android/system.raw.img.bk ]; then
    echo "Using /opt/google/containers/android/system.raw.img.bk"
  else
  
    if [ -f /home/chronos/user/Downloads/system.raw.img ]; then
      echo "Using /home/chronos/user/Downloads/system.raw.img"
    else
      echo
      echo "Error!"
      echo "System.raw.img not found"
      echo
      exit 1
    fi

  fi

fi

# Unmount any previous instances

umount -l /usr/local/Android_Images/system.raw.expanded.img 2>/dev/null
umount -l /usr/local/Android_Images/system.raw.expanded.img 2>/dev/null
umount -l /usr/local/Android_Images/Original 2>/dev/null
umount -l /usr/local/Android_Images/Mounted 2>/dev/null

detect_architecture

create_image

echo "Mounting system.raw.expanded.img"

if [ -e /opt/google/containers/android/system.raw.img ]; then
    
  if [ -L /opt/google/containers/android/system.raw.img ]; then
    
    if [ -e /opt/google/containers/android/system.raw.img.bk ]; then
      umount -l /usr/local/Android_Images/Original 2>/dev/null
      mount -o loop,rw,sync /opt/google/containers/android/system.raw.img.bk /usr/local/Android_Images/Original 2>/dev/null
    else
  
      if [ -e /home/chronos/user/Downloads/system.raw.img ]; then
        umount -l /usr/local/Android_Images/Original 2>/dev/null
        mount -o loop,rw,sync /home/chronos/user/Downloads/system.raw.img /usr/local/Android_Images/Original 2>/dev/null
      else
        echo
        echo "Error!"
        echo "System.raw.img not found"
        echo
        exit 1
      fi
        
    fi
    
  fi
    
fi
  
if [ ! -L /opt/google/containers/android/system.raw.img ]; then

  if [ -e /opt/google/containers/android/system.raw.img ]; then
    umount -l /usr/local/Android_Images/Original 2>/dev/null
    mount -o loop,rw,sync /opt/google/containers/android/system.raw.img /usr/local/Android_Images/Original 2>/dev/null
  else
  
    if [ -e /opt/google/containers/android/system.raw.img.bk ]; then
      umount -l /usr/local/Android_Images/Original 2>/dev/null
      mount -o loop,rw,sync /opt/google/containers/android/system.raw.img.bk /usr/local/Android_Images/Original 2>/dev/null
    else
      
      if [ -e /home/chronos/user/Downloads/system.raw.img ]; then
        echo "Mounting /home/chronos/user/Downloads/system.raw.img and copying files"
        umount -l /usr/local/Android_Images/Original 2>/dev/null
        mount -o loop,rw,sync /home/chronos/user/Downloads/system.raw.img /usr/local/Android_Images/Original 2>/dev/null
      else
        echo
        echo "Error!"
        echo "System.raw.img not found"
        echo
        exit 1
      fi
      
    fi
      
  fi
    
fi
        #ORIGINAL_ANDROID_ROOTFS=/opt/google/containers/android/rootfs/root
        ANDROID_ROOTFS=/usr/local/Android_Images/Original

# We want to set SELinux to 'Permissive' so we can copy rootfs files with their original contexts without encountering errors.
# At one point, the ability to 'setenforce' was removed in an OS update. (it was later restored in another update).

setenforce 0

# Check if it worked

SE=$(getenforce)
if SE="Permissive"
then

echo "SELinux successfully set to 'Permissive' temporarily"

echo "Copying Android system files"

mount -o loop,rw,sync /usr/local/Android_Images/system.raw.expanded.img /usr/local/Android_Images/Mounted

cp -a -r $ANDROID_ROOTFS/. /usr/local/Android_Images/Mounted

else

# In case we can't set SE Linux to 'Permissive', the following is a workaround to copy files with correct contexts in 'Enforcing' mode.

echo "Copying Android system files"

# We should be able to copy files/dirs in 'Enforcing' mode by mounting with -o fscontext.
# Directories mounted with special contexts:
    
          #u:object_r:cgroup:s0 acct
          #u:object_r:device:s0 dev
          #u:object_r:tmpfs:s0 mnt
          #u:object_r:oemfs:s0 oem
          #u:object_r:sysfs:s0 sys

mount -o loop,rw,sync,fscontext=u:object_r:cgroup:s0 /usr/local/Android_Images/system.raw.expanded.img /usr/local/Android_Images/Mounted

cp -a -r $ANDROID_ROOTFS/acct /usr/local/Android_Images/Mounted/acct

umount -l /usr/local/Android_Images/Mounted

mount -o loop,rw,sync,fscontext=u:object_r:device:s0 /usr/local/Android_Images/system.raw.expanded.img /usr/local/Android_Images/Mounted

cp -a -r $ANDROID_ROOTFS/dev /usr/local/Android_Images/Mounted/dev

umount -l /usr/local/Android_Images/Mounted

mount -o loop,rw,sync,fscontext=u:object_r:tmpfs:s0 system.raw.expanded.img /usr/local/Android_Images/Mounted

cp -a -r $ANDROID_ROOTFS/mnt /usr/local/Android_Images/Mounted/mnt

umount -l /usr/local/Android_Images/Mounted

mount -o loop,rw,sync,fscontext=u:object_r:oemfs:s0 /usr/local/Android_Images/system.raw.expanded.img /usr/local/Android_Images/Mounted

cp -a -r $ANDROID_ROOTFS/oem /usr/local/Android_Images/Mounted/oem

umount -l /usr/local/Android_Images/Mounted

mount -o loop,rw,sync,fscontext=u:object_r:sysfs:s0 /usr/local/Android_Images/system.raw.expanded.img /usr/local/Android_Images/Mounted

cp -a -r $ANDROID_ROOTFS/sys /usr/local/Android_Images/Mounted/sys

umount -l /usr/local/Android_Images/Mounted

mount -o loop,rw,sync /usr/local/Android_Images/system.raw.expanded.img /usr/local/Android_Images/Mounted

cp -a -r $ANDROID_ROOTFS/storage /usr/local/Android_Images/Mounted/storage

umount -l /usr/local/Android_Images/Mounted

# Copying rootfs files

mount -o loop,rw,sync,fscontext=u:object_r:rootfs:s0 /usr/local/Android_Images/system.raw.expanded.img /usr/local/Android_Images/Mounted

cp -a -r $ANDROID_ROOTFS/. /usr/local/Android_Images/Mounted

fi
# If we were copying files from the original Android rootfs, unmount it now we've finished..
if [  -f /opt/google/containers/android/system.raw.img ]; then
  umount -l /opt/google/containers/android/system.raw.img  > /dev/null 2>&1 || /bin/true
fi

# Unmount the new rootfs too, so we can mount it again without special context later
umount -l /usr/local/Android_Images/system.raw.expanded.img 2>/dev/null


# If the original rootfs exists, before replacing it with a symlink, make a backup.
# In the event of errors, re-running the script, or post-powerwash, the original may be restored by reversing the 'mv' command.
# i.e. mv /opt/google/containers/android/system.raw.img.bk  /opt/google/containers/android/system.raw.img.

if [ -e /opt/google/containers/android/system.raw.img ]; then

  if [ ! -L /opt/google/containers/android/system.raw.img ]; then
    echo "Moving original Android rootfs image to /opt/google/containers/android/system.raw.img.bk"
    mv /opt/google/containers/android/system.raw.img  /opt/google/containers/android/system.raw.img.bk
# Make the symlink from the original pathname to our writeable rootfs image
    echo "Replacing original Android rootfs image path with symlink to /usr/local/Android_Images/system.raw.expanded.img"
    ln  -s /usr/local/Android_Images/system.raw.expanded.img /opt/google/containers/android/system.raw.img
  fi
  
  else
  
  if [ -e /usr/local/Android_Images/system.raw.expanded.img ]; then
    echo "Creating symlink to /usr/local/Android_Images/system.raw.expanded.img at original Android rootfs image file path"
    ln  -s /usr/local/Android_Images/system.raw.expanded.img /opt/google/containers/android/system.raw.img
  fi
  
fi

cd /usr/local/Android_Images
mkdir -p /usr/local/Android_Images/Mounted

# Mount our new Android rootfs

mount -o loop,rw,sync /usr/local/Android_Images/system.raw.expanded.img /usr/local/Android_Images/Mounted 2>/dev/null


}

main "$@"