Installing Debian Linux on the Galaxy Tab 10.1

Ever since I bought the Galaxy Tab I'd read that it was possible to run Linux on Android. I soon saw that this could be useful: having a complete Linux system at your fingertips. Even better: I even bought the original Samsung keyboard dock and a bluetooth mouse to make the whole thing even nicer.

Debian Linux Squeeze running on the Galaxy Tab 10.1 with Android ICS.

There are two apps in the Play Store that do this "job" for you.

The Linux Installer Standard was the first one I learned about. It lets you install the Debian or Ubuntu distributions and you can even select the version. I tried installing with it since it's the one with the most features for customizing your Linux. I had no success. The debootstrap process never finished. I tried every possible alternative, tricks, hacks, and nothing. I just wasted time. Maybe it'll be different for you.

An alternative was the Complete Linux Installer. This one is dead easy to use and worked well for me. It allows installing the Debian, Ubuntu, Arch, Backtrack and Fedora distros. Its problem is that you don't have many choices for customizing the image to be created, since it's already prebuilt and it just downloads it to your Android device. But the main problem was that I wanted to install Debian Wheezy, but the app only has Debian 4 with xfce. I didn't like that.

For the reasons I described above, I decided to create my own disk image of the size I wanted and with Linux configured the way I wanted. If you'd like, you can download it from the link below. It was tested on the Galaxy Tab 10.1 but should work on any Android with an arm processor.

http://www.4shared.com/archive/iDICVTs_/squeeze-armel-android-chrootim.html

I made a video demonstrating Linux on the Galaxy Tab:

Requirements:

---

• A machine with Debian or Ubuntu (I used my Linux Mint Debian Edition).
• A Galaxy Tab 10.1 rooted with BusyBox installed.
• Lots of patience.

Creating the Image:

---

On the Linux machine you'll need to install debootstrap.

sudo apt-get update
sudo apt-get install debootstrap

Create a blank image, then format and mount it.

dd if=/dev/zero of=squeeze.img bs=1M count=2048

sudo mkfs.ext4 -F squeeze.img

sudo mkdir /mnt/squeeze/
sudo busybox mount -t ext4 -o loop squeeze.img /mnt/squeeze/

Note: The image file above is for 2GB. Change the count to whatever size you want (the lxde installation takes up more than 800 MB)

Run debootstrap and install the system into the image.

sudo debootstrap --verbose --arch armhf --foreign squeeze /mnt/squeeze/ http://ftp.debian.org/debian

Unmount the image

sudo umount /mnt/squeeze

Installing the Image on Android

---

Create a folder on Android. I put it in /sdcard/Debian. Copy the image into the folder.

The installation boils down to:

• Creating a mount point and mounting the image.
• Chroot into the Debian image.
• Setting environment variables.
• Running the second part of debootstrap

I suggest installing a terminal emulator for Android. I use Better Terminal Emulator. You can use adb shell too.
Type the following commands in the terminal. The code is commented to make it easier to understand.

# Torne-se root.
su

# Crie um ponto de montagem e monte a imagem nele.
mkdir /data/local/debian
busybox mount -o loop,noatime -t ext4 /sdcard/Debian/squeeze.img /data/local/debian

# Faça chroot para o Debian
chroot /data/local/debian/ /bin/sh

# Defina algumas variáveis de ambiente
export PATH=$bin:/usr/bin:/usr/sbin:/bin:$PATH
export TERM=linux
export HOME=/root
export USER=root

# Defina o prompt do shell
export PS1='$USER@$HOSTNAME:${PWD-?} # '

# Termine o debootstrap
/debootstrap/debootstrap --second-stage

# Inicie um shell do bash
/bin/bash

Don't exit the shell before moving on to the next section.

First Boot

---

Technically the system is running, but we still need to do one last thing:

# Adicione os repositórios para instalação de pacotes.
echo "deb http://ftp.debian.org/debian/ squeeze main contrib non-free" >> /etc/apt/sources.list
echo "deb-src http://ftp.debian.org/debian/ squeeze main contrib non-free" >> /etc/apt/sources.list

# Faça o primeiro update
apt-get update

Return to Android by running the following command:

exit

The system is ready to use, so we need a script to make starting Linux easier. Copy this script to the directory where you placed the image and name it linux.

#!/bin/sh
if [ $EUID -ne 0 ]
then
	echo "Tornando-se root!"
	su -c linux
	exit 1
fi

mnt=/data/local/debian

# Soh eh preciso caso use o nautilus. Se usar outro
# gerenciador de arquivos nao eh necessario.
echo "Remontando a raiz para escrita para escrita..."
busybox mount -o rw,remount /

echo "Montando o Debian Squeeze..."
busybox mount -t ext4 -o loop,noatime squeeze.img $mnt/

echo "Definindo variáveis de ambiente..."
export PATH=$bin:/usr/bin:/usr/sbin:/bin:/sbin:$PATH
export TERM=linux
export HOME=/root
export USER=root
# export PS1='$USER@$HOSTNAME:${PWD-?} # '
export PS1='\[\e[1;31m\][\u@\h \W] \$\[\e[0m\] '

echo "Montando devpts/proc/sysfs..."
busybox mount -t devpts devpts $mnt/dev/pts
busybox mount -t proc proc $mnt/proc
busybox mount -t sysfs sysfs $mnt/sys

# Voce pode colocar aqui o comando para montar o cartao de
# memoria externo tambem. No meu caso o galaxy tab nao tem.
echo "Montando o cartaão de moemória..."
if [ ! -d $mnt/mnt/sdcard ]; then
    mkdir $mnt/mnt/sdcard
fi
busybox mount --bind /mnt/sdcard $mnt/mnt/sdcard

echo "Entrando no Debian Squeeze..."
echo " "
chroot $mnt/ /bin/sh /root/.init.sh

# busybox fuser -m $mnt -k

echo "Desmontando devpts/proc/sysfs..."
busybox umount $mnt/mnt/sdcard
busybox umount $mnt/dev/pts
busybox umount $mnt/proc
busybox umount $mnt/sys

echo "Desmontando Debian Squeeze..."
busybox umount $mnt/

Now whenever you want to run Linux, open the Android terminal emulator and type the commands:

cd /sdcard/Debian
su
sh linux

LXDE or GNOME and VNC Server

---

LXDE performs much better than Gnome on slower machines, but you can install both, as I did.

LXDE:

apt-get install lxde

Gnome:

# Não instale o pacote gnome pois é gigante e cheio de dependências.
# Instale os seguintes pacotes separados:
apt-get install gnome-session gnome-themes gnome-terminal xserver-xorg-core gdm

During installation, two configuration windows will appear. Leave the default settings and continue.
Install the VNC Server.

apt-get install tightvncserver

tightvncserver is the default vnc server. For better performance, download the source code of turbovnc and libjpegturbo and compile them.

TurboVNC: http://www.virtualgl.org/Downloads/TurboVNC

Libjpeg-turbo: http://libjpeg-turbo.virtualgl.org/

To start and stop the vncserver using "service start", create the script below at /etc/init.d/vncserver and run chmod 755 on it.

export HOME="/root"
export USER="/root"
STARTCMD="vncserver -geometry 1280x752"
STOPCMD="vncserver -kill :1"

case $1 in
    start)
        if [ -e /tmp/.X1-lock ] ; then
            echo "VNCServer already running"
        else
            $STARTCMD
        fi
            ;;
    stop)
        $STOPCMD
        ;;
    restart)
        $STOPCMD
        $STARTCMD
        ;;
    *)
        echo "$0 start|stop|restart"
        exit 1
        ;;
esac

exit 0

Run the command below to start the vncserver automatically.

echo "service vncserver start" >> /root/.bashrc

The first time you run it, it will ask you to enter the vnc password.

Configure the Android vncviewer to connect to localhost on port 5901.

Done! We have Debian 6 running in parallel with Android.

Some tips:

---

If the exit script can't unmount the Linux image, try running the following command:

killall menu-cached

To increase the image size after it's been created (replace 256 with the number of megabytes you want to add):

dd if=/dev/zero bs=1M count=256 >> data.img
e2fsck -f data.img
resize2fs data.img
e2fsck -f data.img

To switch to gnome:

update-alternatives --config x-session-manager