KDE on scratchbox for maemo 4

This article describes how to compile KDE for maemo. It takes the Nokia N810 as example device. It uses the cross-compiling environment scratchbox on an Intel-based computer.

Contents

Overview

  • maemo is the core software stack that runs on mobile devices like Nokia's N810 or N900
  • garage is where the projects for maemo are hosted, somewhat compareable to Sourceforge.
  • OS2008 is maemo 4.x (more info). Compare it with Debian's Lenny.
  • Diablo is the version (feature upgrade 2008) of maemo.
  • Scratchbox is a cross-compiling environment to enable you to create software for maemo on an i386.
  • Busybox is a single binary that allows you to run commands like ls, cat and bunzip2
  • Hildon is an application framework and desktop shell for maemo, compare it to the role that Plasma plays in KDE 4

On the Nokia itself 

ssh root@localhost
apt-get install subversion

On your desktop

You cannot install scratchbox on an X64 computer, so, install an i386 into a VMWare virtual machine. The following describes how to install scratchbox into a SUSE 11.1 32bit installation. It might work same or similar with any Linux.

Set up scratchbox

First, we want to compile a "hello world" program for the Nokia. Here is how.

  • Set up VMWare Server 2.0
  • Install a virtual machine into VMWare Server, 40GB hard drive, 1024 GB RAM
  • Install SUSE Linux 11.1 from DVD. At the bootscreen, type F7 and select X86 instead of X86_64. That way, you will get a 32bit operating system.
  • Take a VMware SNAPSHOT from your virtual machine so you can revert to this state
  • Boot your virtual machine
  • Set up scratchbox 
root@i386 # useradd -m scratchboxuser
root@i386 # passwd scratchboxuser
root@i386 # wget http://repository.maemo.org/stable/diablo/maemo-scratchbox-install_4.1.2.sh
root@i386 # chmod 777 maemo-scratchbox-install_4.1.2.sh
root@i386 # ./maemo-scratchbox-install_4.1.2.sh -s /scratchbox
root@i386 # /scratchbox/sbin/sbox_adduser scratchboxuser
root@i386 # su - scratchboxuser
  • set up the SDK 
scratchboxuser@i386 $ wget http://repository.maemo.org/stable/diablo/maemo-sdk-install_4.1.2.sh

Start the install script and accept all choices: 

scratchboxuser@i386 $ sh maemo-sdk-install_4.1.2.sh
  • start scratchbox 
scratchboxuser@i386 $ /scratchbox/login
[sbox-DIABLO_ARMEL: ~] > sb-conf select DIABLO_ARMEL

Re-login

To re-login after a reboot of your virtual machine run 

/scratchbox/sbin/sbox_ctl start
scratchboxuser@i386 $ /scratchbox/login

Hello world

Now we write the canonical hello world program in C. 

[sbox-DIABLO_ARMEL: ~] > cat > main.c << EOF
#include <stdio.h>

int main()
{
  printf("hello world");
}
EOF
[sbox-DIABLO_ARMEL: ~] > gcc main.c
[sbox-DIABLO_ARMEL: ~] > file a.out
a.out: ELF 32-bit LSB executable, ARM, version 1 (SYSV), for GNU/Linux 2.6.8, dynamically linked (uses shared libs), not stripped
  • copy the file to your Nokia N810 using scp

=> the file is executable on the Nokia

Install Qt

Now it's time to install qt. Add to your /etc/apt/sources.list: 

deb http://repository.maemo.org/extras/ diablo free non-free
deb-src http://repository.maemo.org/extras/ diablo free

and tell the system to re-read it: 

apt-get update

install the qt development package: 

apt-get install libqt4-dev

verify it has been installed: 

mkdir qttest
cd qttest/
cat >main.cpp
#include <QApplication>
#include <QPushButton>
int main(int argc, char ** argv)
{
  QApplication qa(argc,argv);
  QPushButton* qp=new QPushButton("hello world");
  qp->show();
  return qa.exec();
}
qmake -project && qmake && make && ./qttest
g++ -c -pipe -O2 -Wall -W -D_REENTRANT -DQT_NO_DEBUG -DQT_GUI_LIB -DQT_CORE_LIB -DQT_SHARED -I/targets/DIABLO_ARMEL/usr/share/qt4/mkspecs/linux-g++ -I. -I/targets/DIABLO_ARMEL/usr/include/qt4/QtCore -I/targets/DIABLO_ARMEL/usr/include/qt4/QtGui -I/targets/DIABLO_ARMEL/usr/include/qt4 -I. -I. -o main.o main.cpp
g++ -Wl,-O1 -o qttest main.o    -L/usr/lib -lQtGui -lQtCore -lpthread
qttest: cannot connect to X server

Good - it tries to connect the X server, so it works.

See graphics

To see graphics, you need to start Xephyr. This example shows how to install and run it on SUSE Linux 11.1. 

root@i386 $ yast -i xorg-x11-server-extra
root@i386 $ Xephyr :4

Now back in your scratchbox 

[sbox-DIABLO_ARMEL: ~/qttest] > export DISPLAY=:4
[sbox-DIABLO_ARMEL: ~/qttest] > ./qttest
Retrieved from "http://bugs.maemo.org/KDE_on_scratchbox_for_maemo_4"