XFCE

Xfce is a lightweight but powerful desktop environment that will work well on the XO. The following is a tutorial for using Xfce on the XO based on the article from the Free Like GNU article and several forum posts.

Preamble

Please read the following steps before proceeding to make sure you understand what is involved! We take no responsibility for you making your XO unbootable. Although the process is reasonably safe for your XO, you should know how to and have the ability to wipe the XO and start fresh using a USB stick in case you get into trouble!

Please also note that xfce and other third-party modifications (all non .xo bundled applications) to your XO may be rendered inoperative when you upgrade the base OS to a new build. (See http://dev.laptop.org/ticket/6317)

Instructions

Get Root

Establish a connection to the internet. You will need the ability to connect to the internet to retrieve and update files from the OPLC's repositories. "yum" is the command that will retrieve the files you request and it will automatically install them. You will need to have "root" access to use yum.

If you can't get an internet connection first because of missing WPA encryption, follow WPA instructions first. These even work with Sugar.

Get "root": Use the terminal activity and type su at the prompt and hit the return key. Your command prompt will now end with "#" this means you have "root" and can change any file on the computer.

$ su
#

Install Packages

Install xfce, this will give you a very basic desktop environment and the ability to customize it. This will download about 40MBs to RAM then install the files automatically. Make sure, no other Activity is running. Otherwise during installation you will get 'error: can't allocate memory'. To proceed, stop Terminal Activity, reboot, restart the process. If you get a "Socket Error" that returns you to a prompt, use the up arrow to restore your original command and enter to restart the process.

# yum install xfdesktop xfce-utils xfce-mcs-plugins xfce4-session

Optional packages: xmms (audio player), orage (calendar), xfce-mixer (volume control), system-config-date (set datetime/timezone), genmon (generic monitor - can be used to output battery status, for example), systemload (shows CPU and memory usage)

# yum install xmms orage xfce4-mixer system-config-date xfce4-genmon-plugin xfce4-systemload-plugin

Install Firefox 2

Installing firefox 2 requires that you remove its exclusion from the XO's repository list Open the repository file with the following command:

# nano /etc/yum.repos.d/olpc-koji-ship2.repo 

NOTE: in the latest builds (here tested on candidate-691) the command should be:

# nano /etc/yum.repos.d/olpc-koji-update1.repo

Remove the firefox entry from the last line so it looks like this:

exclude=seamonkey,mozplugger,kdebase,kernel

then save using CTRL+X and confirm with "y" Install Firefox 2 by running this command

# yum install firefox

Manage WiFi Networks

You can use wifi-radar to manage your wireless connection within xfce.

# yum install wifi-radar

You can run wifi-radar through the xfce menu under "Networking". After running it once, a file will be created at /etc/wifi-radar/wifi-radar.conf. Open this file in a text editor, and change the line which reads:

interface = eth1

to read:

interface = eth0

Now, running wifi-radar should allow you to see the available wireless networks and connect to one. You may need to disable the default wireless network manager, by running:

# /etc/init.d/NetworkManager stop

You can permanently disable network manager by

# /sbin/chkconfig NetworkManager off

If you want to run wifi-radar as a daemon which will automatically connect to a preferred network:

$ wifi-radar -d

You should start the daemon while booting

# nano /etc/rc.local

Insert last line read

# wifi-radar -d

Now reboot. If you run into problems, there are some hints in the following section.

Manage WPA2 and WPA Keys with XFCE

You can connect to Wireless Access Points using WPA and WPA2 keys. Following solution don't require wifi-radar, thus work stand-alone for preferred WiFi-connection. This method, once applied, even works with Sugar persistently.

Add WPA Keys

Prepare your wireless network configuration. Edits can be added muliple for various connection types.

# nano /etc/wpa_supplicant/wpa_supplicant.conf 

Adding following lines for WPA2 or WPA1 keys

WPA2 Connect Entry

network={
	ssid="MyHome WiFi Name"
	scan_ssid=1
	proto=RSN
	key_mgmt=WPA-PSK
	pairwise=CCMP
	group=CCMP
	psk="My Paraphrase"
}

WPA1 Connect Entry

network={
       ssid="MyHome WiFi Name"
       scan_ssid=1
       proto=WPA
       key_mgmt=WPA-PSK
       pairwise=CCMP TKIP
       group=CCMP TKIP
       psk="My Paraphare"
}

Using WPA, options pairwise and group may vary between 'CCMP' or 'TKIP'. Get Wireless Access Point settings by running command line program 'iwlist scanning', looking for preferred wifi connection. 'CCMP' seems preferrable.

Edit sysconfig

Edit file

# nano /etc/sysconfig/wpa_supplicant 

Read line INTERFACE="-iwlan0". Set to

INTERFACES="-ieth0"

Restart eth0

For some reason you must reset network device while booting.

# nano /etc/rc.local

After read "touch /var/lock/subsys/local" (and before wifi-radar -d) insert

ifdown eth0
ifup eth0

Disable NetworkManager

Disable network manager permanently by

# /sbin/chkconfig NetworkManager off

Sugar Notice: NetworkManager manages Sugars 'Neigbourhood'. Once turned off, Neigbourhood will stay empty. But you'll win a 'hidden' stable and persistent WiFi connection instead. When turned on again, NetworkManager ask for password, which fails. Turn off again and reboot to connect.

Install wpa_supplicant demon

Enable wpa_supplicant permanently by

# /sbin/chkconfig --level 2345 wpa_supplicant on

Your system must be rebooted to access the web.

Xfce startup message

While launching Xfce there is a dhcp warning 'Could not lookup <hostname>'. You could continue anyway. To get rid of this nagging message, or if you are running Wifi-Radar, you should follow the instructions given! In the warning message, there is a hostname named 'dhcppc1' or similar. Insert this given hostname in your systems hosts-list

# nano /etc/hosts

Insert line read

# 127.0.0.1 dhcppc1

Wifi-Radar setting

You need Wifi-Radar only if you move between different networks. Wifi-Radar with WPA keys IS working. First of all, Wifi-Radar only runs with root privilege! That means, on XO you cannot run WR from the XFCE menue. In XFCE, open a terminal window, get root and start

# su
# wifi-radar 

Now, check your preferred WPA network - the one you installed before - and click Edit. Set

Use WPA 
 Driver: wext

Connection commands
 Before: ifup eth0
 After: ifdown eth0

Save changes. Close program, start again in the terminal. Now try to disconnect and connect. If Wifi-Radar get hooked, just kill it in the terminal window by pressing CTRL + C twice. In the terminal window, you can see WR acting. If it is allright, end WR with the Close-Button. For some reason, after you 'touched' WR once per session with root in the terminal window, you can now start WR with XFCE menue. If you want to connect to another network listed, you must edit according profile. If you want to connect to another WPA network, you must add an entry in the wpa_supplicant.conf. (There may be some ways to use visudo to avoid root.)

Using nm-applet instead of Wifi-Radar in xfce

With the xfce desktop, one can use nm-applet to connect much more easily to a variety of wifi-hotspots. I find it to be much easier to set up than wifi-radar.

Setting up nm-applet

1. Connect to some sort of wifi hotspot, any way you can. You could also use a usb key, but it is easier to explain with yum
2. download nm-applet. As root, yum install NetworkManager-gnome --enablerepo=fedora
3. download some gnome UI elements yum install libgnomeui download is less than 4 megs
4. add nm-applet & to your .xsession file found at /home/olpc/.xsession
5. undo your wifi radar, wpa supplicant, or any other hacks you did to connect to the internet. nm-applet uses the same setup as sugar default. Make sure you turn NetworkManager back on
6. restart, and enjoy nm-applet!

NOTE: IF you get an error(something about d-bus) just ignore it, nm-manager should still work. NOTE 2: With Build 656 it seems impossible to install NetworkManager-gnome because of lacking dependencies relating 'redhat-artwork'.

If you are having trouble reconnecting to a locked hotspot using nm-applet

nm-applet seems to suffer from the same issue of corrupted wifi password file (networks.cfg) which plagues sugar. Here's my attempt at a work around.

1. On a toolbar in xfce, create a launcher (right click a toolbar, hit add) which runs the text rm /home/olpc/.sugar/default/nm/networks.cfg in the terminal (check the box when creating it) you only need to do this once!
2. right click nm-applet in your systray, and click "disable wireless." right click again and click "disable networking"
3. click your launcher to delete the networks.cfg file. You could also open a terminal and paste rm /home/olpc/.sugar/default/nm/networks.cfg into the terminal
4. Then, right click nm-applet and restart networking, wireless
5. click on nm-applet and "connect to other network" Manually type in your wireless network name and password, do not click on your wireless in the drop down if you see it. Sometimes it works, and sometime it doesn't, so inputting manually seems to work more often.
6. you should be connected!

Screen Brightness/Rotation, Sound Volume, and Battery Status Control

The keys on your XO can be easily made functional again by installing the rpm on this page: olpc-keybind. This RPM contains the scripts to perform the operations and the instructions to configure your default olpc user account to use them.

This rpm depends on xbindkeys. Because this rpm doesnt yet exist in the official repositry you have to do the following in a terminal (as root) to install it:

yum install xbindkeys
rpm -Uhv http://favias.org/files/olpc-keybind-1-2.noarch.rpm

To remove this functionality the following command as root in terminal will suffice:

yum remove olpc-keybind xbindkeys

Screen rotation note: Rotation does not automatically resize the windows. If you are using fullscreen mode this may be fixed by pressing Alt-F11 twice.

NOTE: On error 'scriplet failed' run as root /usr/bin/olpc-keybind manually. Run xbindkeys & for testing screen rotation. You can add /usr/bin/xbindkeys to Xfce Autostarted Applications via Setting Menue.

If xbindkeys is giving you errors you may need to open olpc-keybind and change all references .xbindkeysrc from "/home/olpc/.xbindkeyssrc" to "/root/.xbindkeysrc"

Nb: For me, screen brightness did not initially adjust, as root I had to:

chmod a+rw /sys/class/backlight/dcon-bl/brightness 
chmod a+rw /sys/class/backlight/dcon-bl/max_brightness

Displaying Battery Status in panel

• Install olpc-keybind rpm for the battery-status binary it provides
• use genmon (see above) to display the battery status in a toolbar
  • right-click on a blank spot on an Xfce toolbar, chose Add Item, select Generic Monitor and clicked Add
  • right-click the new Generic Monitor item, select Properties, and apply the following settings:
    • Command: battery-status
    • Label: B
    • Period: 300

Another option is to create a small script in /home/olpc called battery.sh (or whatever you would like) with the following line in it:

"echo hal-device | grep charge_level.percentage | sed 's/$/%/' /sys/devices/platform/olpc-battery.0/power_supply/olpc-battery/capacity"

save this script and make sure that the user 'olpc' owns it (chown olpc /home/olpc/battery.sh) and it is executable (chmod +x /home/olpc/battery.sh) Then...

• • right-click on a blank spot on an Xfce toolbar, chose Add Item, select Generic Monitor and clicked Add
  • right-click the new Generic Monitor item, select Properties, and apply the following settings:
    • Command: /home/olpc/battery.sh
    • Label: B
    • Period: 300

Getting normal fonts for web browsing, xfce desktop

If you think your fonts look a little funny on xfce, you may appreciate more "typical" fonts for your web browser and your desktop. I think it makes things look much nicer, and make my eyes bleed less. However, this is not entirely "free," but the package itself is distributable for free

1. Download the mscorefonts rpm from this website Mscorefonts rpm
2. open a terminal as root, in the folder you downloaded the rpm to, and type: rpm -i Micro Pressing tab should auto-complete the file name
3. restart your computer, and you should notice fonts in browser looking more like your other computers. you may have to reinstall opera/firefox/konquer, but I don't think so

Also, you can change your default user interface fonts in the xfce "User interface settings"(check me on this) and changing the font to a size and font you recognize. Its also good to turn on anti-aliasing (slight) to make the fonts look even better.

Mounting Removable Filesystems

1. Insert SD card or usb drive.
2. Run thunar, the Xfce File Manager.
3. The removable media should appear in the left-hand column. Click on it to mount it. A df will show that it has been mounted in the appropriate place (/mount/VOLUME_NAME)
4. To unmount, right click on the media name in the same place and choose unmount.

Change default desktop

Turn Xfce to default desktop

In /home/olpc/ create a copy of .xsession-example called .xsession:

#cp /home/olpc/.xsession-example /home/olpc/.xsession

Edit the .xsession file to launch Xfce on startup:

# nano /home/olpc/.xsession

Find the commented line that reads #exec xterm - below that line, add the following code:

exec startxfce4

• use CTRL+X to save and exit
• use CTRL+ALT+BACKSPACE to restart X, starting Xfce

Turn back to XO Sugar desktop

To make the original XO Sugar desktop the default boot again, rename the .xsession file to anything other than .xsession (.xsession.xfce for instance). Applied changes, e.g. networking, may stay persistent.

Trouble?

Defreeze Boot Animation

If you reboot and get stuck at the XO logo (with circle around it), hold down power to shutdown then power up again.

Warning! This is advanced and can potentially screw up your boot. To bypass the boot anim manually, hold down the checkmark while turning the OLPC on, then wait for the machine to tell you to release it.

You can prevent boot freezing by disabling the startup logo animation:

• Open the startup animation logo file /etc/init.d/0-boot-anim-start
• Above the line saying "# i'm the child", change if os.fork() == 0: to if os.fork() == 'debug': to prevent the animation code from being executed.

XO Wipeout

This document is under continued construction and may contain malicious strategies. In case of major trouble be prepared to wipe out your XO with an USB-Stick. This will clearly erase all data and any changes. Read and understand instructions following http://wiki.laptop.org/go/Secure_Upgrade first, before apply major changes to XO.

Learn Linux

After all, DO NOT forget you are half-blinded low-level hacking a machine designed for the rugged world with a sugared usability for small children... To do that, yes, you have to learn about Linux.

References

• OLPCNews Forum
• Free Like GNU
• Moving To Xfce On The XO
• Setting The XO Time And Date