Building a Debian Live based USB stick image for a thinlinc terminal

• For more information on Debian, see http://debian.org.
• For more information on thinlinc, see http://www.cendio.com.

1 Pre-requisites:

1.1 A system running Debian Testing.

Other systems may work (Debian Stable, Ubuntu, etc.), but they are not tested.

1.2 The live-build package:

$ sudo apt-get install live-build

1.3 The contents of this repository.

Simply clone this repository using git:

$ cd <wherever>
$ git clone http://github.com/dme/terminal-live

1.4 The thinlinc client package.

This must be acquired from http://www.cendio.com/downloads/clients/. Place it in config/packages.chroot. For example:

$ cd <wherever>/terminal-live
$ wget -O \
  config/packages.chroot/thinlinc-client_4.0.0-3717_i386.deb \
  http://www.cendio.com/downloads/clients/thinlinc-client_4.0.0-3717_i386.deb

1.5 A USB stick.

The resulting image is around 240MB, so almost any USB stick available today will be adequate.

2 Building the image:

$ cd <wherever>/terminal-live
$ sudo lb build
  < wait quite a while >

You should now have a new image ready to write to your USB stick:

$ cd <wherever>/terminal-live
$ ls -l binary.hybrid.iso 
-rw-r--r-- 1 root root 238026752 Jan 29 07:28 binary.hybrid.iso

3 Writing the image to a USB stick:

Please be careful - don’t overwrite the wrong device. If you don’t know what you are doing, ask someone for help.

THIS WILL DESTROY THE EXISTING CONTENTS OF THE USB STICK.

$ sudo dd if=binary.hybrid.iso of=/dev/fishstick

/dev/fishstick in that previous line is clearly wrong - it should be /dev/sdb or /dev/sdc or something similar. You can examine the tail of dmesg output to see what name was assigned to the USB stick that you just inserted.

4 Booting the image:

Boot your terminal from the USB stick. Exactly what is required to achieve this differs between systems. Often it requires pressing F12 when the BIOS messages are being shown.

The system will boot from the USB stick and provide two options:

- Live- ()
- Live- ( rescue)

The second entry will be selected, but we want to use the first. Move the selection using the arrow keys to the first entry, then press ‘Enter’. The system should boot Linux, configure the network and then start the X server and thinlinc client.

The USB stick should not be removed while the terminal is being used (though see notes about toram below).

5 Using the image:

The thinlinc client should appear (you might need to move the mouse or press a key). Modify the thinlinc parameters (server, username, etc.) and instruct it to connect. The client should connect to your thinlinc server and work as normal.

When you’re done, simply turn off or reset the terminal.

6 Notes

6.1 The image is big!

240MB is more than twice the size expected, though no attempt has been made to minimise the number of packages, etc. For potential terminals with 1G or more of memory, this doesn’t appear to be a problem.

6.2 Network configuration is fixed.

Wired systems that can use DHCP work easily.

Wireless systems currently require that the relevant network information be added to /etc/network/interfaces and /etc/wpa_supplicant/wpa_supplicant.conf.

A better approach would be to add wicd and wicd-curses (and maybe wicd-gtk) to the image and figure out how to pre-configure a small number of known networks.

6.3 IPv6 is not enabled on any interfaces.

See above - should be a simple change to /etc/network/interfaces with the current implementation.

6.4 The ‘rescue’ boot option is the default.

Two options are added to the image, but the second ‘rescue’ option is the default. This should be fixed so that the normal option is the default, and the timeout set to 5 seconds, in order that the terminal can boot automatically.

6.5 The boot options don’t have useful names.

6.6 The Caps-Lock key is mapped to Control.

This is a personal preference. How might it be implemented in a more friendly way?

6.7 Copying the image to memory can be useful.

Adding the toram option to the boot arguments (either by adding it to LB_BOOTAPPEND_LIVE in config/binary and rebuilding the image or by hitting ‘TAB’ at the boot loader) causes the contents of the USB stick to be read into RAM during the booting of the terminal.

This means that the USB stick can be removed once the terminal has booted, and also that some operations are faster (as the filesystem is stored in memory rather than on the relatively slow USB stick).

6.8 tlclient could be pre-configured for a particular server.