Frequently Asked Questions

From Joggler
Jump to: navigation, search

Whether you're new to the Joggler or have become quite familiar with it, there are bound to be a few questions that crop up from time to time. This FAQ aims to answer some of those common queries.

Will This Destroy My Joggler?

Obviously this depends on what you're doing, but if you're not opening the case then it is very unlikely that you will cause any permanent damage. The Joggler is surprisingly robust, and unless you have some underlying hardware fault then none of the software modifications discussed here should permanently disable your device.

There are two very important exceptions.

Exception 1: Firmware

If you do anything that involves firmware modification (and by this we mean messing with the software on the EFI chip, such as modifying the boot logo) you run a very high risk of turning your Joggler into a brick. This is because the EFI software controls, at a very low level, all of the booting options on your device. Break it and you will either end up stuck at the O2 (or OpenPeak) logo, or getting nothing on screen at all.

However, even in this extreme example all is not lost, and if you are modifying your firmware you WILL be aware that you are doing it. It's not something you'll wander into accidentally.

Exception 2: Thermal Trip Points

Looking at the specification sheet of the Intel Atom Z520 shows a figure of 90degC as the maximum recommended junction temperature for the processor. In good hardware design, a chip should generally be kept around 20 degrees below its stated junction temperature, and that's exactly what is hard-wired into the Joggler's design. At 70degC something called dynamic frequency scaling or 'processor throttling' takes place, reducing the operating speed of the chip to prevent it from overheating.

However, the Joggler does not have a normal metal heat sink. Although the metal stand is used as a sink, heat from the components is transferred to it via a sticky, rubbery material, and onto a plastic heat sink. On an unmodified operating system this is fine, as the CPU really isn't worked that hard, but when running Ubuntu it is quite easy to push your Joggler up to this magic temperature. When you do everything crawls to a halt, and some people have resorted to hacking up their Joggler cases to fit metal heat sinks. This isn't really necessary.

You can override the passive thermal trip point using a boot option, with 80degC often being used instead. Obviously this comes with the risk of shortening the life span of the processor, although in practice the CPU temperature rarely exceeds 74degC even under the heaviest of loads (and without any hardware modifications). The choice is yours.

The Disclaimer

Of course, this isn't exhaustive. If you make any modifications you are running the potential risk of shortening the lifespan of your device, be it through overheating, increased read/write wear on the internal memory, punching it because your latest tweak hasn't worked and it's swallowed the past few hours of your life... Hopefully this Wiki and the Forum will help you through, but to be plain:

Nobody is responsible for what happens to your device except yourself. Nobody here accepts any liability for your device or what you do with it. If you run software that is not approved by O2, don't expect O2 to replace your device for you if it all goes wrong.

Lecture over.

How Do I Get Access?

Original OS

To make any modifications, you'll first need to install and enable SSH or telnet. This gives you access to the Linux command line, from which you can begin to make your changes. Follow the links for instructions, which, in the easiest methods, basically consist of copying the appropriate files to a USB stick and booting the Joggler. SSH is the preferred option, as it is more secure. Only enable telnet if you have a particular need for it.

You'll then need to use the Terminal app on Mac OS X or Ubuntu, or PuTTY on Windows to log in and issue commands. Depending on how SSH was enabled, the default username and password will either be:

USER: joggler

PASS: joggler

or:

USER: letmeinssh

PASS: joggler1234

How Do I Change My Password?

Take a look at the SSH page for details.

Alternative OS

Other operating systems will have their own methods for gaining access, which should be outlined in their own instruction and installation pages. Once running, these won't be any different from the versions running on a normal PC, so don't be afraid to ask for help from the community that supports that specific OS.

The general convention with the Joggler is that alternative operating systems will use the following as the default username and password:

USER: joggler

PASS: joggler

For security and identification reasons, alternative operating systems shouldn't really be supplied with an SSH server installed. One can be added on a Debian/Ubuntu based system using the following commands:

sudo apt-get update
sudo apt-get install ssh openssh-server

How Do I Backup My System?

You get full marks for reading this bit. No doubt if you're just starting out, you'll want to try everything and see what fits. But when you've discovered what works and what doesn't, it's likely that you don't want to spend your time faffing around uninstalling apps, with the inevitable cruft that can leave behind.

What follows is a 'gold standard' backup technique that will revert your Joggler's internal flash memory back to the state it was in when you backed it up. Ideally, do this before you've ever even turned it on. ;)

You will need:

  1. Ubuntu for Joggler on at least an 8GB USB stick.
  2. Access to the remaining space on the stick, either by:
    1. Expanding Ubuntu to fill the whole stick, or:
    2. Creating an additional FAT32 partition in the remaining space (quicker and easier)
  3. Something else to do while the backup happens.

Pop the prepared USB stick into the Joggler and power on. It should boot into Ubuntu. Load the Terminal app and issue the following command:

sudo dd if=/dev/mmcblk0 of=./joggler_internal.img bs=10M

Or this one if you've created that additional partition:

sudo dd if=/dev/mmcblk0 of=/media/<NAME OF PARTITION>/joggler_internal.img bs=10M

This will copy out everything from the 1GB internal flash memory in 10MB blocks into a file on your USB stick. It will take a little time, so be patient. Shut down Ubuntu, remove the USB stick, attach it to your PC and copy off the .img file. Or if you have an abundance of memory sticks, just keep that one safe.

Restoring the Backup

Boot again from the prepared stick with the internal memory .img file on it. Load the Terminal again. Run the following commands to push the image file back onto the internal flash.

sudo umount /dev/mmcblk0*
sudo dd if=./joggler_internal.img of=/dev/mmcblk0 bs=10M

Or this if you've created that additional partition:

sudo umount /dev/mmcblk0*
sudo dd if=/media/<NAME OF PARTITION>/joggler_internal.img of=/dev/mmcblk0 bs=10M

Again, this will take a little time, and shouldn't be interrupted as you'll end up with an incomplete reflash. If you do interrupt it, don't worry too much; you can always try again.

How Do I Add More Software?

If you're running an alternative operating system, this is where you should consult the documentation about your particular OS. Each will have their own installation procedure and useful applications.

If you're running the native operating system, you have a few choices. For full details please check the Native Applications page, but there are three main methods (in decreasing order of ease):

Plug and Pimp

This method is the quickest and easiest to use. Simply download the appropriate files, copy them onto a USB stick, connect the stick to your Joggler and power on. After installation your Joggler will be accessible with a web browser, providing a one-click installation method for a large number of add-ons and software applications.

Before installing PnP, you may want to back up your Joggler using one of the methods outlined above so you can easily return to a clean slate should you need to.

Little App Launcher

This is a launching program that allows additional applications to be added to your Joggler without messing around with configuration files by hand. Primarily designed for application developers, the launcher (or whole app) just needs to be dropped into Little App Launcher's app folder, which will then take care of adding it to the Joggler's screen and providing a simple web interface for launching and quitting apps.

Installing Applications by Hand

To do this, you need to have a good grasp of Linux and be comfortable modifying system files. Not for the beginner.

How Do I Remove Software?

This depends on how you installed it originally. Most apps, including PnP, will provide an uninstall procedure of their own. If they do not, you will need to resort to the command line and remove individual components. It is usually a lot easier to simply reflash the Joggler's internal memory with the backup that you took.

How Do I Reset My Joggler?

If you're reading this, you've probably noticed that the Joggler's own reset procedure often doesn't do very much. It does remove some files and settings, but a lot of data is retained, particularly if it was added by a third-party installer. The recommended method back to a perfectly clean Joggler is to restore the backup you took. If you didn't take a backup, you can try to Restore with the O2 Image or ask on the Discussion Forum to see if anyone has a blank image available.