Turn the Evo T20 into a usable mini computer that consumes very little power but also offers rock solid stability and heaps of features.

[System]

• Only Supports USB 1.1.
• No PS2, parallel, or serial ports.
• No motherboard expansion slots (no PCI, ISA, AGP, etc).
• No internal clock (can be set but is lost the minute the PC is rebooted)

• 1 Ethernet cable.

Installing

[Power Supply]

During the testing of the units, they were being run from the 5v rail off an old ATX PSU, mainly becuase it was the only source I was able to get that had 5V and >5amps. Thats was until this on ebay;

With 5v and 6amps; its got more then enough juice. Also, when using the molex connectors for the inter-connectors I was able to touch the 12v rail to +5v rail of another Evo T20 and killed it... Lesson learnt.

The Evo T20 needed more storage for the new OS (Etch); it has USB ports but only boots from the internal flash memory. To get around this problem we can place a small program in the flash memory that will load the rest of the operating system off a USB storage drive. For you to do this you need:

• An old copy of the firmware
• Grub source (boot loader)
• The boot kernel and initrd of the chosen Linux distro.

All of this can be done by following the clear instructions given here: http://mowson.org/karl/evo_t20/. Even though this tutorial only shows how to use DSL (Damn Small Linux), it can be adjusted to use with just about any Linux distro.

Basic setup

• Download a copy of the original firmware from the HP website.
• Edit it and patch it as listed in the above article.
• change the network card settings on the computer you have hooked up to the EVO's ethernet card to 10.0.0.1 (this isnt very well documented but worked for me).
• Start the windows program Netxfer (downloadable from the HP website).
• Turn on the EVO and continue to press 'P', until you see a screen that's displaying Netxfer at the top.
• The firmware will then be downloaded and flashed to the internal memory and it'll be rebooted to try the new firmware.
• At this stage you should be able to load the Kernel and the Initrd up until the stage where it says something similar to this: "Kernel Panic VFS... no root found". This is good because we havent setup a USB storage device yet.

After the boot process has been installed into the firmware and the firmware has been uploaded you now need to install Linux on to the preferred USB thumb drive. To do this you'll need a PC that supports USB mass storage devices natively. Remove the SATA/IDE/SCSI cables from any of the hard drives and allow the PC to boot the install CD Just like a normal installation. When it comes to asking where you'd like to install the file system, make sure you pick the USB drive. When it asks you to install GRUB into the MBR, it's recommended you pick yes, that way you’ll be able to test it and edit it before installing the USB into the Evo.

[Grub - menu.lst]

[/dev/sdb1]

Maintenance

Objectives Completed

Currently the EVO has been able to run Debian's Etch at a reasonable speed, but requires more ram (which is on it's way). If it's given too many high impact jobs at once to perform, it will no longer respond to pings and doesnt automatically detect when a USB keyboard is plugged back into it (Etch problem).

So far the lil trooper has been able to do the following:

• Run 7 different graphs for MRTG - It was desired to use Cacti but the over heads were too high, and getting it to support SQLite was a pain.
• Torrentflux - This little gem was great for downloading other Linux distros, and with it's feature set it could happily run without noticing a drop in speed across the network (Thanks to QOS)
• Having a security camera at home can always give peace of mind, which is why I also installed a very cheap, generic USB camera. The frame rate at 320x240 was about 2 FPS, and at 640x480 is was 1 frame for about 10 seconds, which isnt that great but I also didnt stop any of the processes or try to tune it's performance.
• Standard Linux shell is always good for doing MTR's, Dig's, etc..
• If you used the Damn Small Linux installation HERE then you would have been able to use a GUI with heaps of other features, but I found having an X desktop load was unnecessary load and I'd never use it.

Future Objectives

• I'd Like to use the USB camera in conjunction with my Sniper project so the camera could be rotated left-right, up and down.
• I graphical USB LCD on the side displaying current memory usage and CPU usage would be great, but both are already being logged via MRTG, so it wouldn't realy be of any benifit.
• I'll be adding a USB WiFi device to the modem with an extended range antenna to do some sniffing.
• General all round preformance needs to be looked at. The CPU cant be upgraded but I have been able to purchase a 256MB SODIMM for it which will arrive soon, and hopefully that will enhance the performance enough to make it more usable.

Quick Useless Info

cat /proc/cpuinfo