What Do You Need?

Background

This is, by far, the most asked question about this project. The answer is not as simple as you might think. It depends, first of all, on whether you are going to do this legally or illegally. It also depends on where your PS2 comes from, whether it is a slimline model or not, whether it is chipped or not, whether you wish to boot from a hard drive or over a network and what other hardware you may have lying around.

Closed Source: The Official Sony Kit

Linux on the PS2 all began back in 2002 when Sony officially released a kit. This kit contained a keyboard, mouse, network adapter, monitor adapter, 40GB hard drive and the all-important DVDs. If you happen to own the kit, congratulations! All you need is a memory card and you've probably got one of those already. If you haven't got the kit, things are a little less straightforward. The kit itself is now only available in Australia and New Zealand. If you live in either of those places, grab it while you still can! If you live elsewhere, you can try your luck on eBay but it's usually rarer than hens' teeth and more expensive than gold dust. However, all is not lost. It is possible to get the necessary hardware in other ways. Read on...

Open Source: Kernelloader

Since 2007 there is an open source solution availbale for booting Linux. It is called kernelloader. You don't need the official Sony kit for it. The program can be started by memory card exploit, naplink, ps2link, ARmax, uLaunchELF or by any other homebrew booting method. Everybody can use it for free. Currently the binary supports loading Linux from memory card and USB memory stick. To install Linux on your hard disc, you need just a kernel and an initial ram disk. You then can load the remaining installation files via network or USB. The program is based on TheGreatExperiment.

Input Devices

Let's start with the easy stuff. Unless you plan on using your PS2 through SSH all the time, you will need an input device or two. The PS2 has two USB ports on the front. Any Linux-compatible keyboard or mouse should suffice, providing it is USB1.1 compatible. Standard PS2 game controllers or their third party equivalents can also be used but these are probably only useful when playing games.

Video Output

Again, unless you plan on using your PS2 through SSH all the time, you will need some form of video output. You can use whatever TV you normally use your PS2 with but bear in mind that using Linux applications on a TV is far from ideal and the resolution is limited to 640x480ish (depending on whether your TV is PAL or NTSC) interlaced. Your eyes won't thank you for it. Using a monitor instead is highly recommended. This output is comparable to that of a PC and resolutions as high as 1280x1024 are supported. As mentioned above, a monitor adapter was included with the official Linux kit. Only monitors that support sync-on-green will work with this adapter. Here is a compatibility list. Failing that, other adapters have been manufactured by companies such as Blaze.

Storage

The Linux kernel is usually stored on a memory card. Despite claims to the contrary, this memory card doesn't have to be exclusively for Linux. Standard memory cards hold 8MB. The average Linux kernel takes up around 2MB, leaving plenty of space for your saved games. The kernel can be loaded from a DVD instead but this requires extensive measures and isn't recommended. You also need somewhere to store the rest of your Linux installation. Here are the available options.

Option #1: Buy the official Sony network adapter…

The first and most common option is to purchase the official Sony network adapter. As well as providing you with an ethernet connection, it also has a connector for a 3.5" IDE hard drive. Chewi is unsure whether Sony still manufactures the adapter but there are plenty still available on eBay. The adapter is not a valid option for slimline PS2 models because they have no expansion bay.

Option #2: Use an external USB hard drive…

The second option hasn't been tested by us but it should work in theory. The existence of USBeXtreme proves to us that the PS2 itself is capable of using an external hard drive connected via USB. The question is whether Linux would be able to boot from a hard drive connected in this way. We see no reason why not. The only catch is that USB1.1 is notoriously slow. You would also need a hub or a device with pass-thru to be able to use a keyboard, mouse and external hard drive all at the same time.

Not An Option: Use an external FireWire? hard drive…

There was going to be another option similar to the previous one but without the catch. Several PS2 models have a 400Mbps FireWire? port. Unfortunately, however, there is currently no support for it in Linux. Some sources say that this is simply due to the lack of a driver though we suspect that the RTE may also lack support for it.

Option #3: Boot over the network…

The third option is to boot over the network instead of using a directly connected hard drive. This has been extensively tested by us and it is actually easier than you might imagine. We would go as far as saying that it's easier than using a hard drive. See BootingOverTheNetwork? for details on how to do it. There is a catch though, which is mentioned under Networking below.

Option #4: Prepare a LiveDVD…

The forth option isn't very practical. You would prepare a DVD image in much the same way that you would prepare any Linux LiveDVD but in addition, you would also include the RTE and its necessary files. To make the image bootable on the PS2, you would need to finalise the image using CDGENPS2 rather than the veritable mkisofs. For the rest, consult TheLessThanLegalMethods.

Option #5: Boot from a memory card…

The fifth and final option is even less practical. It is possible to boot from an initrd stored on a memory card. As mentioned above, standard memory cards only hold 8MB. You can get larger ones but we're not going to be breaking any records here. No memory card is big enough to hold a Gentoo installation and the system would be read-only too, limiting its usefulness. This option is really only good for "rescue" situations.

Networking

There are basically three options for networking. Slimline PS2s have built-in network adapters. Older PS2s can use the official Sony network adapter. Any model is capable of using a USB-based network adapter. However, there is a problem. The driver for the official adapter (both built-in and external) is horribly slow. While the adapter seems to perform at 100Mbps speeds on homebrew software outside of Linux, these speeds drop to below 10Mbps while inside Linux. USB-based network adapters may offer better performance but you'll still be limited to just 12Mbps because of USB1.1.

Software

So that's the hardware dealt with but what about the software? For some people, this may the hard part (no pun intended). You may be wondering why since Linux is free (as in beer) and we are providing you with an alternative distribution to the one included on the official DVDs. The problem is that Sony never intended us to run Linux directly on the hardware, probably in an effort to prevent piracy and such like. Instead, they built an RTE (run-time environment) to provide an abstraction layer between Linux and some of the real PS2 hardware. For obvious reasons, this RTE is not open source. It isn't freely available either, simply because booting it in a legal way requires it to be on a bona-fida PS2 disc. The good news is that the official DVDs are still sold along with the monitor adapter from linuxplay.com to users in Europe, Africa, India and the Middle East for the reasonable price of €25 plus delivery and tax. Chewi acquired his copy from there but he believes there aren't very many left so grab yours while you can. If you live elsewhere or if linuxplay.com have sold out by the time you read this then, short of spending a fortune on eBay, your only remaining option is to obtain a copy of the first DVD illegally. The first DVD is the one containing the RTE. The second DVD isn't required. Please do not ask where you can download a copy of the first DVD from. It is available in the usual places. Once you have it, you need to follow one of TheLessThanLegalMethods.