IRX Files for Playstation 2

Edit on Github | Updated: 25th March 2021

Introduction

If you are interested in the Playstation 2, especially reversing or developing games for it, you will eventually come across files with the .IRX extension.

What are IRX Files?

IOP Relocatable eXecutable (IRX) are the library files that you can dynamically link your application code to and will run on the I/O Processor (IOP) in the PS2. So they are the result of compiling C/C++ code targetted to run on the Playstation 2’s I/O processor, the code is compiled into MIPS R3000A Assembly and the. assembled to create the final IRX file.

What are they used for?

Most IRX files are used for Input devices, such as the joypads, Light Guns, Eyetoy, Memory Cards etc, this is why they run on the Input/Output processor. However as the processor is just a standard general purpose MIPS processor any code can technically be put in an IRX file as long as it doesn’t need to be particularly fast.

How are they used?

You can load an IOP Module from Emotion Engine code using one of the following API commands:

• sceSifLoadModule()
• sceSifLoadModule()
• sceSifLoadStartModule()
• sceSifLoadStartModule()
• sceSifLoadModuleBuffer()
• sceSifLoadModuleBuffer()
• sceSifLoadStartModuleBuffer()
• sceSifLoadStartModuleBuffer()

Where do I find them?

You should be able to find some of these in the MODULES folder of a Playstation 2 disk (but the folder depends on the disc).

What are the known IRX Modules?

‘Official’ modules are modules provided to game developers in the official Sony PS2 Dev Kit. Note that more modules than the ones marked below might be official.