Open PS2 Loader (OPL)

Open PS2 Loader (OPL) is a homebrew application loader that loads PS2 games and applications from digital devices.

General Information

Installation

You can download the OPNPS2LD.ELF from GitHub directly and launch it from wherever you want. You can also copy it to your memory card.

Otherwise, you can use the PSU file from the PS2 Homebrew Store, which installs OPL as an SAS compliant app to the memory card, following the Universal Memory Card Structure.

In either case, you need to install or launch it using LaunchELF.

How it works

OPL works by loading special software to both the Emotion Engine (EE) and the I/O CPU, which interfere in the game normal behavior. The IOPCORE, which runs in the I/O(PS1) CPU is in charge of replacing the CDVDMAN module amongst others. Its main purpose is the CDVDMAN module replacement, since this one is in charge of disc tray I/O. The replacement module is coded to load of a digital device (USB, network, HDD, MX4SIO, iLink). For all intents and purposes, the game believes it is loaded from the disc drive.

The EE program (known as EECORE) is in charge of hooking up several syscalls, and interfering in certain operations that would remove the IOPCORE (such as rebooting the I/O CPU, or uploading an IOPRP image to the I/O CPU).

Supported Devices

OPL supports loading media from different devices, each having their pros and cons:

USB:
- easy to set up
- cheap (only USB drive required)
- slow loading
- mediocre compatibility
MX4SIO:
- easy to set up
- still cheap: MX4SIO, essentially a SD card to Memory Card adapter, required (can be bought from ebay for cheap) + SD card
- slightly faster loading
- slightly better compatibility
HDD:
- easy or a bit more work to set up, depending on wheter the drive is formatted as exFAT or APA
- rather costly: HDD/SSD required and Network Adapter; original adapters are used for best compatibility but need to be modded for SATA support
- only works on Fat consoles or SCPH-700xx consoles with heavy modifications, other Slim models are not supported
- fast loading (faster than disc)
- good compatibility
SMB share
- rather hard to set up
- Works by sharing a folder on a PC using the SMB protocol. The console needs to be connected to the PC. Essentially no extra cost if you already got a PC
- fast loading
- good compatibility
i.Link
- Requires i.Link (IEEE 1394/FireWire) storage device
- still in early stages, mediocre compatibility
- fast loading
- only on Fat consoles up to SCPH-390xx, later Fat and all Slim models don't have the port

Folder Structure

OPL uses a specific folder structure for files.

📂OPL drive
┣ 📂APPS
┃ ┗ Your homebrew/ELF files go in here
┣ 📂ART
┃ ┗ Artwork for games and homebrew
┣ 📂CD
┃ ┗ CD games (700MB or less)
┣ 📂CFG
┃ ┗ .cfg files for games. These files can contain information about your games like a description, developer, release date, etc.
┣ 📂CHT
┃ ┗ Cheat files for games in raw .cht format
┣ 📂DVD
┃ ┗ DVD games (more than 700MB)
┣ 📂LNG
┃ ┗ language files for OPL
┣ 📂THM
┃ ┗ Themes
┗ 📂VMC

┗ Virtual memory cards

This structure is generated automatically when OPL is started and a device is connected that doesn't have these folders yet. If you are using a new drive and already want to add files before connecting it to the PS2, you can also create the necessary files yourself.

Your game backups will go in the CD and DVD folders depending on what disc type they had originally come on, with CD games being 700MB or less in size. If you have games larger than 4GB and are using FAT32, use the Splitting Games section on this page to deal with them.

Compatibility Issues

See the updated compatibility list (OPL-CL) or alternatively the OPL Game Compatibility List on PS2-HOME.

Every game is different. The PS2 library has more than 4,000 games, all of which are coded with different versions of the Sony SDK, on different years, by different companies. To worsen things, the IOP core has to maintain the smallest footprint possible due to the limitation of 2MB of RAM. The only PS2 models with extra RAM are the development tools and the PSX DESR, so the RAM issue will be a problem for 99% of the PS2 models around the world.

RAM consumption is also tied to the device that is hosting the game image. The most demanding devices are SMB network and USB. And the ones which consume the least of IOP RAM are MX4SIO and internal HDD.

Later slims (SCPH-75xxx+) had slightly worse compatibility. Fortunately, in 2023 OPL got support to operate the XPARAM module, which is in charge of changing the compatibility configurations of the DECKARD emulator. Ensuring compatibility with the ~286 games listed on the PS2TV internal compatibility list (the newest one), no matter which slim version and region you're using.

In-Game Reset (IGR)

By holding +++++ at the same time, it will trigger the in-game reset (IGR) feature and return you to OPL from a running game.

Setting up OPL

USB & MX4SIO SD Card Setup

The OPL 1.2.0 beta versions and newer support exFAT and FAT32, with exFAT being the recommended one. If you are using OPL 1.1.0 or older the USB or SD card must be formatted as FAT32, which means games larger than 4GB will need to be split.

If your drive doesn't already have the DVD and CD folders, create them on the root the device and add your games. If you have games larger than 4GB and are using FAT32, use the "Splitting Games" section on this page to deal with them.

Using SD cards via MX4SIO

New in OPL 1.1.0 is support for MX4SIO Block Devices which provides a faster way to load backups than USB while maintaining the same compatibility and file structure.

To enable SD card Block Device support in OPL:

Format your SD card as exFAT or FAT32. Use the MBR partition table in both cases.
Go to Settings and change BDM Start Mode to Auto (Auto seems to freeze often on release 1.1.0) or Manual: press , press down once then press again.
Go to the right to Block Devices, press X, go to MX4SIO, press to enable, go down to OK press . (Do not press to go back, it will forget the settings!)
- Optional: change default menu to "BDM Games", go down to OK, press
Select Save changes on the menu screen
Press to go to games list
Go left to select BDM, If you selected the manual start mode, press to Start Device
Select your game and use OPL as normal!

Using USB drives

You can also connect USB drives using the consoles front ports. The device can be a USB thumb drive, HDD or even SD card to USB adapter. Games load slower and have more compatibility issues via USB, so if possible, use one of the other methods.

Don't forget to split your games if you're using FAT32 and not exFAT.

Format your USB drive as exFAT or FAT32. Use the MBR partition table in both cases.
Go to Settings and change BDM Start Mode to Auto (Auto seems to freeze often on release 1.1.0) or Manual: press , press down once then press again.
Go to the right to Block Devices, press , go to USB, press to enable, go down to OK press . (Do not press to go back, it will forget the settings!)
- Optional: change default menu to "BDM Games", go down to OK, press
Select Save changes on the menu screen
Press to go to games list
Go left to select BDM. If you selected the manual start mode, press to Start Device
Select your game and use OPL as normal!

HDD Setup

Using an HDD has good compatibility and short loading times, usually shorter than when playing from disc. You also need a Network Adapter. The original ones only support IDE drives. Since the distance between the IDE and power connector is not standardized, not all IDE drives from back in the day will work. There are also generic adapters that go from IDE to SD cards or SATA, however fitment will vary. The best option is to mod an original Network Adapter to have a SATA connector directly, which will allow a modern full size 3.5" drive to fit.

There are also aftermarket Network Adapters which lack the actual network features, but HDDs do work. They often already come with a SATA port meaning that it's cheaper to get one of these instead of an original one and modding it. However, compatibility is not as good as the original ones.

The HDD can be formatted 2 ways:

The OPL 1.2.0 beta added support for exFAT formatted drives, making the whole process easier and also allowing you to install games by drag and drop without an extra piece of software.
The other option is to format the drive using APA, Sony's partition scheme. Using APA is the original supported way for using HDDs. You will need a software like PFS-Batchkit-Manger (Windows) or hdl_dump (Linux/Mac) to install games. You also need access to a version of LaunchELF to format the drive as APA.

exFAT formatted drive

Format your drive as exFAT, MBR and GPT are supported. 512 byte sector size is recommended.
Add your games to the DVD and CD folders respectively.
In OPL, go to settings and set BDM Start Mode to Auto.
Press right to BDM Devices and press , then scroll down to HDD (GPT/MBR) and set it to on. Press ok at the bottom, then again ok at the bottom. Do not press , since this will not keep your settings.
Change Default Menu to BDM Games.
On the main screen, select Save Changes at the bottom as well.
Now you can press to return to your games list. Your games will appear on the BDM section on the left. If you have multiple devices with games connected, use the left and right on the dpad to select the HDD.

APA formatted drive

Format your drive using a version of LaunchELF.
In OPL, go to settings and set HDD (APA) Start Mode to Auto.
Change the Default Menu to HDD Games.
Select Save Changes at the bottom.
Now you can press to return to your games list. After you installed some games, they will appear on the HDD section.

todo

i.Link Setup

todo

Splitting Games

Games larger than 4GB on USB will need to be split if the SD card or USB disk are formatted with FAT32. If you have used OPL 1.2.0 or newer and have used exFAT you do not need to split large games.

Download a splitting tool such as USBExtreme, and extract the contents to your Desktop and launch it.
Mount the ISO that you wish to split by right-clicking it and selecting "Open with..." > Windows Explorer. If you are not using Windows 8 or 10, you will need to use a tool such as Daemon Tools Lite to mount it. Take note of the drive letter that is assigned.
Navigate to where you extracted USBExtreme.exe and open it.
Click on the drop down menu under "CD/DVD ROM Drive" and select the drive letter of the mounted ISO.
Click on the drop down menu under "Media Type" and select "DVD".
Click on the drop down menu under "Hard Drive" and select the drive letter that corresponds with your USB storage device.
In the "Game Name" field enter the name of the game you will be splitting.
Click the "Start" button, then click "Yes" to start the install. The program will begin splitting the game and will copy the split files to the root of your USB storage device. The games will be playable from the default location.

Applying Themes

Themes are distributed as a folder with images and other files inside of them. Simply place the whole folder in the THM folder of your OPL installation, and it will appear as an option under "Display Settings" under the "Theme" option. Simply choose the new theme and save changes.

Themes may be designed for specific screen aspect ratio (4:3 vs widescreen) or for specific resolutions (480p or 720p). If the theme does not properly fit or is flickery, this is likely why. You can change your resolution and 4:3 / widescreen options under Display Settings.

Applying Cheats

Cheat files (.cht) can be created and copied to the CHT folder of your OPL installation. After copying the cheat file matching your chosen game's Game ID, simply press Triangle on the game and choose "Cheat Settings" and set "Enable PS2RD Cheat Engine" to On. Note that it will allow you to change "PS2RD Cheat Engine Mode" to "Select Game Cheats" but it is not functional. Cheats are enabled without any feedback on whether or not they applied.

A database of widescreen cheat files can be found on the PS2-Widescreen GitHub.

A video tutorial can be found on Filmire's YouTube channel. For more detailed information on cheats, see this PS2-HOME thread.

Adding Homebrew (APPS)

OPL also has the ability to launch homebrew ELF files from different media.

Installing Homebrew

In your APPS folder of your drive, create a new folder named after the program you want to add.
In that folder, add the ELF executable. It doesn't need to have the same name as the folder.
Also add a text file named title.cfg.
Open the file and add the following 2 lines
- title=NAME
- boot=ELFNAME
Replace NAME with the name you want the application to be shown as and ELFNAME with the name of the executable.
For example, the file could look like this:
- title=LaunchELF
- boot=BOOT.ELF
Now your apps can be started from OPL!

Adding Artwork

You can create your own artwork or download some online. For example, you can use the cover pack by Berion.

In OPL, go to Display Settings and enable the Cover Art option.
Go down to OK and then to Save Changes.
On your PC, go to your ART folder and add a .png file for the your app.
Rename the image file to the exact same name as the corresponding ELF file including the file extension (.ELF), followed by _COV.png.
- For example, rename your image for LaunchELF to BOOT.ELF_COV.png.
Now you'll have artwork for you homebrew apps!

PC Management Tools

Historically, OPL Manager (OPLM) was the most popular, but it requires your PS2 to have a HDL server running, which was removed from OPL in favor of a NBD server. OPLM can still be used if another tool on your PC is connected to the console via NBD and you choose "Local PS2 HDD" mode.

There exists multiple PC tools able to interact with OPL to install games, update cover art and metadata, setup cheats, and more. PFS BatchKit Manager is one such tool with full usage instructions on its GitHub.

Troubleshooting

Game won't load

If the game won't load, or loads to a white screen, check the following:

That the game ID matches the one found on redump's database. You can try to set the correct ID via Game Settings and see if it fixes the game. If the game reads "666.66", it is likely a modified copy, such as a translation or other hack, so you may want to provide a clean dump of the game with the correct ID.
That the source ISO hashes of the game match the ones found on redump's database.
If the game was installed to the hard drive using WinHiip, use HD Loader Game Installer.
Check the OPL Compatibility List to see if any specific combination of settings may be required to work.
Try resetting all game options to default. PadEmu especially can break many games when enabled.

Exiting OPL just reboots it

From the menu, choose Exit and press to confirm. Immediately hold , and it should return you to LaunchELF.