The complete guide to configure cores

How to add new emulation cores to Age of Joy (AoJ).

We’ll use as an example the SwanStation core, which is an amazing Sony Playstation core which runs fantastically in AoJ.

Basic core installation

The first (and mandatory) step is to add the emulation core itself to the AoJ filesystem. AoJ uses Libretro core binaries targeting the arm64-v8a architecture, which can be found here: https://buildbot.libretro.com/nightly/android/latest/arm64-v8a/

This repository features the latest “nightly” builds used in RetroArch, and is exhaustive and always up to date.

So, the installation procedure is :

• Download swanstation_libretro_android.so.zip
• Unzip
• Copy swanstation_libretro_android.so to the \cores\ directory of AoJ.

The \cores\ folder is where libretro core binaries reside.

It is important not to rename the .so file and use the original filename. The core name is derived from the filename and will be set to the string portion preceding “_libretro_android.so”. In our example, the core name that will be used further will therefore be “swanstation”. If we were using core mednafen_saturn_libretro_android.so the core name would be “mednafen_saturn”…

Once you have added a core to \data\ it will be autodetected by AoJ on startup and you can reference it in you cabinets:

description.yaml:

core: swanstation

AoJ will also automatically create a subdirectory named after the core in the \download\ folder for your games for you to keep things nice and tidy.

Note that you can actually update internal AoJ cores (like fbneo) by specifying a more up to date binary for that core. It will take precedence over the bundled one.

Getting familiar with the core

While some cores work great out of the box, some others need extra steps to function. It’s therefore a good idea to get familiar with the core’s documentation.

Three good resources are:

• The official libretro documentation which shows basic info for many cores: https://docs.libretro.com/guides/arcade-getting-started/
• The documentation from Recalbox, a distribution of Libretro for Raspberry Pi etc: https://wiki.recalbox.com/fr/emulators/consoles/playstation-1/libretro-swanstation The website is in french, but it’s the most exhaustive documentation around and well worth the look.
• The source code for the core. This is the ultimate source of truth, but it’s for advanced users, not the faint of heart :) https://github.com/libretro/swanstation

The important information you’ll want to spot are mainly :

• The file format support for the core (does it support zip files ? does it support chd files ? what are some specific file extensions used by the core ?…)
• The need for specific system files (BIOS requirements, name of the files and where to put them…)
• Core configuration options (discussed later)

System files

Some cores will not work without specific system files.

In the case of SwanStation, as the RecalBox website informs up, the following files are needed: scph5500.bin, scph5501.bin, scph5502.bin. You’ll need to obtain these files one way or another (don’t ask me how or where to find them) and copy them to the \system\ folder in AoJ.

The \system\ folder is where libretro core system files reside.

Core configuration

You may want to customize the core by specifying environment configuration.

In the case of SwanStation for example, memory card support is not enabled by default. A look at the core documentation tells us enabling memory card support is done thru the swanstation_MemoryCards_Card1Typesetting.

We can act on the core configuration by adding, and tweaking a yaml configuration file in the \configuration\cores\ folder.

The \configuration\cores\ folder is where libretro core configuration files reside.

In our example, we’d drop a file named swanstation.yaml in the \configuration\cores\ folder:

environment:
   properties:
     swanstation_MemoryCards_Card1Type: PerGameTitle

Some cores will work without a configuration file. Others will need tinkering and use of specific options.

For example, the mamearcade core will not work in AoJ without setting mame_media_type: rom

Core configuration is handy to customize the experience to your likings. For example, you may want to set settings such as these to tweak the fbneo core:

environment:
   properties:
     fbneo-force-60hz: enabled
     fbneo-samplerate: 48000
     fbneo-sample-interpolation: 4-point 3rd order
     fbneo-fm-interpolation: 4-point 3rd order
     fbneo-lowpass-filter: enabled
     fbneo-neogeo-mode: UNIBIOS

Using an installed core in your cabinets

Using a core in a cabinet is very simple, you simply have to specify the core name in the description.yaml file.

description.yaml:

core: swanstation

You may also specify core configuration settings directly in the description.yaml for your specific cabinet (for a light gun game, for instance).

The syntax is exactly the same as global core configuration files

environment:
   properties:
     swanstation_MemoryCards_Card1Type: PerGameTitle

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