Java ME Core

[Ciocolici]

Hey, guys, I was wondering, where are the Java ME Cores in Retroarch?
I can't find them as DLCs or "in-app". The internet says RetroArch should have "SquirrelJME". But I can't find it..

I also heard there is a "FreeJ2ME" Emulator which works best, but not as core for RetroArch. In case there is no way to install a Java ME Core on RetroArch, is "FreeJ2ME" the best emulator out there?

EDIT: I did not manage to make SquirrelJME work, but I finally managed to get the .dll, .jar, and .info files for the FREE2JME core. I can load the core, but I can't load content.... I get the new window error:

"Java Virtual Machine Launcher Error: Unable to access jarfile C:\Program"

[Fili]

It doesn't exist on Steam yet but you can get it directly from their repository and it's compatible with the Steam version as it's the same one you get with Standalone Retroarch.

https://buildbot.libretro.com/nightly/windows/x86_64/latest/squirreljme_libretro.dll.zip

Place it in the "cores" folder.

[Ciocolici]

awesome! thank you so much!

[Ciocolici]

Publicado originalmente por Fili:

It doesn't exist on Steam yet but you can get it directly from their repository and it's compatible with the Steam version as it's the same one you get with Standalone Retroarch.

https://buildbot.libretro.com/nightly/windows/x86_64/latest/squirreljme_libretro.dll.zip

Place it in the "cores" folder.

uhm, I downloaded it, and put it in the cores forlder, but it is not being seen in RetroArch for some reason

EDIT: All good. I needed the linux one. I found it.

[Ciocolici]

Publicado originalmente por Fili:

It doesn't exist on Steam yet but you can get it directly from their repository and it's compatible with the Steam version as it's the same one you get with Standalone Retroarch.

https://buildbot.libretro.com/nightly/windows/x86_64/latest/squirreljme_libretro.dll.zip

Place it in the "cores" folder.

It seems that core does not work, not on Linux neither on Windows, not as nightly neither as stable version. It only gives an image, in RetroArch, saying it is a work in progress and it is expected to be done in 2023.

I will try Free2jme

[Fried Brains]

don't forget cores need .info files
https://buildbot.libretro.com/assets/frontend/info.zip
.info files go in info folder on windows and in cores folder on linux

[Ciocolici]

Publicado originalmente por Fried Brains:

don't forget cores need .info files
https://buildbot.libretro.com/assets/frontend/info.zip
.info files go in info folder on windows and in cores folder on linux

I cam completely confused. I just can't make it work, with our without your info file.

As of FREEj2me, I can't manage to install/download it through the instructions of the github. ( https://github.com/hex007/freej2me/tree/master )
Oh man...... Why is there not one place with a guide of either of the two cores?

[Fried Brains]

inside the zip file is the info file you need. Unzip info.zip into the info folder. On windows Put core .dll in core folder and .info in info folder on Linux they both go in cores folder and .dll is .so

[Ciocolici]

Publicado originalmente por Fried Brains:

inside the zip file is the info file you need. Unzip info.zip into the info folder. On windows Put core .dll in core folder and .info in info folder on Linux they both go in cores folder and .dll is .so

I did understand that part, but the core still doesn't work. When I try to load it it gives me an image saying it is under development. If I try to load a game jar file it is not seen.

[Ciocolici]

Publicado originalmente por Fried Brains:

inside the zip file is the info file you need. Unzip info.zip into the info folder. On windows Put core .dll in core folder and .info in info folder on Linux they both go in cores folder and .dll is .so

I managed to get the .dll file and .jar for the freej2me cores, and the .info from your website, I manage to load the core, but when I try to load content I get out of RetroArch and get this error in a new window:

"Java Virtual Machine Launcher Error: Unable to access jarfile C:\Program"
o.O

[Fried Brains]

Some cores also need system files in the system folder. Load a core then click 'Information> Core Information', if it says firmware missing then put the missing files in the system folder, restart RetroArch and see if it says firmware present. FYI: when thru load content first then select a core

most cores need 3 things:
.dll in core folder
.info in info folder
firmware in system folder

[Ciocolici]

Publicado originalmente por Fried Brains:

Some cores also need system files in the system folder. Load a core then click 'Information> Core Information', if it says firmware missing then put the missing files in the system folder, restart RetroArch and see if it says firmware present. FYI: when thru load content first then select a core

most cores need 3 things:
.dll in core folder
.info in info folder
firmware in system folder

I am trying with all 3 of them. Free2jme won't work with .dll system file on pc, neither with .so file on my Steam Deck
I am losing way too much time with this that it is worth already...
As with the squirrel one, I can't find any System file anywhere on the internet.... I have the core and the info, but no the system one, if it has one

[Fried Brains]

Edit: says squirljme.sqc is optional, sorry for confusion, just realized I didn't read well and you already had a .info file

[Ciocolici]

Publicado originalmente por Fried Brains:

says you need to put squirljme.sqc in system folder

https://archive.org/download/retroarchbiospack1.0312020/Retroarch%20BIOS%20Pack%20%2804-23-2023%29.zip/system%2Fsquirreljme.sqc

Downloaded, put it in system (yes, the core and the info are also in their right places) and trying to either load the core or load content brings this up: https://imgur.com/a/j9sfYjI loading endless stuff like that in the screenshot.

I think I am giving up and will try again as soon as there is one of the two cores officially as DLCs on Steam. I've already wasted way too much time than this is worth. Nonetheless I thank you very much for trying to help me out!

[Phobos]

Any progress on this on your side ?

I'm facing the same error on Win 10 x64.

Not sure what's wrong.

EDIT: Okay, I managed to make Free2JME work.

I tried to download it already built from Github first, but it just doesn't work, I compiled it myself. It's not difficult, and the guide on Github is easy to understand.

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For windows: To build the libretro core for windows, first you'll need mingw, or MSYS2 64. This guide uses MSYS2 as it's easier to set up and works closer to linux syntax.

Download MSYS2-x86_64 and install it on your computer.

By default it will create a linux-like 'home' folder on C:\msys64\home\ and will put a folder with your username in there.
This is where you have to move the freej2me folder to, so: C:\msys64\home\USERNAME\freej2mefolder for example.

With the folder placed in there you can build the core, open the MSYS2 UCRT64 terminal from your pc's start menu, and run the following commands:

# Installing 'mingw-w64' and 'make' on msys2
> pacman -S mingw-w64-ucrt-x86_64-gcc
> pacman -S make

# libretro core compilation
> cd freej2mefolder/src/libretro
> make

This will build freej2me_libretro.dll on freej2mefolder/src/libretro/, which is the core libretro will use to interface with freej2me-lr.jar.

Move it to your libretro frontend's cores/ folder, with freej2me-lr.jar on system/ and the frontend should be able to load j2me files afterwards.

To download free2jme-lr.jar :
https://github.com/AShiningRay/freej2me/releases/download/FreeJ2ME_10122023/freej2me-lr.jar

Also, download this package and extract freej2me_libretro.info to your folder :
Retroarch/info

https://buildbot.libretro.com/assets/frontend/info.zip

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