Use FEX to make AppImages of x86 only binaries

[Samueru-sama]

We basically need to be able to build fex for archlinuxarm.

There used to be a PKGBUILD of this many years ago but it was removed...

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cc @Link4Electronics @crueter

[Samueru-sama]

I cannot even find a .deb or binary to have an idea on how this works and what dependencies it needs 😹

[crueter]

The Asahi overlay contains the package. May be of use: https://github.com/chadmed/asahi-overlay/tree/main/app-emulation

[Link4Electronics]

I was making the appimage
You can test with qemu
Using qemu userspace (can be with the qemu appimage that we made), qemu-aarch64 ./fex-emu*.appimage

https://github.com/Link4Electronics/FEX-Emu-AppImage

Instructions how to use fex is here https://wiki.fex-emu.com/index.php/Development:Setting_up_FEX, main executable is FEX and can use FEXBash, the appimage that was trying to make can download the rootfs but is not finding it
FEXRootFSFetcher can be used to download the rootfs, FEXConfig is a GUI to config it

If it wasn't for the issue about it not finding the rootfs, it would be like qemu-aarch64 ./fex-emu*.appimage FEXBash ./neverball*x86_64.appimage as example just to see if it's really working
but unfortunatelly it's not finding the rootfs, FEx-emu allow to use the rootfs inside the suashfs file or extracted, but I read that people has more succes in rootfs extracted mode

[Samueru-sama]

Oh woah, that's great!

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My idea is the following:

Take the x86 AppDir but instead of using the x86 uruntime, we use the aarch64, this all can be done from the x86 runner.

Then the AppRun would change exec "$TO_LAUNCH" "$@" to instead exec "$FEX" "$TO_LAUNCH" "$@" with the var being the path to the fex binary.

[Link4Electronics]

On my postmartketOS phone, have fex-emu installed, but I need to run it inside a rooted distrobox container, then can launch steam like FEXBash steam and it launches it (the recommended rootfs is ubuntu extracted)

[Samueru-sama]

On my postmartketOS phone, have fex-emu installed, but I need to run it inside a rooted distrobox container, then can launch steam like FEXBash steam and it launches it.

check the discord pls

[crueter]

Also, you will need muvm in the AppImage for 16KB page systems. Should be easy to detect in the AppRun.

[Link4Electronics]

oh, now I get what you want to do, you want to get rid of aarch64 appimages?
:sad:
fex doesn't perform that well compared to a native arm64 appimage, and fex has another issue that they plan to drop support for ARMv8.2 and only keep for ARMv8.4 and up. My smartphone is ARMv8.2 (snapdragon 845), appimages will stop working then for users with old armv8

[Samueru-sama]

oh, now I get what you want to do, you want to get rid of aarch64 appimages?

The title of the issue literary says: Use FEX to make AppImages of x86 only binaries

x86 only binaries are apps like epsxe.

[Link4Electronics]

ohhhhh, okay, you wanna try to make appimages that are x86 only, to work with arm64 too
that's lovely!!! I'm down for it.

[Samueru-sama]

Alright feature has been added and a aarch64 release of epsxe with it has been made:

https://github.com/pkgforge-dev/ePSXe-AppImage/releases

Right now this depends on the FEX on the system since the appimage is not ready.

[crueter]

Will test 2nite if I remember

[Link4Electronics]

Moved fex-emu appimage repo to pkgforge, but it's not working properly as already mentioned it