(WiiU) Update WUT and add RetroArch target for WUHB files (Aroma enviroment)

[ShadowOne333]

Description

A few weeks ago, the WiiU received a new form of CFW called "Aroma", which runs apps under the WUHB extension.
What this is effectively creating a coldboot option for the system, and also adds a bunch of features and other things as plugins directly on boot.

One of said options is the ability to be able to run Homebrew apps straight from the WiiU's home menu, as if it they were official apps on the system. This way, each homebrew app can be threated as their own app within the system.

In order to make RetroArch compatible with this setup, an update of WUT is required, as well as having a TV logo image (tv_splash.png, 1280x720), the gamepad image (drc_splash.png, 854x480) and the home menu image (icon.png, 132x179).
With that, creating the WUHB file out of the rpx should be easy enough by following these recommended instructions after updating both wut and wut-tools:
https://gbatemp.net/threads/release-aroma-environment-for-wii-u.618474/page-17#post-9940681

Expected behavior

Updating to the Aroma-friendly WUHB format would allow for RetroArch to be recognized and properly loaded on the system, alongside their proper boot logo, icon, and message.

Actual behavior

RetroArch currently cannot run under this environment since; while Aroma does have support for RPX apps, upon loading it simply stays on a black screen.

[vgmoose]

Maschell added the following info in the Aroma discord about rpx-loading:

Retroarch currently loads a core by loading into a special area in the memory and then using some old HBL magic to launch it. With aroma we can't use this region, because it's reserved for aroma and it's plugins. You can load a .rpx via Aroma though, Mocha_LaunchRPX is too "low" level, but librxpload (https://github.com/wiiu-env/librpxloader) could be extended to load a different .rpx which is inside the .wuhb.

[grockk]

I wonder if the vWii retroarch could be updated to support the sign_c2w_patcher in a forwarder or inject. We'd be limited to 480p but for retro games on Wii U that seems like it'd work pretty good enough. And then it would be compatible with Aroma.

[ashquarky]

I think I'm going to have a go at a wut port, at least depending on my availability over the holidays... I wrote up a bit of a game plan that might work but there are a few key questions:

• Merging changes to all the cores and the frontend and the docker image at the same time is going to be a pain. Do we try and make a new platform= (wiiu-wut alongside wiiu?) to ease that or do we just wait for a release and then merge immediately after? I would prefer the latter but I don't know how RetroArch's release cycle works
• Should wut be added in-tree? Since all the builds run on Docker now I don't see a reason to (especially considering that wut versions are somewhat tied to devkitPPC versions) but since libogc is in-tree it's worth asking

cc @LibretroAdmin @gblues

[LibretroAdmin]

wiiu-wut - as in a new platform/target - seems like a good idea. Overall I'm fine with whatever @gblues thinks we should do.

Should wut be added in-tree? Since all the builds run on Docker now I don't see a reason to (especially considering that wut versions are somewhat tied to devkitPPC versions) but since libogc is in-tree it's worth asking

How big is it ?

I would prefer that we avoid adding WUT in-tree. We should consume WUT artifacts, and we can control the version we get without resorting to completely duplicating the source tree. Adding it in-tree creates a bunch of toil. If we needed to add functionality to WUT, it should be contributed upstream. Which yes, may take a little longer, but it means that more projects than just RetroArch benefit.

I am in favor of having a separate build target. I propose that we just call it wut (which already implies wiiu). I also propose that once all cores have successful wut builds that the wiiu target builds be left deprecated. This is because the whole point of WUT is to provide a stable dev toolkit and I have no interest in maintaining 2 builds indefinitely.

[gblues]

whoops, I was signed into my work github account. ^ that's me. sorry!

[ashquarky]

I will mention that my current draft of RetroArch (frontend) does not keep both codepaths - it assumes wut.

Also, the differences in the cores might not be that bad - snes9x at least was just some (backwards-compatible) compiler flag changes; thus for that core a new target isn't needed. I assume other cores will be more complicated though.

(specifically -mwup needs to be replaced - I swear I've PRed this to some cores before but I can't find it now..)

[ashquarky]

For those following along:

• RetroArch tree: https://github.com/ashquarky/RetroArch/tree/wiiu-wut
• toolchain (docker): https://git.libretro.com/quarky/libretro-build-wiiu/-/tree/wut

Right now it mostly works under Tiramisu, aside from some long load times. Toolchain container is not well-tested, and cores still need to be updated.

[ashquarky]

Just submitted the makefile changes for snes9x - with luck, all the cores will be like this. The core now builds fine on both old and new devkitPPC (with and without wut) at the cost of some extra meaningless warnings on the old version.

[ShadowOne333]

I didn't see the last messages, this all sounds fantastic.
Did the recent commit that got merged for the makefile changes add .wuhb cores for RetroArch on WiiU?
Or is that still WIP?

[ashquarky]

As an update for everyone:

• Basically everything is working except for Salamander, which bootloops for some reason
• I've had to disable libfat for the SD card since many Aroma modules mount the SD using the Cafe driver, and it's unsafe to have two drivers mounting the same filesystem at once. This makes startup really slow so I may re-enable it on Tira only. Playlists might be broken due to sd: becoming fs:/vol/external01.

I didn't see the last messages, this all sounds fantastic.

Did the recent commit that got merged for the makefile changes add .wuhb cores for RetroArch on WiiU?

Or is that still WIP?

wuhbs aren't in for this initial porting stage, though it may end up being a solution to the loading time issue.. we'll see! I'll probably try and land initial support first.

[ShadowOne333]

As an update for everyone:

* Basically everything is working except for Salamander, which bootloops for some reason

* I've had to disable libfat for the SD card since many Aroma modules mount the SD using the Cafe driver, and it's unsafe to have two drivers mounting the same filesystem at once. This makes startup really slow so I may re-enable it on Tira only. Playlists might be broken due to sd: becoming fs:/vol/external01.

I didn't see the last messages, this all sounds fantastic.
Did the recent commit that got merged for the makefile changes add .wuhb cores for RetroArch on WiiU?
Or is that still WIP?

wuhbs aren't in for this initial porting stage, though it may end up being a solution to the loading time issue.. we'll see! I'll probably try and land initial support first.

That's awesome! Really looking forward to what you come up with for the RA rework for WiiU. Hope it all goes well with the last tidbits of nuances