Homebrew Need help with vWii gc adapter for project M

[huma_dawii]

How to make this work? What files I need!


I downloaded a zip file called wup-028-bslug-v1.01
put it in the SD card, loaded it with Homebrew Channel and it doesn't work... where is the USB Adapter supposed to be plugged In the back? Is there a way to make this work from a wbfs file ?


EDIT: I finally read the whole thread just to find out it is currently NOT WORKING. And this projects hasn't been updated in like 3 months....

:'(

 

[JacobM]

I finally read the whole thread just to find out it is currently NOT WORKING. And this projects hasn't been updated in like 3 months....

:'(

It is working. There is an implementation specifically for CTGP (embedded in the mod), an implementation for all* disk based games (https://github.com/Chadderz121/wup-028-bslug), and an implementation for USA Brawl / Project M (https://github.com/wilm0x42/wii-gc-adapter-inject). All 3 implementations require a physical disc and work! I’ve tested them fairly thoroughly myself.


*no compatibility list exists, bslug implementation is known to not work with Brawl

 

[huma_dawii]

It is working. There is an implementation specifically for CTGP (embedded in the mod), an implementation for all* disk based games (https://github.com/Chadderz121/wup-028-bslug), and an implementation for USA Brawl / Project M (https://github.com/wilm0x42/wii-gc-adapter-inject). All 3 implementations require a physical disc and work! I’ve tested them fairly thoroughly myself.


*no compatibility list exists, bslug implementation is known to not work with Brawl

Yeah sorry, I meant the USB Loader version, I did in fact try the Wii GC adapter inject with the gecko os and it works, but the wup028blsug doesn't work with Brawl, just with MKWii.

It's something I guess. :v

 

[freshkilz]

Is this project now dead?

 

[krueger96]

Is it possible to play wiiware games with this? what about imports? i normally use wiiflow to play the latter, any chance it'll work? It's mostly for curiosity's sake since i could just use a wiimote adapter with my gamecube controller... but there are certain games (very few actually) that only support the GC controller or wiimote, no classic controller

 

[Deleted User]

I heard this can be used with ctgp-r. How?

 

[dcx6723]

I heard this can be used with ctgp-r. How?

Just boot ctgp-r and plug your Gamecube controller, easy!

 

[Deleted User]

Just boot ctgp-r and plug your Gamecube controller, easy!

thanks!

 

[JacobM]

Welcome back @wilm0x42! Looks like we may get some development on this project again. Anybody have a USB Gecko to share? https://github.com/wilm0x42/wii-gc-adapter-inject

## Current State of Development (June 2019)
(Just gonna retrofit the wall of text from #5)

So, I sorta hit a brick wall last year in debugging this stuff and ultimately
got a bit too burnt out on it. (debugging stuff in a dormant hacking scene
can take a lot out of you ) However, I'm now returning to it, and starting
to retrace my last steps.

Where things left off, the overall functionality was pretty much finished,
only needing final polish, except for the one big issue of not working
with USB loaders. Turns out, USB loaders make the USB interface a LOT
harder to work with in a hack like this, and supporting both USB loaders
AND official disc makes things even harder. The main issue that halted
everything was that the hack would be working fine on dolphin emulator
in every way, but it would crash on console, with no good method of
debugging, since I don't have a USB gecko :/ (In the unlikely chance that
you're reading this and you have one that I can buy from you, PLEASE get in touch.

So yeah, sorry for the unannounced year-long hiatus

Going forward, I'm hoping I can find some way to hook into the game, on console,
while it's running, and poke around at the USB interface to see if I can coax
the right functionality out of it. (Normally the easiest/best way to communicate with
the wii from a computer, other than a USB gecko, would be the USB
ports themselves. But alas, that's the very subject of this debugging. :facepalm

https://smashboards.com/threads/wii...cube-adapter-beta.453431/page-2#post-23400582

 

[freshkilz]

Is this project still in development?

 

[Hello_switch]

Is there a possibility yet to play Bomberman Blast Wiiware with 8 players on Wii U (4 controllers Wii and 4 controllers GC on GC adapter) ? Thanks

 

[Famus484]

Hey everybody!

Has anyone tried the new project+ with this? I could not seem to get it to work, as wii launcher complained about too many lines in their gct code.
If I remember correctly, I might have had a similar problem using the GCT code here to try and make PM work on my 64 GB sd card.

I will try other configurations I can think of.

 

[geoGolem]

looks like the project has been abandoned but if it ever came to fruition it would be a great solution for making DDR dance pads work on wii u.. for DDR games on vWII.

EDIT: I ended up reading the entire thread to try and figure out what happened with this project... I found Cyan's post most informing about the challenges in making the GC adapter work for WII games on vWII:

The need to activate at least one ocarina has been fixed. I changed it to load gameconfig.txt only by enabling one hook type, which loads the geckoOS patcher sources.
So, if gameconfig.txt work fine with geckoOS itself, maybe the problem is the cIOS ?


I'm sorry I took this conversation midway, so maybe I might not understand what this patch is doing.
Is it a way to add gamecube pad support to Wii games, or is it a way to add HID USB support to wii games?

That's two completely different things.


If you are on wiiu, or using the official gamecube controller adapter, then it's NOT gamecube ! it's HID USB.
It works fine with nintendont because Crediar added HID USB Support to nintendont (and not to gamecube game !). Nintendont is loaded in memory and responsible for communicating with the USB. it then converts HID controller signal by writing the corresponding button value into the memory address where the gamecube game is expecting it. it acts as a gateway (interpreter more than emulator).

When you play a wii game, there's no program in memory doing this conversion HID->button writing to memory. The loader is not in memory anymore and can't act as interface between hardware and the game.

So, tell me what this patch is doing :
1. replacing Wii controller drivers with gamecube controller's driver ? (if it's a generic patcher, it should work only on games using the exact same controller driver version, and located at the exact same address, unless it's a "search&replace" patch)
or
2. replacing Wii controller driver with HID support writing HID value to memory like nintendont does?


If it's doing the first one, then you can only use your Wii and a real gamecube controller port.
if it's doing the second one, then you (might) need cIOS r53 to enable USB Port1 ! if you use cIOS it's limiting the available USB Port.


So, when you tried to connect the adapter on back bottom port of WiiU, did you use d2x r52 or r53?
try r53 please
I don't have a GC adapter to test.

I literally have no experience with wii/wii u homebrew etc.. but I was trying to think of a different solution since it would be much better to have a solution that doesn't require each individual game to be hacked..

I had a few things I am still confused about or would like more information about if possible:

1) Since WII VC injects on WIIU are able to use the gamepad as a classic controller, could something similar be accomplished for the GC adapter ports for WII VC injects -> i.e. make the USB GC adapter be recognized as native GC ports.

2) It might not be possible (I really have no idea what I am talking about), but since the vWII mode can't really be hacked to redirect GC I/O to USB HID without actually patching each individual game, could something not be done in WIIU mode -> I literally have no idea but I have heard of the ability to unlock the clockspeed for vWII injections or something which allows the vWII mode to work at higher WIIU clock speeds --> perhaps something could be done at the WII U level that would make the vWII be able to see the GC usb adapter as regular GC ports? I mea it would be awesome if there could be some redirection occurring at the WIIU level and the vWII simply just saw the GC ports... Again --> probably wishful thinking - I really dont know much of what I am talking about.

I realize its probably never going to happen at this point but adding back native GC ports or their corresponding functionality to the WII U vWII would make the vWII basically a complete WII replacement. I really appreciate al the work the community has done for the WII/WIIU. It really is amazing what people can accomplish..

 

[Famus484]

Alright, it's been a long time, and I really wish for it to be fully working, without brawl disc (and hopefully with large SD cards). First, I have since understood I had the wrong gameconfig.txt, so the mod works well with project+ (brawl disc inside wiiu).

Did anyone try making it work with Wii game injection? In another thread, I brought up that if we injected both Brawl ISO and autoboot of Gecko, we may be able to load this project+mods directly (since the physical drive is replaced with some kind of virtual drive containing the injected game, I'd expect we wouldn't run the same issues as with USBloaderGX). It would be just like Gamecube games injection, where we inject both the ISO (which appears as being in disc drive) and forwarder to Nintendont. For now, I have no means to implement that myself (maybe someone that knows Teconmoon's injector could fork it/add the functionality?). I want to though, any help with this would be really appreciated.

I had another idea: since for now we can't leave the injected game without rebooting to Wii U menu, we could use smash stack exploit to run GeckoOS (happens to be an elf) and load up both this project and the projectM/+. All that happens without exiting injected ''disc channel'', and so shouldn't kick us out back to Wii U menu.

The good news is I can actually run the exploit, gecko and Project+ (probably project M if I tried).

The less good news is that the exploit doesn't seem as stable here than with disk (for example, it freezes if gamepad is used as classic controller). Furthermore, even though I get no error message from gecko, I can't use GC controllers in Project+ (while I can if I run smash stack the same way using disk instead of injection.

It is not clear to me why it doesn't work here (USB access should be possible? Adapter works with injected Nintendont and CTGP). I don't know whether it's because it's ran through an exploit of a Wii Retail injection (in which case a proper homebrew injection would work), or if it's because USB access works differently in injection than in Wii mode (again, if it's the case, why does the same Nintendont app access adapter in both scenarios?). To distinguish, I'd test trying to run Nintendont directly from injected Smash Stack, but I don't know how to do so.

Anyways, here I am, again I have no experience or intuition with any of the source codes, any help would be so much welcomed, thanks.

 

[JacobM]

This is just about the only feature I can think of left for the Wii U in order to help it become the ultimate "retro" station for Nintendo.

Unfortunately, lots of ideas similar to those you mentioned have been tried over the years.

1. Wii game dol patching was attempted with no success (maybe some room for improvement)
2. Various c(ustom)IOS combinations (disk, USB, or SD) were attempted with no success
3. Booting from wiiVC into USB and SD loaders could not load ISOs due to locked IOS modules
4. Neek2o drive emulation was unsuccessful
5. The patch was determined to be very iOS module specific. https://gbatemp.net/threads/need-help-with-vwii-gc-adapter-for-project-m.498236/page-10#post-7906063 & https://gbatemp.net/threads/need-help-with-vwii-gc-adapter-for-project-m.498236/page-10#post-7924225

Pretty much yes, but the issue isn't technically with the cIOS, but with IOS itself; some IOSes have different USB interfaces, which are currently incompatible with the hack. The issue is that most (if not all) cIOSes are based off of newer IOS versions (IOS58 in particular) which change the internal USB interface. I've been (slowly) working on adding support for both interfaces, which should solve all our problems. That said, you can theoretically install the hack onto an ISO as described no problem, but it won't work unless you can somehow launch that ISO while running an unmodified IOS36.

*Notices this response took 1.5 weeks*
Sorry I don't check GBATemp very often...

wiiVC is locked to a special WiiU Gamepad official IOS module made by Nintendo that can't be forced to switch over to a cIOS at any point. Nintendont operates through numerous IOS releases including the WIiU Gamepad IOS and does not require any cIOS to function unlike Wii games. There are many other difference that makes the Nintendont vs Wii Loaders not exactly a comparable situation.

RVLoader is a new loader in active development that doesn't rely on any cIOS and was probably our best bet, but the devs are focused on portable Wiis and have no interest in WiiU support or USB support all together.

Lastly, I reached out to wilm0x42 a few weeks ago on github and he responded. He published a few commits from 2020 and and mentioned that he may pick up the project one day now that he has a USB Gecko.

Besides wilm, it seems like the only knowledgeable people still around who may be able to solve this are Maschell and Gary.

 

[Famus484]

Thank you very much for the reply, it helps putting all things into perspective! Very good news about wilm owning a USB Gecko!

About attempt 3. From my very limited understanding of WiiVC, from any loader, shouldn't we be able to load the game in the virtual drive (as in the one injected in title, not ISO from USB or SD card) without any cIOS?

The same way the chain Wii U menu->Injected Retail Brawl (WiiVC)->Smash Stack Exploit->Gecko OS->Boot game in virtual drive (injected Brawl) with cheats->Project+ works for me. It's obviously not a solution yet, as GCA didn't work (and from what you told me because different IOS). But I wanted to point out that USB loaders can load that way in WiiVC (if it was obvious and already considered, my b).

From scrolling in the forum, at some point you tested that a GCT version of the project worked with wbfs? I'm trying to find/create that one, so that I can test it in the above chain (I do hope that in the future we can avoid the smash stack exploit and just boot any dol file while clean Wii game in virtual drive, unless there is an obvious roadblock I'm not seeing).

What is Wii dol patching?

 

[JacobM]

Thank you very much for the reply, it helps putting all things into perspective! Very good news about wilm owning a USB Gecko!

About attempt 3. From my very limited understanding of WiiVC, from any loader, shouldn't we be able to load the game in the virtual drive (as in the one injected in title, not ISO from USB or SD card) without any cIOS?

The same way the chain Wii U menu->Injected Retail Brawl (WiiVC)->Smash Stack Exploit->Gecko OS->Boot game in virtual drive (injected Brawl) with cheats->Project+ works for me. It's obviously not a solution yet, as GCA didn't work (and from what you told me because different IOS). But I wanted to point out that USB loaders can load that way in WiiVC (if it was obvious and already considered, my b).

From scrolling in the forum, at some point you tested that a GCT version of the project worked with wbfs? I'm trying to find/create that one, so that I can test it in the above chain (I do hope that in the future we can avoid the smash stack exploit and just boot any dol file while clean Wii game in virtual drive, unless there is an obvious roadblock I'm not seeing).

What is Wii dol patching?

I'm confused, could you clarify?
So far you have been successful with injecting Retail Brawl, triggering smash stack to Gecko OS and then returning to a playable brawl modified under WiiVC without any USB adapter support?

If I am understanding that correctly, I believe that may be the expected behavior. At some point after the IOS30's, USB communication interface was changed. The WiiVC gamepad IOS255 version is built based on a really late IOS version. This meant all USB peripherals (ethernet lan adapters & keyboards) could not function in WiiVC with official software like SSBB/MKWii/Animal Crossing written for IOS36/38. Nintendont was able to communicate to USB peripherals because it was built to interface on a later generation IOS modules.

Link me to the post regarding the GCT + WBFS. I probably have it somewhere still, but based on the paragraph above, you likely will run into the same roadblock because of the USB interface. Immediately prior to tackling USB Loader support (which broke the scripts support everywhere else), wilm was updating his code to allow for later generation USB interfacing. I do not believe a GCT of that step was ever publicly released. That probably has the best chance of working with your smash stack strategy.

By Wii DOL patching I am referring to attempts to patch the main.dol file inside of a games ISO/WBFS directly to add USB support which was theorized to be possible.

It has been a long time since I have tinkered in this subject so I may not be recalling, understanding, or explaining anything as accurately as it may come off. YMMV

 

[Famus484]

I'm confused, could you clarify?
So far you have been successful with injecting Retail Brawl, triggering smash stack to Gecko OS and then returning to a playable brawl modified under WiiVC without any USB adapter support?

Yes, that is correct. I have been successful in both loading Project+ directly (through boot.elf) or indirectly (through Gecko elf file) in WiiVC, through Smash Stack on injected Brawl. To make testing easier, it would be better if I had a way of loading any dol file WiiVC with injected Brawl, but so far I haven't found anything (using smash stack only allows for elf).

So maybe an .elf homebrew that can load .dol files, making it possible to work with smash stack. Or better, injecting both a dol file on boot and a retail game (just like in GC injection, where it boots the Nintendont on SD while gamecube game is injected to virtual drive).

I am thinking of maybe trying to mess with a gamecube injection to replace the gamecube game with a wii game (and replace nintendont in sd card by usb loader), I would install to a random USB drive to avoid bricking my wiiu.

If I am understanding that correctly, I believe that may be the expected behavior. At some point around ~IOS56 USB communication interface was changed. The WiiVC gamepad IOS version is built based on a >IOS56 version. This meant all USB peripherals (ethernet lan adapters & keyboards) could not function in WiiVC with official software like SSBB/MKWii/Animal Crossing written for IOS36/38. Nintendont was able to communicate to USB peripherals because it was built to interface on a later generation IOS modules.

That makes me wonder, how does the gpf file work in normal conditions? Does it rely on Brawl's internal USB communication (which it would need for online through USB lan adapter)? And you're saying that makes it completely, black on white, no workarounds, impossible to make work in WiiVC unless a way was found for cIOS to be used in WiiVC (which is very unlikely to ever happen)?

Finally got around to installing a b52 cIOS base 38 (in slot 238) on my original Wii.
USB HDD in bottom USB port w/ Nintendo GCA adapter black port in top USB port.
The following were all tested with my cIOS 238...
Disc Loading: Works
Disc + GCT Adapter Script: Works
Brawl WBFS: Works
Brawl WBFS + GCT Adapter Script: WORKS
Project M + GCT Adapter Script: DOES NOT WORK

1. It appears Project M is not compatible with IOS 38 based cIOS. It seems like the homebrew Project M patcher reloads the IOS. I forget what a ProjectM WBFS does but it doesn't accept the GCA script in any form.
2. I was unsuccessful in patching the GCT data to a Brawl WBFS.




@wilm0x42 's project is focused on Brawl / Project M / Brawl mods. In its current state it only works with a physical Brawl disc in the drive, but he his working to make it compatible with the existing vWii cIOS.

@Chadderz 's project works for most other disc games. The latest version of his code remains exclusive to CTGP, but I believe he intends to update the github page in the future. A fork of Brainslug can most likely accept Wii Channels with some source code modification. This could potentially allow for games like Bomberman Blast to work and possibly even USB Loaders missing HID support.

Here is what I meant. I was hoping to use that very GCT file to try it in Brawl injected WiiVC Gecko, since it works with USB loaders.

 

[JacobM]

The way I understand it, there are three theoretical ways to accomplish your goal.
1. Rewrite of Wilm's code to be compatible with a Base50+ cIOS, and boot from vWIi, not WiiVC (1. Most probable to succeed 2. Requires a minimal amount of technical challenges for the average user to configure through a fully vetted process with safety measures 3. Provides a low risk of people messing up their vWii)
2. New custom IOS36/38 in normal vWii / USB Loading with the current GCT available (1. Very unlikely for any developer knowledgeable enough to make this 2. extremely risky for the average user with a high risk of messing up their vWii)
3. Rewrite of Wilm's code to be compatible with WiiVC IOS255 and regains USB peripheral support / understanding of support (1. Would have to get lucky with the rewrite from #1 also happening to be compatible with IOS255. 2. We would dependent on the results of testing a wiimmfi patched game and Phantasy Star Online)

I am thinking of maybe trying to mess with a gamecube injection to replace the gamecube game with a wii game (and replace nintendont in sd card by usb loader), I would install to a random USB drive to avoid bricking my wiiu.

I can't remember how that process worked. I recall everybody was cautious not to permanently integrate Nintendont versions into WiiVC games because there was very rapid development both with WiiVC and Nintendont when WiiVC was discovered. I believe there is an embedded forwarder that checked the SD for the latest Nintendont release and passed argument commands to "boot to disk" with certain nintendont settings. I don't have much experience with that way of installing Gamecube games since I preferred WiiVC to boot to Nintendont or USB Loader GX to select which gamecube game I wanted to load from SD instead. This method retained gamepad support but had an ARGs boot issues if the Gamecube Adapter was plugged in prior to the gamecube logo (if you had iplusa.bin installed). Thankfully there is a workaround by disabling args boot and retain gamecube adapter support in WiiVC.

It may be possible to forward to USB Loader GX and have a "game disc" ready in the virtual drive, click the mount disc button in the USB Loader GX UI. I vaguely remember trying that but I couldn't figure out how to mount a game and boot to homebrew, but might be possible. This could allow you to have GCT support, but I'm fairly confident it will lead to a non-responsive Gamecube Adapter and all other USB periperharls. If you have the Official LAN adapter I would start with testing to see if your router can ping the adapter once you are booted into SSBB or MKWii WIiVC. If it can, there is potential for the Official Gamecube Adapter to work one day alongside a new version of WIlm's code.

That makes me wonder, how does the gpf file work in normal conditions? Does it rely on Brawl's internal USB communication (which it would need for online through USB lan adapter)? And you're saying that makes it completely, black on white, no workarounds, impossible to make work in WiiVC unless a way was found for cIOS to be used in WiiVC (which is very unlikely to ever happen)?

WiiVC is functionally limited and will never be able to do any of the following:

• Cannot be forced to switch to any cIOS
• Cannot boot from USB Gamecube (IOS limitation) or Wii games (IOS & cIOS limitation)
• Cannot boot any Wii games from SD (cIOS limitation)

WiiVC was never documented well enough to understand the USB peripheral limitations. Keep in mind Nintendont was built from the ground up to operate on official IOS modules. So any added functionality possible with an official IOS module isn't guaranteed with a cIOS module. I would start my investigation here if you are adamant about one day being able to use the Gamecube adapter for Wii games exclusively under WiiVC if I were you.

• We know Nintendont can see the Gamecube Adapter
• We know Wii games that rely on wiimmfi cannot use the LAN Adapter in WiiVC, but we don't know if thats a Wiimmfi or USB issue. This may be able to be tested by pining the WiiU from the router once you are in a WiiVC Wiimmfi patched game and have initiated lan (tests Wii game USB communications). I don't believe I have ever seen results of somebody pinging, just Wiimmfi error codes.
• It is unclear if Nintendont can see keyboards or the lan adapter in WiiVC. This may be able to be tested by generating a WiiVC of Phantasy Star Online (look out for the & symbol in the name) to test both keyboard (confirms IOS input works as expected) and ethernet adapter (confirms IOS USB is full feature and wiimmfi is the source of the issues previously documented). Even if both the keyboard and LAN adapter work, since this game is reliant on Nintendont, the results aren't conclusive that a Wii game would work with only a GCT patch, but it opens the door for that possibility in the future. Success with Phantasy Star Online only proves that the IOS255 module is not restrictive.

Here is what I meant. I was hoping to use that very GCT file to try it in Brawl injected WiiVC Gecko, since it works with USB loaders.

It worked with a USB Loader because the loader had the ability to switch to a base 36 or base 38 cIOS on a Wii not on a Wii U. This remains impossible on a WiiU.

The results outlined were obtained on an original Wii, not a Wii U. The WBFS + GCT needed an older cIOS based on IOS38 which never existed for vWIi, and is only possible to install on an original Wii. It was only a troubleshooting step to determine if the theory on IOS 36/38/55+ was correct. This had no way of translating to a Wii U without a newly developed cIOS or a rewrite of Wlm's code to interface with later IOS/cIOS versions that exist on WiiU.

There were only two official versions of the GCT ever released. It seems like I used the first one in the testing I linked above. If you perform the test on an original Wii w/ cIOS 238 and still can't get it to work, I'll pull the GCT file from my WiiU, but I am positive its one of the two below.
Version 1: https://gbatemp.net/threads/need-help-with-vwii-gc-adapter-for-project-m.498236/page-6#post-7875438
Version 2: https://gbatemp.net/threads/need-help-with-vwii-gc-adapter-for-project-m.498236/page-7#post-7875799

 

[Famus484]

Thank you again for the reply, that reply helps clear things out, a lot.

can't remember how that process worked. I recall everybody was cautious not to permanently integrate Nintendont versions into WiiVC games because there was very rapid development both with WiiVC and Nintendont when WiiVC was discovered. I believe there is an embedded forwarder that checked the SD for the latest Nintendont release and passed argument commands to "boot to disk" with certain nintendont settings. I don't have much experience with that way of installing Gamecube games since I preferred WiiVC to boot to Nintendont or USB Loader GX to select which gamecube game I wanted to load from SD instead.

What I've experienced corroborates this. In order to control which slot the gamepad takes, I disabled autoboot in one of my GC injects, so it boots to nintendont every time. To access the title, I just boot to disk (or I can boot any game in my SD card from that same injected title). That is what gave me the ideas to ask around for Dol+game injection, and then to use smash stack in WiiVC.

It may be possible to forward to USB Loader GX and have a "game disc" ready in the virtual drive, click the mount disc button in the USB Loader GX UI. I vaguely remember trying that but I couldn't figure out how to mount a game and boot to homebrew, but might be possible. This could allow you to have GCT support, but I'm fairly confident it will lead to a non-responsive Gamecube Adapter and all other USB periperharls. If you have the Official LAN adapter I would start with testing to see if your router can ping the adapter once you are booted into SSBB or MKWii WIiVC. If it can, there is potential for the Official Gamecube Adapter to work one day alongside a new version of WIlm's code.

Even if GCA never worked that way, IMO there would still be a plus value in being able to do this. For example, it would provide a way to play every Brawl mod using a Wii U gamepad (even those that cant be esaily patched into ISO). I can do it through smash stack, but it doesn't work every time. It would also enable gamepad for other Wii game mods (like CTGP? testing required).

In the injector script, I think there is an option to change the forwarder dol, so I suppose we could put anything there. The problem is that the software prevents a Wii ISO from being injected if GC mode is enabled. I wonder if trying to bypass that is possible, and if it would work.

I have a USB ethernet adapter compatible with Wii U, I can test with that.

WiiVC is functionally limited and will never be able to do any of the following:

• Cannot be forced to switch to any cIOS
• Cannot boot from USB Gamecube (IOS limitation) or Wii games (IOS & cIOS limitation)
• Cannot boot any Wii games from SD (cIOS limitation)

WiiVC was never documented well enough to understand the USB peripheral limitations. Keep in mind Nintendont was built from the ground up to operate on official IOS modules. So any added functionality possible with an official IOS module isn't guaranteed with a cIOS module. I would start my investigation here if you are adamant about one day being able to use the Gamecube adapter for Wii games exclusively under WiiVC if I were you.

Actually, I went WiiVC route because I had thought it would actually be easier to help make GCA work there (My intuition was ''problem is with USB loading, but in WiiVC it's just (virtual) disk loading''). I don't mind carrying a USB flash drive just for PM/P+ (I'd rather not need a Wiimote, but at least with hbl2hbc I don't need the sensor bar). I do tend to prefer WiiVC for all other games, since they all fit on my hard drive (although I keep some games on my SD, like Melee mods).

The results outlined were obtained on an original Wii, not a Wii U. The WBFS + GCT needed an older cIOS based on IOS38 which never existed for vWIi, and is only possible to install on an original Wii. It was only a troubleshooting step to determine if the theory on IOS 36/38/55+ was correct. This had no way of translating to a Wii U without a newly developed cIOS or a rewrite of Wlm's code to interface with later IOS/cIOS versions that exist on WiiU.

There were only two official versions of the GCT ever released. It seems like I used the first one in the testing I linked above. If you perform the test on an original Wii w/ cIOS 238 and still can't get it to work, I'll pull the GCT file from my WiiU, but I am positive its one of the two below.
Version 1: https://gbatemp.net/threads/need-help-with-vwii-gc-adapter-for-project-m.498236/page-6#post-7875438
Version 2: https://gbatemp.net/threads/need-help-with-vwii-gc-adapter-for-project-m.498236/page-7#post-7875799

Thank you for those!