Question about Gamecube Mode

Hi All,

Please move this if I am posting it in the wrong category...

Does anyone have a good reference for how the Wii works in "Gamecube Mode"? I am pretty unfamiliar with it, but I want to learn as much about it as I can. I want to start investigating if it is possible to independently use Starlet in any way while in a GC game.

This probably sounds lame (because I honestly don't know what I'm talking about yet), but I want to start investigating a way to write to system memory asynchronously using code executed on Starlet while a GC game is running. The primary motivation for this is to see if I can somehow get OHCI/Bluetooth input from the Wiimote to "work" in a GC game (by overwriting memory or perhaps patching a game). I ultimately envision a way to play GC games without the need for a GC controller or GC memory card.

There's probably no way to do this right now unless I hack on IOS or wait for a full MINI implementation with OHCI and BT, but I was wondering if anyone who was more familiar with the hardware/software architecture could fill me in or at least point me to some information on this.

Thanks a lot!!

Don't know much about this, but I do now that when a gamecube game is executed it runs trought MIOS instead of IOSs.

What I think you have to do is patch MIOS not to disable bluetooth communicatino with wiimotes (as these are shut down when a with MIOS I think) and maybe translate the wiimote/classic controller/nunchuk input to gamecube input. I certaionly don't know how unfortunately. (I barely know anything).

Saving to the wii's internal memory is a great idea, I think! And I cannot understand why Nintendo didn't make this themselves (or maybe I can... I guess it's for the profit they get of sold mem. cards).

If there is anything you need help with which I can handle I'd be glad to help. The problem is that my wii programming skill is currently low, but if you need help with some basic stuff, I think I could handle it!

This is indeed a great idea, as some GC games really could take advantage of classic controller controls!!

>This is indeed a great idea, as some GC games really could take advantage of classic controller controls!!

And if one translates the Wifi as the GC Broadband Adapter (etc) then it could be possible for some online crap through those games that use it.

You could play GC online?

If someone gets this to work, I would highly recommend putting in an option to customize controls. Directly mapping the GCN A, B, X and Y buttons to the CC A, B, X and Y buttons might not always be the best way to handle things.

there is a lot of unused memory in gamecube mode

Quote
GCLinux
Nintendo GameCube

* IBM PowerPC, 486 MHz
* ATI graphics
* 24+16 MB of RAM



* 8 cm optical drive
* (optional) 10/100 Ethernet

Nintendo Wii

* IBM PowerPC, 729 MHz
* ARM SoC
* ATI graphics
* 24+64 MB of RAM



* 12 cm optical drive
* Wi-Fi
* Bluetooth
* USB

the extra 48 megs of ram should be perfect to do this. if you patch BC to not change clock speed (and somehow get Boot2 and/or Bootmii to recognise that) or get MIOS to patch it back then it would be a lot better, and faster. however, if things go down this road then we'll probably be making a 100% homebrew MIOS

just as a addon question, would we need to use homebrew for creating the control settings or could this be done on the PC using a bluetooth adapter and creating a code to patch a gamecube game

@borbz: You're really just going to have to go and disassemble MIOS; there's not much to say. MIOS sets some flags to allow the PPC to talk directly to parts of the hardware (HW_AHBPROT), loads the GC IPL into memory, boots the PPC off the GC IPL, and then goes into an idle loop; if anything, it handles IRQs for the power and reset buttons, and that's all.

It's conceivably possible to shoehorn the OHC modules from IOS back into MIOS, but then you have to add in a HID driver to IOS and then figure out a good way for it to communicate back to your (presumably patched on-the-fly) PPC code in the game.

At what address is HW_AHBPROT located bushing? Also, any idea if this register enables Broadway to use the original GC DI drive registers at 0xcc006000? Never mind, noticed bootmii-devel post.



Edited 1 time(s). Last edit at 08/17/2009 11:03PM by yellowstar.