Hacking Devolution Speculation thread

[Taleweaver]

So let me get this straight, someone has finally cracked Gamecube USB Loading, this isnt a hoak.

Wow ok um speculation ok, first off here's hoping it can be implemented into our usb loaders like GX

Not quite. That devolution may be real is part of the speculation. With the recent video, the chance of it being a hoax may be less (why go through such trouble if the end result is nothing?), but there have been no confirmation from anyone but tueidj himself and the basic premise (one guy on his own does what more than a few talented hackers couldn't figure out) isn't exactly the most likely thing ever.

Implementation in other loaders would be highly unlikely without the source code. But hey...speculate away.

 

[wiismodrome]

Not quite. That devolution may be real is part of the speculation. With the recent video, the chance of it being a hoax may be less (why go through such trouble if the end result is nothing?), but there have been no confirmation from anyone but tueidj himself and the basic premise (one guy on his own does what more than a few talented hackers couldn't figure out) isn't exactly the most likely thing ever.

AFAIK, previous attempts at USB loading Gamecube games on Wii used Gamecube mode. However, this doesn't work because of a hardware conflict between Gamecube and USB memory mapping = no USB access. Devolution runs Gamecube games in native Wii mode, thus allowing USB access.

 

[Coto]

Not quite. That devolution may be real is part of the speculation. With the recent video, the chance of it being a hoax may be less (why go through such trouble if the end result is nothing?), but there have been no confirmation from anyone but tueidj himself and the basic premise (one guy on his own does what more than a few talented hackers couldn't figure out) isn't exactly the most likely thing ever.

AFAIK, previous attempts at USB loading Gamecube games on Wii used Gamecube mode. However, this doesn't work because of a hardware conflict between Gamecube and USB memory mapping = no USB access. Devolution runs Gamecube games in native Wii mode, thus allowing USB access.

MEM2 lives/shares the same memory the USB resources uses in Wii mode (GC uses ARAM, being a slice of MEM2).

 

[Taleweaver]

Not quite. That devolution may be real is part of the speculation. With the recent video, the chance of it being a hoax may be less (why go through such trouble if the end result is nothing?), but there have been no confirmation from anyone but tueidj himself and the basic premise (one guy on his own does what more than a few talented hackers couldn't figure out) isn't exactly the most likely thing ever.

AFAIK, previous attempts at USB loading Gamecube games on Wii used Gamecube mode. However, this doesn't work because of a hardware conflict between Gamecube and USB memory mapping = no USB access. Devolution runs Gamecube games in native Wii mode, thus allowing USB access.

That's the thing with oversimplifying things: it starts leading its own life. No...it was never "gamecube mode" that was the issue. Even though I've seen that response been given to MANY people without any hacking knowledge who just kept asking "but why doesn't it work?". The real answer reason didn't stick because it was too complex to remember. I can't tell much more either, apart that it had to do with not having memory space to cater for both memory for the gamecube and USB (Coto is probably correct, but I can't remember the exact terms to say for sure).

It's at times like this I'm glad I'm not a wii hacker. I'd hate it to give up on a problem I couldn't solve and then get told the solution would be as simple as "just use wii native mode". Especially if that someone doesn't know what the fuck that even means*.



*feel free to correct me

 

[wiismodrome]

Without knowing the hardware specifics, from what I understand, the Wii does have a Gamecube mode where the clock speeds are reduced, accessible RAM is reduced, USB ports, Bluetooth, and WiFi are disabled, and it uses MIOS, which is basically the Gamecube OS. So, effectively, the Wii becomes a Gamecube. Although I didn't give the specifics, I believe that I am right about there being a conflict in memory mapping while in this mode.

 

[DeadlyFoez]

Personally, I trust that tuiedj is telling the truth about this. He is certainly one of the more knowledgeable people in this scene and it would not surprise me for him to be the one to make it happen if it is in fact possible.

 

[obcd]

All I can say is that USB ports, Bluetooth and Wifi are not disabled in GC mode.
USB needs MEM2 for it's dma buffers, and in GC mode, that memory is used to emulate GC ARAM.
It wouldn't suprise me that the Bluetooth and Wifi devices are usb devices as well.
So, without working usb, it's normal that those don't work either.
Dios Mios (without the Light) was a proof of concept that the USB keeps working.

It's not relevant for this thread as devolution seems to run in wii mode and not in gamecube mode.
Besides Tueidj, nobody knows how it works exactly, and I don't think he will share that knowledge in the near future.

 

[Jacobeian]

Besides Tueidj, nobody knows how it works exactly, and I don't think he will share that knowledge in the near future.

and that's what I would have liked this thread to be about... oh well

Please someone correct me but I think that this makes use of a feature of Wii CPU where you can configure some part of the memory map to be protected and where an exception is triggered anytime game code is trying to write or read such memory area.
By adding your own exception handler when loading the gamecube game apploader in memory, you could check the memory accessed (be it anything gamecube-specific i.e ARAM, DVD, PAD, HW timers, etc) and *theoretically* emulate the access using Wii-specific code & hardware. Since the Wii CPU is running 1.5x faster than Gamecube CPU, additional processing power could be used for exception handling and gamecube hardware access redirection.

 

[wiismodrome]

Here's an overview of the Wii hardware architecture:

 

[wiismodrome]

All I can say is that USB ports, Bluetooth and Wifi are not disabled in GC mode.

Guess that depends on what is meant by 'disabled'. AFAIK, MIOS lacks the ability to communicate with these devices.

 

[Jacobeian]

Here's an overview of the Wii hardware architecture:

and according to YAGCD, here is gamecube CPU memory map:

http://hitmen.c02.at...chap4.html#sec4

Address are obviously different (in Wii mode at least) but you can see the similarities. Either you patch the code to use 0d8xx instead of 0ccxx, 0c8xx, etc for shared hardware (EXI,AI, SI...) or you route them into similar exception processing like the rest
I don't know if APB bus is accessible directly from Power PC CPU in Wii mode (I think it's only in GC mode) but with AHBPROT disabled, PowerPC theoretically have access to "everything" without having to go through Starlet IOS

 

[tueidj]

If I have time (and I can't promise that I will), I will make a series of blog-type posts describing how most of the technical stuff inside Devolution works (at some later time after it has been finished, since I don't want to go back and rewrite parts every time I change my mind about something).

 

[WiiUBricker]

I think the reason why everyone failed to make a decent GC USB loader is not the lack of knowledge, but rather looking at it from the wrong perspective.
Everyone believed that it's more than naturally that GC games run in GC mode, the mode where Nintendo's software tells the Wii's hardware to adapt itself for the requirements of running GC games, hence why DIOS MIOS arrived at the surface. This however I believe was bound to fail, since Nintendo was not that stupid to develop a software that could enable USB loading without massive issues.

The solution to this is to develop own software which tell the Wii's hardware exactly how to adjust itself for running GC games from USB. I believe one can make a connection to Team Cyclops iEVO and their compatibility layer, which allows normal DS software to run in DSi mode. If we use this analogy further we can tell that DIOS MIOS was an attempt to run DS games in DS mode with DSi mode exclusive features. And that's basically the reason why it failed.

 

[wiismodrome]

If I have time (and I can't promise that I will), I will make a series of blog-type posts describing how most of the technical stuff inside Devolution works (at some later time after it has been finished, since I don't want to go back and rewrite parts every time I change my mind about something).

Do you know if frame rates improve at all due to the increase in processing power from running GC games in "Wii mode"? It seems like they should.

 

[diddy81]

If I have time (and I can't promise that I will), I will make a series of blog-type posts describing how most of the technical stuff inside Devolution works (at some later time after it has been finished, since I don't want to go back and rewrite parts every time I change my mind about something).

Do you know if frame rates improve at all due to the increase in processing power from running GC games in "Wii mode"? It seems like they should.

im quite sure i remember tueidj say he had a frame limiter in the app

 

[wiismodrome]

im quite sure i remember tueidj say he had a frame limiter in the app

Ah... I thought he mentioned that GC games run with proper timing if they are "told" about the specifics of the system they were running on. Don't recall anything about frame limiting.

 

[tueidj]

There was never any frame limiter. There was a time limit to stop me spending all day playing games instead of working.

 

[diddy81]

There was never any frame limiter. There was a time limit to stop me spending all day playing games instead of working.

guess i was mistaken then
oh well cant be right all the time LOL

 

[wiismodrome]

guess i was mistaken then
oh well cant be right all the time LOL

Well... tueidj was limiting the time frame spent playing games instead of working....

Still curious about whether the framerates improve with the faster GPU/CPU clocks.

 

[tueidj]

They're not related. Frame rate depends solely on the video mode.