Homebrew The Truth behind GBA emulation

[browner87]

For everyone who said :facepalm: to my question, READ! THE VERY NEXT SENTENCE! I know perfectly well that it makes no logical sense to be able to rename GBA to NDS and have it work - I was just stating the exact problem to be solved. You can't find a solution or answer to anything if you don't have a question! The ISO vs. Filesystem comment is exactly the beginning of the perfect answer. I have to run to a RIM interview thing right now, but I think Normmat and Cracker understand what I'm saying. The best (not necessarily simplest) answer to all of this is NOT to try and play GBA games on the DS, but to make GBA games INTO NDS games. Any yes, it may involve complex logic and reverse engineering the game back very far, and possibly a bit beyond AI of a program to do. I'm just asking and making suggestions here.

 

[Rabbi Nevins]

when i finish getting my computer engineering degree, ill look into it

too bad that wont be for 3 years...

 

[DanTheManMS]

For everyone who said :facepalm: to my question, READ! THE VERY NEXT SENTENCE! I know perfectly well that it makes no logical sense to be able to rename GBA to NDS and have it work - I was just stating the exact problem to be solved. You can't find a solution or answer to anything if you don't have a question! The ISO vs. Filesystem comment is exactly the beginning of the perfect answer. I have to run to a RIM interview thing right now, but I think Normmat and Cracker understand what I'm saying. The best (not necessarily simplest) answer to all of this is NOT to try and play GBA games on the DS, but to make GBA games INTO NDS games. Any yes, it may involve complex logic and reverse engineering the game back very far, and possibly a bit beyond AI of a program to do. I'm just asking and making suggestions here.

I think the main assumption you're making here is that we have the ability to gain access to the source code of the GBA files, which we can recompile into DS format. Which we don't. You can try to reverse-engineer the compiled binary if you'd like, but I don't think you're going to get all that far. A major roadblock is that the ARM7 functions entirely differently depending on if it's in DS mode or GBA mode. In DS mode, it handles certain functions like wifi, touchscreen, and audio, while on the GBA it controls EVERYTHING. In addition, I believe there are some math functions that exist only in GBA mode, which you'd have to work around, but I could be wrong about that.

Somewhat off-topic, but regarding the person earlier who claimed that the GBA didn't have stereo sound, yes it does. Plug in headphones and you'll hear stereo clear as day. It's just that it has only one speaker, so if you're playing without headphones of course you're going to hear "mono" sound. VBA wouldn't have a "reverse stereo" sound option if it didn't have stereo in the first place.

 

[LivingToDie]

is there one of us willing to spend his time on a gba emulator for ds?
there are many people that would want this(including me)
(i wont make because i dont understand ANYTHING of it...)

 

[Sanoblue]

its not possible.....

even if we could it would be a waste of time.... buy a 3 in 1... they are cheap

 

[LivingToDie]

and what about dsi ?

 

[Sanoblue]

and what about dsi ?

your... s**t out luck...

keep your ndsl.... dsi looks like its gonna suck but will have its good sides

 

[LivingToDie]

well... but what about all the people that are buying a dsi (many)
because you say it sucks there will be no emulator

please...any1 ?

 

[Sanoblue]

there is no way to emulate a gba game on the dsi... or just using nds .... u need a slot 2 device,.... so either keep your ds or but a flashcart and a gba sp....

even if we could reverse the game and turn it into a nds game... ud never be able to get the compadiblity up high enough to be worth it

 

[DanTheManMS]

@12philip12:
Take a look at some of the earlier pages. Specifically, Exophase's posts on http://gbatemp.net/index.php?showtopic=72623&st=45 and http://gbatemp.net/index.php?showtopic=72623&st=120

Yes, the big long posts with lots of words. Read them. Even if you don't understand the technical jargon, just read them anyway.

He's basically saying that even if one hacked something together, it would be almost entirely unplayable, and that while it would be interesting to see from a technical standpoint, it would not be a feasible option for actually playing GBA games. To put this in context, Exophase made "magic" when he made the first full-speed GBA emulator for the PSP. If he says GBA emulation here would not work well at all, I'd be inclined to agree with him.

Another example: remember Dwedit? The guy who made the GBC emulator for the GBA that runs almost all games at full speed? He too says it would not work, and that even if such an emulator was made, it would run at 1 fps tops. Source for this: http://www.dwedit.org/dwedit_board/viewtopic.php?id=344

As for the DSi, until it's cracked, we will have no more resources to work with than we currently do with the DS. We have no clue of knowing how long it will take for the DSi to be cracked, or if it will happen at all.

 

[Diosoth]

I'm not sure why someone would pay more for a DSi and then try to get GBA emulation, anyway. The DS Lite is much cheaper and has the actual hardware.

 

[cracker]

I'm not sure why someone would pay more for a DSi and then try to get GBA emulation, anyway. The DS Lite is much cheaper and has the actual hardware.

The DSi interface is much nicer -- Wii-esque. The two cameras are gimmicky but they could be useful for homebrew or even commercial titles. And the big reason why is the DSiWare. If the DSi has titles only available on it then chances are that something cool will be on distributed for the DSi and (at the very least) until someone can decrypt the wads DS/Lite owners are sol.

 

[browner87]

I guess the easy answer is, GO and BUY A PSP! It can emulate GBA I hear

and yes, ATM, reverse engineering such software is beyond me, but by the time I'm done my OS design course in 4th year, I hope I'll know a bit more about this. I also hope that I'll be a bit beyond most GBA games by then

and if not Nintendo will probably have a new system out that will be fast enough to emulate GBA. Then the problem will be DS games

 

[EverlongNDS]

get a gba expansion pack,and its all great

 

[CrashmanX]

o.o 11 pages in 6 days, wow

Anyways could someone remind me of the point of wasting HOURS of your life to code something like this when you could easily do either of 2 things:
A. Buy the EZFlash V 3in1
B. Buy/Rent the game you want to play

Really both solutions run $20 but are almost Always worth it.

 

[DanTheManMS]

o.o 11 pages in 6 days, wow

Not quite. 1 year and 6 days.

 

[how_do_i_do_that]

you can see if someone from any of the manufacturers of the flashcarts wants to make a interface for the flashcarts look like the dsi.

 

[JDandy]

Edit:

Never mind.

 

[cracker]

Now, I'm sure you've been told many many times that gba emulation on the nds is impossible well this is entirely untrue.

It is however impossible to software emulate the gba on nds well at any descent frame rate anyway.

It is possible to create a hypervisor using the mpu that translates the writes to the graphics and sound hardware of the gba to the nds hardware this however is hard to do which is why no one has done it well except for someone who will not under no circumstances release it because he does not condone piracy.

Using the hypervisor approach you can get full speed, maybe even faster, not to mention you could potentially add things such as save states etc but first someone would need to create a hypervisor and release it to the public.

I will not be creating a hypervisor but i thought i'd let others know that running GBA games from slot1 is not entirely impossible its just no one has bothered to code something that the nds hardware does natively and release it to the public.

Oh, so the one person who has the skills to code the Mighty Hyper Visor will not release it to the public because he does not condone piracy?
This means that NOBODY CARES. The EZFlash 3-in-1 does GBA just fine.

It was just a private proof of concept and IIRC it was said that it was very limited in what it could run because of the RAM issue. I just don't see any way around the lack of RAM problem because the game can't be loaded in segments as the ROM jumps around so much during gameplay. Dynamically loading the code jump after jump would make it extremely slow (and I'm sure buggy).

 

[JDandy]

Well,...

WORDS WORDS WORDS

...wesome!

Oh fuck I just noticed you bumped a year old thread.
*facepalm at self*