random 3DS discussion

[ShotgunNinja]

All right! Glad to see that there is movement in the homebrew world towards the newer platforms, as the classic DS/DS Lite are soon to be antiquated by the 3DS...

By the way, not to be that guy again , but do you think that there's gonna be any work on 3DS homebrew in, say, the year or so after its release? Obviously, it's probably gonna use a totally different hardware architecture which will need to be hacked and documented, not to mention there's gonna be the arduous task of finding a hack to run homebrew code on the new platform, what with Nintendo's constant stream of "security updates" which destroy homebrewers' best intentions, but I figured that I'd say something now so people start thinking about it ahead of time. I'd be willing to commit what skills I have to that cause, but I don't have the knowledge or tools required for the all-important hardware documentation step.

[WinterMute]

Firstly, DS/DS Lite will be far from "antiquated" platforms for quite a while to come - there were 125 million DS units out there at the end of 2009, I don't see any particular reason for the homebrew scene to die off. If nothing else there will probably be a whole set of new homebrewers arriving when gamers dump their DS/DSi consoles on to the second hand market to buy a 3DS. Word on the grapevine also says that 3DS is a whole different beast, allegedly gamecube level complexity.

Secondly, 3DS will be hacked when it's hacked, if it's hacked at all. DSi security is way better than Wii security was and I fully expect 3DS security to be better still.

Right now we don't even know what the processor is in the 3DS, it'll probably be ARM but who knows, it might even be something new.

[sverx]

Right now we don't even know what the processor is in the 3DS, it'll probably be ARM but who knows, it might even be something new.

It is supposed to run DS/DSi games, I've read, so I think it should have both an ARM9 and an ARM7... well, maybe an ARM9 but faster (2x? 4x? 8x?) ... just like what Nintendo did with ARM7 when they decided that the DS would run GBA games...

Or maybe they've put in there a third processor?

[Gryphon93]

It is supposed to run DS/DSi games, I've read, so I think it should have both an ARM9 and an ARM7... well, maybe an ARM9 but faster (2x? 4x? 8x?) ... just like what Nintendo did with ARM7 when they decided that the DS would run GBA games...

Or maybe they've put in there a third processor?

I'm quite sure that Nintendo will use one processor, not two or more. It's just my guess though, I don't know for sure, but if they would use dual CPUs, I think those won't be two "physical" CPUs, but two cores in one (You know, a dual core processor. I'm just making it way more complicated for me to explain than it really is...). This is just my guess though.

[WinterMute]

It is supposed to run DS/DSi games, I've read, so I think it should have both an ARM9 and an ARM7... well, maybe an ARM9 but faster (2x? 4x? 8x?) ... just like what Nintendo did with ARM7 when they decided that the DS would run GBA games...

Or maybe they've put in there a third processor?

I'm quite sure that Nintendo will use one processor, not two or more. It's just my guess though, I don't know for sure, but if they would use dual CPUs, I think those won't be two "physical" CPUs, but two cores in one (You know, a dual core processor. I'm just making it way more complicated for me to explain than it really is...). This is just my guess though.

Not entirely sure why you feel the need to differentiate here. Most modern processor architectures for game consoles are SoC (System on Chip) which means the chip package contains several processors amongst other things. This doesn't mean that it's one processor, merely that everything is in one package.

As an aside, the DSi already has a 3rd processor, not sure about the 3DS but the new 3D chip on there looks rather scary -> http://techreport.com/discussions.x/19124

Also split this discussion off the announcement into Off Topic.

[Discostew]

The DSi has a 3rd processor? I thought it was just the same as the DS, but boosted.

[zeromus]

The DSi has a 3rd processor? I thought it was just the same as the DS, but boosted.

A DSP doesn't do dishes. It does processing. That, apparently, warrants its title as a processor.

[Discostew]

The DSi has a 3rd processor? I thought it was just the same as the DS, but boosted.

A DSP doesn't do dishes. It does processing. That, apparently, warrants its title as a processor.

Didn't know it had a DSP. All info I heard about the DSi was that, other than the obvious hardware like cameras and such, the ARM9 CPU got a boost (not ARM7?) and the main RAM increased in capacity. That was it.

[Discostew]

According to IGN, the 3DS specs have been leaked to them by an "anonymous" tipper.

http://gear.ign.com/articles/112/1122613p1.html

Now, while I usually take what IGN says with a grain of salt, let's assume they are correct.

2x 266Mhz ARM11 CPUs
1x 133Mhz PICA200 GPU
4MB dedicated VRAM
64MB RAM
1.5GB Flash RAM

Of these, the CPUs have piqued my interest. Same number of CPUs as the DS has, but unlike the DS, they are both ARM11. From the little research I've done, the ARM11 is capable of running ARM9 code, but not ARM7. This makes me believe one of two things to get backward compatibility running on the 3DS.

The first is emulation. Assuming it has the power to emulate it, it would drain the battery because of the need of processing power multiple times more than what is being emulated, but in such a case, DS games would work, as well as our homebrew unless their emulation technique includes some form of checking.

The second is to dismiss the ARM7 binary in the games, and have an ARM11 binary stored on the 3DS, that handles everything the ARM7 did. Why I think this is a possibility is because of Nintendo not letting developers have direct access to the ARM7, but through APIs Nintendo made. In a sense, unless I'm mistaken, the ARM7 binary in every game is the same. If this were true, and ARM7 access is done via API usage on the ARM9, Nintendo could just develop their own ARM11 binary that is loaded after the ARM9 binary is loaded. With that, if the ARM11 binary handle everything just like the ARM7 did, it would theoretically allow backward compatibility to all "official" releases. The downside? Anything "not" using the default ARM7 binary and APIs to access it would break, including homebrew.

[WinterMute]

What makes you think an ARM11 can't run ARM7 code?

We were discussing this the other day on IRC and I said something similar but what I was thinking was that it's impossible to make an ARM11 behave exactly like an ARM7 - it's a faster processor even at the same clock speed and it has cache. Recently I realised that doesn't actually matter since neither of those things will have any significant impact on what the ARM7 in the DS actually does. There's nothing in the standard arm7 binaries that is actually timing sensitive at all.

Not all games have the same arm7 binary although they should in theory all be API compatible. The idea of using a fixed arm7 binary and not loading the one from the game card was something that was suggested they might do with DSi but they didn't. It's certainly possible they might choose to do it with 3DS.