Hacking DSi - GBA internal hardware?

[omatic]

how much ram and processing power is needed to emulate a gba?

If I remember correctly, you need 10x the processor power to emulate a CPU, so that'd be 167.8MHz. If one of the chips is truly an ARM11, then this shouldn't be a problem. I know that the GBA had 256KB of RAM, but I don't know how that'd translate to its emulation on the DSi.

Something I've been wondering is whether the SD slot would suffice as a replacement for the Slot-2 expansion. I'm just speculating, but an ARM11 combined with the 4MB (or more) of ram and a fast enough slot-2 replacement should be enough for emulation.

On the financial side, if GBA emulation is possible, then Nintendo would be foolish to not release GBA games as DSiWare. People who missed out on GBA classics, or who just want a whole bunch of them on their person at a time, would make for an easy 5-10 bucks.

 

[DokiDoki98]

DSI FAILS

Such as life.......Mr. Alien

 

[gosp]

The problem with the ram is that we'd need to load the entire game into memory before playing it and having the game itself use memory. The slot 2 device was used to work exactly like a gba game; the technical details weren't very innovative. If the ARM7 is indeed gone, we'd actually have to emulate stuff instead of just letting the processor do it's thing. This is also why I doubt the SD slot would work as a replacement.

 

[UltraMagnus]

I do wonder, if the DSi does have the hardware, or something that is backwards compatible with it, would it be possible to solder on the card from an ez-3-in-1 modchip style.... of course, that would assume nintendo has been friendly enough to leave the now unused buses that were used by teh gba slot exposed.... which i doubt.

[/ramble]

 

[Canonbeat234]

If Nintendo believes they can download the GBA roms (not games since they aren't cartilages anymore) to the DSi then that MUST be a vital firmware update you need to do for the DSi.

 

[fgghjjkll]

how much ram and processing power is needed to emulate a gba?

If I remember correctly, you need 10x the processor power to emulate a CPU, so that'd be 167.8MHz. If one of the chips is truly an ARM11, then this shouldn't be a problem. I know that the GBA had 256KB of RAM, but I don't know how that'd translate to its emulation on the DSi.

Something I've been wondering is whether the SD slot would suffice as a replacement for the Slot-2 expansion. I'm just speculating, but an ARM11 combined with the 4MB (or more) of ram and a fast enough slot-2 replacement should be enough for emulation.

On the financial side, if GBA emulation is possible, then Nintendo would be foolish to not release GBA games as DSiWare. People who missed out on GBA classics, or who just want a whole bunch of them on their person at a time, would make for an easy 5-10 bucks.

you know? i think its possible. i use my 4gb sd card with Windows ReadyBoost and its a bit slow....

 

[nitro2k01]

Well it lacks the ARM7 (The GBA core). There have been reports that the DSi is now running an ARM9 (The normal DS processor) and an ARM11 (We think, we haven't identified it yet). We know that ARM7 has to be emulated somehow, being a major component of the DS. The question becomes if they are emulating the full GBA mode, or only the DS instruction set on the ARM7.

I'm actually pretty sure that it still has the ARM7, and just a beefed up ARM9.

The old GB/GBC chipsets were getting expensive, so they cut them out of the design and emulated their functions (Within the GBA architecture, not it's GB/GBC functions) with a more powerful chip.

Everything else you said made sense. But, with the micro and the DS, the way that the GBAs played GB/GBC games was with a switch in the slot (pressed when the corners of the old game paks hit it) so that it cut some processor power. This mechanism was too large to fit in the micro or the DS, and that's why they cut support.

Even if it is new hardware, if Nintendo's planning to give us GBA games on VC, they probably have a way of emulating the hardware.

Err, that's off. That switched just controlled which processor got the power. It was literally a tiny switch with a few Motherboard leads running off of it.

Shabadage, please, please, please, stop talking so much out of your ass.
About GBA and GBC: The switch you're talking about is not a "power switch" but a switch that the CPU can read and then acitvely decide which mode to enter. What's the difference? The switch can be in either position, and still the CPU can be in either mode. If you press the switch when in GBA mode, the GBA doesn't always go into GBC mode. And you can enter GBC mode from software. I've disassembled the GBA BIOS and found that piece of code. I've written a GBA program that enters GBC mode through software. I've closely investigated the behaviour of the GBA related to this switch. I know that it works.
Furthermore, the GBC mode exists even on the GB Micro! If you run the code that starts GBC mode, even the GB Micro will enter it. It's a bit glitchy in some ways, but it works well enough to prove that the GBC core is still in the GB Micro. However, the Micro doesn't contain the voltage regulator used to get 5 V for the external interfaces.

In general, two (or more) CPU's can be etched on chip. A CPU is nothing but a collection of logic gates, and as long as they all fit on the same silicon substrate, nothing stops anyone from having several CPU's on the same substrate. ( =in the same chip) So just because there's just one CPU chip on the DSi doesn't mean there can't be two CPU's on there.

About DSi and bunnie: Nothing suggests that the ARM7 would've been removed, and nothing suggests that the DSi is using an ARM11. That is a rumour that people picked up from Bunnie's blog. He even points this out in the comment section. (This comment)

Wow…it’s amazing to see how rumors spread on the internet. I can’t overemphasize the point that my post is entirely *speculative*; attributing the reduced battery life to a faster CPU as a fact is overstating my post by quite a bit. I wrote it in a hotel room after playing around with the device for about half an hour.

I've heard from somewhere else (A believable source) that the CPU is in fact clocked at 166 MHz, which would suggest that it has a double speed mode, much like GBC has a special GBC mode with double clock speed compared to the original Gameboy, and some extra features. And still, nothing suggests that the ARM7 was removed. No matter how you look at it, emulating an ARM CPU would be slow and error prone. Not to mention the costs for redesigning the peripheral hardware to the lack of the ARM7.

About DSi and a GBA mode: This should be easy to test. There are instructions here on how to enter GBA mode. (4000301h) A small piece of code could be written to test this. If someone has a DSi with a working flashcart, they could try it out today!
Download this and run it. If the GBA startup screen shows up, then we know for a fact that the DSi can run theoretically run GBA code in some shape or form.

 

[Trigger_Happy]

There's something about this guy's response that sends good shivers down my spine... whoo...

 

[Narin]

All this doesn't really matter as all DS games and flashcarts run in a DS compatibility mode which is hard coded into the actual hardware and firmware. Unless the encryption is broken, theres no way to leave the compatibility mode. Now what is this compatibility mode you ask? Basically it restricts all DS games (and flashcards) to what is only used and accessible to a normal DS. This means that new DS games and flashcarts can't access the increased RAM nor attain processing power greater than what is capable on a normal DS. Also games and flashcards can't access the DSi features like the cameras, the SD slot, DSiWare, WPA WiFi encryption and all the other cool DSi features.

So even if the DSi does have better hardware, it can't be used by flashcarts anytime soon until the DSi encryption is broken which I don't see happening anytime soon due to Nintendo learning from their mistakes with the Wii and used stronger encryption. To run in DSi mode, you need to encrypt and digitally sign the device/game to run with full DSi/Hardware support otherwise it defaults to DS Compatibility mode.

Nintendo added the DS Compatibility mode to make sure that all DS games run as they should and as they do on a normal DS and also restrict developers from adding DSi features in the game which could break on a normal DS. So if a developer want to access the better hardware and features the DSi has to offer, they have to make the game specifically for the DSi.

So even if the DSi does have better hardware would could make GBA emulation possible, it will not work under the AKK2i, DSTTi or any DS flashcart that was updated to run on the DSi under DS compatibility mode. A new flashcard with new hardware will be required as well as someone breaking the encryption Nintendo used before this is possible.

 

[reuven]

About DSi and a GBA mode: This should be easy to test. There are instructions here on how to enter GBA mode. (4000301h) A small piece of code could be written to test this. If someone has a DSi with a working flashcart, they could try it out today!
Download this and run it. If the GBA startup screen shows up, then we know for a fact that the DSi can run theoretically run GBA code in some shape or form.

Well, the GBA screen does not show up on my DSi. The top screen is white, and the bottom black.