Hi,
just some thoughts about "upgrading" the m3i zero to be DSi-Mode compatible:
First there are economic aspects for the release groups. Even if your cart might be upgradeable, you just could say it isn't and sell new carts. The Flash cart market is probably not the biggest market in the world but it's a nice niche market. The shops, the groups and the fabs (who make the carts) want their $-slice

. If you think all groups are selfless hackers, go and take a look at the TV-Smartcard scene. You can buy perfectly upgradeable haxxor-smartcards, but once in while you have to buy a new one sometimes even if the pay-tv provider didn't issue new cards.
Second there are technical aspects. I'm really not that deep into the homebrew and cart-console hacking scene, but I've got a degree in computer science - so basically I know my stuff. On the one side you have your console (DSi) and on the other hand you've got your memory-device aka flash-cart. When you turn on your DSi it reads your flash-cart (or whatever is in your slot1). Depending on what it reads it decides whether DSi mode will be enabled or not (in other words it finds some certificates or stuff that allow the use of DSi-mode-features). So if there is a piece of home-brew software that brings all the certificates and stuff to run in DSi Mode it would be sufficient for the flash-cart to hand the home-brew.rom to the DSi. This can always be done by a firmware upgrade (if needed). If Nintendo adds some RSA-processing-chip to their DSi-"only" carts, it could be difficult for the flash cart to emulate (calculate) the RSA-challenge and response codes in time. That would be similiar to usb or lpt dongles on your computer. If your flash cart is not powerful to do fast rsa-calculations then there is no way a software upgrade would make your cart DSi-mode compatible.
All this is based about my general knowledge of cryptò-systems and rom-carts. If someone has more information about the DSi-mode I'd happy to read some stuff.
- Are there any real Nintendo carts out, that use DSi-features? Whate distinguishes those carts from normal carts (if you open them and take a look at the hardware).
- In order to access the DSi-Mode from SD-cards or the internal memory you obiously need to use Nintendo signed software. If you inject your own code thru a savegame your code might run in DSi mode, even it might be able to install a homebrew channel, that allows to easy boot non signed software. Is there any more information about this?
bye
Darky