Hacking Rewriting ROM on NAND save games?

[The Real Jdbye]

I've been wondering about this one for a while.
For games with NAND saving would it be possible to rewrite the ROM, as it is stored on a rewritable NAND chip, or is that part of the NAND write protected in some nonrevertable way?
If possible then this could serve as a sort of flashcart, minus saving for games not using NAND saving, and it would work on all current and future firmware versions as it would be equivalent to a retail cartridge.

 

[how_do_i_do_that]

already brought that up as a possibility. the only problem is that games that use the eeprom will have a hard time writting to something that isn't on the PCB.

 

[Foxi4]

I don't think I quite follow you, The Real Jdbye - are you 100% sure that the games aren't stored on a separate ROM chip and the SLC-NAND plays the role of a save chip only (two chips on the board)? Do you happen to have any photos of an SLC-NAND game cartridge PCB, for example Animal Crossing?

 

[Duo8]

They might prevent writing to a certain portion of the NAND as a safety measure.

I don't think I quite follow you, The Real Jdbye - are you 100% sure that the games aren't stored on a separate ROM chip and the SLC-NAND plays the role of a save chip only (two chips on the board)? Do you happen to have any photos of an SLC-NAND game cartridge PCB, for example Animal Crossing?

There's a pic on the forum.
And there's only one chip on the PCB. That's where both the game and save are.

 

[The Real Jdbye]

I don't think I quite follow you, The Real Jdbye - are you 100% sure that the games aren't stored on a separate ROM chip and the SLC-NAND plays the role of a save chip only (two chips on the board)? Do you happen to have any photos of an SLC-NAND game cartridge PCB, for example Animal Crossing?

What Duo8 said. I've seen the picture before. I've also read several times that it's stored on the same chip as the ROM (actually, one time was earlier today when I decided to make this topic)

I'm assuming no one has tried this yet, it certainly would be interesting to see someone try.

already brought that up as a possibility. the only problem is that games that use the eeprom will have a hard time writting to something that isn't on the PCB.

EEPROM-based games could certainly be troublesome, but then again would you really want to play those if you can't save? Most likely the game would just show an error and allow you to proceed, like it would if the save was corrupted. Or it might just get stuck at the save loading. I have a feeling more and more games are going to be NAND save-based as time passes, so this might be a more useful idea in the future.

 

[driverdis]

a good way to test if its even possible to flash the SLC-NAND is to attempt to flash another region's animal crossing game's 1:1 dump of the SLC-NAND to their cart. since the games almost the same, and the hardware is the same (only the contents of the SLC-NAND is different)

the result of doing this ahould be either
1. It works, game plays on a same region 3ds of the dump that was flashed, but did not work before as the region was different.
2. the "Read Only" section of the SLC-NAND cannot be flashed via any conventional hardware flashers and it fails.

 

[minexew]

It seems they're using hardware write protection.