Homebrew Answer to running DS backups on 3DS without a flashcart?

[Deleted User]

Chaos_Therum on Reddit found an old forum: https://gbatemp.net/threads/nds-rom-patcher-released.27468/

Spoiler: Chaos's Quote

Chaos_Therum - "So from what I can gather this tool patches ds games so they could save to a slot 1 device. I know that one of the main problems with running ds games right now is accessing the SD card. Could what they learned in creating this utility be of any use? It seems that it wasn't super popular when it was released so I figured maybe people had forgotten about it. Now I know that saving and reading data are totally different things, but at least it could be further researched."

So how is this tool relevant to DS "Emulation"?

Well, remember the good old days of ROM Hacking? Well, we could patch the code of this tool to make the patched roms read code from another location - the SD card

The feasible solution is editing TWL_FIRM to emulate a Slot-2 in FCRAM, like how AGB_FIRM does, and loading the Slot2-patched ROM there.

Well you could rewrite parts of TWL_FIRM to create a virtual slot-2 in FCRAM (perhaps on SD if possible. But it may not be fast enough) and create a simple passme NTR CIA that will load a rom to it and boot it. Booting DS game off slot-2 was what the pre slot-1 flashcarts use to do, so you could do that on a 3DS if you can find a way of mapping unused FCRAM for the virtual slot-2.

It's feasible. AGB_FIRM loads the game rom into FCRAM as well so the process would be similar.

You'd have to work out how you'd load the rom into FCRAM in the first place. NTR mode titles don't normally have SD access. FCRAM is limited (though you'd have a bit more wiggle room with n3DS), so it may not be the best method.

Not to mention the serious changes you'd have to do to TWL_FIRM to allow this. It would probably be less overhead for Arm7/Arm9 then trying to load the roms directly from SD.

But the problem is finding a way of unlocking the extra FCRAM space normally disabled in TWL/NTR mode.

Good luck with that.

 

[Deleted User]

@smealum @Apache Thunder @Bobesh8 Tagging you guys in case you could make any since in it

 

[RocketRobz]

Exactly the tool I was talking about in the TWL hacking thread. I downloaded it already.

 

[Nyap]

incoming: oh mer gerd just by a fleshcart

 

[Deleted User]

Tagging @TuxSH @Aurora Wright because they have worked with TWL_Firm before

 

[Mrrraou]

 

[Uziskull]

Mass-tagging people to see an hypothesis like we see once per week might not be a good idea.

EDIT: So, basically, to all of those who "have ideas", please pay close attention to the post above mine.

 

[Deleted User]

Oh my! Not that video! XD

 

[VinsCool]

How could a GBA Flashcard tool be related to this?

 

[Deleted User]

How could a GBA Flashcard tool be related to this?

Read all of the first post

 

[Ricken]

How could a GBA Flashcard tool be related to this?

iirc, GBA Games run based off of the (TWL?) Partition, like DS games

 

[Deleted User]

iirc, GBA Games run based off of the (TWL?) Partition, like DS games

Wait a second.... Maybe we could just boot the patched games from AGB_FIRM?

 

[Ricken]

Wait a second.... Maybe we could just boot the patched games from AGB_FIRM?

Wait, was my info accurate?

This is usually where I get corrected

 

[Deleted User]

Wait, was my info accurate?

This is usually where I get corrected

From what I see, that's what this tool is doing

 

[mysamdog]

My understanding of slot2 nds flashcarts is that there is a slot1 device that tells it to load (NDS) code starting from a location in memory that happens to be mapped to slot2. The gameboy compatability has nothing to do with it, its just the fact that the slot is accessible from nds mode.

 

[RocketRobz]

If we can somehow contact that person who created NDSPatcher to make a new version that patches code to read from DSiWare NAND/SD, or to give us the source code, our lives would be complete!

 

[Deleted User]

My understanding of slot2 nds flashcarts is that there is a slot1 device that tells it to load (NDS) code starting from a location in memory that happens to be mapped to slot2. The gameboy compatability has nothing to do with it, its just the fact that the slot is accessible from nds mode.

But if Slot 2 is able to boot into NDS mode, wouldn't that mean that that NDS mode is just accessible from the Gameboy mode .... Meaning we could boot into it from AGB?

 

[mysamdog]

Slot 2 is not booting in to nds mode, nds mode is booting and reading code from slot 2. Very big difference

 

[Deleted User]

Slot 2 is not booting in to nds mode, nds mode is booting and reading code from slot 2. Very big difference

Ok, then we'd need to edit the patched somehow to replace all instances of Slot 2 with SD card

--------------------- MERGED ---------------------------

If we can somehow contact that person who created NDSPatcher to make a new version that patches code to read from DSiWare NAND/SD, or to give us the source code, our lives would be complete!

The forum says someone named "]{ain" made it. Either we could contact the forum creator or just go google "]{ain"

 

[linkinworm]

just because something works on one system, doesn't mean it can work for what ever on another system, while anything is possible, there are X Y Z reasons things can and cant work, common ones being things like physical limitations within software and how much exploits can access, i'm sure the smart guys would have already tried to get something like this working in their own time for their personal use for learning purposes with possibly no luck. It's easy to just say "omg they can just do it why don't they do it" which is what you see all the time with "can we get an exploit for this game i own please" not that simple