Homebrew DS(i) Mode hacking progress thread

[Zidapi]

- the arm11 is responsible for fetching the DS frame buffers from lgyfb and displaying it. so you can totally change the way it does that, apply some post processing to that if you're into that, but that's basically it. I have some documentation on lgyfb, but the gist of it is there's some configuration for the upscale filter, and then it uses its own DMA engine to fetch the actual data.

Any documentation you made as a result of research into this would really help the community should you share it.

One of the early system updates, probably 2.0, implemented considerable improvements to the way DS were displayed (imagine how bad they were before!).

It'd be interesting to see if we could improve on the current settings. Would it be outside the realm of possibility to implement "standard" emulator filters such as Super Eagle or Hq2x to improve/modify the way DS games are displayed?

I'm not even sure what this LGYFB (Framebuffer perhaps?) is you're referencing

Let's Get You Frame Buffs obviously

 

[hacksn5s4]

so would making ar codes work be possble

 

[froggestspirit]

So from what I'm gathering, is that it's not only saving that wouldn't work, because it looks for a non-existant cart, but also reading game data?
@smealum Do you think it would be reasonable to have a program parse the ARM code of DS roms, and have it auto-patch code that uses cart reading/writing with Nand/SD? iirc, the asm was word aligned

 

[dubbz82]

So from what I'm gathering, is that it's not only saving that wouldn't work, because it looks for a non-existant cart, but also reading game data?

That's also how I read it. Basically the problem of saving a game isn't even an issue until we work out how to have data transfer somehow redirected from the cartridge slot to a rom file, and AFTER that's worked out, then the issue of save redirection comes into play...I won't go so far as to say it sounds impossible, but it sounds like it's going to end up being far from trivial (that being said, I do like some of the other things that have been brought up, for example the possibility of fixing the resizing of stuff in twl and/or agb firm). Really, any improvement that can be done to the dsi/gba modes is a plus in my book.

 

[Billy Acuña]

So from what I'm gathering, is that it's not only saving that wouldn't work, because it looks for a non-existant cart, but also reading game data?
@smealum Do you think it would be reasonable to have a program parse the ARM code of DS roms, and have it auto-patch code that uses cart reading/writing with Nand/SD? iirc, the asm was word aligned

you could potentially force it to run in twl instead of ntr and redirect rom and save to sd or nand

 

[hacksn5s4]

thing is would it also be possible to hack ar codes in and have a rom selector on the thing

 

[froggestspirit]

@Billy Acuña

you could potentially force it to run in twl instead of ntr and redirect rom and save to sd or nand, it the game might not even run due to some funky memory mapping differences. (something to do with mirrors iirc)

That's why I'm curious about an automated solution

 

[dubbz82]

thing is would it also be possible to hack ar codes in and have a rom selector on the thing

Lets see if even one-off rom loading is viable first. I'd guess after that's worked out, implementing stuff like ar codes will be...not trivial, but at least doable.

EDIT:Although...I do wonder how difficult it might be to enable ar codes with retail carts?

 

[jaksy]

thing is would it also be possible to hack ar codes in and have a rom selector on the thing

so would making ar codes work be possble

No.
Basically all Smea did was explain why we can't load nds roms without a flashcart, as all we have control over is the way the arm11 renders the image being output from ds mode.
This does mean we can mess with the image clarity though.

OP UPDATED!!!
Thank you so much @smealum for seeing this post!!!

2.- Not WIP at all, but here's Smea's theory from this thread of how to load DS roms from the SD (with some limitations):

From my understanding it's not really a theory on how to load DS roms, more of an explanation on why it's not viable.

 

[dankzegriefer]

No.
Basically all Smea did was explain why we can't load nds roms without a flashcart, as all we have control over is the way the arm11 renders the image being output from ds mode.
This does mean we can mess with the image clarity though.



From my understanding it's not really a theory on how to load DS roms, more of an explanation on why it's not viable.

But we have ARM9 control on 9.2 and lower.

 

[Supster131]

This does mean we can mess with the image clarity though.

While quite unrelated to what people are trying to achieve, this is still pretty cool. Being able to go back and play DS games which a much quality, sounds exciting!

 

[Billy Acuña]

From my understanding it's not really a theory on how to load DS roms, more of an explanation on why it's not viable.

Nope, what I saw is the problems with DS Mode and its potential solutions, howerver, with his contribution we finally know (more or less) where to start.

 

[jaksy]

But we have ARM9 control on 9.2 and lower.

even with legit games, you're pretty limited in terms of what improvements you could make to the twl_form experience. basically switching into twl mode completely disconnects the arm11 (the only thing running 3ds mode code at that point) from fcram, which is where most (?) twl memory lives. I tried but failed to bring that bus back up. so basically arm11 can't affect twl stuff : can't edit memory, can't control execution in any way (in fact, hitting home doesn't even pause execution iirc)

 

[dankzegriefer]

-snip-

ARM9 ain't ARM11
ARM9 is the NDS processor.

 

[Billy Acuña]

ARM9 is the NDS processor.

Not only that.

 

[dankzegriefer]

Not only that.

Well, and responsible for security. But we're talking about NDS/DSi injection on 3DS.

 

[hacksn5s4]

well ar codes could be possble because smea said its its possble to inject homebrew so you could inject a game pacher to use ar codes or patch game temporally

 

[dubbz82]

While quite unrelated to what people are trying to achieve, this is still pretty cool. Being able to go back and play DS games which a much quality, sounds exciting!

Realistically, I think what the purpose of this thread is (or at least should be) is how to improve upon the DSi mode in any way possible. Granted the primary focus thus far has been "zomg romz!", really anything that we can add to/improve upon the DSi mode to make it better than what it comes with out of the box is a huge plus.

 

[hacksn5s4]

sounds like cheating coud be bpossble by injecting homebrew that patches game into ds mode then putting your game in and hitting start on it

 

[Zidapi]

thing is would it also be possible to hack ar codes in and have a rom selector on the thing

One step at a time kid, we haven't even taken one step yet.