Hacking [IDEA] Launch a minimal CFW (like SaltFW) if no arm9loaderhax binary is found on SD

[gamesquest1]

can't you just adjust the ncsd partition table to take up a small section of the twl partition, iirc the partition table has the offset and size so you could just shrink the twl partition and create a small void for housing the payload, although i have always liked the idea of the extra 700mb on some n3ds consoles being put to use, but i guess all these things are taking the system further and further from the original stock setup

 

[Pokéidiot]

Well, I will try ShadowNAND's solution to test my stage2 mod myself. Some users are saying that it's better to load a binary from CTRNAND. For those, I have good news: I created a folder on my sysNAND CTRNAND partition and nothing bad happened. Space will not be problem since ... a9lh payloads are small enough.

 

[xXDungeon_CrawlerXx]

Well, I will try ShadowNAND's solution to test my stage2 mod myself. Some users are saying that it's better to load a binary from CTRNAND. For those, I have good news: I created a folder on my sysNAND CTRNAND partition and nothing bad happened. Space will not be problem since ... a9lh payloads are small enough.

it isn't a problem to add custom files into CTRNAND. Just added a txt called "HowToTrollNintendo.txt" some months ago and nothing bad happened.

 

[daxtsu]

Well, I will try ShadowNAND's solution to test my stage2 mod myself. Some users are saying that it's better to load a binary from CTRNAND. For those, I have good news: I created a folder on my sysNAND CTRNAND partition and nothing bad happened. Space will not be problem since ... a9lh payloads are small enough.

It's not space that others are worried about, it's fragmentation, apparently (you'd think FIRM would be intelligent enough to deal with it, but I guess this is Nintendo code we're dealing with).

 

[Pokéidiot]

Sacrifice a bit of TWLNAND space to put payloads in it. You don't need all dat space to get DS games running.

 

[GerbilSoft]

can't you just adjust the ncsd partition table to take up a small section of the twl partition

The NCSD header (including the encrypted TWL MBR) is signed. Any modifications would cause a Boot ROM error.

(Sidenote: The O3DS NCSD injection used for 2.1 downgrades on N3DS work because it's using a valid NCSD header from an O3DS, so the signature passes verification.)

 

[Pokéidiot]

The NCSD header (including the encrypted TWL MBR) is signed. Any modifications would cause a Boot ROM error.

(Sidenote: The O3DS NCSD injection used for 2.1 downgrades on N3DS work because it's using a valid NCSD header from an O3DS, so the signature passes verification.)

For patching signature checks at a level like that, we need a bootrom exploit.

 

[gamesquest1]

yeah i figured with it being on a9lh sig checks would be bypassed anyway, or are those verified prior to a9lh kicking in?

if thats not possible i guess sticking it inside twl/ctr FS will probs be for the best then

 

[GerbilSoft]

yeah i figured with it being on a9lh sig checks would be bypassed anyway, or are those verified prior to a9lh kicking in?

NCSD signature is verified by the Boot ROM before it even attempts to load FIRM0. See https://www.3dbrew.org/wiki/Bootloader for more information.

 

[gamesquest1]

NCSD signature is verified by the Boot ROM before it even attempts to load FIRM0. See https://www.3dbrew.org/wiki/Bootloader for more information.

ah ok good to know, oh well there goes my side plan to adjust my partition tables to use the extra 700mb on my n3ds XD

 

[Pokéidiot]

yeah i figured with it being on a9lh sig checks would be bypassed anyway, or are those verified prior to a9lh kicking in?

if thats not possible i guess sticking it inside twl/ctr FS will probs be for the best then

A9LH isn't a bootrom exploit. A9LH is a pre-kernel (firmware loader) exploit.

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

I'm going to redo my A9LH mod, but I fell that I will need to borrow lots of code.

 

[Jawertae]

It's not space that others are worried about, it's fragmentation, apparently (you'd think FIRM would be intelligent enough to deal with it, but I guess this is Nintendo code we're dealing with).

If there is one thing nintendo strives for, its stability.

 

[Pokéidiot]

If there is one thing nintendo strives for, its stability.

Too much stability to prevent NAND fragmentation

 

[Shadowhand]

If that's out, then could we not examine how much unused space there is in a typical NAND (being out of the boundaries of CTRNAND's free space/max size, of course) and install our own small FAT12 or FAT16 partition somewhere? If a common place could be agreed on, then I'd think support for it could easily be added to tools like GM9.

That is technically possible, but (don't quote me on this) some NAND types don't have extra available space on n3ds, and have no space on o3ds at all. I really find that it's safer to have the CFW in stage2 rather than somewhere else on the NAND.

 

[Zan']

That is technically possible, but (don't quote me on this) some NAND types don't have extra available space on n3ds, and have no space on o3ds at all. I really find that it's safer to have the CFW in stage2 rather than somewhere else on the NAND.

Even the snallest o3DS chip (943MB) has about 1MB spare.
The problem is, it wont be that easy to simply create a new partition in the end because it msy possibly kill your data.
However you could use a NAND backup and put a partition you want properly aligned in the end and reflash that NAND backup, which would basically give you exactly that.

 

[Shadowhand]

Even the snallest o3DS chip (943MB) has about 1MB spare.
The problem is, it wont be that easy to simply create a new partition in the end because it msy possibly kill your data.
However you could use a NAND backup and put a partition you want properly aligned in the end and reflash that NAND backup, which would basically give you exactly that.

That's still way too risky and there won't be a way to recover from brick without hardmod.

 

[zekepliskin]

This is an interesting idea. I was thinking it might be nice to have something more basic though, i.e. if an SD card isn't inserted rather than black screen and console shutting down as it does now, how about a simple white text on black background message showing on the top screen :-

"Arm9LoaderHax.bin Not Found (No SD Card Inserted). Please Insert SD Card Containing Payload And Try Again."

Then after ten seconds or so it times out and shuts the console down.

 

[Shadowhand]

This is an interesting idea. I was thinking it might be nice to have something more basic though, i.e. if an SD card isn't inserted rather than black screen and console shutting down as it does now, how about a simple white text on black background message showing on the top screen :-

"Arm9LoaderHax.bin Not Found (No SD Card Inserted). Please Insert SD Card Containing Payload And Try Again."

Then after ten seconds or so it times out and shuts the console down.

*cough*