Hacking Sys/EmuNand linking technical background

w0dash

noob
OP
Member
Joined
May 29, 2012
Messages
151
Trophies
0
XP
526
Country
Gambia, The
Hello,

it is well known that the system and emulated nand are linked after creation and unlinked after formatting one of them.

Can someone explain in which way they are connected, as they don't share the same memory partition?
 

zoogie

playing around in the dsiware
Developer
Joined
Nov 30, 2014
Messages
8,456
Trophies
2
XP
14,022
Country
Micronesia, Federated States of
Here is a little visual representation of the unlinking concept I just whipped up. Hope it helps some.

NANDunlinking.PNG
 

lPolarisl

Well-Known Member
Member
Joined
Jan 24, 2015
Messages
334
Trophies
0
XP
164
Country
Hungary
Let's say you have your sysnand. You decide to have an emunand. The program creates an emunand on your SD card, this just copies your 3DS's firmware to the SD card, your personal files (games, pictures, or anything not related) stay on the SD card.
Now, every 3DS has a custom "signature", this is why you can't play another 3DS's 3dsware, the "signatures" don't match up.

Your emunand is a clone of your sysnand, therefor they have the same "signature", so if you meddle with one's personal files, it is in conflict with the other's personal files. Because the filesystem wasn't designed to be used by two different 3DSs.

When you format one of your nand's, you change that nand's "signature", as such it will now use different files. You'll be running two different 3DS on the same system.

I don't know if I was clear, feel free to ask away :)

everyone else : correct me if I made any mistakes.
 
  • Like
Reactions: thorasgar

scynetic

New Member
Newbie
Joined
Jan 29, 2015
Messages
1
Trophies
0
Age
32
XP
31
Country
United States
When formatting sysnand or emunand, do you always pull out the SD card? Is there a best spot to do this in the format process?
 

cearp

瓜老外
Developer
Joined
May 26, 2008
Messages
8,639
Trophies
2
XP
7,867
Country
Tuvalu
it's just one smaller little file called movable.sed that is stored in nand.
it is the same file that gets transferred when you system transfer, so that all your old content will work on the 3ds you changed to.
when you format you get a new moveable.sed file.
 
  • Like
Reactions: Obi123

thorasgar

Checkout my evil Soon-in-ator™
Member
Joined
Jul 3, 2010
Messages
3,783
Trophies
1
XP
2,493
Country
United States
When formatting sysnand or emunand, do you always pull out the SD card? Is there a best spot to do this in the format process?
When you format sysnand you pull the SD card out before you confirm the format.

I have never tried pulling the card out while formatting emunand. Considering emunand is on the SD card I think it rather unwise, but what the hell give a try and see what happens. :)
 

cearp

瓜老外
Developer
Joined
May 26, 2008
Messages
8,639
Trophies
2
XP
7,867
Country
Tuvalu
When you format sysnand you pull the SD card out before you confirm the format.

I have never tried pulling the card out while formatting emunand. Considering emunand is on the SD card I think it rather unwise, but what the hell give a try and see what happens. :)

it crashes
 

cearp

瓜老外
Developer
Joined
May 26, 2008
Messages
8,639
Trophies
2
XP
7,867
Country
Tuvalu
Didn't know that, thanks for the information. :)

that is why some people say to remove the sd card when you system format in settings, if the sd card is not there, it cannot delete your stuff :D
(but you will still get a new movable.sed file in nand) - so the stuff that would have been deleted would no longer work with this nand -- but if you have another nand that you did not format, and you have just 'unlinked' them, then the stuff will work with the other nand...
i hope that makes sense, maybe i explained it badly :)
 

cearp

瓜老外
Developer
Joined
May 26, 2008
Messages
8,639
Trophies
2
XP
7,867
Country
Tuvalu
Is it true you can't make your own .cia files once you unlink? It seems to be the only downside to unlinking

well, you cannot decrypt your own stuff no, not if you extract your movable.sed file and put it on the sd card, so it will be used when decrypting :)
but if you use something like FunkyCIA, you will be ok, because it does not need to decrypt anything
 

FR0ZN

Well-Known Member
Member
Joined
Nov 2, 2013
Messages
1,238
Trophies
0
Age
36
XP
2,965
Country
United States
Here is a little visual representation of the unlinking concept I just whipped up. Hope it helps some.

View attachment 15105

This is strange, I have never unlinked my NANDs but they are seperated. I looked inside the Nintendo 3DS folder and there is only one sub folder in there. I also don't have this unwrapping bug everybody is tallking about for CIA titles. The only thing I noticed after I created my emuNAND back at the time, was that the WiFi configuration carried over to sysNAND, but I was able to delete it there and let it remain for emuNAND.
But apart from that I never ever formatted either NAND.

EDIT: Another Thing I noticed is that, when I install a CIA on emuNAND, I can see it in sysNAND. And I remember that I tried to create a Homebrew folder in emuNAND to put all my CIAs in there, but it didn't carry over to sysNAND, it just reset that Setup for both NANDs and I actually had to create a folder on both NANDs for them to stay like this.
 

Maximilious

*whistles his distinct tune*
Member
Joined
Nov 21, 2014
Messages
2,570
Trophies
0
XP
1,834
Country
United States
This is strange, I have never unlinked my NANDs but they are seperated. I looked inside the Nintendo 3DS folder and there is only one sub folder in there. I also don't have this unwrapping bug everybody is tallking about for CIA titles. The only thing I noticed after I created my emuNAND back at the time, was that the WiFi configuration carried over to sysNAND, but I was able to delete it there and let it remain for emuNAND.
But apart from that I never ever formatted either NAND.

EDIT: Another Thing I noticed is that, when I install a CIA on emuNAND, I can see it in sysNAND. And I remember that I tried to create a Homebrew folder in emuNAND to put all my CIAs in there, but it didn't carry over to sysNAND, it just reset that Setup for both NANDs and I actually had to create a folder on both NANDs for them to stay like this.


That sounds a little messed up. I would backup your SD card and emuNAND with emuNAND Tool, remove SD card, format sysNAND again, format emuNAND, restore emuNAND from backup. Then you can copy over one of the two folders to see which one is the correct one for emuNAND.
 

FR0ZN

Well-Known Member
Member
Joined
Nov 2, 2013
Messages
1,238
Trophies
0
Age
36
XP
2,965
Country
United States
That sounds a little messed up. I would backup your SD card and emuNAND with emuNAND Tool, remove SD card, format sysNAND again, format emuNAND, restore emuNAND from backup. Then you can copy over one of the two folders to see which one is the correct one for emuNAND.

There is no second folder ... only one folder in the "Nintendo 3DS" folder :D
 

You may also like...

General chit-chat
Help Users
  • No one is chatting at the moment.
    CupheadtheCritic @ CupheadtheCritic: Ello +1