ROM Hack [Tutorial] Decrypt and modify MK7 files like KartParts_Param_Accel.bin

[Faewui]

Hey everyone ! I struggled to understand how the MK7 params files works. So I decided to make a tutorial for begginers

What you will need:
- a decrypted mk7 rom

WTF ? What that is !

Look at this thread bro !

- Every File Explorer
- an basic hex editor
- anddd... A brain.

So, let's starting !!

1/ Let's extract KartParts_Param_Accel ( for example )

If you already have the file you want, you can skip this part.

Spoiler: Instructions

For this part, you will need every file explorer, and your decrypted MK7 rom.

Open EFE, and then click on the folder icon, and open the "common.szs" file in your rom ( maybe in a folder called "romfs" )

Then, a window will pop-up, now select the file you want and export it where you want.

2/ Let's open the file, and modify/decrypt it !

Open your file with a hex editor, you will see something like that:

You can see pointers ( Default, Lv1... etc,).
The first 4 bytes (01 00 00 00) seem to be useless, but the bytes after ( 15000000 and 02000000 ) seem to be used.
15000000 in hex converted to a signed int is "21".
02000000 in hex converted to a signed int is "2".
21 + 2 = 23.

So we know that our file contain 23 values/pointers !!!


We know that one pointer name is 32 bytes long ( use the brain... ),
so we go count 32 * 23 AFTER the 12 first bytes, andddddddd,
I remove this part because it's not the values, only the pointers and the file structure info. ( do not remove this part, it's only for the tutorial ! )

So we know that there are 23 value... There is 46 "little packets"...
46 / 23 = 2 !!!
You're right !!! There is 2 "little packets" for each values.
So it's better like that:

Now, for example if I want to modify the value of "Default", we remember that "Default" is the first pointers, so we need to modify the first two packets !
You can save your file and start being rich.

3/Reinjecting the file into "common.szs"

If you are a god, you can skip that =D

Spoiler: Instructions

Now, reopen "common.szs" like in the first chapter, and click on the file you want to replace (here, KartParts_Param_Accel.bin), right-click on, then click on replace and select your modified file !
Now you need to rebuild the rom, and you're rigth.

345678/End

I'm new on this site, but I used it multiple times, so I decided to help a little.
The only thing to say about me: I love everything that touch to the computers, skate and bear.

If you know what is the name of the "little packets", you find some non-english words (im french), you can send me a pm .

Good hacking ^^