Hacking ROM Hack Help to rebuild a GameCube iso

[creedof69]

Hello everyone,

So I'm trying rebuild a GamecCube disc image after I changed some files in It. I used either Wiimm's, GCRebuilder or GC iso tool to extract the iso into files, but now in order to rebuild the iso I'm having some problems.
First GCrebuild doesn't allow me to save a new iso because files that I've replaced are bigger than original ones. Then I tried to rebuild the iso with gc iso tool but When I try to rebuild it choosing "full size image" the result is a "non gamecube iso", when I choose Trimmed iso the image is an actual gamecube iso and the game kinda work but the system file list may not proper so any tool display the game wrong for exemple Dolphin doesn't manage to get the banner img and banner detail are false or non-existent (see image 1, 2, 3).

I also tried to use Wiimm's tool with WIT, the extraction is good, but whatever i tried the rebuild build a 4GB Wii iso, even if in extracted file, wit bat file precise that he know it a gamecube "disc-type".

Then I heard about pyisotools, this is where I need help, I don't manage to make the software work. I can open it, open an iso but ever when I try to extract one or open a root folder the software display a error message, I tried the windows .exe alone because I thought it could run as a standalone, install the latest python, uninstall python, install a previous python 3.11 like the github provide.
Any Youtube video which mention this software doesn't show what should We have to make it works, it just works already.
Is there anyone familiar with it ? Or have any way to build a gamecube iso with the good file allocation ?
Thanks in advance.

 

[XFlak]

Can u successfully rebuild it if you weren't to modify any of the contents? If so, it helps you narrow down your issue

 

[TheSunGodNika]

Try out gc_fst if you're rebuilding it from a folder: https://github.com/AlexanderHarrison/gc_fst

This command should end up generating a new GameCube ISO:

gc_fst rebuild <folder path> [iso path]

 

[creedof69]

Can u successfully rebuild it if you weren't to modify any of the contents? If so, it helps you narrow down your issue

Nope, I tried every version of the iso, modified and untouched. No work. And as I have an error even for extracting, I guess the software just not found necessary files to work properly.

Post automatically merged: Aug 10, 2025

Try out gc_fst if you're rebuilding it from a folder: https://github.com/AlexanderHarrison/gc_fst

This command should end up generating a new GameCube ISO:

gc_fst rebuild <folder path> [iso path]

Thanks I'll try today. But this part scares me a little bit :
"The gc_fst binary does not support editing metadata (banner image, game name, description, etc.) contained in opening.bnr."
Isn't it the thing I need to conserve that I don't manage to keep with gc iso tool ? ^^

Edit : I may be dumb, but I've never been talented with cmd line software.

For example after I download 2 files gc-fst and gc-fst.exe I tried to build an iso from my root folder so opening cmd and write : "gc_fst rebuild <C:/user/downloads/root> [C:/user/downloads/test.iso]"
and it just says me "unable to find file"

Ok at the very bottom of the GitHub page it's written that the software is in rust language so I should have install that.

 

[creedof69]

Well, no, I don't manage to make it works.
Even after installing rust, the command line instruction I wrote doesn't run anything. "Syntax is bad" etc

 

[TheSunGodNika]

Nope, I tried every version of the iso, modified and untouched. No work. And as I have an error even for extracting, I guess the software just not found necessary files to work properly.

Post automatically merged: Aug 10, 2025

Thanks I'll try today. But this part scares me a little bit :
"The gc_fst binary does not support editing metadata (banner image, game name, description, etc.) contained in opening.bnr."
Isn't it the thing I need to conserve that I don't manage to keep with gc iso tool ? ^^

Edit : I may be dumb, but I've never been talented with cmd line software.

For example after I download 2 files gc-fst and gc-fst.exe I tried to build an iso from my root folder so opening cmd and write : "gc_fst rebuild <C:/user/downloads/root> [C:/user/downloads/test.iso]"
and it just says me "unable to find file"

Ok at the very bottom of the GitHub page it's written that the software is in rust language so I should have install that.

"opening.bnr" will still be built within the ISO. The part where it discusses about it is only for editing it externally.

--------

You need to remove the "<>" and "[]", those are just there to show each different argument.

And if you got spaces on your path/filename, you'll need to use quotes (") at the beginning where it displays the drive letter to where either the path or extension of the file ends at on the filepath.

And since it's been compiled already, you don't need to install rust

 

[creedof69]

"opening.bnr" will still be built within the ISO. The part where it discusses about it is only for editing it externally.

--------

You need to remove the "<>" and "[]", those are just there to show each different argument.

And if you got spaces on your path/filename, you'll need to use quotes (") at the beginning where it displays the drive letter to where either the path or extension of the file ends at on the filepath.

And since it's been compiled already, you don't need to install rust

So yesterday I manage to do it, very lately lol.

For those in 5 years which may have the same problem.
I had to install Rust in my PC, the language of gc_fst which isn't understandable by the stock Windows cmd, in the install proccess I had to install Microsoft Visual Studio too. With rust installed I had now to install gc_fst. You have to write in cmd "cargo install gc_fst" or "cargo install --git http:.....(The GitHub url).
I didn't even know that We could install those hidden software through cmd like how rust server already know that this GameCube iso tool exist lol.

But only with that, I always had an error after the the download when he tried to build the app, "linker.exe" was not found "make sure you have C++ modules when you installed Visual Studio".

Alright, I opened Visual Studio installer, I already had a c++ module but I downloaded ALL OF THEM. 7.5Gb just to know if it would solve the issue. And it did !

Now directly typing "gc_fst" in cmd doesn't write "ohoho it is not a known command" but the list of command gc_fst can do.

I wrote gc_fst extract C:User\.... And it freeze the cmd, so that mean it WORKS

But as I was afraid of the extract cmd, you don't set a output path, so I had to look for the folder in all my PC but it is just in C:user.

"opening.bnr" will still be built within the ISO. The part where it discusses about it is only for editing it externally.

--------

You need to remove the "<>" and "[]", those are just there to show each different argument.

And if you got spaces on your path/filename, you'll need to use quotes (") at the beginning where it displays the drive letter to where either the path or extension of the file ends at on the filepath.

And since it's been compiled already, you don't need to install rust

After that the cmd rebuild "this" to "that" worked well as well and yes I tried many "bad syntax" with either no "" or with those <>. But I'v though if for files location We need those "" and without only used for directory location. And that was that.

After the rebuilding all the banner and the files system are displayed correctly.

Thank you SollaceEllery. Byw pyisotools still not work even with the python version of it (I could install it the same way with cmd "py -m pip install pyisotools") but it displays the SAME errors than the windows exe version so for me it's a problem from the app itself, idk what black magic those YouTubers did to make it work