Homebrew [How-to] Load a fw.img for Any File Dumping + WiiUBru status update


Garage Flower
Dec 4, 2011
Manchester UK
Hi everyone,

For the past three weeks there has been heavy active development on our WiiUBrU forums regarding the IOSU exploit by generous users of the community. It has been developed in the public-eye, and as a result was able to gain speed quickly by not creating a barrier for people who wanted to get involved.

Today, one very important thing is being "officially" released:
CFW Booter - A .elf file for the Homebrew Launcher which will boot a custom fw.img off the root of the SD card. In other words, this is a stable version of the long-coveted "IOSU exploit" for 5.5.x users only !!

As usual, the file can be downloaded here or on the Homebrew App Store. If your Wii U isn't set up at all for homebrew, you can visit wiiubru.com/go on your Wii U.

However! A "CFW Booter" is not useful without a modified fw.img file to use it with... Thanks to the effort of @smealum several months ago, and his release of iosuhax, making a fw.img with modified patches is as easy as reading and running his code. Anyone can do this now using the above booter, BUT if you use random fw.img's lying around, that's at your own risk.

In short, the IOSU exploit elf provided above ALONE cannot hurt you or your console. It alone also cannot get you nand backups or redNAND.

So, from here on the deliverables will likely be in the form of new fw.img to boot with the above elf. Yes, this means the goal is no longer"omg teh iosu exploit", but rather a properly patched fw.img files, that does what you want it to do.

And don't freak out!

There's been "rumors" spreading about our team, and some people even go as far as to call this typical developer arrogance/elitism. It is not that. If you know where to look, and you are willing, you can find us, talk with us, test this stuff out. It's not ready for end users. Don't blindly run it. If you're brave and willing to get your hands a tad dirty come talk to us.

And before I say more, our current RedNand progress does not currently allow installation of unsigned tiles. It cannot be used install homebrew titles, only signed ones. It is actively still being worked on! So yes, we have redNand. We have NAND dumps. You could too, but don't take that as a challenge! Come and chat with us. If you don't want to get your hands dirty, wait for somehthing official either from us or Salt. Again, we have not cracked title installation so right now RedNand isn't very useful to the non-developer!

Also, the reason we are not releasing a NAND dumper right now is the backup format is pretty glitchy (dumps fail, writes raw bytes to hardcoded values on SD, ec). Again, if you're willing, stop on by and work on it with us. Otherwise, this shouldn't be interesting to anyone.

And for the hopefully near future, you will also want a 64GB sd card or bigger if you have a 32GB console. You don't have to worry when we say soon™ cause all the work is already out there if others want to pick it up. The way it should be. We also have no info on a coldboot hack, but if anyone has any suggestions or ideas, hit us up!

Okay, but that's it for bad news. We have some good news too. :) We are providing a fw.img that we do think is ready for the public to use with the above elf. It won't dump NAND, and it won't boot redNand, and it certainly won't patch titles, but it will let you dump some files using IOSU access from your Wii U.

If you copy this fw.img in sd:/fw.img and run our elf at the top of this post, you will boot into a mode that runs Smea's "wupserver". Once it boots, it will look like the normal Wii U menu, but it will be running a server in the background that can connect to from your computer. You then dump and mount various things from the Wii U that you normally couldn't.

As fw.img files are copyright Nintendo, we cannot provide them to you directly. Instead here are the instructions on how to make a wupserver fw.img, and here is a patch that you can apply to one downloaded from NUS. You can do this with the latest JNustool with We know these instructions aren't great, but you can ask if you have questions. Just please /please/ stop running unfinished, dangerous "rednand fw.img's"

Once you run the wupserver on your Wii U by placing that fw.img on the root of your SD and running our elf above, you can connect to it either with a modified version of smea's wupclient.py or the new wupclientgui.py that was developed. Both are available here:http://www.wiiubru.com/appstore/wupclientgui.zip . And if you hate python, a Java Gui version is on the way.

As it has been repeated do not run any files you see "from us" running around in the wild. You will hear from us through our twitter page at http://twitter.com/wiiubru or you can ask us. But chances are if we haven't tweeted, it's not ready. (from us)

We're aware the community has been burned by at least two maybe three teams in the past on public releases, but this is different. You can play along this time, there's no special rules to play!

Anyway, please understand. Thank you

Last edited by vgmoose,


Well-Known Member
Nov 3, 2015
There are some mistakes on the pastebin, which are probably going to confuse everyone:

(Line 14+15)
two keys and iv in sections/gensections.py
one key and iv in bin/getfwimg.py

change it to:
two keys and iv in bin/getfwimg.py
one key and iv in scripts/anpack.py

(Line 21)
python getsections.py

change it to:
python gensections.py

Also I'm unable to boot it, for some reason it gets stuck on "Welcome to rednand 00000000" for me.

Good work tho :)


Well-Known Member
Feb 23, 2016
Seattle, WA
United States
I run into an issue running getfwimg.py saying I don't have module Crypto.Cipher
If you have pip installed, you can install the pycrypto package with "pip install pycrypto". You should be able to look up more info about installing pycrypto for your environment with google if that isn't enough to make it work alone.

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