This is now obsolete, my CFW guide covers this, please follow this instead of the guide here.

THIS MAY BRICK YOUR WII U PERMANENTLY! ME/GBATEMP WILL NOT BE RESPONSIBLE.

Installing Haxchi :

Spoiler: Requirements

Requirements :

• redNAND setup, follow this to set it up.
• All of the requirements that are needed for redNAND setup.
• Some money, around 10$.

Spoiler: Installing Haxchi

Installing Haxchi

• Purchase a compatible DS VC game off of the eShop, here are some compatible games. MAKE SURE IT'S INSTALLED TO NAND, DO NOT LEAVE IT ON USB.
• Set up haxchi by following the guide here, it's under Installation.

Setting up coldboothax :

Spoiler: Editing system.xml

Editing system.xml a.k.a installing coldboothax

• Boot up iosuhax for sysNAND, compile this.
• Place the fw.img you receive from compiling iosuhax on your sd card.
• Boot up the homebrew launcher.
• Run cfwbooter.
• You should have a wupclient folder where you compiled iosuhax, open it and edit wupclient.py and add your IP address.
• Open a command prompt window in the folder where you have wupclient.py and run "python -i wupclient.py"
• Run "w.dl("/vol/system_slc/config/system.xml")" without the first and last quotation marks
• Open system.xml in a text editor like Notepad++ and edit the default_title_id, set it to the title id of your haxchi'd game.
• Save and run "w.up("system.xml", "/vol/system/config/system.xml")" without the first and last quotation marks.
• Reboot your Wii U, pray, glhf.

CREDITS:
@smealum - Original IOSUHax
@FIX94 - IOSUHax improvements

 

[iAqua]

This thread is now ready, thank you for waiting.

 

[Lightyose]

If only I had a Wii U...

 

[iAqua]

If only I had a Wii U...

Maybe get one when they're really cheap soon ;p.

 

[Lightyose]

Maybe get one when they're really cheap soon ;p.

There is no more gamestop in my country...

 

[iAqua]

There is no more gamestop in my country...

Gamestop isn't the only retailer.

 

[Lightyose]

Yeah, but, in other stores they are harder to find and more expensive, plus, there is no best buy or EB games anymore.

 

[MattKimura]

Still loads the IOSUHAX screen twice huh?

For now I'm gonna stick to booting it manually, especially with the new SigPatcher2SysMenu

 

[TeconMoon]

Plus by doing this, you're system is pretty much doomed to always boot RedNAND forever, which currently kills all vWii functionality, and if you swap out the fw.bin and try and boot SysNAND, you'll just get stuck in a bootloop. It becomes impossible to recover your SysNAND.

 

[sj33]

This is certainly interesting and it's easy to see why it is appealing, but I won't be doing it just yet.

People need to be clear on this - this is NOT like A9LH. Why? Because A9LH is an exploit that runs extremely early in the boot process, before the system software begins to boot. This is important because it adds a level of recovery to your device - to an extent, you will always be able to recover a bricked system because you can load a backup to install fresh system software. In this sense, it is like bootMii on the Wii. The exploit is executed PRIOR to the system software.

Coldboothax is NOT like this. It is a modification of the system software itself to load a specific title on initialisation. This is nice, but is irreversible and you will NOT be in a position to recover your system should anything break or fail. Couple this with the fact that it may not be desirable to permenently boot into redNAND (which remember, ties you to your one specific SD card) with no way to revert to SysNAND and you have a exploit which could easily backfire. Should your SD card fail, it's not clear how you would be able to create a new one.

It's a nice exploit, but I think haxchi remains the safest, most flexible exploit which also gives the user something to fall back onto should their redNAND break.

 

[ItsKipz]

This is not safe to use, but if people are really going to use this, could you add a note that if someone bricks from this they should contact me on here ASAP, i'm testing an idea for a potential unbricking method.

 

[vgmoose]

@iAqua, You should probably point out that 5 of the 6 reported IOSU bricks are due to attempting coldboothax unsuccessfully: http://wiiubru.com/rip/

Personally, I think the only way I see this taking off is if someone makes an automated system.xml patcher that won't ever perform it incorrectly, and ensures that the title ID is properly configured. But I'm not sure who would want the potential blood on their hands.

Also worth noting that some text editors take it upon themselves to do annoying things like mess up the line endings or the end of file, and I personally think people should experiment system.xml title booting on rednand first (it won't activate on the first rednand boot, but will work when trying to return to system menu).

For a data point, I've not attempted sysnand coldboothax and probably will never be, considering the risk, and that it takes like 10 seconds to just press the HBL icon installed to sysnand from haxchi v2 anyway.

 

[iAqua]

Coldboothax is NOT like this. It is a modification of the system software itself to load a specific title on initialisation. This is nice, but is irreversible and you will NOT be in a position to recover your system should anything break or fail. Couple this with the fact that it may not be desirable to permenently boot into redNAND (which remember, ties you to your one specific SD card) with no way to revert to SysNAND and you have a exploit which could easily backfire. Should your SD card fail, it's not clear how you would be able to create a new one.

It's not permanent, you can easily remove it, if you lose out on your SD card you can get another one and remove coldboothax, it's not permanent whasoever.

 

[DocAmes1980]

Plus by doing this, you're system is pretty much doomed to always boot RedNAND forever, which currently kills all vWii functionality, and if you swap out the fw.bin and try and boot SysNAND, you'll just get stuck in a bootloop. It becomes impossible to recover your SysNAND.

Not if you have compiled the latest coldboot CFW and have a copy of your original system.xml named syshax.xml in /vol/system/config. Also you could setup Haxchi to launch something else when you hold a button.

 

[iAqua]

syshax.xml

don't need it, just re-edit it to have the Wii U's home menu title id.

 

[DocAmes1980]

@iAqua, You should probably point out that 5 of the 6 reported IOSU bricks are due to attempting coldboothax unsuccessfully: http://wiiubru.com/rip/

Personally, I think the only way I see this taking off is if someone makes an automated system.xml patcher that won't ever perform it incorrectly, and ensures that the title ID is properly configured. But I'm not sure who would want the potential blood on their hands.

Also worth noting that some text editors take it upon themselves to do annoying things like mess up the line endings or the end of file, and I personally think people should experiment system.xml title booting on rednand first (it won't activate on the first rednand boot, but will work when trying to return to system menu).

For a data point, I've not attempted sysnand coldboothax and probably will never be, considering the risk, and that it takes like 10 seconds to just press the HBL icon installed to sysnand from haxchi v2 anyway.

Funny thing is that in one of the threads he linked in the OP he implied that people were being reckless and stupid for using sigpatched sysNAND because "...bricks are easy." He even closed the post with, "...stop risking your console for minor convenience. In conclusion, it's not worth the risk." Obviously, installing redNAND coldboothax is many times more difficult and has an actual potential for bricks whereas what he was advocating against in his previous post is very safe by comparison.

That being said I see nothing wrong with posting this guide. I think redNAND can be a PITA to deal with and is pretty much pointless (for just installing titles), but some people might benefit from a unbrickable sandbox. Really this isn't risky if you follow instructions and do a sanity check before you reboot. It's pulling a file off the NAND, changing one value and pushing it back. Sure there's a few ways you can screw the process up, but that's why I did like three sanity checks. Anyways, people should do what they want. If they aren't comfortable then they shouldn't do it. But we don't need to treat them with kid gloves. The red capital letters should provide them full disclosure. If they fail to follow instructions and brick that's too bad. Anyways, I'm just commenting on the inconsistency of his position. I'm new and I don't know how well known or respected he is in the community but he was a total d___ in his above mentioned thread so I'm not really concerned.

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

don't need it, just re-edit it to have the Wii U's home menu title id.

Sure, I was just saying worst case scenario if your Haxchi was just setup to boot just redNAND (no button options set) and something happened to your the dump on your SD card where redNAND wouldn't boot and you are unable to reinject it because you don't have a backup. Of course that's provided you have syshax.xml. If you didn't have the foresight to configure optional buttons for Haxchi you probably would have the contingency set up.

 

[DanTheMan827]

I feel like coldboothax could be much safer if:

1. it had a installer / uninstaller app that included the haxchi installer and only let you use SysNAND titles
2. Had a fail-safe where if there was no RedNAND detected it would display a screen giving you the option to remove coldboothax or shutdown

Of course this is still extremely risky given the fact that accidentally deleting the game would irreversibly brick your system...

Any thoughts @dimok, @FIX94?

Maybe it'd be possible to revoke any delete or modify permissions on the haxchi game? I did see a chmod method in wupclient.py

 

[TeconMoon]

Not if you have compiled the latest coldboot CFW and have a copy of your original system.xml named syshax.xml in /vol/system/config. Also you could setup Haxchi to launch something else when you hold a button.

That's exactly what I'm doing, but this guide is specific to RedNAND. It doesn't mention a thing about coldbooting SysNAND

It's not permanent, you can easily remove it, if you lose out on your SD card you can get another one and remove coldboothax, it's not permanent whasoever.

Coldbooting isn't permanent when you're coldbooting a cfw-coldboot fw.img, correct, because then you can just modify system.xml back to normal if you need to. If you're coldbooting rednand, it's pretty much permanent since you can't edit system.xml on your sysnand anymore, unless you had syshax.xml on your system ahead of time and switch to a cfw-coldboot fw.img. If you switch to a cfw fw.img you'll just bootloop, and no fw.img will obviously just crash.

 

[DocAmes1980]

That's exactly what I'm doing, but this guide is specific to RedNAND. It doesn't mention a thing about coldbooting SysNAND


Coldbooting isn't permanent when you're coldbooting a cfw-coldboot fw.img, correct, because then you can just modify system.xml back to normal if you need to. If you're coldbooting rednand, it's pretty much permanent since you can't edit system.xml on your sysnand anymore, unless you had syshax.xml on your system ahead of time and switch to a cfw-coldboot fw.img. If you switch to a cfw fw.img you'll just bootloop, and no fw.img will obviously just crash.

The process for sysNAND is fundamentally the same except that you're putting a different fw.img on your SD card and you are making a copy of system.xml before you change the default title ID, renaming it syshax.xml, and pushing it to the same directory that you will place your modified system.xml. I'm not sure why the pull system.xml from "/vol/system_slc/config" instead of "/vol/system/config". Not saying it's wrong because I have no clue. I pulled "/vol/system/config/system.xml" for coldbooting sysNAND.

Below is a guide specifically for sysNAND coldboothax. One thing it doesn't mention is disabling standby and quick start prior to modifying your system.xml. I think if you have quick start enabled you will brick your box. Not sure about standby but I wouldn't recommend testing it. Follow the steps and do a triple sanity check prior to pushing your modified system.xml to the Wii U.

https://gbatemp.net/threads/coldboothax-solving-infinite-loop-with-sysnand-cfw.449683/

Even if you're coldbooting redNAND you'll be fine unless you go out of your way to paint yourself in a corner. The lastest Haxchi installer by default will get you a Haxchi'd title that boots fw.img by default and boots homebrew launcher if the A button is held down. So if it wouldn't matter if you didn't have a usable fw.img. You could hold down the A button and it would boot sysNAND and launch the homebrew launcher.

 

[TeconMoon]

The process for sysNAND is fundamentally the same except that you're putting a different fw.img on your SD card and you are making a copy of system.xml before you change the default title ID, renaming it syshax.xml, and pushing it to the same directory that you will place your modified system.xml. I'm not sure why the pull system.xml from "/vol/system_slc/config" instead of "/vol/system/config". Not saying it's wrong because I have no clue. I pulled "/vol/system/config/system.xml" for coldbooting sysNAND.

Below is a guide specifically for sysNAND coldboothax. One thing it doesn't mention is disabling standby and quick start prior to modifying your system.xml. I think if you have quick start enabled you will brick your box. Not sure about standby but I wouldn't recommend testing it. Follow the steps and do a triple sanity check prior to pushing your modified system.xml to the Wii U.

https://gbatemp.net/threads/coldboothax-solving-infinite-loop-with-sysnand-cfw.449683/

Even if you're coldbooting redNAND you'll be fine unless you go out of your way to paint yourself in a corner. The lastest Haxchi installer by default will get you a Haxchi'd title that boots fw.img by default and boots homebrew launcher if the A button is held down. So if it wouldn't matter if you didn't have a usable fw.img. You could hold down the A button and it would boot sysNAND and launch the homebrew launcher.

I guess all I'm trying to say is that setting up coldboot rednand according to this guide is a bad idea.