WiiU Hacking in 2020

A journey begins

Well, we’re on the cusp of buying in to Switch (pretty late now in 2020), and WiiU is getting pretty old, so now every time I insert a disc I’m thinking “perhaps this will be the last time this works”. So, I’m looking to be able to backup data from the WiiU (savegames) and install discs we own like Legenda of Zelda: Breath of the Wild.

Unfortunately it’s not been going well …

FSOpenFile failed

I’ve been having “FSOpenFile failed” a common problem trying to run haxchi following a Howto Geek guide.

Spent half a day using various SD cards. That guide says that you need 32kB allocation unit size for the FAT32 file system (see this ArchLinux page on FAT) on the SD card …but I use Linux and there’s no simple way to do that.

I tried [from a dash shell on Kubuntu Linux distro]:

sudo mkfs.fat -f2 -F32 -s64 -S512 /dev/sdg1
# format as FAT32 with a 32KB block size, for WiiU;
# -s is sectors per cluster, -S is sector size, need 32KB per cluster

[Aside, lsblk, fdisk or cfdisk, and fsck.fat -v are useful for checking on your SD card to see if it’s the right format. gdisk and gparted (I use kdeparted) are also good.]

but gave up and found a laptop with Win10 on, used PowerShell (as admin) and did:

format /FS:FAT32 /A:32K E:

where E is the drive letter of my SD card (/A:32K sets the allocation unit size).

Note that these will fail on smaller SD cards as you need a certain number of blocks to make a FAT32 filesystem. You will also need special techniques to work with very large SD cards, which normally come formatted as exFAT, to work with FAT32 beyond the usual maximum system size.

I’d unzipped all the necessary, so that the root folder of my SD card had a wiiu folder, and inside had “payload.elf” file. I confirmed that the sha1sum of the file was A2..DC (full sum a2841c2dfc85177bf6fbab59b910719fed17a8dc) on the SD card from both Linux and Win10.

I’d also confirmed access to the SD card was possible by using MiiMaker to save images to it. Even tried using “SD Card Formatter” from Tuxera, as someone on a gbatemp thread had mentioned it seems to do something special; didn’t help me.

But with several SD cards I just got “FSOpenFile failed” over and over …

Now people will tell you “your file structures wrong”, “your SD card is broken”, “the reader is dirty, blow on it”, “payload.elf is corrupted”, or “payload file is in the wrong place”, etc., but it’s possible that none of those is the issue at all.

Then it worked … try a different SD card

Today, used with an adapter, as one last try before giving up. Had opened up discord to try and get help (having looked in multiple other places) … and what do you know, works first time. I’ve not installed yet as I need to buy my DS game.

For those many others struggling — check you have the right file tree, unzipped on your SD card (number one error I’ve seen mentioned) — try different SD cards!

So FSOpenFile solved/solution for me, inasmuch as it works no for no apparent reason!!

Alternate solution?

Edit: a comment by SGL3286 on gbatemp, [Guide] Community noob guide to Wii U hacking; post-8658276 suggest that I may have been using the wrong homebrew_launcher.elf:

“Using the other instructions figured out the mistake. So apparently the FSOpenFile can ALSO refer to not locating the homebrew_launcher.elf which in my case was caused by downloading the v2.1 RPX version of the homebrew_launcher, not the v1.4.”

So that’s definitely worth checking on too — if that works for you then please report back in a comment, thanks.

Postscript: Downloading files

Also, RikuMax was a really easy way to get the files needed, as opposed to hunting around on GitHub for zip releases from wiiu-env, dimok789, FIX94 (haxchi), vgmoose (wiiu-hbas), etc..

Further help?

Cemu; Discord & Reddit

I’m just coming to terms with Discord and don’t really get it yet. The reason this is here is that I posted on there and some people basically said “we don’t do it that way”, so it seemed best to avoid ruffling feathers and post to my own blog where I can just go “meh” if people don’t like it. Anyway, your mileage might vary, there appear to be active WiiU and Switch communities like #wiiu-assistance on Discord and /r/cemu (for the CEMU non-Nintendo WiiU emulator) on Reddit and they may be good places to seek further help.