# Cemu - General Guide

<img src="../../../wiki_images/logos/cemu-logo.png" width="150">

Cemu is a Wii U emulator that is able to run most Wii U games and homebrew.

---

### Cemu Links:

[Cemu Compatibility Guide](https://compat.cemu.info/)

[Cemu Wiki](https://wiki.cemu.info/wiki/Main_Page)

[Cemu Github](https://github.com/cemu-project/Cemu)

[Cemu Webpage](https://cemu.info/)

---

## Where to put the games?

WiiU games should be put under the `retrodeck/roms/wiiu/` directory.

## What file formats are supported?

**Encrypted formats:**

```
.wud 
.wux 
```

**Decrypted formats**

```
.wua 
.rpx 
```

**Note:** 

`.wua` is the preferred format to use for Wii U games. 

## Does Cemu require BIOS or Firmware?

Yes, `keys.txt` if the file format is encrypted.

`otp.bin` and `seeprom.bin` if you want to play Online.

### Where to put the BIOS / Firmware files?

`~/.var/app/net.retrodeck.retrodeck/data/Cemu`

This will be changed in a later update to the `retrodeck/bios/cemu` folder.

## Folder structure

| Type    | Folder                 |          Comment     | 
|  :---:  | :---:                  |             :---:     |
| ROMs Folder |`retrodeck/roms/wiiu/` |                               |  
| Saves Folder |`retrodeck/saves/wiiu/cemu/` |                               |  
| Config Folder |`~/.var/app/net.retrodeck.retrodeck/config/Cemu/`         |   `settings.xml`, `gameProfiles` folder, `controllerProfiles` folder|
| BIOS Folder | `retrodeck/bios/Cemu` | Contains `usr` and `sys` folders |
| Data Folder |`~/.var/app/org.retrodeck.retrodeck/data/Cemu` |     |

## Guide - How to install DLC and Updates

**NOTE:**

Do not keep DLC and Update files in: `retrodeck/roms/wiiu/`

**Instructions:**

1. Open the `Configurator` and Open `Cemu`
2. `Press File` -> `Install game title, update, or DLC...`
3. Navigate to where you have your files.
4. Choose the DLC or Update file and press `Open` and it will install.
5. Repeat for each DLC / Update you want to install.

## Guide - How make .wua files and install the games

**NOTE:** 

- Encrypted ROMs can't be converted to `.wua`. 
- Before you make the `.wua` install any updates or DLC first to the base game. 

**Instructions:**

1. Open the `Configurator` and Open `Cemu`
2. `Press Tools` -> `Title Manager`
3. Search for the game you want to convert and check so the `Type` colum says: `base`.
4. Right click and press the `Convert to compressed Wii U archive`.
5. Verify in the prompt that everything you want is there: base game, updates and DLC.
6. Select the output target folder: `retrodeck/roms/wiiu/`.


## Pretendo Account for online play

To create a Pretendo Network account.

1. Use the provided link to register:

[Pretendo: Register Account](https://pretendo.network/account/register).

2. Then, follow the instructions to log in with your Pretendo Network account on a Wii U.

[Pretendo: Install WiiU](https://pretendo.network/docs/install/wiiu) 

- Note: Existing NNIDs are not usable on Pretendo Network, so you must create a Pretendo account.

3. Follow the guide to generate and dump the required user files for your Pretendo Account: 

[Cemu: Online Play Guide](https://cemu.cfw.guide/online-play.html) 

**RetroDECK specific file locations:**

-  Wii U User Account’s `usr` and `sys` folders
    - Located in the `MLC Path` configured in `RetroDECK Configurator` -> `Open Cemu` -> `Options` -> `General settings`  (default: `retrodeck/bios/cemu`) 
  
- `otp.bin` and `seeprom.bin`:
    - Located at `~/.var/app/org.retrodeck.retrodeck/data/Cemu`.

## Known issues
    
### Certain UI elements of emulators GUI are cramped / outside of the screen on the Steam Deck

Check the following link for `Certain UI elements of emulators GUI are cramped / outside of the screen`:

[Known Issues](../../wiki_general/known-issues.md)