Wii U GBA Virtual Console Save Hex Editing

This page is to document something I have discovered overtime by wanted to reactivate inter-game communications from the Gamecube and GameBoy Advance era of Virtual Console games for the Wii U.

*These items can not be obtained in the latest Nintendo Classics Ports for the Nintendo Switch.

I've found myself wondering why I couldn't access the following contents:

Fire Emblem

* Mario Kart Double Dash Bonus Disc Bonus Items (Connect to GBA via GBA to GameCube Link Cable)

Fire Emblem Sacred Stones

* Event Exclusive Items (Eirika’s set and Ephraim’s set)

Metroid Zero Mission

* Metroid Fusion Endings Gallery (Connect with Metroid Fusion via Link Cable)

 

More info can be found regarding the Fire Emblem items here: https://serenesforest.net/general/download-events/ 

This is how I managed to get this working

Pre-Requisits

* Soft Modded Wii U Console
* SD Card Reader for PC
* SD Card in Wii U
* SaveMii App for Wii U Version 1.6.5i (https://github.com/Xpl0itU/savemii/releases/tag/1.6.5i)
* Save file in SAV format for the game you want to add the data to
* HxD installed on your PC (https://mh-nexus.de/en/hxd/)
* Patiance

How-To
In this example, Virtual Console GBA Metroid Fusion USA release will be used

Wii U - Part 1

1. Start SaveMii on the WiiU
2. Take a backup of the save file for the game you want to add the data to
3. Return to Wii U Home Menu
4. Eject SD Card 

PC - Part 1
1. Connect to PC
2. On the WiiU SD Card, navigate to wiiu\backups\0005000010157100\0\80000007
3. Copy the "data_008_0000.bin" file to the same folder where the SAV format save file is located
4. Open both files in HxD

HxD Part
Important Information:
BIN Format: Save data starts at Offset (h) 00004080 and ends at 00014070
SAV Format: Save data starts at Offset (h) 00000000 and ends at 0000FFF0

1. Open both the data_008_0000.bin BIN and the selected SAV file in HxD
2. Select all lines in the SAV file.
3. Notice the length(h) of 10000 (Can be seen in bottom portion of the screen)

4. Copy ALL Lines from Offset (h) 00000000 to End of SAV file
5. In order for the file to remain at the same size and be recognized properly by the WiiU once restored, we must restore the exact same number of lines in the BIN file.
6. To do so in the BIN file, Highlight from Offset (h) 00004080 to 00014070
7. Highlight from Offset (h) 00004080 to 00014070
8. Notice the length(h) value is 10000

9. Paste

*If a warning message appears stating the file size will change, the current line highlight selection is not correct


10. Save the BIN File (Overwrite with same name) and copy it back to SD:\wiiu\backups\0005000010157100\0\80000007


PC - Part 2
1. To make sure the restore process works properly, Delete any file starting with "data_012" from SD:\wiiu\backups\0005000010157100\0\80000007 

*These files are for the "Restore Point" Feature and will break the save edit as VC will load it on boot instead of the new save. This will overwrite the new file.

2. Eject the SD Card from the PC.

Wii U - Part 2
1. Start SaveMii
2. Use option Wipe SaveData (Do not backup current save file)
3. Restore Edited SaveData (Accept all warnings + Do not backup current save file)