GBA Bios Dumping Guide

By: GlaZed_Belmont


Hello, in this guide, I will show you how to dump a GBA bios via multiple methods

These methods are:

  • Via a GameBoy Advance / SP / Micro / DS / DS Lite
  • Via a Virtual Console title from a 3DS

These methods are indicated in the margin so feel free to skip to the one you prefer.


GameBoy Advance / SP / Micro / DS / DS Lite

What you'll need:


  1. Download the Bios_Dumper.gba file and put it on your flashcart's micro SD card.
  2. Boot your console and run Bios_Dumper.gba.

  3. You'll be met with a red screen like this:
  4. Wait until the screen turns green like so:
  5. Wait 5 seconds or so before turning off the system to prevent SD corruption.


  6. After that, open your micro SD card on your PC


  7. Either drag & drop the .sav file onto the Bios_Shrinker.py file or run it with python3, this will output a file called bios.bin which is the correct bios.


    Here are the hashes of a clean bios

    MD5:a860e8c0b6d573d191e4ec7db1b1e4f6
    SHA256:fd2547724b505f487e6dcb29ec2ecff3af35a841a77ab2e85fd87350abd36570


  8. Done!

Virtual Console title from a 3DS

Note that not all VCs come with GBA bios, the GBA and GameGear don't seem to come with one


What you'll need:

  • A 3ds family system (3ds,2ds,etc.)
  • CFW (Luma+B9S) if you don't have CFW, go on https://3ds.hacks.guide/ to install it.
  • Godmode9 (You should already have it due to the CFW guide.)
  • Access to your SD card
  • Any valid 3DS Virtual Console game

  1. Boot while holding the Start button to access Godmode9.
  2. Navigate to 《[A:] SYSNAND SD》 and press A.
  3. Hover on 《title》 and press R+A.
  4. Press A on 《Search for titles》 and wait until it finishes searching.
  5. At this point, you will see all your installed titles.

  6. Find the Virtual Console game that you want to extract the GBA bios from and press A on it.

  7. Press A on 《TMD file options...》.
  8. Press A on 《Mount CXI/NDS to drive》.
  9. Confirm with A.
  10. You will see a folder called 《romfs》 , press A on it.
  11. In the 《romfs》 folder, if there is a file called 《agb.bin》, guess what, that's your GBA bios.
  12. Press A on 《copy to gm9/out》 and you now have a legally obtained GBA bios.


Please join this server for further assistance


~ GlaZed_Belmont