The reason for this functionality is that some flashcarts *cough* EZ Flash Omega (DE) *cough* can't be hotswapped IN. When you try this, they will trigger a reset of the gba.
This is only relevant for the use case in which you first launch the rom from a flashcart in the first place.
I suppose this can only be relevant for flashcarts which offer "single cart mode". (mode B for EZ Flash Omega).
So, I added an option to upload the rom to another GBA from the "game_load_error" screen if you press the SELECT button.
So, with this change, you could
- launch Poke Transporter GB on GBA 1 from a flashcart.
- eject the flashcart on GBA 1
- make sure the EZ Flash Omega or other "single cart mode/mode B" capable flashcart is set to this mode.
- insert this flashcart into GBA 2
- connect GBA link cable (narrow plug on GBA 1, wide plug on GBA 2)
- Power on GBA 2 and press both SELECT and START while the gameboy logo is still shown
- On GBA 1, in the "game_load_error" screen, press SELECT
- On GBA 1, now press A -> The multiboot upload will now start
- Once finished, GBA 2 will now be running Poke Transporter GB as well
- GBA 2 will recognize the gen III save!
- You can now disconnect the GBA link cable and turn off GBA 1. (you may use it later for the GBC game alongside a GBC link cable to start the actual PKMN transfer)
