lr-mgba port 2 controller setup?

[Shin Kusanagi]

Hi all,

I am fairly new to the retropie scene so I figure that I come here for some help. So I have:

Raspberry PI 4 (4gb)
Retropie 4.7.1 (premade image from the RetroPie website)
SD boot (not using USB Boot)
Microsoft 360 wired controller
Argon One V1 case
Official Raspberry Pi 4 micro hdmi cable
Official Raspberry Pi 4 power adapter
lr-mgba 1.8.8 (0.8.3 20f007c)

My question: I have been reading this article from Nintendo Life that says that Takara ports of SNK games like King of Fighters '95 for the Gameboy has built in two player mode via the Super Gameboy using a second SNES controller. According to the Gameboy advance document lr-mgba supports local cable games. I use this emulator for King of Fighters '95 for the Gameboy and I can enter 'Single Vs' or 'Team Vs' with my controller just fine. There is a cursor for player 2 but when I check the retroarch options for port 2 controller, there is no Gameboy buttons for me to bind a controller to. Has anyone figured his out yet? Any help would be greatly appreciated.

Example from Port 1
Auto: 1-----------------B
Auto: 0-----------------Turbo B
Auto: 8-----------------Select
Auto: 9-----------------Start
Auto: Hat #0 up------Up
Auto: Hat #0 down--Down
Auto: Hat #0 left------Left
Auto: Hat #0 right----Right
Auto: 2------------------A
Auto: 3------------------Turbo A
Auto: 4------------------L
Auto: 5------------------R
Auto: 6------------------Turbo L
Auto: 7------------------Turbo R

Example from Port 2
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