What does "64 MiB GBA Video cartridge support" mean?

[7743]

>mGBA 0.7 beta 1
>GBA Memory: 64 MiB GBA Video cartridge support

What does "64 MiB GBA Video cartridge support" mean?

I understand that the maximum capacity of GBA's ROM is 32 MB.
Is this function to support it up to 64 MB?

If so, it is very interesting.
Expanding the available capacity broadens the possibilities of Hack Rom.

I tested it using nightly builds.
I added 0x00 behind the ROM with hexeditor to create a ROM that exceeds 32 MB.
When reading it, the following error occurred and it did not work.

Crash
The game has crashed with the following error:
Jumped to invalid address: 5AFFFFF8

Is the upper limit of the GBA ROM capacity 32 MB?
If so, what does "64 MiB GBA Video cartridge support" mean?

[endrift]

It's support for a special type of cartridge that uses a mapper to swap memory into the 32MB range. It's not really suitable for ROM hacks.