> it may just be that the DSi is not able to reboot in a "different mode", which Nintendo did release for the 3DS?
From GBATEK:
"The memory regions and IRQ bits do still exist internally, but the DSi does basically behave as if there is no GBA cartridge inserted. Reading GBA ROM areas does return FFFFh halfwords instead of the usual open bus values though."
Since the memory map isn't flexible and GBA games expect to load data from the cartridge at the hardcoded area, games won't function on the ARM7. I assume the 3DS has special hardware to handle this properly.
From GBATEK:
"The memory regions and IRQ bits do still exist internally, but the DSi does basically behave as if there is no GBA cartridge inserted. Reading GBA ROM areas does return FFFFh halfwords instead of the usual open bus values though."
Since the memory map isn't flexible and GBA games expect to load data from the cartridge at the hardcoded area, games won't function on the ARM7. I assume the 3DS has special hardware to handle this properly.