You will see slots for bios7.bin , bios9.bin , and firmware.bin . Tap each one and select the corresponding file from your device's Files app .
The ARM7 processor managed the touch screen. Without the specific instructions contained within bios7.bin , an emulator may not correctly interpret inputs on the lower screen. This renders many DS games unplayable, as the touch screen is central to the console’s design. ds bios7.bin file