ARMfuck shows that ARM's LDM and STM instructions are Turing-complete by using them, and no other instructions, to implement an interpreter for a version of a Brainfuck. For more information on how it works, read this blog post.
This repository comes provided with a compiled ROM that has quine.bf (the program running in the image) loaded. To load a new Brainfuck program or change the input, it must be converted into a form the interpreter can understand and inserted into the ROM by running
python scripts/loadprogram.py <brainfuck file> [input text]Once you've selected a program, you can run armfuck.gba on a Game Boy Advance emulator of your choice or use a flashcart to run it on a real system.
The base ROM can be compiled with the included FASMARM using the command
.\FASMARM\fasmarm.exe header.s armfuck.gbaon Windows or
./FASMARM/fasmarm header.s armfuck.gbaon Linux.
If you intend to run or test on the mGBA emulator, you must add -d MGBA=1 or it won't be detected as a valid ROM.
Changes to certain parts of the header additionally require you to run
python scripts/headercompliment.py armfuck.gbaor modify the header compliment value in header.s.