Tools I have created to help with NES/Famicom development.

Note: this is under heavy development and it's not currently usable.

nasm

nasm is an assembler specifically tailored for the NES/Famicom. Build it and run it with cargo, or you can install it somewhere in your $PATH and simply:

$ nasm awesome.s

This will produce an out.nes file placed under the same working directory. You can change the name of the file with the -o/--output flag. Hence, you can call it like so:

$ nasm -o awesome.nes awesome.s

Moreover, you can actually tell nasm to redirect the output to stdout instead with the --stdout flag. This is useful when debugging the binary format with another CLI tool. For example:

$ nasm --stdout awesome.s | hexdump -C

By default it will assume the configuration for an NROM mapper, but this can be changed with the -c/--configuration flag, which accepts the following values:

• empty: just HEADER and CODE. Useful for one-liners (e.g. "how is this instruction encoded in binary?").
• nrom: the default configuration. It has the following segments: HEADER, CODE, VECTORS, and CHARS.
• nrom65: same as nrom but it also has STARTUP for compatibility with the default linker configuration from cc65.
• unrom or uxrom: a configuration for UxROM chips, with seven swappable banks bound at 0x8000 and 16KB of size (PRG0..PRG6), and a fixed bank on 0xC000 and 16KB of size as well (FIXED).

Alternatively, you can also pass a path to a configuration of your own. Check out the ones already bundled on this application for reference.

readrom

The readrom program reads a given ROM file and shows all the information that can be gathered from it. For now this only applies to information on the header, but in the future we might want to add disassembling user-specified segments, for example.

License

This repository holds two licenses, as you can also note on the Cargo.toml file. As it's written there:

• The source code on the crates/ directory is licensed under the GNU GPLv3 (or any later version).
• The source code on the lib/ directory is licensed under the GNU LGPLv3 (or any later version).

In practice, for the libraries under lib/ this means that if you plan to compile your binary statically, you still need to abide by the LGPLv3+ license. This means at least providing the object files necessary to allow someone to recompile your program using a modified version of these libraries. See the LGPLv3 license for more details.