miu

This is Miu, a 6502 cross-assembler written in Prolog.

Requirements

• SWI-Prolog 7.x (I currently use 7.5.10. It will likely require the pcre module in the future, which was introduced in 7.5.4.)

Rationale

Since Prolog predicates are often multi-directional, I wanted to explore the idea of using the same code as both an assembler and a disassembler. The idea actually seems to work. :-)

More specifically, you can feed assemble0/3 and assemble/4 either lines of Prolog-formatted assembler instructions, or a list of bytes, and it will produce the other. Consider these simple test cases:

test(labels_scan_forward) :-
    assemble0([
        jsr(the_end)/absolute,
        label(the_end),
        rts/implied
    ], Bytes, 0xC000),
    assertion(Bytes = [0x20, 0x03, 0xC0, 0x60]).

test(labels_scan_forward) :-
    assemble0(Lines, [0x20, 0x03, 0xC0, 0x60], 0xC000),
    assertion(Lines = [jsr(0xC003)/absolute, rts/implied]).

Status

The actual assembling and disassembling works, that is, assembling from a Prolog semi-DSL to a list of bytes, and vice versa. What is not implemented yet, is dis/assembling from/to a more regular text format. Nor is there currently a workable user interface or command line options. These will be added once the pcre module is a bit more stable (so code will be less likely to break), or when I master Prolog DCGs, whichever comes first. ;-)