andry-dev / momiji

Basic m68k emulator

momiji

A basic Motorola 68000 emulator infrastructure written in C++17. This is not production-ready and I will only ever implement a subset of the assembler.

"momiji" itself refers to the entire project, from the library (libmomiji), the GUIs (momiji-gl and momiji-qt) to the CLI tools (momiji-as, momiji-dump, momiji-diff, etc...).

Motivation

This was created out of frustration from using EASy68k. I wanted something that could be used to make tools and better GUIs, something that supported backtracking, diffs and other stuff. So I started working on this, initially as a REPL, then it evolved in a compiler and disassembler.

libmomiji

The core of the project. It includes a parser (<momiji/Parser.h>), a compiler (<momiji/Compiler.h>), a decoder/disassembler (<momiji/Decoder.h>) and finally an emulator class (<momiji/Emulator.h>) to make everything work together effortlessly.

momiji-tools

Brief description of the provided CLI tools:

Name	Description
momiji-as	A basic compiler
momiji-dump	Yields a compiled program's trace
momiji-diff	Creates a diff of two programs executions

Keep in mind that, at the time of writing, they are incomplete and really basic.

momiji-gl

Main GUI, using ImGui and tewi. This is where most features will be implemented. This doesn't work on OSX.

momiji-qt

A Qt GUI, provided for the people who can't run momiji-gl (like OSX users). At the time of writing, this is mostly under-developed.

Building

libmomiji

You need asl to build libmomiji. Just create a conan package for that and then:

mkdir build
cd build
conan install ..
cmake ..

And you're done with just the core.

momiji-gl

You also need tewi, you can either use the local submodule (git submdule update --init) or create the conan package.

Then just pass -DMOMIJI_BUILD_GL_GUI=1 to CMake:

cd build
cmake .. -DMOMIJI_BUILD_GL_GUI=1

momiji-qt

You obviously need Qt5.

cd build
cmake .. -DMOMIJI_BUILD_QT_GUI=1

momiji-tools

Since these are simple CLI tools you don't need anything special (apart from libmomiji, obviously).

cd build
cmake .. -DMOMIJI_BUILD_TOOLS=1

Obviously, you can build all of them at once if you feel like.

momiji's Issues

Convert the icon from KRA to SVG

While Krita was useful to sketch the icon (both in bitmap and in vector), it's time to actually create an SVG that doesn't suck: the default exported layer from Krita is kinda bad in some spots.

It should be possible to fix things manually in a couple of hours.

Most of the instructions don't update the status register

The status register is under-developed: beside CMP, MOVE, SUB and ADD the rest of the instructions do not update it.
This depends on #3: the status register is always lying because there is no way to detect a carry.

Moving bytes dosen't work

A basic instruction like move.b #5, d0 dosen't work.

Can't detect if a carry happened

There's no facility to detect if a carry happened during (or after) an instruction (like an ADD)

Missing documentation

This entire project lacks any kind of documentation.

Goals

Write sane documentation that includes an API reference, tutorials, how-tos and explanations. Right now I'm experimenting with LaTeX in a local branch.

Motivation

I used, in the past, tools like Doxygen; while they are nice for keeping in sync declarations between code and the generated pages, they just create an API reference, nothing more nothing less. These kind of things give you a false sense of "documentation", it's no better than using grep on a codebase to figure out what functions are in there and what are the preconditions.
Unfortunately, I also used projects structured like that and the "documentation" was unhelpful, that's why I want to try and make something different.