retrowin32

[post author] I went down some similar paths in retrowin32, though 32-bit x86 is likely easier. I was also surprised by how much goop there is between startup and main. In retrowin32 I just implemented it all, though I wonder how much I could get away with not running it in the Theseus replace-some-parts model. I mostly relied on my own x86 emulator, but I also implemented the thunking between 64-bit and 32-bit mode just to see how it was. It definitely was some asm but once I wrapped my head around it it wasn't so bad, check out the 'trans64' and 'trans32' snippets in https://github.com/evmar/retrowin32/blob/ffd8665795ae6c6bdd7... for I believe all of it. One reframing that helped me (after a few false starts) was to put as much code as possible in my high-level language and just use asm to bridge to it.

See also the authors previous project retrowin32 https://github.com/evmar/retrowin32

Just a couple of hours ago I was thinking about this project from some time ago doing the same thing: https://github.com/evmar/retrowin32 I wondered how much of this could be done with an LLM agent, and here we have the answer

This is super cool! Checkout retrowin32 for something similar but written in Rust and not specifically targeting the web: https://github.com/evmar/retrowin32

There's also another partial Win32 reimplementation in retrowin32, with the different goal of being a Windows emulator for the web, not for Linux or as alternate OS, at https://evmar.github.io/retrowin32/ It thus has an even more sparse path/fileapi.h implementation [2] than WINE and ReactOS. Written in Rust. [2] https://github.com/evmar/retrowin32/blob/main/win32/dll/kern...

Incredible work. May I also interest you in retrowin32 https://github.com/evmar/retrowin32/blob/main/README.md Which is an attempt to collapse the stack so that fewer translation and virtualisation stages are needed.

I have been working on an x86 emulator[1] so I have x86 on the mind. As I read the post I was thinking to myself "there's no way you can iterate the instruction stream without a massive amount of effort to parse through all different instruction types"... and then remembered MIPS has constant-sized instructions. So nice! But also I glanced at some MIPS docs and it seems there there could be additional instructions that modify these registers as outputs, which the code doesn't address. Maybe they just don't occur in practice? [1] https://github.com/evmar/retrowin32

My project https://github.com/evmar/retrowin32 includes a (Windows-agnostic) pure Rust instruction level emulator for x86, and if anyone is interested on hacking on one I'd love the help!

Working on https://github.com/evmar/retrowin32, I disassembled one old demo that wouldn't run on my native Windows machine -- turns out it was requesting 320x200 fullscreen resolution and aborting if it couldn't get it. (Not sure why the Windows machine wouldn't do it...)