Thread by @rsms

What if the first step towards the next OS evolution is something like the Linux syscall API?

I've implemented a small prototype that allows me to write a program and compile it for pretty much any platform.

I think WASI is the wrong approach as it basically makes libc the API which makes the implementation burden heavy for programming-language authors.

Here's the example app running on macOS and in a web browser:

Now, imagine adding ops for io_uring for IO as well as webgpu for drawing.

A real implementation would offer async syscalls (in addition to an io_uring function) but currently WASM on the web platform is the only place where it is not possible to suspend&resume execution and so either the API needs a callback or web wasm needs a suspension feature.

Got suspend/resume working for wasm in browsers via @kripken’s Binaryen asyncify, a pass run on the wasm (so not dependent on any compiler or PL.) Nice! Now open() works w/ FileSystem web api and io_uring will be possible to implement.

Zooming out, with this approach (implementing part of the Linux syscall api) I think it would be possible to compile a wide range of Linux apps to run on web, macOS etc with no or very few modifications. Like, musl might “just work.”

Here's a live demo of the "universal syscall" prototype which you can run in a web browser: rsms.me/etc/xsys-demo/