Aarch64 support: What is missing? about lucet

[iximeow]

As you've noticed, the x86-specific assembly is a real impediment - some of the signal handling machinery relies on knowing the OS's layout for ucontext_t, which will have a different layout on aarch64 (and vary by OS just the same). In context/mod.rs there's some poking and prodding to put arguments in place conformant to the system's calling convention - this could vary but by targeting the sysv calling convention and only supporting linux/macos/freebsd we've not needed to vary there yet. aarch64 would force that need :)

A while ago I tried adding x86-32 support on a lark and I think that would be a good template for how a new architecture would look otherwise. aarch64 wouldn't have the 64/32-bit pointer compatibility pieces though, of course.

This all said, I would highly recommend looking into Wasmtime to run programs on aarch64 systems: the current plan is to merge the two runtimes, or at least contribute Lucet's distinct features to Wasmtime (Wasmtime is already approaching a similar precompilation story with compiled code caching, for example). Unless you have a pressing need for Lucet-specific features, Wasmtime will be the better choice, with support for reference types and other future-facing WebAssembly standards implementation.

[PhilippGackstatter]

Thanks for the reply!

the current plan is to merge the two runtimes

That's really cool, looking forward to that. Then I will focus on wasmtime instead. Thanks again.