jnode VS rust

Source code here: https://github.com/jnode/jnode

Go has been used to implement OS kernel code,

but it's an interesting piece of software.

Agreed. And I didn't mean to imply that it's impossible to use Go that way, but I think it's fair to say that it's less common and perhaps even less desirable to do that.

OTOH, people have written (at least parts of) Operating Systems in Java[1] even, so never say never...

[1]: https://github.com/jnode/jnode

For what it's worth, this is the script I'm using to build for our platform: build.ps1 / build.sh

Note that before I got the target triple upstream, I had to provide my own target json file. That's here: https://github.com/betrusted-io/rust/blob/1.53.0-xous/riscv32imac-unknown-xous-elf.json and you can adapt it as necessary. Simply creating the file in the correct path is enough. This is the code that does that: https://github.com/betrusted-io/rust/blob/e39344c5473d49a0cb4d45de119ad23713a00ed4/rebuild.ps1#L65

Everything you need to know to build for our platform is at https://github.com/betrusted-io/rust/ and maybe the scripts or patches there will be interesting to you.

Rust does use a Rust port of dlmalloc on platforms that don't provide malloc() and free(). We did port this to Xous, but ran into a feature bug that caused locking to be disabled. That was the source of weird and subtle bugs, which is how he discovered that fact about allocators.

This is correct.

When you tell someone to install Rust, they go to rustup.rs and install the latest version. Therefore, we need to have a libstd port for the latest version. Which effectively means we need to release libstd as soon as possible after the compiler is released. Our `sys` directory is at https://github.com/betrusted-io/rust/tree/1.61.0-xous/librar... and isn't too complicated. It's about 50 patches that need to be carried forward every six weeks.

Fortunately libstd doesn't change too much, at leaset not the parts we need. And I can usually pre-port the patches by applying them to `beta`, which means the patches against the release version usually apply cleanly.

It's still better than requiring nightly, which has absolutely no stability guarantees. By targeting stable, we don't run into issues of bitrot where we accidentally rely on features that have been removed. Rather than adjusting every service in the operating system, we just need to port one library: libstd

I've considered trying to upstream these, but I'm not sure how the rust team would feel about it.