Try to build using libhermit-rs

[tomaka]

No description provided.

[tomaka]

It is cool that the core successfully compiles, but I'd like to have an actual binary, so will delay this until it's the case.

[tomaka]

The docker image unfortunately doesn't have rustup or the wasm32-wasi target installed.

[tomaka]

Obviously we don't have to build the WASI in the libhermit docker image, but this raises the question of how to properly build all this, and how to design the bootstrapping process (as in: which preloaded processes should be part of the kernel?).

Let's delay this more until it's figured out.

[tomaka]

Build is now failing because libm seems to be missing.

[tomaka]

The Rust libm story: rust-lang/rust#63455 (comment)

[tomaka]

Passing +soft-float doesn't prevent calls to libm: https://rust.godbolt.org/z/jipgAR

[kpp]

Try -Ctarget-feature=-soft-float

[tomaka]

Thanks for the help, but this doesn't change anything :(

[kpp]

nametbd-standalone-kernel depends on nametbd-core which is built as cargo build --locked --package nametbd-core --target x86_64-unknown-hermit (without -soft-float). Still it's a guess...

[tomaka]

I was somehow assuming that this would pass the flag to all dependencies.
I passed -soft-float everywhere now, and I think it doesn't work :(

[kpp]

docker run -i -t -v tomaka_os/:/os rwthos/hermitcore-rs:latest
cd /os/
RUSTFLAGS="-L/usr/lib/x86_64-linux-gnu/ -Clink-args=-lm" cargo build --package nametbd-standalone-kernel --target x86_64-unknown-hermit

[tomaka]

Oh nice, it's working 🎉
Thank you 🤗

[tomaka]

Running the kernel in uhyve yields an unknown instruction error, which I'm assuming is because the kernel terminates.
Running it in qemu doesn't work on my machine, because my qemu is old enough that it doesn't support 64bits kernels 🤦‍♂️

I'm going to merge this PR (maybe after a bit of clean-up), and then probably start working on an actual freestanding code.