crosvm/tools/examples/baremetal
..
.cargo
src
build.rs
Cargo.toml
layout.ld
README.md
rust-toolchain
x86_64-naked.json

This is a small baremetal x86_64 application that can be booted with crosvm. You can simply do cargo run and it'll build it and use crosvm from PATH to launch it. Alternatively you can build it with cargo build and run with crosvm run --disable-sandbox path/to/target/x86_64-naked/debug/baremetal

The application does nothing but output Hello World! log line over serial port and go into infinite loop. This is expected and you'll need to kill crosvm to stop it.