A very simple example of using sel4-sys and sel4-start to create an initial thread executable. Here's how you can test it out...

Set up a build environment

If you haven't yet, set up a build environment.

Also install qemu or another hypervisor if you want to test in a VM.

Build seL4

Clone https://gitlab.com/robigalia/sel4, initialize submodules, and run make x64_qemu_defconfig && make. This will put a kernel into sel4/stage/kernel-x86_64-pc99.

Build this crate

cargo build --target x86_64-sel4-robigalia --release

Run it in a VM

qemu-system-x86_64 -nographic -kernel /path/to/our/sel4/stage/kernel-x86_64-pc99  -initrd target/x86_64-sel4-robigalia/release/hello-world

You'll see some hardware-related debug spam and then

Starting node #0
Hello, world!

Caught cap fault in send phase at address 0x0
while trying to handle:
user exception 0x6 code 0x0
in thread 0xe01f9900 "rootserver" at address 0x804865d

Yay! If you forget -nographic, qemu will display the VGA buffer. This example prints to the serial port, though, so you won't see anything.

If you forget -cpu Haswell, sel4 will complain about XSAVE not being supported.

To quit out of the qemu console, use the command Ctrl-a x (that is, hold control and press a, release both, then press x).