About the operating system
The operating system currently runs on 32-bit RISC-V QEMU or WebAssembly with Emscripten. Eventually, the RP2350 will be added as a real hardware target, possibly using the RISC-V mode.
The easiest way to use it is using the WASM web demo.
The source is under the os directory of the otium repository.
Building
Section titled “Building”Development so far has happened on a Macbook with Homebrew. Due to the odd toolchains involved, it’s probably likely that building on another system will require some work. There are the beginnings of a Nix build which builds the WASM target, and that’s probably the best bet for running on any given system.
That being said,
compile-riscv.sh
and
compile-wasm.sh
Build the RISC-V and WASM versions.
Reach out if you’d like help.
Running
Section titled “Running”You can run the WASM version after building with
node run-wasm.js
And the RISC-V version under qemu with
run-riscv.sh
There are different kernel “programs” intended to test various facets of the OS; the default one is a Tcl language shell that runs as a separate user-space process and allows entering arbitrary commands.
Architecture
Section titled “Architecture”There’s so little code there’s not much of an architecture to speak of, but here are the current philosophical aims:
- Cooperative scheduling
- Real process separation to the extent allowed by the system
- Microkernel; the OS kernel will only handle memory management, scheduling and inter-process communication