An open-source reimplementation of the proprietary RTOS microkernel "HorizonKernel" that is used in the Nintendo Switch.
The original Horizon kernel is written in modern C++, using a recent LLVM toolchain.
It is a fully custom design heavily based around reference-counted C++ object. Using a custom IPC system, most of the work in the system is orchestrated between sandboxed processes following a microservice model.
This project tries to combine Horizon's modern design choices with the capabilities Rust provides as a systems programming language.
We try to achieve semantic equivalence in reimplementation, less effort is put in trying to generate matching assembly. Nonetheless, it is a goal for the kernel to work as a drop-in replacement on real hardware.
Eventually, it may be ported to more architectures than just AArch64 in the future.
TODO: Write me.
The cargo kernel command shall be used for building and testing Saturnus.
Most commonly, one will want to use the cargo kernel -t aarch64-qemu run --release
which builds the Kernel for the aarch64-qemu target and runs it in QEMU.
The build and run commands will always produce a ready kernel image as
target/dist/kernel.bin.
See cargo kernel help for a full list of usable commands and their options.
TODO: Write once we have proper tests.
TODO: Write me.
Due to the required familiarity with the mechanics of the proprietary kernel that is being reimplemented here, this project is unlikely to accept significant code contributions from outsiders without prior bikeshedding discussion.
Saturnus consists of many small crates which compose the full kernel.
Generally, each of these crates may be licensed under either the ISC License or the GNU GPLv2.
See the Cargo.toml file of a particular crate to learn its license. All
code in a crate shall be licensed under the license stated there unless
where specifically noted.