Building and running

One command

From a clean clone, cargo run builds everything and boots the system in QEMU, and cargo test boots whole systems to run the integration suite.
The build system is an ordinary Rust program; it names anything missing before it starts.
Linux and macOS are supported hosts.

ToyOS carries its own forks of the Rust compiler and of LLVM, where the ToyOS targets live.
One LLVM is both rustc’s code generator and the clang that builds C programs, and its linker links the UEFI loader, the kernel and every program.
Nothing installed on the host goes into anything that boots.
The first build bootstraps the toolchain once per machine; later builds rebuild only what changed.

Every build produces GPT-partitioned, UEFI-only disk images, ready to write to a USB stick. One kernel and loader serve three boot configurations:

Image	Purpose
The system	The whole desktop and its services; what QEMU boots
Diagnostic	Nothing may claim the display, so the kernel’s log and panics stay readable on a machine with no serial port
Console	A shell on the raw framebuffer, without the compositor

Development images are signed with a key generated for the checkout; an image for an owner’s machine is signed with the owner’s key.