A minimal kernel in Swift runs on QEMU, no OS required
A minimal kernel in Swift, running in QEMU
A developer built a bare-metal AArch64 kernel in Embedded Swift, running on QEMU's virt machine. The project uses a custom assembly entry point, a hand-written linker script, and minimal implementations of putchar and memmove to bridge Swift's runtime to the PL011 UART. After printing "Hello, Embedded Swift", the kernel was extended to echo typed characters via polling, turning a one-way greeting into a basic interactive prompt.
This is the first point where the project stops being ordinary application programming. Here, I am no longer calling an operating-system API to print a string, but I am implementing the lower-level functions that the language runtime needs in order to exist.