ukernel-sys

System interface types for µKernel — a Rust microkernel with hypervisor, container runtime, and real-time scheduling. DO-178C certification in progress.

This crate defines the ABI between userspace domains and the kernel:

• KernelOp — ~30 primitive kernel operations (memory, VFS, network, threads, signals)
• SubmitEntry / CompleteEntry — submission ring entry types for batched syscalls
• SubmitRing — shared-memory ring buffer layout
• SubsystemId — hashed identity for loadable domain types (POSIX, VMM, etc.)

Architecture

µKernel uses a vectorized syscall model inspired by io_uring. Userspace queues operations into a shared-memory ring and flushes them with a single SYS_SUBMIT syscall. The kernel processes the batch, capability-checks each operation, and writes results to the completion ring. One ring transition for N operations.

Application
    ↓ (std or no_std)
libposix / ukernel-std
    ↓ queues KernelOps
Submission Ring (shared page)
    ↓ SYS_SUBMIT (one ring transition)
µKernel (capability check + execute per op)
    ↓
Completion Ring (results)

Usage

use ukernel_sys::{KernelOp, SubmitEntry, SubsystemId};

// Define a subsystem
const MY_SUBSYSTEM: SubsystemId = SubsystemId::from_name(b"my-runtime");

// Create a submission entry
let entry = SubmitEntry::new(
    KernelOp::DebugPrint as u16,
    [buf_ptr, buf_len, 0, 0, 0],
    42, // user_data — returned in completion
);

no_std

This crate is #![no_std] with zero dependencies. It contains only type definitions and constants — no I/O, no allocation, no unsafe code.

License

MIT OR Apache-2.0

Links

• µKernel — product information and licensing
• Vinci Consulting — engineering services
• POSIX Conformance Suite — syscall-level PSE53 tests