tpt-archon-kernel

Phase 2b of tpt-archon: a capability-based microkernel with a unified page cache.

"Microkernel" means a user-space process model first. Per spec.txt's Risk 1 mitigation, the architecture is validated as a user-space process on a host OS before any bare-metal or hardware-driver work. The crate does not yet run on bare metal. Its scheduler is a cooperative, hand-rolled round-robin scheduler (not preemptive), but I/O tasks can now be backed by a real Linux io_uring reactor (see the io-uring-backend feature below) rather than a synchronous stand-in.

Modules

• scheduler — a cooperative, round-robin async Scheduler running one Task per DB connection (not an OS process). It always makes progress while any task is runnable.
• ipc — capability-bearing Message passing via a MessageRouter. A message is only delivered if the sender holds a write capability for the destination channel.
• memory — UnifiedMemory, where the kernel page cache is the database buffer pool: a single allocation shared through the bridge's UnifiedPageCache trait, with capability-checked access. Also exposes map_read_zero_copy (mmap feature) over the bridge's MmapPageSource trait — real OS-mapped, read-only shared memory, not just an in-process reference.
• io_uring_backend (Linux only, io-uring-backend feature) — a Reactor wrapping a real io_uring submission/completion ring, plus IoReadTask/IoWriteTask, ordinary Tasks that submit a read/write and yield Pending until the kernel reports completion. Plugs into Scheduler unchanged: a pending I/O task stays in the same ready queue as any other pending task, so the scheduler's deadlock-freedom argument (formal-proofs/scheduler.telos) still covers it.

Features

• std (default) — forwards to the lower crates' std features. Build with --no-default-features for no_std.
• io-uring-backend — enables the real io_uring reactor (implies std). Linux only; the io-uring dependency doesn't build on other platforms, so this is off by default and meant to be enabled explicitly (e.g. a Linux-only CI job or a Linux deployment target).
• mmap — enables real, read-only, OS-mmap-backed zero-copy page access (implies std). Cross-platform (memmap2: mmap(2) on Unix, CreateFileMappingW on Windows) — unlike io-uring-backend, no target gating is needed and this is exercised on every OS in CI.

Publishing note

The dependencies on tpt-archon-core/tpt-archon-bridge are path dependencies during development. Switch them to version requirements before publishing.

License

Licensed under either of MIT or Apache-2.0 at your option.