ADR-0006: Chimera Nano-Kernel (CNK)

Status

Accepted (Phase 6)

Context

Chimera must eventually run beyond desktop OS hosts — UEFI appliances, microcontrollers, and other silicon — while sharing framing, determinism, and security with the mesh.

Decision

Introduce chimera-nano-kernel (cnk/): a #![no_std] + alloc core with:

  • block-pool allocator, postcard framing, deterministic TxLog, softfloat/fixed-point
  • wasmi interpreter tier (feature) vs host Wasmtime JIT
  • smoltcp sim framing (feature) — not QUIC-over-smoltcp
  • ML-KEM/ML-DSA hybrid handshake (feature)
  • host shim for Windows tests; UEFI/Cortex-M/RISC-V stubs only

Consequences

  • Workspace stays green on Windows with default host features.
  • Bare-metal targets verified via cargo check --no-default-features --target ….
  • Real firmware boots remain future work (documented honestly).