- CMD_MEMWRITE now carries a target page-table root (cr3) as its first field;
cr3 == 0 keeps the kernel address-space default (backward-compatible). A control
that has discovered a process's cr3 through its own read-only perception can
write that process's private memory under the same exclusive write lease.
Freshness of the cr3 is the control's responsibility — signaling does not
validate it (that is perception, not coherence), mirroring the read side.
- A socket control can now carry an SRC larger than the inline frame budget: a
length-prefixed SRC tail follows the CMD_MEMWRITE frame (flag SRC_PAYLOAD, the
length being the frame's own len). A per-connection two-phase receiver
accumulates the tail into a fixed conn-owned buffer up to the extent bound,
matching the in-process payload path. A zero or over-bound length is a framing
violation that closes the connection: leaving the promised tail unread would
desync the stream and draining an arbitrary length would be a denial of service.
The capability, exclusive lease, source and extent gates are unchanged and
reused; only the event header gained the cr3 field and the socket transport
gained the tail receiver. The adapter resolves cr3 == 0 to the kernel root on
its worker thread and writes atomically.
An epoll-driven, neutral transfer-event bus that connects sensors and input
actuators to one or more controls, bidirectionally. It owns the transfer context
and events — delivery order, priority, protocol-level timing, and an
interrupt-driven event model over fd sources (eventfd/timerfd/sockets) — and
stays agnostic to both the sensor/input drivers and the control.
What lives here:
- memctx: a coherent address-space context per endpoint — the guest address-space
root paired with a pre-opened read-only RAM-region fd, with per-endpoint epoch
invalidation and retained replay to late subscribers. Perception lives in
out-of-tree sensor libraries that consume this datum read-only.
- exclusive-ownership leases for destructive resource classes (input, power,
memory-write).
- write-signaled memory writes (MEMWRITE): an atomic write to guest memory routed
through the seam under an exclusive lease, never a writable mapping.
- a host-management seam for VM lifecycle/status and a neutral input-injection
command path.
- multi-VM endpoints; capability-gated, audited control authorization over an
in-process or unix-socket transport.
Builds against headers only by default (a stub mode that exercises the seam
without a VM); armed builds link the real sensor/input libraries behind flags.