The microkernel message backbone the VFS server and drivers will ride on.
- src/kernel/ipc_sync.zig: Endpoint (sender FIFO threaded via Task.next +
a recv WaitQueue for servers + a small notification ring). call() (client
sends, wakes a server, blocks) and replyWait() (server replies to the held
caller, then receives the next). Reply routing keys on Task.ipc_client —
synchronous IPC owes one reply at a time. Payloads copy frame-to-frame
through the physmap (copyAcross on arch.translate, added in M5); an unmapped
page fails the copy instead of #PF-ing. MSG_MAX 256.
- Bootstrap naming: an integer name registry (danos.ServiceId, vfs=1) with
create_endpoint / ipc_register / ipc_lookup — any process finds a server
without threading a handle through spawn.
- notifyFromIsr(): ISR-safe async wake (badge with the high bit set), the
hook M10's IRQ-as-message needs. Unused/untested until then.
- Task gains handles[16] (opaque *Endpoint, to avoid a sched<->ipc import
cycle) + ipc_client/send/reply/status fields; sched gains
blockCurrentLocked/readyLocked; arch gains setSyscallResult2 (rdx badge).
- Syscalls 6..10 wired in process.zig; exit() now drops the caller's endpoint
refs. lib/ipc.zig: user-side createEndpoint/register/lookup/call
(server-side replyWait lands with the first server in M9).
- New `ipc-call` test: two kernel tasks ping-pong 100 calls, every reply
request+1. Suite 29/29.
Daniel Samson
eabb81684a