Programs can now subscribe to keyboard events (key_down/key_up/key_press)
and drivers can broadcast them, through a new user-space input service.
The delivery model is forced by danos IPC: a synchronous rendezvous holds
one pending reply, so a server cannot park N subscribers blocked in a
"wait for next event" call — delivery must be push. But a synchronous push
has no timeout and the kernel never wakes a sender parked on a dead peer's
endpoint, so one dying subscriber would hang all input. So this lands the
roadmap's planned asynchronous buffered send and builds the service on it:
- ipc_send (syscall 26): non-blocking post to an endpoint's bounded payload
ring, delivered through reply_wait as a buffered message (notify_message_bit).
A full ring drops the oldest. It can never hang on a dead/slow peer.
- input-protocol + runtime.input helpers (subscribe/next, connectSource/
publish) — the first real consumer of M13 capability passing: a subscriber
hands the service its own endpoint as a capability.
- input service (fan-out via ipc_send, dead-subscriber pruning), a synthetic
input-source, and input-test; the ps2-bus keyboard driver publishes to it.
Real IRQ1 scancode decoding (which must live in the bus, the PNP0303 owner)
is a documented follow-up; the source is synthetic for now.
- build/init wiring, an `input` QEMU case, and docs/input.md.
Full QEMU suite 48/48, including the new input case and every IPC/endpoint
regression (ipc, ipc-call, ipc-cap, vfs, hpet, bus, irqfree).
Retire the kernel's spawn-every-initial-ramdisk-binary loop, resolving the
service/driver split into a real three-level supervision hierarchy:
kernel -> spawns init (PID 1) only, and publishes the initial-ramdisk
init -> the service supervisor: spawns the system services (vfs, device-manager)
device-manager -> spawns the drivers it matches (hpet)
The kernel now only hands the initial-ramdisk image to the process layer
(publishInitialRamdisk) so user space can system_spawn from it; it launches nothing
bundled itself. init gains a boot-services list ("vfs", "device-manager") and spawns
them best-effort before settling into its heartbeat — policy lives in user space,
where a microkernel keeps it. Drivers are absent from that list on purpose: the
device manager owns them. Test-only binaries (vfs-test, bus) no longer run at boot;
their kernel self-tests still spawn them directly.
This removes increment 2's transitional double-spawn: a real boot now brings hpet up
exactly once (verified — kernel -> init -> vfs/device-manager -> hpet, zero "claim
failed"). The automated suite is unaffected: test builds run their case and halt
before the normal boot path, so each already spawns its own binaries. Suite 36/36
plus host tests; normal boot verified by hand under QEMU.
The reorg moved user binaries under /system (init -> /system/services/init,
drivers -> /system/drivers/<name>, vfs-test -> /system/services/vfs/vfs-test), but
many comments and log strings still named the old /sbin/ home. Retarget them all:
kernel/loader/test comments and the two boot log lines, plus vision.md and the
driver-model.md proposed tree (also dropped the stale `d` suffixes and rt->runtime
there). The initial-ramdisk spawn log no longer fakes a /sbin/ prefix, since those
binaries live in different homes (services vs drivers).
Left the FSH design doc's /sbin and /lib rows alone — whether /sbin stays a
directory at all is a design call for its owner, not a stale-comment fix.
The source layout now mirrors the runtime filesystem hierarchy
(docs/danos-file-system-hierarchy-FSH.md): what lives under system/ in the
source is what a running danos represents under /system. Each service and
driver is a sub-project directory that is its own Zig module — cross-project
references go by module name, never by a path into another project's files.
Moves (all git mv, history preserved):
- src/ -> system/ (danos internals; the self-representation)
root.zig -> danos.zig (the kernel<->user contract module)
kernel/arch/ -> kernel/architecture/ (arch -> architecture)
device/ -> devices/ (what /system/devices reflects)
boot/ -> /boot (the loaders, top level)
- sbin/ -> split by role:
init, vfs -> system/services/<name>/<name>.zig
hpetd, busd -> system/drivers/<name>/<name>.zig
vfs-test -> system/services/vfs/vfs-test.zig (inside the vfs project)
- lib/ -> library/runtime/ (room for other libraries beside runtime)
The VFS wire protocol becomes its own module, system/services/vfs/protocol.zig
("vfs-protocol"): the vfs sub-project exposes its interface, and the runtime's
file layer imports it by name. First instance of the "protocol module" pattern
(docs/driver-model.md); usb/block will expose theirs the same way.
Also: fix a naming-standard violation in the protocol — Op -> Operation (and
req -> request, _pad -> _padding). Docs updated: /system/services added to the
FHS doc, a repository-layout section added to the docs index, and stale source
paths swept across comments and docs.
Runtime boot paths are unchanged (the bootloader still loads /sbin/init);
aligning the runtime filesystem to the FHS is a separate follow-up. Suite 35/35
plus host tests green.
Daniel Samson