Daniel Samson
1bf91115dd
Extend the input service beyond the keyboard so mouse and joystick/gamepad drivers can broadcast too, with per-device publish and subscribe methods. - protocol: KeyEvent joins MouseEvent (motion/buttons/scroll) and JoystickEvent (axes/buttons), all carried in a common InputEvent envelope tagged with a DeviceKind. A subscribe request carries a device_mask, so a subscriber names the classes it wants and the service routes each event only to interested subscribers (a mouse-only listener never wakes for keystrokes). - runtime: per-device publish methods (publishKeyboardEvent/publishMouseEvent/ publishJoystickEvent) and subscribe helpers (subscribeKeyboard/Mouse/Joystick, each typed, plus subscribe(mask)/subscribeAll returning the tagged envelope). - service: subscriber table gains a device_mask; broadcast routes by the event's device class. - mouse driver now publishes (synthetic) mouse events like the keyboard driver; input-source cycles all three classes; input-test subscribes to all and only emits its "ok" marker once it has received one of each class — so the passing test proves per-device routing, not just delivery. Real HID decoding stays a follow-up. No kernel changes: ipc_send is generic and the 36-byte InputEvent fits its 64-byte payload. Full QEMU suite 48/48; serial log confirms keyboard, mouse, and joystick all reach one subscription.
DanOS
Codename: Shodan Version: 1
A small operating system, written from scratch in Zig — a bootloader (boot/)
and a microkernel (system/kernel/), sharing a neutral handoff contract (system/boot-handoff.zig).
It boots x86-64 via UEFI, and so far has a framebuffer console, a physical frame
allocator, its own paging with W^X permissions, interrupt/exception handling, a
LAPIC timer, a kernel heap, a fixed-priority preemptive scheduler, and in-kernel IPC
channels. See docs/ for how each piece works.
Prerequisites
- Zig 0.16.x — the build is pinned to this line (
.zig-version); other minor versions are rejected, because Zig makes breaking changes between releases pre-1.0. A toolchain manager such as zvm orzigupwill pick up.zig-versionautomatically. - QEMU (
qemu-system-x86_64) — to run and test the kernel. On macOS,brew install qemualso bundles the OVMF firmware below. - OVMF UEFI firmware — the
edk2-ovmfpackage (Arch),ovmf(Debian/Ubuntu), oredk2-ovmf(Fedora); on macOS it ships inside the Homebrewqemuformula. Both the build and the test harness probe the known Arch/Debian/Fedora/macOS layouts and use the first that exists, so no configuration is normally needed. Override with-Dovmf-code=/-Dovmf-vars=(build) if yours lives elsewhere. - Python 3 — for the QEMU integration test harness.
Build
zig build
Produces a FHS-shaped zig-out/ that is the danos filesystem and the boot volume:
the UEFI bootloader at zig-out/EFI/BOOT/BOOTX64.efi, the kernel at
zig-out/system/kernel, init at zig-out/system/services/init, drivers under
zig-out/system/drivers/, and the initial-ramdisk at zig-out/boot/.
Run
Boot it in QEMU with OVMF (opens a display window):
zig build run-x86-64
# distro with OVMF elsewhere:
zig build run-x86-64 -Dovmf-code=/path/OVMF_CODE.fd -Dovmf-vars=/path/OVMF_VARS.fd
Test
zig build test # host unit tests (the platform-independent shared code)
python3 test/qemu_test.py # QEMU integration tests: boots the kernel and asserts
# on its serial output (see docs/testing.md)
The integration harness builds and boots the kernel once per test case, checking memory, the frame allocator, paging (incl. NX and the null guard), the heap, interrupts, and exception handling. It exits non-zero on any failure, so it drops straight into CI.
Documentation
Design notes explaining the why behind the code live in
docs/ — start with docs/README.md.
Logo
San Serif Text "Dan OS" with a black karate belt around it.