EEVDF scheduler & SMP
Earliest Eligible Virtual Deadline First with per-CPU runqueues, migration, load balancing, IPI preemption and Priority Inheritance futexes.
vruntime · deadline · vlag · PI-futex
v0.4.0 · boots Alpine Linux 3.23
UNIX-like x86-64 kernel, written from scratch.
Uinxed is a monolithic UNIX-like x86-64 kernel in C — Limine boot on UEFI/Legacy, SMP bring-up, and a Linux-compatible syscall ABI.
187/*
188 * EEVDF core: eligibility check
189 *
190 * A task is eligible iff lag >= 0, i.e. its ideal service time
191 * exceeds its actual service time. In discrete form:
192 * avg_vruntime >= (vruntime - min_vruntime) * avg_load
193 */
194
195/* Whether a vruntime is eligible given the runqueue state */
196static int entity_eligible_vruntime(eevdf_rq_t *rq, uint64_t vruntime)
197{
198 __int128 avg = rq->avg_vruntime;
199 uint64_t load = rq->avg_load;
200
201 if (rq->curr && rq->curr->state == TASK_RUNNING) {
202 uint64_t weight = rq->curr->weight;
203 avg += (__int128)(int64_t)(rq->curr->vruntime - rq->min_vruntime) * weight;
204 load += weight;
205 }
206
207 /* The key*load term can overflow s64 on a long-lived or heavily loaded rq. */
208 int64_t key = (int64_t)(vruntime - rq->min_vruntime);
209 return avg >= (__int128)key * load;
210}
Verbatim from the kernel source tree.
Browse source
- License
- Apache-2.0
- Language
- C
- Target
- x86-64
- Firmware
- UEFI + Legacy
- Scheduler
- EEVDF
- Syscall ABI
- Linux 6.12
Capabilities
01
Six subsystems, all in-tree
A practical, self-contained kernel with modern design principles — no borrowed kernel underneath.
Memory management
Binary-buddy frames, 4-level paging, higher-half direct map, slab heap, unified page cache with LRU reclaim, writeback, readahead — plus swap.
HHDM · page cache · writeback · swap
VFS & filesystems
UNIX-style VFS with tmpfs root, procfs/sysfs/devtmpfs/cgroupfs, plus FAT/exFAT, ext2/3/4, NTFS (write) and ISO 9660 (Rock Ridge).
tmpfs · ext4 · NTFS · ISO 9660
In-house network stack
Ethernet, ARP, IPv4/IPv6, ICMP(v6), NDP, UDP and TCP with e1000/RTL8139 drivers, Linux socket ABI, DHCP and /proc/net views.
IPv6 · TCP · DHCP · AF_NETLINK
Linux ABI & IPC
Linux 6.12 x86-64 syscall numbering (0–462, unimplemented return -ENOSYS), epoll, eventfd/timerfd/signalfd, pipes, PTYs, modules and inotify.
0–462 · epoll · futex2 · PID 1
Drivers & security
AHCI/NVMe/USB storage, HDA audio, DRM/KMS display, USB HID, ACPI/PCI/USB stacks — with seccomp, no_new_privs and ptrace.
AHCI · NVMe · DRM/KMS · seccomp
Project status
02
It already boots a real distro
Experimental, but past “hello world” long ago — validated on virtual machines and physical servers.
-
Alpine Linux 3.23 boots
Current image brings up Alpine userland on x86-64, including an Xfce (X11) desktop with a working terminal.
-
Real hardware proven
Runs on physical servers including Dell PowerEdge R410, via UEFI, Legacy or Ventoy boot.
-
Under active validation
PS/2 input, evdev consumers, poll/epoll wakeups and scheduler behavior are being hardened right now.
Experimental software
GPU, VirtIO, audio and parts of the ABI are still incomplete. Use disposable disks or VMs — not production data.
-
01
Limine → kernel_entry()
UEFI / Legacy handoff
-
02
Early init
SIMD → serial → framebuffer → allocator → paging → heap
-
03
Platform
ACPI → TPM → TSC → SMP bring-up → PCI
-
04
Drivers
net → storage → input → audio → USB → display
-
05
Filesystems
VFS → tmpfs root → procfs / sysfs / devtmpfs
-
06
Kernel services
scheduler → process → IPC → syscalls → cgroups
-
07
init (PID 1)
Userspace starts, scheduling begins
Hardware support
03
What it talks to
Every driver below lives in-tree. Some subsystems ship disabled by default in Kconfig — turn them on with `make menuconfig`.
Input
PS/2 keyboard & mouse · evdev · USB HID (keyboard, mouse, consumer control)
Storage
IDE/ATA · AHCI (SATA) · NVMe · USB Mass Storage (BOT / SCSI)
Audio
Sound Blaster 16 · Intel HD Audio · ALSA-compatible PCM/control ABI
Display
DRM/KMS core + GPU driver registry · VirtIO-GPU · GOP framebuffer console · software fb fallback
Network
e1000/e1000e (82540EM, 82545EM, 82546EB, 82541PI, 82574L) · RTL8139 / RTL8169
Bus
PCI/PCIe (ECAM + legacy) · USB UHCI / OHCI / EHCI / xHCI · I2C
Platform
ACPI · HPET · RTC · serial · IEEE 1284 parallel · TPM (TIS/CRB, 1.2 + 2.0)
Security
seccomp filters + user notifications · no_new_privs · ptrace · cgroups pids controller
Codebase
04
182,656 lines, all written here
No borrowed kernel underneath — every subsystem below is in-tree C, counted straight from the source tree.
- Lines of C
- 182,656
- Files
- 452
- Sources
- 238 .c
- Headers
- 214 .h
drivers
49,317
99 .c
fs
44,904
46 .c
kernel
29,519
40 .c
include
26,930
214 .h
net
13,063
15 .c
ipc
7,236
6 .c
mem
5,828
11 .c
libs
3,731
15 .c
security
1,343
2 .c
init
441
1 .c
tools
215
1 .c
boot
129
2 .c
Line counts come from the kernel source tree — `find` + `wc -l` over every *.c and *.h.
Quick start
05
Build it and boot it
Three commands from clone to a running kernel on QEMU.
01
Prerequisites
make, gcc 13.3+, qemu, xorriso — plus clang-format / clang-tidy and kconfig-frontends for development.
# Debian / Ubuntu
$ sudo apt install make gcc qemu-system xorriso \
clang-format clang-tidy kconfig-frontends \
libncurses-dev dos2unix
# Arch Linux
$ sudo pacman -Sy make gcc qemu-system xorriso \
clang-format clang-tidy kconfig-frontends \
libncurses-dev dos2unix
02
Build the image
Produces UxImage (kernel) and Uinxed-x64.iso (bootable CD image).
$ git clone https://github.com/ViudiraTech/Uinxed-Kernel.git
$ cd Uinxed-Kernel
$ make
03
Run in QEMU
Boots the ISO on q35 with OVMF firmware; serial output appears in your terminal.
$ make runUinxed-Kernel/
├── boot/ Boot protocol structures and interfaces
├── init/ Kernel entry and initialization routines
├── kernel/ Core subsystems and runtime services
├── mem/ Memory management subsystem
├── fs/ VFS and filesystem implementations
├── net/ Network stack and protocols
├── drivers/ Hardware drivers and device support
├── ipc/ Inter-process communication mechanisms
├── security/ Security and policy components
├── include/ Kernel headers and public interfaces
├── libs/ Internal kernel libraries and utilities
├── tools/ Development, debugging and auxiliary tools
├── scripts/ Build, configuration and maintenance
├── assets/ Build and boot resources
├── Kconfig Kernel configuration system
└── Makefile Build systemReal hardware
- UEFI: GPT + ESP, copy assets/Limine to the ESP, UxImage to EFI/Boot, Secure Boot off.
- Legacy: burn Uinxed-x64.iso to a drive and boot on a 64-bit machine.
- Ventoy also works — copy the ISO onto the drive and select it from the menu.
FAQ
06
Frequently asked
Short answers — details live in the kernel README and DeepWiki.
Are all Linux syscalls implemented?
No. The table follows Linux 6.12 x86-64 numbering (0–462), but only a subset is implemented. Unimplemented calls return -ENOSYS instead of crashing, and coverage grows over time.
How do I read the kernel log?
Logs go to the boot console (default tty0). For reliable debugging, set kernel_cmdline to console=ttyS0 in limine.conf and rebuild — make run already attaches QEMU serial to stdio.
A driver I expected is not working (e.g. VirtIO-GPU)?
Some subsystems default to off in Kconfig (e.g. VIRTIO, VIRTIO_GPU, SOUND_SB16). Enable them with make menuconfig and make sure the device exists in your VM or hardware.
Can I run it on real hardware?
Yes, as an experiment. Prefer disposable machines or test disks — filesystem drivers (especially the NTFS writer) are not yet safe for important data.
Which dev commands are available?
Run make help for all targets: format, check (clang-tidy), menuconfig, gen.clangd and more.
Can I contribute?
Yes. Issues are welcome in any language. For patches, run make format and make check first so the diff stays reviewable.
Hack on a real kernel.
Star the repo, open an issue in any language, or send a patch — polite reports welcome.
Discord · QQ 1084955319