Architecture support: aarch64 and x86_64
Kernel/userspace preemptive multithreading
Kernel-space multitasking with async/await runtime
Symmetric Multiprocessing
Unix-like virtual filesystem: files, directories, block/char devices, symlinks, mounts
Kernel-user ABI generated from a rust-like description language
In-memory read-write filesystem for tar-based initrd
sysfs/devfs
Binary formats: ELF + #!/... shebangs
Rust-style interfaces for most of the stuff like memory management, devices etc.
PCI Express devices
- NVMe drive support (read/write, currently x86_64 only, due to lack of MSI-X support on aarch64).
- AHCI SATA drive support (read/write)
- xHCI USB host controller
USB HID keyboards

aarch64-specific:

PSCI for SMP start-up and power control
PL011 serial port
ARM generic timer as system/monotonic timer
GICv2 IRQ controller

x86_64-specific:

UEFI boot through yboot (no plans for legacy boot)
I/O and Local APIC IRQ controllers
PS/2 keyboard
i8253-based timer (got some problems with HPET on real hw, had to revert, lol)
COM ports
ACPI, work in progress, mostly broken on real hardware
- ACPI shutdown
- PCI IRQ pin routing
- Events like power button, etc.
Fancy framebuffer console

Userspace features:

Sanitized system calls better suited for Rust
Userspace threads
Synchronization primitives through futex-like interface
Unix-like signals and exceptions

Building the OS

Prerequisites:

Decent CPU and a sizable amount of RAM
~20G of free disk space
Patience

NOTE Full OS build requires you to build the *-unknown-yggdrasil Rust toolchain, which may take quite a while, so be prepared.

Steps:

Install the prerequisite software

### For Arch Linux based systems

# pacman -Sy cmake ninja llvm dosfstools mtools

### For MacOS

$ brew install cmake ninja llvm dosfstools mtools
$ export PATH="$PATH:/opt/homebrew/Cellar/llvm/.../bin"

NOTE Nightly Rust version and rustup are required, for details see the rustup page.

Clone this repo

$ git clone https://git.alnyan.me/alnyan/yggdrasil
$ cd yggdrasil
# Optionally, checkout a release/snapshot branch

Run cargo xtask toolchain to fetch, build and link the toolchain
Run cargo xtask to build the OS.

Once the OS has been built, you can run it in QEMU by executing cargo xtask qemu. For more xtask commands, see cargo xtask --help.

General plans (in no particular order)

Better unification of architecture code
async for VFS (?)
Code cleanup, I've been doing quite a lazy job at that lately...

Kernel: /kernel
Userspace: /userspace
ABI definitions: /lib/abi-def

README.md

yggdrasil-kernel

Main features

Building the OS

General plans (in no particular order)

Navigation