Aether

Aether is a hybrid kernel designed for bare-metal execution with POSIX and glibc compatibility.

🎉 Current Milestone: BusyBox Shell

Aether now boots directly into a BusyBox shell (static musl build), making it a functional POSIX-compatible operating system!

Features Implemented

• ✅ 30+ POSIX Syscalls - read, write, open, close, fork, execve, mmap, brk, etc.
• ✅ ELF Loader - Full ELF64 parser with PT_LOAD segment handling
• ✅ Dynamic Linker Support - PT_INTERP detection, Auxiliary Vector (Auxv) setup
• ✅ Virtual Filesystems - /dev (null, zero, urandom, tty), /proc (self, meminfo, cpuinfo)
• ✅ BusyBox 1.35 - Static musl binary embedded in kernel initrd

Architecture

┌─────────────────────────────────────────────┐
│           BusyBox Shell (User Space)        │
├─────────────────────────────────────────────┤
│           POSIX Syscall Interface           │
├──────────┬──────────┬──────────┬────────────┤
│   mm/    │  sched/  │   fs/    │  drivers/  │
│ Memory   │Scheduler │VFS+DevFS │  Keyboard  │
├──────────┴──────────┴──────────┴────────────┤
│              Hardware Abstraction           │
├─────────────────────────────────────────────┤
│          UEFI / Bare Metal Hardware         │
└─────────────────────────────────────────────┘

Building

# Install Rust nightly
rustup toolchain install nightly
rustup target add x86_64-unknown-uefi --toolchain nightly

# Build for x86_64 UEFI
cargo build --release --target x86_64-unknown-uefi

Running on QEMU

Windows

# 1. Install QEMU: https://www.qemu.org/download/#windows
# 2. Download OVMF: https://www.kraxel.org/repos/jenkins/edk2/
#    Extract edk2.git-ovmf-x64-*.noarch.rpm and get OVMF_CODE.fd

# 3. Create ESP directory
mkdir esp\EFI\BOOT
copy target\x86_64-unknown-uefi\release\aether.efi esp\EFI\BOOT\BOOTX64.EFI

# 4. Run QEMU
qemu-system-x86_64.exe -m 512M -bios C:\path\to\OVMF_CODE.fd -drive format=raw,file=fat:rw:esp -serial mon:stdio

Linux

./run-qemu-x86.sh

macOS (Apple Silicon & Intel)

Works on Apple Silicon via QEMU TCG emulation!

brew install qemu
# Requires edk2-x86_64-code.fd (available in qemu package or via homebrew)
./run-qemu-x86.sh

Project Structure

Aether/
├── src/
│   ├── arch/       # x86_64, aarch64 architecture code
│   ├── mm/         # Memory management, paging
│   ├── sched/      # Process sched (Sleep, WaitQueue support)
│   ├── syscall/    # POSIX syscalls, ELF loader
│   ├── fs/         # VFS, RamFS, DevFS, ProcFS
│   └── drivers/    # Serial (UART), Keyboard (PS/2)
├── init/
│   ├── init.bin    # Simple init binary
│   └── busybox.bin # BusyBox 1.35 (musl static)
└── aether-core/    # Shared kernel abstractions

Roadmap

• Phase 14: POSIX Syscall Coverage
• Phase 15: ELF Dynamic Linker (kernel support)
• Phase 16: Virtual Filesystems (/dev, /proc)
• Phase 17: BusyBox Shell (Ring 3 Userspace Isolation)
• Phase 18: Real x86 Hardware Boot (In Progress)
• Phase 19: ext4 Filesystem
• Phase 20: ARM64 Platform Features

Related Projects

• AetherOS - Cross-platform software stack

License

GNU General Public License v3.0 - see LICENSE