Born for AI. Built by AI. — 生于AI，成于AI

A Singapore-inspired AI-native operating system kernel written entirely in Rust, targeting four CPU architectures: x86_64, aarch64, RISC-V, and LoongArch. MerlionOS is a from-scratch hobby OS that boots in QEMU with a full interactive shell, preemptive multitasking, networking, graphics, and built-in AI capabilities — all developed in partnership with Claude.

253 modules | 85,928 lines of Rust | 358 shell commands | 77 releases | 4 architectures

• Preemptive multitasking with per-process page tables and ring 3 user mode
• GDT/IDT, PIT timer, APIC, SMP detection, slab allocator
• Demand paging, stack guard canaries, heap integrity checks
• Signal framework (SIGKILL, SIGTERM, SIGSTOP)
• Loadable kernel modules, kernel symbol table, backtraces

• In-memory VFS with /dev, /proc, /etc, /tmp
• Virtio-blk and AHCI/NVMe drivers, GPT partition support
• FAT16-like filesystem (MF16), RAM disk, disk-backed FS
• File descriptor table (open/read/write/close), ELF-64 loader

• Virtio-net and E1000e drivers, DHCP client
• IPv4/UDP/TCP stack with 3-way handshake
• ARP, ICMP ping, HTTP client (wget), netstat

• 298 commands: process mgmt, file ops, networking, system tools
• Command history, arrow keys, aliases, env variables, scripting
• Interactive apps: text editor, calculator, snake, Forth interpreter
• Screen saver, top, watch, fortune, benchmarks

• Natural language shell (English + Chinese)
• LLM proxy over COM2 serial, semantic VFS with file tags
• AI system monitor, self-healing kernel (page fault / OOM recovery)
• Agent framework, AI-powered man pages, kernel concept explainer

• VGA text console with ANSI colors, framebuffer (160x50)
• PS/2 keyboard, UART serial, audio engine
• ACPI shutdown/reboot, power management

Prerequisites: Rust nightly, QEMU

rustup component add rust-src llvm-tools --toolchain nightly
cargo install bootimage

Build and run (x86_64 default):

make build       # build bootable image
make run         # boot in QEMU (VGA + serial)
make run-serial  # headless (serial only)

Other architectures:

make pi          # build for Raspberry Pi (aarch64)
make run-pi      # boot aarch64 in QEMU
make riscv       # build for RISC-V
make run-riscv   # boot riscv64 in QEMU
make loongarch   # build for LoongArch
make run-loongarch  # boot loongarch64 in QEMU

MerlionOS supports four CPU architectures with a shared kernel core and architecture-specific HAL layers. The primary target is x86_64-unknown-none using the bootloader crate v0.9 with physical memory mapping. The kernel boots with a GDT (kernel + user segments with TSS), sets up an IDT for exceptions and PIC IRQs, initializes a 4MB heap via a linked-list allocator, and starts a preemptive round-robin scheduler driven by the PIT at 100 Hz. User processes run in ring 3 with cloned page tables (kernel in upper half, user in lower half) and communicate via syscalls through int 0x80. The VFS, networking stack, and AI subsystems are all in-kernel modules initialized at boot. Each architecture port provides its own interrupt controller, timer, UART, and boot sequence while sharing the platform-independent kernel subsystems.

• Website: merlionos.org
• Docs: Architecture | AI Native OS | Deep Dive
• 中文文档: README_CN.md
• License: MIT

Built with AI — MerlionOS is developed in partnership with Claude by Anthropic, from architecture design to implementation. Every line of code is a collaboration between human vision and AI capability.