ARM64 BUILD 4520.001

OS/2 Warp
AArch64 Edition

The legendary operating system, reborn for modern ARM64 hardware. Bare-metal performance with classic OS/2 elegance. No Linux. No systemd. Pure OS/2 architecture from the ground up.

Enterprise-grade bare metal

OS/2 Warp 4.52 brings proven stability and elegant design to ARM64. Built for developers, servers, and enthusiasts who demand control.

Bare Metal Performance

Direct hardware access without virtualization overhead. Pure ARM64 AArch64 execution with UEFI boot and native device drivers.

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Multi-Filesystem VFS

EXT4, FAT32, FAT16, and exFAT support out of the box. Advanced VFS layer with mount management and full read/write capability.

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43 Keyboard Layouts

Global keyboard support with dead key composition. Latin, Cyrillic, Arabic, Hebrew, Thai, Georgian, Korean, Japanese, and more.

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CONFIG.SYS Services

Classic OS/2 service management with CRITICAL, AUTO, and MANUAL modes. Simple, deterministic boot sequence—no systemd complexity.

🖥️

OS/2 Shell & CMD

Authentic OS/2 command processor with REXX scripting support. Familiar commands: DIR, TYPE, COPY, SRVSTAT, MOUNT.

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Developer Tools

Full C11 kernel source. CMake build system. Cross-compilation with aarch64-elf toolchain. GCC and Clang/LLVM support.

Built for ARM64

A complete operating system stack: bootloader, kernel, drivers, filesystem, and shell.

UEFI Bootloader

BOOTAA64.EFI with GOP graphics, memory map, and kernel loading. Hand-crafted without gnu-efi dependencies.

Microkernel

C11 kernel with UART serial, memory management, block device abstraction, and VFS dispatcher.

Filesystem Drivers

EXT4 extent tree support, FAT32/FAT16 with LFN, exFAT for large files. GPT partition probing.

Service Manager

CONFIG.SYS-based service orchestration. STARTUP.CMD boot scripts. OS/2-style resource management.

Quick install reference

For ARM64 hardware or QEMU emulation. Full bare-metal installation guide in documentation.

1. Create disk image

Build a 6 GiB GPT disk with 4 partitions (EFI, OS2ROOT, FAT16DATA, EXFATUSB).

./scripts/mkdisk.sh os2warp452.img

2. Build kernel

Compile the OS/2 kernel with CMake and the aarch64-elf toolchain.

cmake -B build -DCMAKE_TOOLCHAIN_FILE=toolchain/aarch64-elf.cmake -G Ninja
cmake --build build -j$(nproc)

3. Run in QEMU

Launch OS/2 Warp in the ARM64 virtual machine.

./scripts/run_qemu.sh build/os2warp452.img

CONFIG.SYS Example

Classic OS/2 system configuration for services and devices.

SERVICE=VFS,CRITICAL
SERVICE=KEYBOARD,AUTO
DEVICE=C:\OS2\KBD.SYS /LAYOUT:en_US

Shell Commands

Service management in the OS/2 shell.

SRVSTAT REM List all services
SRVSTART KEYBOARD REM Start a service
View full guide →

Developer resources

Complete documentation for building, deploying, and extending OS/2 Warp ARM64.

Get in touch

Join the OS/2 ARM64 community — contribute code, report bugs, and connect with developers.