InstantOS

A rewrite of the closed source graphical x86_64 operating system

Features

• Terminal Emulator (with ANSI)
• Userland!
• C/C++ and Rust Support
• Keyboard support
• Mouse support
• Window Manager

Upcoming features

• Custom FileSystem

Building

Requirements

• clang and clang++
• cmake
• nasm
• make
• lld-link through LLVM
• xorriso
• mtools (mformat, mmd, mcopy)
• qemu-system-x86_64
• OVMF firmware files

InstantOS also expects the bundled dependencies under outside/ to be present, So clone this Repository with --recurse-submodules.

Build

Clean and configure the build directory:

rm -rf build
cmake -S . -B build

Build the bootloader, kernel, userland programs, initrd, and ISO:

cmake --build build --target iso --parallel 4

The final bootable image is written to:

build/iboot.iso

Run

Boot the generated image in QEMU with:

./run.sh

run.sh creates build/ahci.img on first run and copies OVMF_VARS.4m.fd into build/ if needed.

USB input modes are selected with USB_MODE:

USB_MODE=xhci ./run.sh   # qemu-xhci with USB keyboard and mouse
USB_MODE=ohci ./run.sh   # OHCI regression path with USB keyboard
USB_MODE=none ./run.sh   # no emulated USB controller

For headless smoke testing without KVM:

QEMU_ACCEL=tcg QEMU_DISPLAY=none USB_MODE=xhci ./run.sh

build and run

If you want the full workflow in one command, use:

./build.sh