# ArkOS

A Linux-based operating system built from scratch — designed to be easy to use, easy to compile, and open for customization.

See [ArkOS: Comprehensive System Architecture](arkos_architecture_guide.md) for more details

## ✨ Features

| Feature | Status |
|---------|--------|
| Custom BIOS bootloader (stage1 + stage2) | ✅ |
| VESA graphics boot animation (60 FPS expanding dot) | ✅ |
| Verified Boot (SHA256 key-signed OS binary) | ✅ |
| Native Swift splash screen via Linux framebuffer | ✅ |
| Linux kernel 7.0 with custom initramfs | ✅ |
| Prebuilt Clang/LLVM toolchain | ✅ |
| `.ark` configuration file format | ✅ |
| Modular build system with progress output | ✅ |
| Service Manager | 🔜 |
| Package Manager | 🔜 |

## 🏗️ Building

### Prerequisites

| Tool | Purpose |
|------|---------|
| `clang` (prebuilt, included) | C compilation |
| `swiftc` | Swift compilation |
| `nasm` | x86 assembly |
| `python3` | Boot image packing & signing |
| `qemu-system-x86_64` | Testing |
| `mkfs.ext4` | Disk image generation |
| `cpio`, `gzip` | Initramfs packing |

### Build & Run

```bash
cd arkos/
make build    # Compiles everything, generates disk images
make run      # Launches QEMU with the built images (BIOS Mode)
make run-uefi # Launches QEMU in UEFI Mode
make clean    # Removes all build artifacts
```

**Note:** UEFI mode (`make run-uefi`) currently has a few known errors and trying it out is not recommended.

The build system uses the prebuilt Clang toolchain at `prebuilts/clang/` for all C compilation. No system compiler dependency.

### Build Output

The build system shows modular progress:

```
╔══════════════════════════════════════╗
║       ArkOS Build System v2.0        ║
╚══════════════════════════════════════╝

[ 1/14] Cleaning previous build
[ 2/14] Creating staging directories
[ 3/14] Integrating frameworks
[ 4/14] Preparing boot files
...
[14/14] Generating disk images

╔══════════════════════════════════════╗
║          Build complete! ✓            ║
╚══════════════════════════════════════╝
```

### Output Images

All images are generated in `finished/`:

| Image | Description |
|-------|-------------|
| `boot.img` | Bootloader + animation + kernel + initramfs |
| `sys.img` | System partition (frameworks, libraries) |
| `vend.img` | Vendor partition (DRM, keys, mirror info) |
| `avb.img` | Android Verified Boot metadata |
| `vbmeta.img` | Verified boot metadata |
| `dtbo.img` | Device tree blob overlay |

## 📁 Project Structure

```
arkos/
├── boot/                    # Bootloader source & configs
│   ├── source/              # Assembly source (bootloader.asm, stage2.asm) and C source (bootloader.c)
│   │   └── animationframes/ # Pre-generated boot animation frames
│   ├── initramfs.img        # Base initramfs image
│   └── *.ark                # Boot configuration files
├── frameworks/              # OS frameworks (Swift, DRM, SwiftUI)
├── kernel/                  # Linux kernel source + prebuilt bzImage
├── prebuilts/               # Prebuilt toolchains
│   └── clang/               # LLVM/Clang 22 toolchain
├── system/                  # Core system components
│   ├── init.c               # PID 1 init process (Verified Boot)
│   ├── display/             # Display compositor (ui_daemon) and boot animation
│   ├── sha256.c/h           # SHA256 implementation for signing
│   └── fb_helper.c          # Framebuffer ioctl helper
├── vendor/                  # Vendor-specific files
│   ├── verify/              # Verified Boot keys & signing tools
│   ├── mirror/              # Mirror configuration
│   └── Widewine/            # DRM (Widevine) integration
├── arkrt/                   # ArkOS runtime monolithic daemon
├── Makefile                 # Top-level build entry point
└── finished/                # Build output (generated)
```

## 🔐 Verified Boot

ArkOS implements a custom Verified Boot chain:

1. The build system reads the signing key from `vendor/verify/securebuild.ark`
2. `sign.py` computes `SHA256(KEY + arkrt_binary)` → `signature.bin`
3. At boot, `init.c` recomputes the hash and compares against `signature.bin`
4. **Mismatch → Kernel Panic** (system halts with security warning)
5. **Match → Boot continues** into the `arkrt` daemon and UI layer

> ⚠️ Never commit your real signing key to a public repository. Use `vendor/verify/key.py` to generate new keys.

## 📄 License

See [LICENSE](LICENSE) for details.