MetalOS/docs/BUILD.md

Building MetalOS

MetalOS can be built either using Docker (recommended for consistent builds) or natively on your system.

Docker Build (Recommended)

The easiest way to build MetalOS is using Docker, which provides a pre-configured environment with all dependencies.

Prerequisites

• Docker: Docker Engine 20.10 or later
  • Install Docker

Quick Start

# 1. Build the Docker image
./scripts/docker-build.sh

# 2. Setup dependencies (downloads AMD GPU firmware, etc.)
./scripts/docker-run.sh scripts/setup-deps.sh

# 3. Build MetalOS
mkdir build && cd build
cmake ..
cmake --build .

# 4. Test in QEMU (headless mode)
cmake --build . --target qemu

# 5. Optional: Interactive shell in container
./scripts/docker-run.sh /bin/bash

What's Included in Docker

The Docker image includes:

• Build tools: GCC, NASM, CMake, Meson
• QEMU: For testing with UEFI firmware
• OVMF: UEFI firmware for QEMU
• Dependency management: Scripts to download AMD firmware, Mesa RADV, QT6

Docker Build Benefits

• ✅ Consistent build environment across all platforms
• ✅ No need to install cross-compiler manually
• ✅ Pre-configured QEMU and OVMF setup
• ✅ Isolated from host system
• ✅ Easy CI/CD integration

Native Build

If you prefer to build natively without Docker:

Prerequisites

Required Tools

1. GNU Compiler Collection (GCC)

   • Cross-compiler for x86_64-elf target
   • Version 11.0 or later recommended

2. GNU Binutils

   • Cross-binutils for x86_64-elf target
   • Includes ld, as, objcopy, etc.

3. NASM

   • Netwide Assembler for x86_64
   • Version 2.15 or later

4. GNU Make

   • Build automation
   • Version 4.0 or later

5. QEMU (for testing)

   • QEMU system x86_64
   • Version 6.0 or later with UEFI support

6. EDK II OVMF

   • UEFI firmware for QEMU
   • Required for UEFI boot testing

Installing Prerequisites on Ubuntu/Debian

# Install basic build tools
sudo apt-get update
sudo apt-get install -y build-essential nasm qemu-system-x86 ovmf mtools xorriso

# Install cross-compiler prerequisites
sudo apt-get install -y libgmp-dev libmpfr-dev libmpc-dev texinfo

# Note: You may need to build the cross-compiler manually
# See docs/CROSS_COMPILER.md for instructions

Installing Prerequisites on Arch Linux

sudo pacman -S base-devel nasm qemu-full edk2-ovmf mtools xorriso

Installing Prerequisites on macOS

brew install nasm qemu x86_64-elf-gcc x86_64-elf-binutils

Building the Bootloader

# From repository root
cd bootloader
make

This produces bootloader/bootx64.efi - the UEFI bootloader.

Building the Kernel

# From repository root
cd kernel
make

This produces kernel/metalos.bin - the kernel binary.

Creating Bootable Image

# From repository root, if you haven't already
mkdir build && cd build
cmake ..

# Create the bootable image
cmake --build . --target image

This creates the bootable disk image at <build-directory>/build/metalos.img (e.g., build/build/metalos.img if your build directory is named build/). The image contains:

• EFI System Partition with bootloader
• Kernel binary
• Any required data files

Testing in QEMU

MetalOS includes comprehensive QEMU support with UEFI firmware (OVMF) for testing.

Prerequisites

Ensure QEMU and OVMF are installed:

# Ubuntu/Debian
sudo apt-get install qemu-system-x86 ovmf mtools cmake

# Arch Linux
sudo pacman -S qemu-full edk2-ovmf mtools cmake

# Fedora
sudo dnf install qemu-system-x86 edk2-ovmf mtools cmake

Boot MetalOS in QEMU

cd build
cmake --build . --target qemu

This will:

1. Build bootloader and kernel
2. Create a bootable FAT32 disk image with UEFI boot structure
3. Launch QEMU with OVMF UEFI firmware in headless mode
4. Boot the system

Boot with Debug Output

cd build
cmake --build . --target qemu-debug

This includes CPU interrupt and reset debugging output.

Boot with GDB Support

For debugging with GDB:

# Terminal 1 - Start QEMU with GDB server
cd build
cmake --build . --target qemu-gdb

# Terminal 2 - Connect GDB
gdb kernel/metalos.bin
(gdb) target remote localhost:1234
(gdb) continue

QEMU will wait for GDB connection before starting execution.

Test QEMU UEFI Setup

To verify QEMU and OVMF are properly installed without needing a bootable OS image:

cd build
cmake --build . --target qemu-uefi-test

This boots directly to the UEFI shell, confirming your QEMU+OVMF setup works correctly.

Managing Dependencies

MetalOS requires several third-party dependencies for GPU support and application framework.

Dependency Setup Script

Use the provided script to download and setup dependencies:

# Setup all dependencies
./scripts/setup-deps.sh all

# Or setup individually
./scripts/setup-deps.sh firmware    # AMD GPU firmware blobs
./scripts/setup-deps.sh ovmf        # UEFI firmware
./scripts/setup-deps.sh mesa        # Mesa RADV (planned)
./scripts/setup-deps.sh qt6         # QT6 framework (planned)

Required Dependencies

1. AMD GPU Firmware (deps/firmware/)

   • Radeon RX 6600 (Navi 23) firmware files
   • Automatically downloaded from linux-firmware repository
   • Files: dimgrey_cavefish_*.bin

2. OVMF UEFI Firmware (deps/ovmf/)

   • EDK II OVMF for QEMU testing
   • Copied from system installation or downloaded

3. Mesa RADV (deps/mesa-radv/) - Planned for Phase 4

   • Vulkan driver for AMD GPUs
   • Will be configured to use custom kernel interface

4. QT6 Framework (deps/qt6/) - Planned for Phase 7

   • Minimal static build for the single application
   • QtCore, QtGui, QtWidgets modules only

See deps/README.md for detailed dependency documentation.

Testing on Real Hardware

⚠️ WARNING: Testing on real hardware can be risky. Always backup your data.

USB Boot Drive Creation

# Create bootable USB (replace /dev/sdX with your USB device)
sudo dd if=build/metalos.img of=/dev/sdX bs=4M status=progress
sync

Requirements for Hardware Testing

• AMD64 system with UEFI firmware
• Radeon RX 6600 GPU (for full functionality)
• USB drive (1GB or larger)
• Ability to boot from USB in UEFI mode

Build Configuration

Build options can be configured in config.mk:

# Debug build (includes symbols, verbose output)
DEBUG ?= 1

# Optimization level (0, 1, 2, 3, s)
OPT_LEVEL ?= 2

# Target architecture
ARCH ?= x86_64

# Enable specific features
ENABLE_LOGGING ?= 1
ENABLE_SERIAL ?= 1

Clean Builds

# Clean all build artifacts
cd build
cmake --build . --target clean

# Or remove the build directory entirely
cd ..
rm -rf build
mkdir build && cd build
cmake ..

Troubleshooting

Cross-Compiler Not Found

If you get errors about missing cross-compiler:

1. Check that x86_64-elf-gcc is in your PATH
2. See docs/CROSS_COMPILER.md for building instructions

QEMU UEFI Firmware Missing

# Ubuntu/Debian
sudo apt-get install ovmf

# Arch
sudo pacman -S edk2-ovmf

Build Fails with "Permission Denied"

# Make sure scripts are executable
chmod +x scripts/*.sh

Next Steps

After successful build:

1. Review docs/ARCHITECTURE.md for system design
2. See docs/DEVELOPMENT.md for development workflow
3. Check docs/DEBUGGING.md for debugging techniques