Section B.1: Repository Structure

Project Mu uses a multi-repository architecture for technical separation and selective consumption.

---

Core Repositories

graph TB
    subgraph "Project Mu Ecosystem"
        MU_BASE[mu_basecore<br/>Core UEFI from EDK2]
        MU_PLUS[mu_plus<br/>Microsoft Extensions]
        MU_TIANO[mu_tiano_plus<br/>Enhanced TianoCore]
        MU_OEM[mu_oem_sample<br/>OEM Sample Code]
        MU_DFCI[mu_feature_dfci<br/>Device Configuration]
        MU_PLAT[mu_tiano_platforms<br/>Reference Platforms]
    end

    subgraph "Silicon Support"
        MU_INTEL[mu_silicon_intel_tiano<br/>Intel Silicon]
        MU_ARM[mu_silicon_arm_tiano<br/>ARM Silicon]
    end

    subgraph "Build System"
        STUART[Stuart Build Framework]
        PYTOOL[edk2-pytool-extensions]
    end

    MU_BASE --> MU_PLUS
    MU_BASE --> MU_TIANO
    MU_PLUS --> MU_OEM
    MU_TIANO --> MU_OEM
    MU_DFCI --> MU_OEM
    MU_INTEL --> MU_PLAT
    MU_ARM --> MU_PLAT
    PYTOOL --> STUART
    STUART --> MU_PLAT

    style MU_BASE fill:#0078d4,color:#fff
    style MU_PLUS fill:#107c10,color:#fff
    style MU_DFCI fill:#5c2d91,color:#fff

---

Repository Details

Repository	Purpose	Content
mu_basecore	Core UEFI guts forked from TianoCore	MdePkg, MdeModulePkg, BaseTools, SecurityPkg, CryptoPkg
mu_plus	Microsoft-contributed optional libraries	MsCorePkg, MsGraphicsPkg, DfciPkg, UefiTestingPkg
mu_tiano_plus	Enhanced TianoCore libraries	Optional modules from TianoCore with enhancements
mu_feature_dfci	Device Firmware Configuration Interface	Cloud-based firmware management
mu_oem_sample	Sample OEM implementation	Front page, boot manager examples
mu_tiano_platforms	Virtual platform firmware	QEMU Q35, ARM SBSA platforms
mu_silicon_intel_tiano	Intel silicon support	Intel-specific packages
mu_silicon_arm_tiano	ARM silicon support	ARM-specific packages

---

mu_basecore Structure

mu_basecore/
├── MdePkg/                 # Industry-standard definitions
│   ├── Include/
│   │   ├── Protocol/       # UEFI protocols
│   │   ├── Library/        # Library headers
│   │   ├── Guid/           # GUID definitions
│   │   └── Uefi/           # UEFI spec types
│   └── Library/            # Base libraries
├── MdeModulePkg/           # Core UEFI modules
│   ├── Core/               # DXE/PEI core
│   ├── Bus/                # Bus drivers
│   └── Universal/          # Universal drivers
├── UefiCpuPkg/             # CPU initialization
├── SecurityPkg/            # Security features
├── CryptoPkg/              # Cryptography
├── NetworkPkg/             # Network stack
├── FatPkg/                 # FAT filesystem
├── BaseTools/              # Build infrastructure
│   ├── Source/C/           # C tools
│   └── Source/Python/      # Python tools
└── .pytool/                # Stuart configuration

---

mu_plus Structure (Microsoft Extensions)

mu_plus/
├── MsCorePkg/              # Microsoft core services
│   ├── Library/
│   │   ├── MathLib/        # Math operations
│   │   └── JsonLiteParserLib/
│   └── Universal/
├── MsGraphicsPkg/          # Graphics and UI
│   ├── Library/
│   │   ├── BootGraphicsLib/
│   │   └── SwmDialogsLib/
│   └── MsEarlyGraphics/
├── MsWheaPkg/              # WHEA (hardware errors)
├── DfciPkg/                # Device Firmware CI
├── UefiTestingPkg/         # Unit testing framework
├── XmlSupportPkg/          # XML parsing
├── PolicyServicePkg/       # Policy management
└── SetupDataPkg/           # Setup configuration

---

Typical Platform Layout

my_platform/
├── .azurepipelines/              # Azure DevOps CI/CD
│   └── Platform-Build.yml
├── .github/
│   └── workflows/
│       └── build.yml             # GitHub Actions CI
├── .pytool/
│   ├── CISettings.py             # CI configuration
│   └── Plugin/                   # Custom plugins
├── Platforms/
│   └── MyPlatformPkg/
│       ├── MyPlatform.dsc        # Platform DSC
│       ├── MyPlatform.fdf        # Flash description
│       ├── PlatformBuild.py      # Stuart build config
│       ├── Library/              # Platform libraries
│       ├── Drivers/              # Platform drivers
│       └── Include/
├── Common/
│   ├── MU/                       # mu_plus submodule
│   └── TIANO/                    # mu_tiano_plus submodule
├── MU_BASECORE/                  # mu_basecore submodule
├── Silicon/
│   └── Vendor/
│       └── REF_CODE/             # Silicon vendor code
├── pip-requirements.txt          # Python dependencies
├── .gitmodules
└── readme.md

---

Layering Philosophy

Project Mu enforces a rigid dependency hierarchy where each layer can only depend on layers below it:

┌─────────────────────────────────┐
│     Platform (Product)          │  ← Your specific product
├─────────────────────────────────┤
│      Silicon (Vendor)           │  ← Intel/AMD/ARM reference code
├─────────────────────────────────┤
│      Common (Features)          │  ← mu_plus, mu_tiano_plus
├─────────────────────────────────┤
│     Basecore (UEFI Core)        │  ← mu_basecore
└─────────────────────────────────┘

This enables controlled scope and predictable dependencies.

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Next Section

B.2 Installation & Setup