4.2 Directory Names

Below sections are the directory naming guidelines for EDK II modules. The guidelines are not just considering the uniformity of directory naming, but they also provide the flexibility of directory name construction for the scenario of different EDK II module designs; such as the support for multiple processor architectures and vendors. It may require further discussions between EDK II maintainers and contributors in order to determine the best naming of the EDK II module directory.

4.2.1 EDKII package directory

<PackageName>Pkg

   <PackageName> REQUIRED  *

4.2.2 EDKII Module directory

• The guideline below is applied to all CPU architectures support, specific CPU architecture and vendors support, or the implementation is shared by certain CPU archs:

<Feature><Phase>[<CpuArch>[<Vendor>]]
  or
<Feature><Phase>[/<CpuArch>[/<Vendor>]]

   <Feature>      REQUIRED    *
   <Phase>        REQUIRED    Base, Sec, Pei, Dxe, DxeRuntime, Mm, StandaloneMm, Smm,
                              Uefi.
   <CpuArch>      OPTIONAL    The <CpuArch> is represented with a BNF,
                              <arch> ::='Ia32' | 'X64' | 'Arm' | 'AArch64' | 'RiscV64' |
                                        'LoongArch64' | 'Ebc'   
                              <CpuArch> ::= <arch>[<arch>]*

                              Example: Ia32X64Arm or RiscV64LoongArch64
   <Vendor>       OPTIONAL    *

Example:
   - SmbiosDxe/
   - CpuDxe/                    # First implementation of CpuDxe.
   - CpuDxeIa32X64Amd/          # Ia32 and X64 AMD specific implementation.
   - CpuDxe/RiscV64/            # RiscV64 specific implementation.
           /                    # Common files for the RiscV64 and other archs.
   - CpuDxe/Ia32X64/Amd/        # Ia32 and X64 AMD specific implementation.
                   /            # Common files for Ia32 and X64 archs.
           /ArmAArch64/         # Arm and AArch64 implementation of CpuDxe.
           /                    # Common files for the Arm, AArch64, Ia32 and X64.

• If the implementation does not have any shared code between phases (e.g. MdeModulePkg/Universal/PCD). The guideline below is applied to all CPU architectures support, specific CPU architecture and vendors support, or the implementation is shared by certain CPU architectures:

<Feature>/<Phase>[/<CpuArch>[/<Vendor>]]

   <Feature>      REQUIRED    *
   <Phase>        REQUIRED    Base, Sec, Pei, Dxe, DxeRuntime, Mm, StandaloneMm, Smm,
                              Uefi.
   <CpuArch>      OPTIONAL    The <CpuArch> is represented with a BNF,
                              <arch> ::='Ia32' | 'X64' | 'Arm' | 'AArch64' | 'RiscV64' |
                                        'LoongArch64' | 'Ebc'
                              <CpuArch> ::= <arch>[<arch>]*

                              Example: Ia32X64Arm or RiscV64LoongArch64
   <Vendor>       OPTIONAL    *
Example:
   Pcd/Dxe/

4.2.3 EDKII Library directory

<Phase>[<CpuArch>[<Vendor>]]<LibraryClassName>[<Dependency>]
  or
<Phase><LibraryClassName>[<Dependency>]/[<CpuArch>[/<Vendor>]]

   <Phase>              REQUIRED     Base, Sec, Pei, Dxe, DxeRuntime, Mm,
                                     StandaloneMm, Smm, Uefi.
   <CpuArch>            OPTIONAL     The <CpuArch> is represented with a BNF,
                                     <arch> ::='Ia32' | 'X64' | 'Arm' | 'AArch64' | 'RiscV64' |
                                               'LoongArch64' | 'Ebc'
                                     <CpuArch> ::= <arch>[<arch>]*

                                     Example: Ia32X64Arm or RiscV64LoongArch64
   <Vendor>             OPTIONAL     *
   <LibraryClassName>   REQUIRED     *
   <Dependency>         OPTIONAL     * (Typically name of PPI, Protocol, LibraryClass
                                       that the implementation is layered on top of).

Example:
   - BaseXApicLib/
   - SmmIa32X64AmdSmmCpuFeaturesLib/
   - SmmArmAArch64SmmCpuFeaturesLib/
   - BaseMpInitLib/RiscV64/        # RiscV64 specific implementation.
                  /Ia32X64/        # Ia32 and X64 specific implementation.
                  /Ia32X64/Amd     # Ia32 and X64 AMD specific implementation.
                  /ArmAArch64/     # Arm and AAch64 specific implementation.
                  /LoongArch64/    # LoongArch64 specific implementation.
                  /                # Common files for RiscV64, Ia32, X64, Arm, AArch64 and
                                   LoongArch64.