2.11 [Components] Section Processing

One or more [Components] sections contain lists of EDK components and EDK II Modules. The format for specifying the INF file for EDK II modules incorporates new scoping capabilities.

This section uses one or more of the following section definitions:

• [Components]
• [Components.IA32]
• [Components.X64]
• [Components.IPF]
• [Components.EBC]
• [Components.common]

EDK components are specified using a fully qualified path to the EDK INF file.

$(EDK_SOURCE)/Path/and/Filename.inf

Because EDK II modules have different requirements than EDK I components, specifying the INF filename in the extended DSC file may require more than just the INF filename and options. A scoping structure, that binds library class (with an optional override instance,) PCD settings (also overriding the values specified in the [PcdsPatchableInModule] or [PcdsFixedAtBuild] sections) and build options for an EDK II module may be required. This scoping structure, containing sub-elements, is enclosed within curly braces: "{}". The opening curly brace, "{", must appear at the end of the inf filename line, before any comments.

Scoping is needed only if specifying a non-default library class (one specified in the [LibraryClasses] section), changing a PCD value from defaults specified in either the [PcdsPatchableInModule] or [PcdsFixedAtBuild] sections, or overriding tool flags set either in the [BuildOptions] section of the DSC file or if an entry in the tools_def.txt file. Scoping can also be used to support building multiple versions of a module where the different versions are built using a different FILE_GUID value declared in the scoping section.

Note: Section 3.11 defines the sub-element content of an INF file specified in a component section. This code paragraph section shows the format of a "scoping structure".

Path/and/Filename.inf {
# Sub-elements - See EDK II INF file statement structure
}

There are four valid, optional sub-elements for EDK II modules. These sub-element are enclosed within angle brackets: <Defines>, <LibraryClasses>, <Pcds*> and <BuildOptions>.

For EDK component INF files, an optional sub-element of <SOURCE_OVERRIDE_PATH> has been defined. If this element is specified, files listed in the directory are used instead of the "same-named" files in the component's directory. If an EDK component directory lists files, A.c, B.c and C.h, and the directory specified in this sub-element contains the file B.c, then the component will be built using files from the component directory: A.c and C.h, and the file B.c from the override directory. Any other files listed in the override directory will NOT be included in the build (no new or additional files are permitted).

An INF file line may also have one argument, EXEC = Filename, that specifies an executable file that takes the INF filename as a parameter. The Filename must be executable, and must take the INF filename. No other arguments are permitted to the Filename.

The parsing tools will call the executable specified by the Filename, as follows:

Filename Path/and/Filename.inf

If the EXEC argument is included on the component or module INF line, EDK II Tools will ignore processing of the module. Additionally, EDK II build tools will not perform any dependency checking for files listed in the INF file nor on the output object file. EXEC example follows:

Path/and/Filename.inf EXEC = exe2bin.exe

The structure for specifying an EDK II INF filename is as follows:

$(EDK_SOURCE)/Path/and/ComponentName.inf [options] {
  # Library Class listing - Required for EDK II components. One or more
  # Library mapping lines are permitted.
  <LibraryClasses>
    LibraryClassName|Path/and/LibraryInstanceName.inf
  # Followed by zero (no pcds are used by the module) or more of the
  # following individual component override statements.
  # Pcd settings are applicable to both Library Instances that
  # are linked to the component and the component itself.
  # If a PCD entry is not specified, however the INF files for either
  # the library classes that are linked to the component, or the
  # component's INF file require Pcd settings, a globally defined
  # value for the Pcd ([Pcd{AccessMethod}] section or the default
  # value from the DEC file that declares the PCD) will be used. If
  # none of these values are specified, build tools processing this file
  # should fail with an error message (indicating the missing PCD # entry.)
  # NOTE: MaximumDataSize is required for VOID* datum type PCDs, and # should NOT be used for either the boolean or numeric datum types.
  # PcdsDynamic and PcdsDynamicEx cannot be specified in a component # scoped section as these values are platform scoped, not module
  # scoped.
  <PcdsFixedAtBuild>
    TokenSpaceGuidCName.PcdTokenName|Data[|MaximumDataSize]
  <PcdsFeatureFlag>
    TokenSpaceGuidCName.PcdTokenName|{TRUE}{FALSE}
  <PcdsPatchableInModule>
    TokenSpaceGuidCName.PcdTokenName|Data[|MaximumDataSize]
  # BuildOption Format is identical to the format used for the
  #tools_def.txt file. Options specified in this section take
  # precedence over the platform build options specified in the
  #[Defines] section. (The [Defines] section options take precedence #over options specified in the tools_def.txt file)
  <BuildOptions>
    TARGET_TOOLCHAIN_ARCH_COMMANDTYPE_FLAGS = string of flags
}

In order to build a module multiple times, the <Defines> tag is used. In the following example, the S3Resume2Pei module is built twice, using different library instances and PCD values (one for use with IA32 architecture and one for the X64 architecture). The first module instance uses the standard FILE_GUID value from the INF file when creating the FFS filename, while the second module instances will use the FILE_GUID value specified in the DSC file for creating the FFS filename.

  UefiCpuPkg/Universal/Acpi/S3Resume2Pei/S3Resume2Pei.inf {
    <PcdsFeatureFlag>
      gEfiMdeModulePkgTokenSpaceGuid.PcdDxeIplSwitchToLongMode|FALSE
    <LibraryClasses>
      NULL|BinaryDistributionModulePkg/Library/SwitchToLongMode/SwitchToLongModeDisabledLib.inf
  }
  UefiCpuPkg/Universal/Acpi/S3Resume2Pei/S3Resume2Pei.inf {
    <Defines>
      FILE_GUID = 35B57EA0-4A41-4a12-B1F5-5F7B79095301
    <PcdsFeatureFlag>
      gEfiMdeModulePkgTokenSpaceGuid.PcdDxeIplSwitchToLongMode|TRUE
    <LibraryClasses>
      NULL|BinaryDistributionModulePkg/Library/SwitchToLongMode/SwitchToLongModeEnabledLib.inf
  }

If the values for the PcdTokenName are specified in the global [Pcds{AccessMethod}] section and no values are specified in the INF filename section, then the global values will be used. It should be noted that only LibraryClassName|library/instance definitions are required. Adding just the library class name without the library instances is for informational purposes only, and they will not be processed.

Example

MdeModulePkg/Universal/Disk/DiskIo/Dxe/DiskIo.inf {
  #EDK II Module
  <LibraryClasses>
    DebugLib|MdePkg/Library/PeiDxeDebugLibReportStatusCode/PeiDxeDebugLibReportStatusCode.inf
    BaseMemoryLib|MdePkg/Library/DxeMemoryLib/DxeMemoryLib.inf
    MemoryAllocationLib|MdePkg/Library/DxeMemoryAllocationLib/DxeMemoryAllocationLib.inf
}