appendix_a_variables.md

Appendix A Variables

One of the core concepts of this utility is the notion of symbols. Use of symbols follows the makefile convention of enclosing within $(), for example $(EDK_SOURCE). As the parsing utility processes files, it will often perform parsing of variable assignments. These variables can then be referenced in other sections of the DSC file. Variable assignments will be saved internally in either a local or global symbol table. The local symbol table is purged following processing of individual Platform (DSC) files. Global symbol values persist throughout execution of the utility. Local symbol values take precedent over global symbols. The following table describes the symbols generated internally by the utility. They can be overridden either on the command line, in the DSC file, or in individual INF files. The symbols in the table below are typically global.

For a pure EDK II build, two environment variables are required to be set prior to executing any build, WORKSPACE and EDK_TOOLS_PATH must be set. point to the Location of the BaseTools directory tree. When EDK II Packages are in directories that are not under a single directory, then the PACKAGES_PATH and EDK_TOOLS_BIN (Windows builds only) directories must also be set.

For a build using EDK components in the EDK II DSC file, the EDK_SOURCE directory must point to the root of the EDK (either a directory containing an EDK tree or the location of the EdkCompatibilityPkg directory) tree.

Table 10 Standard Variables

Variable Name	Description
WORKSPACE	Defines the root directory of the local development tree, for example C:\work. If not defined as an environmental variable when an EDK II tool is invoked, the utility will give an error message and exit. If the development tree contains sub-directories that contain EDK II Packages, then this variable must be set prior to running edksetup.bat.
EDK_TOOLS_PATH	Defines the root directory of the local EDK II BaseTools directory.
PACKAGES_PATH	This variable is not permitted in EDK II meta-data files.
	This variable contains an ordered list of directories that contain EDK
	II Package directories. This is NOT required if the development tree (defined by the WORKSPACE) contains all EDK II Packages used for development. If the development tree contains sub-directories that contain EDK II Packages (i.e., C:\work\edk2\MdePkg,
	C:\work\edk2\MdeModulePkg, C:\work\myplatform\MyPlatformPkg) then this variable must list all directories that contain EDK II Packages (i.e., PACKAGES_PATH=C:\work\edk2;C:\work\myplatform); this variable must be set prior to running edksetup.bat
EDK_TOOLS_BIN	This variable is not permitted in EDK II meta-data files. This a Windows only variable that points to the EDK II BaseTools binary directory. If the WORKSPACE directory contains a
	BaseTools\Bin\Win32 directory and the directory is populated with the build tools, then this variable is not required. If the binaries are located in a different directory, i.e., C:\work\edk2-BaseTools-win32, then this variable must be set prior to running edksetup.bat
EDK_SOURCE	Defines the directory of an original EDK directory tree, for example C:\EFI2.0\EdkCompatibilityPkg. If not defined as an environmental variable when an EDK II tool is invoked, the utility will give an error message and exit.
EFI_SOURCE	Defines the root directory of a local original EDK source tree, for example C:\EFI2.0\MyEdkDriver.
EFI_TOOLS_PATH	Defines the root directory containing the original EDK Tools directory tree, for example C:\Tools.
EFI_TOOLS_BIN	Defines the directory containing the original EDK Tools executable files. Default: $(EFI_TOOLS_PATH)/Bin
PROCESSOR	Defines the EDK target processor for which the code is to be built. This symbol will typically be used only in EDK INF files, and is ignored for pure EDK II builds.
TARGET_ARCH	This defines which of the supported architectures will be built - this value is set in the file: $(WORKSPACE)/Conf/target.txt or it may be specified on a command-line.
BUILD_DIR	Defines the build tip directory for the current platform. For example, this may be $(OUTPUT_DIR)\Platform\Nt32.
SOURCE_DIR	For a component, defines the directory of the component source files.
DEST_DIR	For a component, defines the directory (typically under BUILD_DIR) where the component object files are to be built.
LIB_DIR	Specifies the directory where EFI libraries are deposited after building. Default: $(BUILD_DIR)\$(TARGET)_$(TAGNAME)\$(ARCH)\LIB
BIN_DIR	Specifies the directory where final component binaries (.efi) are deposited during build. Default: $(BUILD_DIR)\$(TARGET)_$(TAGNAME)\$(ARCH)
FV_DIR	Specifies a WORKSPACE relative or absolute directory where the final image files will be placed at the conclusion of a successful build. If the directory does not exist, the tools must create this directory. If not defined, tools must create an FV directory underneath the BIN_DIR.
DSC_FILENAME	Name of the DSC file as specified on the command line. Can be used for dependencies in the makefiles.
INF_FILENAME	Name of the INF file for a given EDK component or EDK II Module. Can be used for dependencies in the makefiles.
MAKEFILE_NAME	Name of the output makefile for the platform. Default is "makefile". The default value can be overridden to support keeping multiple variations of a makefile in the same DEST_DIR directory.