2 INF Overview

This section of the document describes the decisions regarding the format of the EDK II module INF files. The INF files are used by EDK II utilities that parse build meta-data files (INF, DEC, DSC and FDF files) to generate AutoGen.c and AutoGen.h and Makefile/GNU makefile files for the EDK II build infrastructure.

The EDK II INF meta-data file describes properties of a module, how it is coded, what it provides, what it depends on, architecture specific items, features, etc. regarding the module. INF files generated during a build (that allow distribution of binary modules) describe how the module was compiled, linked and what platform configuration database items (PCDs) are exposed. Binary distribution of EDK II modules allows original device manufactures (ODMs) to distribute proprietary drivers, without distributing source code, for inclusion in a firmware image.

EDK II modules may be located in sub-directories of a package (a collection of related objects.) If a module is "a Library", creating the module directory in the "Library" subdirectory of a package is strongly recommended. An "Include" package subdirectory may also be required. Header files for modules that define a library class must be placed in the Include/Library directory using the Library Class Name for the file name.

The Include directory and sub-directories contain header files that define either a library class API or pre-defined ("industry standard") data elements. One and only one header file defines the library class API. Multiple library instances can "produce" the functionality of a library class. The use of library class API headers allows for platform integrators to select a library instance that is suitable for their platform. This usage model frees the driver developer from coding a module to specific library instances. Libraries are really nothing more than modules with pre-defined APIs.

Each module may have one or more INF files that can be used by tools to generate images. Specifically, the EDK Compatibility Package will contain two INF files for any module that contains assembly code. Since the ECP can be used with existing EDK tools (which is only supported by Microsoft and Intel Windows based tools,) a separate INF file to support the multiple tool chain capability of the EDK II build system must be provided for the modules that contain assembly code. The EDK II ECP will use the basename_edk2.inf for the filename of the EDK II build system compatible INF files for non-Windows based tool chains, and use just the basename.inf for the filename of EDK only INF files used by the EDK build system.

Note: Path and Filename elements within the INF are case-sensitive in order to support building on UNIX style operating systems.

Note: GUID values are used during runtime to uniquely map the C names of PROTOCOLS, PPIS, PCDS and other variable names.

Note: This document uses a backslash "\" to indicate that a line that cannot be displayed in this document on a single line. Within the DSC specification, each entry must appear on a single line.

Note: The total path and file name length is limited by the operating system and third party tools. It is recommended that for EDK II builds that the WORKSPACE directory be either a directory under a subst drive in Windows (s:/build as an example) or be located in either the /opt directory or in the user's /home/username directory for Linux and OS/X.