UEFI Platform Initialization

The Platform Initialization Specification (PI Specification) is a specification published by the Unified EFI Forum that describes the internal interfaces between different parts of computer platform firmware. This allows for more interoperability between firmware components from different sources. This specification is normally, but not by requirement, used in conjunction with the UEFI specification.

Current version
Platform Initialization Specification 1.7, Released January 2019.

Contents
As of version 1.3, the PI specification contains five volumes:
 * Volume 1: Pre-EFI Initialization Core Interface
 * Volume 2: Driver Execution Environment Core Interface
 * Volume 3: Shared Architectural Elements
 * Volume 4: System Management Mode Core Interface
 * Volume 5: Standards