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

Computer

A computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem...

 platform firmware

Firmware

In electronic systems and computing, firmware is a term often used to denote the fixed, usually rather small, programs and/or data structures that internally control various electronic devices...

. 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

UEFI Platform Initialization Specification version 1.2, published May, 2009. Errata B published July, 2010.

Contents

As of version 1.2, 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