Introduction

The Platform System Interface Specification, or PSI spec, is a collection of documents for hardware and software co-design from a general perspective. It describes how microprocessors provide an environment for booting operating systems or otherwise bare-metal applications, typically starting from intermediate, rewritable code that initializes clocks, DRAM and peripherals, commonly referred to as boot firmware or platform initialization firmware.

In the following sections, PSI spec describes principles and abstractions that apply agnostic of vendors and products.