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.