Embedded Power Architecture Platform Requirements Specification v1.1

Power.org announced that the latest version of the Embedded Power Architecture Platform Requirements (ePAPR) specification is available for download. ePAPR version 1.1 includes some incremental changes and clarifications to ePAPR 1.0 and adds a new chapter on virtualization. The ePAPR specification defines standards for Power Architecture system regarding how a boot program starts a client program (e.g. an operating system) including device trees and how multiple CPUs are initialized and started on a multi-core processor.

ePAPR v1.1 Highlights

  • Includes incremental changes to ePAPR 1.0
  • New chapter on virtualization, leveraging Power ISA
  • Expected to contribute to lower development costs
  • Virtualization chapter defines a standard para-virtualization interface for use by a hypervisor and guest operating systems enabling implementations by different software vendors to seamlessly work together
  • Virtualization features include an ABI and APIs for a set of hypervisor services including — a virtual interrupt controller, byte-channels, and inter-partition doorbells
  • Representation of CPUs in device trees is extended to better support representation of processors with a large number of CPUs, multi-threaded CPUs, and to define which Power ISA categories a CPU implements
  • Several device tree properties in common use are now formally standardized
  • Document revision history v1.1 identifies the specific changes and additions from v1.0
  • Addresses scalability of embedded systems for multi-core processors and multithreading

More info: Power.org ePAPR Specification v1.1 (pdf)