PCI Firmware 3.x Specification

The PCI Firmware Specification describes the hardware independent firmware interface for managing PCI, PCI-X, and PCI Express systems in a host computer. This specification is developed based on the PCI BIOS Specification, Revision 2.1. It continues to provide the PCI BIOS support on the PC-compatible systems. In addition, it also provides the descriptions or references of the following:

  • PCI related firmware services for DIG64-compliant systems.
  • Advanced Configuration and Power Interface (ACPI) services for supporting PCI, PCI-X, and PCI Express devices and systems.
  • Extensible Firmware Interface (EFI) services for supporting PCI, PCI-X, and PCI Express devices and systems.
  • Requirements and services for supporting PCI Expansion ROMs

All specifications are available for download by members. Non-members have the ability to obtain specifications by purchasing them.

  • Download the PCI Firmware Specification 3.1.
  • Download the PCI Firmware Specification 3.0.
  • PCIe Hot Plug Final ECN (98k PDF):  This ECN affects the PCI Firmware Specification Ver 3.1 and allows certain errors to be suppressed by platform if software stack ensured error containment. Also removes the implementation note in section which is not representative of OS behavior.

  • PCI OSC Clarifications Final ECN (49k PDF):  This ECN attempts to make clarifications such that the system firmware and multiple operating systems can have the same interpretation of the specification and work interoperably.  Please view the supplemental document (167k PDF) for additional information.
  • Unoccupied Slot Power Hand-off State Clarification Final ECN (106k PDF):  This ECN allows the unoccupied slots' power to be off at hand-off, which is a reasonable implementation and many systems implement that way today.
  • PCI Option ROM CLP Final ECN (214k PDF): This ECN rectifies the differences between the DMTF SM CLP Specification and its supporting documents with the current PCI Firmware 3.0 Specification. Also, it clarifies the supporting documents required for successfully implementing CLP in an X86 PCI FW 3.0 compatible option ROM.
  • Ignore PCI Boot Configuration_DSM Function Final ECN (156k PDF): This ECN adds a function to the _DSM Definitions for PCI to provide an indication to an operating system that it can ignore the PCI boot configuration setup by the firmware during system initialization.
  • Update DMTF SM CLP Specification References Final ECN (90k PDF): This update references to sections in the DMTF Server Management Command Line Protocol (SM CLP) Specification (DSP0214) to match the most recent version SM CLP Specification (v1.0.2). It also clarifies that the references to the DMTF SM CLP specification are referencing v1.0.2. and adds a reference to the DMTF SM CLP specification in section 1.2 Reference Documents.
  • UEFI PCI Services Update Final ECN (163k PDF): This is a request to update the UEFI PCI Services. No functional changes. In the case of the UGA reference, UGA has been obsolete by the UEFI Specification and is replaced by the new GOP.
  • ACPI Additions for ASPM, OBFF, LTR ECN (78k PDF)
  • PCIe Device Labeling under Operating Systems ECN (126k PDF)



Note: This specification is posted for archive purposes only; be sure to reference the PCI Firmware 3.0 specification above for the most current version.

The PCI BIOS document describes the required System BIOS functions for accessing PCI configuration space. The specification describes everything necessary for a BIOS vendor to implement the PCI BIOS functions, and everything necessary for application/driver programmers to make the BIOS calls. The BIOS calls should be used in all operating environments where there are no operating-system functions for accessing PCI configuration space. This specification applies only to Intel architecture-compatible PCs.

Members-only download: