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Resources/
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TCG EFI Protocol Specification

Specification

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Latest version

Errata Version 0.6 for TCG EFI Protocol Specification Version 1.0 Revision 0.13

Last updated:Nov 13, 2023
Nov 13, 2023
8 pages
229 KB
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The purpose of this document is to define a standard interface to the TPM on an UEFI platform. It defines data structures and APIs that allow an OS to interact with UEFI firmware to query information important in an early OS boot stage. Such information include: is a TPM present, which PCR banks are active, change active PCR banks, obtain the TCG boot log, extend hashes to PCRs, and append events to the TCG boot log.

The latest revision of this specification is written with platforms with TPM 2.0 devices in mind, but nothing in this specification prevents the use with platforms with TPM 1.2 devices.

TCG EFI Protocol and Platform Specification Version 1.22 for TPM 1.2 FAQ

January 2014

Why was this update needed?

These specifications were last updated in 2006. Since then, a number of errata and issues were identified and several new measurements were requested. There was confusion due to overlaps and inconsistencies between the EFI and Conventional Bios specifications.

What changed in the TCG EFI Protocol Spec?

  • Incorrect return codes were fixed
  • Unnecessary typedefs were removed
  • Numerous typos and formatting issues were corrected

What changed in the TCG EFI Platform Spec?

  • Duplications between the Conventional Bios Spec and the EFI Platform Specification were removed and the EFI Platform Specifications dependence on the Conventional Bios Specification was clarified.
  • Several measurements were moved to different PCR’s to be consistent with the Conventional Bios Specification. The GPT measurement is now optional.
  • Support for UEFI Secure Boot policy measurements was added.
  • Optional support for NIST Special Publication 800-155 was added.
  • An EFI SpecID event, based on the Conventional Bios SpecID event was added to indicate if this update is being supported.
  • Numerous typos and formatting issues were corrected.
Previous versions
Mar 30, 2016TCG EFI Protocol Specification for TPM 2.0 Version 1.0 Revision 0.13
Mar 30, 2016Errata Version 0.5 for TCG EFI Protocol Specification for TPM 2.0 Version 1.0 Revision 0.13
Mar 30, 2016TCG EFI Protocol Specification for TPM 1.2 or 1.2 Version 1.22 Revision 5
Mar 30, 2016TCG EFI Protocol Specification for TPM 1.2 or 1.2 Version 1.2 Revision 1
Published by Work Groups
PC Client
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This Specification complies with the TCG Component Reference Integrity Manifest Information Model Specification and provides additional requirements for a CoRIM
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TCG PC Client Device Driver Design Principles for TPM 2.0

Reference for a PC Client platform. May also be used as a device driver design reference for other platform architectures.
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