wolfTPM Support For Das U-Boot Bootloader

[aidangarske]

Description

Support for u-boot with wolfTPM.

• Recommended to use the SOFT SPI driver in U-boot
• wolfTPM serves as a TPM 2.0 driver thanks to its internal TIS layer
• wolfTPM provides native API with full access to all TPM 2.0 commands
• wolfTPM offers wrappers API for complex and common TPM 2.0 operations
• Two paths customers can take:
  __linux__ utilizes the existing tpm interface through tpm2_linux.c
__UBOOT__ directly talks to TPM with SPI through tpm_io_uboot.c

U-Boot TPM commands to be added:

• Get Capability (report device details including key group)
  Tested in QEMU with SWTPM
• Start Firmware Update (not tested)
  manifest_addr manifest_sz firmware_addr firmware_sz
• Cancel / Abandon (not tested)

Testing

Refer to readme - tested caps with qemu and swtpm simulator

Documentation

examples/u-boot/README.md

[Copilot]

Pull Request Overview

This pull request adds support for U-Boot in wolfTPM by implementing new IO callbacks and wrapper functions for TPM operations while also updating documentation for clarity. Key changes include:

• Introducing new U-Boot–specific IO implementation (tpm_io_uboot.c) and corresponding header adjustments.
• Refactoring TPM reset and shutdown functions, including renaming wolfTPM2_Shutdown to wolfTPM2_Reset and adding dedicated wrappers.
• Enhancing documentation for TPM API wrappers to clarify functionality and usage.

Reviewed Changes

Copilot reviewed 13 out of 14 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
wolftpm/tpm2_wrap.h	Added documentation for TPM reset and hierarchy auth change with minor spelling fixes.
wolftpm/tpm2_types.h	Updated include conditionals and removed redundant includes.
wolftpm/tpm2_packet.h	Added guard macros for endian helper definitions.
wolftpm/tpm2.h	Introduced TPM2_GetAlgId and TPM2_GetHierarchyDesc functions.
src/tpm2_wrap.c	Renamed and refactored TPM shutdown/reset functions and updated logging.
src/tpm2_linux.c	Added U-Boot branch to support new IO callbacks.
src/tpm2.c	Implemented TPM2_GetAlgId function.
hal/tpm_io_uboot.c	Added U-Boot specific IO callback implementation.
hal/tpm_io.h and hal/tpm_io.c	Updated IO callback header and source to include UBOOT branch.
examples/wrap/*.c and examples/u-boot/README.md	Updated API calls to use the new reset function and added U-Boot documentation.

Files not reviewed (1)

• hal/include.am: Language not supported

Comments suppressed due to low confidence (1)

src/tpm2_wrap.c:5793

• The error message in wolfTPM2_ChangeHierarchyAuth prints the error string and hierarchy description in a confusing order. Swap the parameters so that the hierarchy description (desc) appears immediately after the error code and the error string from TPM2_GetRCString(rc) is shown last.

            printf("Error %d setting %s auth! %s\n", rc, wolfTPM2_GetRCString(rc), desc);