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Update U-boot Support with SPI use #451

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Merged
dgarske merged 3 commits into from
Jan 26, 2026
Merged

Update U-boot Support with SPI use #451

dgarske merged 3 commits into from
Jan 26, 2026

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@aidangarske
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@aidangarske aidangarske commented Jan 9, 2026 •
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Description

  • Add U-Boot SPI HAL support for native TPM communication
  • Fix build compatibility for U-Boot environment

Testing

  • Build wolfTPM with U-Boot (sandbox target) (Complete)
  • Verified MMIO mode still works with swtpm/QEMU linux path fine
  • Test SPI communication with TPM hardware (TODO)
  • tested with latest code here

Changes

hal/tpm_io.c

  • Add U-Boot SPI HAL implementation (TPM2_IoCb_Uboot_SPI)
  • Implement TIS SPI protocol with wait-state handling (WOLFTPM_CHECK_WAIT_STATE)
  • Add configurable SPI bus/CS via TPM_SPI_BUS, TPM_SPI_CS, TPM_SPI_MAX_HZ
  • Use U-Boot's spi_get_bus_and_cs() and spi_xfer() APIs

src/tpm2.c

  • Guard close(ctx->fd) with !defined(UBOOT) to prevent build error (U-Boot doesn't have file descriptors in this context)

Configuration

When UBOOT is defined:

  • Uses U-Boot's SPI driver model via <spi.h> and <dm/uclass.h>
  • SPI settings configurable in user_settings.h or board config
  • Supports both wait-state polling and direct transfer modes

@aidangarske aidangarske self-assigned this Jan 9, 2026
@dgarske dgarske self-requested a review January 9, 2026 21:49
@dgarske dgarske self-assigned this Jan 9, 2026
@aidangarske aidangarske marked this pull request as ready for review January 24, 2026 01:08
@aidangarske
Add hardware SPI support for Raspberry Pi 4
01a2bb2 
  - Change default TPM_SPI_CS to 1 (CE1/GPIO7) to match official
    Raspberry Pi tpm-slb9670 overlay used by LetsTrust and Infineon HATs
  - Use _spi_get_bus_and_cs() with explicit speed/mode parameters
    for proper SPI device initialization
  - Add required includes for asm/io.h and dm/device-internal.h
  - Improve debug message prefixes for clarity

  Tested on Raspberry Pi 4 with Infineon SLB9672 TPM HAT.
@aidangarske
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aidangarske commented Jan 24, 2026

@dgarske this is ready to be review/merged now. I tested everything on latest wolftpm uboot changes

@dgarske dgarske merged commit 6898e84 into wolfSSL:master Jan 26, 2026
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@dgarske dgarske dgarske approved these changes

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@aidangarske @dgarske