tpm_ftpm_tee.rst 947 B

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  1. =============================================
  2. Firmware TPM Driver
  3. =============================================
  4. This document describes the firmware Trusted Platform Module (fTPM)
  5. device driver.
  6. Introduction
  7. ============
  8. This driver is a shim for firmware implemented in ARM's TrustZone
  9. environment. The driver allows programs to interact with the TPM in the same
  10. way they would interact with a hardware TPM.
  11. Design
  12. ======
  13. The driver acts as a thin layer that passes commands to and from a TPM
  14. implemented in firmware. The driver itself doesn't contain much logic and is
  15. used more like a dumb pipe between firmware and kernel/userspace.
  16. The firmware itself is based on the following paper:
  17. https://www.microsoft.com/en-us/research/wp-content/uploads/2017/06/ftpm1.pdf
  18. When the driver is loaded it will expose ``/dev/tpmX`` character devices to
  19. userspace which will enable userspace to communicate with the firmware TPM
  20. through this device.