This patch adds basic documentation to describe the new fTPM driver.
Signed-off-by: Sasha Levin sashal@kernel.org --- Documentation/security/tpm/index.rst | 1 + Documentation/security/tpm/tpm_ftpm_tee.rst | 27 +++++++++++++++++++++ 2 files changed, 28 insertions(+) create mode 100644 Documentation/security/tpm/tpm_ftpm_tee.rst
diff --git a/Documentation/security/tpm/index.rst b/Documentation/security/tpm/index.rst index af77a7bbb070..15783668644f 100644 --- a/Documentation/security/tpm/index.rst +++ b/Documentation/security/tpm/index.rst @@ -4,4 +4,5 @@ Trusted Platform Module documentation
.. toctree::
+ tpm_ftpm_tee tpm_vtpm_proxy diff --git a/Documentation/security/tpm/tpm_ftpm_tee.rst b/Documentation/security/tpm/tpm_ftpm_tee.rst new file mode 100644 index 000000000000..8c2bae16e3d9 --- /dev/null +++ b/Documentation/security/tpm/tpm_ftpm_tee.rst @@ -0,0 +1,27 @@ +============================================= +Firmware TPM Driver +============================================= + +This document describes the firmware Trusted Platform Module (fTPM) +device driver. + +Introduction +============ + +This driver is a shim for firmware implemented in ARM's TrustZone +environment. The driver allows programs to interact with the TPM in the same +way they would interact with a hardware TPM. + +Design +====== + +The driver acts as a thin layer that passes commands to and from a TPM +implemented in firmware. The driver itself doesn't contain much logic and is +used more like a dumb pipe between firmware and kernel/userspace. + +The firmware itself is based on the following paper: +https://www.microsoft.com/en-us/research/wp-content/uploads/2017/06/ftpm1.pd... + +When the driver is loaded it will expose ``/dev/tpmX`` character devices to +userspace which will enable userspace to communicate with the firmware TPM +through this device.