Re: [PATCH v7 2/2] fTPM: add documentation for ftpm driver
From: Randy Dunlap
Date: Tue Jun 25 2019 - 19:13:43 EST
On 6/25/19 1:13 PM, Sasha Levin wrote:
> This patch adds basic documentation to describe the new fTPM driver.
> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
Acked-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
> Documentation/security/tpm/index.rst | 1 +
> Documentation/security/tpm/tpm_ftpm_tee.rst | 31 +++++++++++++++++++++
> 2 files changed, 32 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
> diff --git a/Documentation/security/tpm/tpm_ftpm_tee.rst b/Documentation/security/tpm/tpm_ftpm_tee.rst
> new file mode 100644
> index 000000000000..48de0dcec0f6
> --- /dev/null
> +++ b/Documentation/security/tpm/tpm_ftpm_tee.rst
> @@ -0,0 +1,31 @@
> +Firmware TPM Driver
> +| Authors:
> +| Thirupathaiah Annapureddy <thiruan@xxxxxxxxxxxxx>
> +| Sasha Levin <sashal@xxxxxxxxxx>
> +This document describes the firmware Trusted Platform Module (fTPM)
> +device driver.
> +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.
> +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:
> +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.