On 6/25/19 12:52 PM, Sasha Levin wrote:
> This patch adds basic documentation to describe the new fTPM driver.
>
> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
> ---
> 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
> 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..29c2f8b5ed10
> --- /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.
> +
> +Introduction
> +============
> +
> +This driver is a shim for a firmware implemented in ARM's TrustZone
for firmware
> +environment. The driver allows programs to interact with the TPM in the same
> +way the would interact with a hardware TPM.
they
> +
> +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.pdf
> +
> +When the driver is loaded it will expose ``/dev/tpmX`` character devices to
> +userspace which will enable userspace to communicate with the firmware tpm
TPM
> +through this device.
>
Oh, that's the same comments that I made on 2019-06-18:
https://marc.info/?l=linux-integrity&m=156087157019368&w=2
--
~Randy
