On 10/12/23 10:29, Simon Glass wrote:
Hi Eddie,
On Thu, 12 Oct 2023 at 08:08, Eddie James eajames@linux.ibm.com wrote:
Briefly describe the feature and specify the requirements.
Signed-off-by: Eddie James eajames@linux.ibm.com Reviewed-by: Simon Glass sjg@chromium.org
This could use a bit more detail. What pieces are measured? What DT binding is used for the TPM? How is the info checked by the OS or whatever?
Sure, I'll add a little bit more. The DT binding is described in the requirements section.
doc/usage/index.rst | 1 + doc/usage/measured_boot.rst | 23 +++++++++++++++++++++++ 2 files changed, 24 insertions(+) create mode 100644 doc/usage/measured_boot.rst
diff --git a/doc/usage/index.rst b/doc/usage/index.rst index fa702920fa..fb043a8923 100644 --- a/doc/usage/index.rst +++ b/doc/usage/index.rst @@ -14,6 +14,7 @@ Use U-Boot partitions cmdline semihosting
measured_boot
Shell commands
diff --git a/doc/usage/measured_boot.rst b/doc/usage/measured_boot.rst new file mode 100644 index 0000000000..8357b1f480 --- /dev/null +++ b/doc/usage/measured_boot.rst @@ -0,0 +1,23 @@ +.. SPDX-License-Identifier: GPL-2.0+
+Measured Boot +=====================
+U-Boot can perform a measured boot, the process of hashing various components +of the boot process, extending the results in the TPM and logging the +component's measurement in memory for the operating system to consume.
+Requirements +---------------------
+* A hardware TPM 2.0 supported by the U-Boot drivers +* CONFIG_TPM=y +* CONFIG_MEASURED_BOOT=y +* Device-tree configuration of the TPM device to specify the memory area
- for event logging. The TPM device node must either contain a phandle to
- a reserved memory region or "linux,sml-base" and "linux,sml-size"
- indicating the address and size of the memory region. An example can be
- found in arch/sandbox/dts/test.dts
+* The operating system must also be configured to use the memory regions
- specified in the U-Boot device-tree in order to make use of the event
- log.
Regards, Simon