[PATCH v5 6/6] doc: Add measured boot documentation

Eddie James
2023-02-02T17:08:35Z

Briefly describe the feature and specify the requirements.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
---
Changes since v4:
- Use bullets for the requirements list

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 3804046835..371ab8179f 100644
--- a/doc/usage/index.rst
+++ b/doc/usage/index.rst
@@ -12,6 +12,7 @@ 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.
--
2.31.1