On 2/22/23 14:26, Heinrich Schuchardt wrote:
Am 22. Februar 2023 19:02:42 MEZ schrieb Eddie James <eaja...@linux.ibm.com>:
Briefly describe the feature and specify the requirements.
Signed-off-by: Eddie James <eaja...@linux.ibm.com>
---
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 cde7dcb14a..0cf78cb0e7 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
+=====================
This completely misses o describe measured boot with UEFI.
@Ilias, do you want to add that in a follow up patch?
+
+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.
Please, provide enough information such that a reader can set this up. This
should include example code.
Hi Heinrich,
I'm not sure what example code you mean. No additional code is necessary
for U-Boot to perform the measurements, only the requirements stated. If
you mean the operating system setup, I don't think here is the right
place to document that, as it has nothing to do with U-Boot. Either way,
Linux would not require any code, only a similar devicetree entry and
TPM driver.
Thanks,
Eddie
Best regards
Heinrich
