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authorIlias Apalodimas <ilias.apalodimas@linaro.org>2020-05-17 22:25:47 +0300
committerHeinrich Schuchardt <xypron.glpk@gmx.de>2020-05-17 21:59:53 +0200
commite498dac43e6270f156f1cc90cb9f40b359477853 (patch)
tree4dafa5b4ae99c35348007eb5a320fa75b3f33fbd /doc
parente4acbe4e34b0e9bc0243b9d21720111128a1b5b3 (diff)
doc: uefi.rst: Add OP-TEE variable storage config options
If OP-TEE is compiled with an EDK2 application running in secure world it can process and store UEFI variables in an RPMB. Add documentation for the config options enabling this. Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org> Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Diffstat (limited to 'doc')
-rw-r--r--doc/uefi/uefi.rst17
1 files changed, 17 insertions, 0 deletions
diff --git a/doc/uefi/uefi.rst b/doc/uefi/uefi.rst
index 4fda00d687..03d6fd0c6a 100644
--- a/doc/uefi/uefi.rst
+++ b/doc/uefi/uefi.rst
@@ -188,6 +188,23 @@ on the sandbox
cd <U-Boot source directory>
pytest.py test/py/tests/test_efi_secboot/test_signed.py --bd sandbox
+Using OP-TEE for EFI variables
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Instead of implementing UEFI variable services inside U-Boot they can
+also be provided in the secure world by a module for OP-TEE[1]. The
+interface between U-Boot and OP-TEE for variable services is enabled by
+CONFIG_EFI_MM_COMM_TEE=y.
+
+Tianocore EDK II's standalone management mode driver for variables can
+be linked to OP-TEE for this purpose. This module uses the Replay
+Protected Memory Block (RPMB) of an eMMC device for persisting
+non-volatile variables. When calling the variable services via the
+OP-TEE API U-Boot's OP-TEE supplicant relays calls to the RPMB driver
+which has to be enabled via CONFIG_SUPPORT_EMMC_RPMB=y.
+
+[1] https://optee.readthedocs.io/ - OP-TEE documentation
+
Executing the boot manager
~~~~~~~~~~~~~~~~~~~~~~~~~~