Mention COT build option in trusted-board-boot-build.rst

Since commit 3bff910dc1 ("Introduce COT
build option"), it is now possible to select a different Chain of Trust
than the TBBR-Client one.

Make a few adjustments in the documentation to reflect that. Also make
some minor improvements (fixing typos, better formatting, ...)  along
the way.

Change-Id: I3bbadc441557e1e13311b6fd053fdab6b10b1ba2
Signed-off-by: Sandrine Bailleux <sandrine.bailleux@arm.com>
This commit is contained in:
Sandrine Bailleux 2020-03-03 13:03:36 +01:00
parent 316c5cc6a2
commit d935b95161
1 changed files with 13 additions and 11 deletions

View File

@ -32,25 +32,28 @@ images with support for these features:
- ``TRUSTED_BOARD_BOOT=1``
- ``GENERATE_COT=1``
By default, this will use the Chain of Trust described in the TBBR-client
document. To select a different one, use the ``COT`` build option.
In the case of Arm platforms, the location of the ROTPK hash must also be
specified at build time. The following locations are currently supported (see
``ARM_ROTPK_LOCATION`` build option):
- ``ARM_ROTPK_LOCATION=regs``: the ROTPK hash is obtained from the Trusted
root-key storage registers present in the platform. On Juno, this
root-key storage registers present in the platform. On Juno, these
registers are read-only. On FVP Base and Cortex models, the registers
are read-only, but the value can be specified using the command line
are also read-only, but the value can be specified using the command line
option ``bp.trusted_key_storage.public_key`` when launching the model.
On Juno board, the default value corresponds to an ECDSA-SECP256R1 public
key hash, whose private part is not currently available.
- ``ARM_ROTPK_LOCATION=devel_rsa``: use the default hash located in
plat/arm/board/common/rotpk/arm_rotpk_rsa_sha256.bin. Enforce generation
of the new hash if ROT_KEY is specified.
``plat/arm/board/common/rotpk/arm_rotpk_rsa_sha256.bin``. Enforce
generation of the new hash if ``ROT_KEY`` is specified.
- ``ARM_ROTPK_LOCATION=devel_ecdsa``: use the default hash located in
plat/arm/board/common/rotpk/arm_rotpk_ecdsa_sha256.bin. Enforce generation
of the new hash if ROT_KEY is specified.
``plat/arm/board/common/rotpk/arm_rotpk_ecdsa_sha256.bin``. Enforce
generation of the new hash if ``ROT_KEY`` is specified.
Example of command line using RSA development keys:
@ -64,9 +67,8 @@ images with support for these features:
all fip
The result of this build will be the bl1.bin and the fip.bin binaries. This
FIP will include the certificates corresponding to the Chain of Trust
described in the TBBR-client document. These certificates can also be found
in the output build directory.
FIP will include the certificates corresponding to the selected Chain of
Trust. These certificates can also be found in the output build directory.
#. The optional FWU_FIP contains any additional images to be loaded from
Non-Volatile storage during the :ref:`Firmware Update (FWU)` process. To build the
@ -102,8 +104,8 @@ images with support for these features:
The result of this build will be bl1.bin, fip.bin and fwu_fip.bin binaries.
Both the FIP and FWU_FIP will include the certificates corresponding to the
Chain of Trust described in the TBBR-client document. These certificates
can also be found in the output build directory.
selected Chain of Trust. These certificates can also be found in the output
build directory.
--------------