diff options
Diffstat (limited to 'docs/components/firmware-update.rst')
| -rw-r--r-- | docs/components/firmware-update.rst | 18 |
1 files changed, 7 insertions, 11 deletions
diff --git a/docs/components/firmware-update.rst b/docs/components/firmware-update.rst index 30bdc24b..2bff00f5 100644 --- a/docs/components/firmware-update.rst +++ b/docs/components/firmware-update.rst @@ -14,8 +14,8 @@ be complemented by other, higher level firmware update software. FWU implements a specific part of the Trusted Board Boot Requirements (TBBR) specification, Arm DEN0006C-1. It should be used in conjunction with the -`Trusted Board Boot`_ design document, which describes the image authentication -parts of the Trusted Firmware-A (TF-A) TBBR implementation. +:ref:`Trusted Board Boot` design document, which describes the image +authentication parts of the Trusted Firmware-A (TF-A) TBBR implementation. Scope ~~~~~ @@ -53,10 +53,11 @@ The primary requirements of the FWU feature are: at other Exception Levels. #. Export a platform interface to provide FWU common code with the information it needs, and to enable platform specific FWU functionality. See the - `Porting Guide`_ for details of this interface. + :ref:`Porting Guide` for details of this interface. TF-A uses abbreviated image terminology for FWU images like for other TF-A -images. An overview of this terminology can be found `here`_. +images. See the :ref:`Image Terminology` document for an explanation of these +terms. The following diagram shows the FWU boot flow for Arm development platforms. Arm CSS platforms like Juno have a System Control Processor (SCP), and these @@ -70,8 +71,8 @@ Image Identification Each FWU image and certificate is identified by a unique ID, defined by the platform, which BL1 uses to fetch an image descriptor (``image_desc_t``) via a call to ``bl1_plat_get_image_desc()``. The same ID is also used to prepare the -Chain of Trust (Refer to the `Authentication Framework Design`_ -for more information). +Chain of Trust (Refer to the :ref:`Authentication Framework & Chain of Trust` +document for more information). The image descriptor includes the following information: @@ -394,11 +395,6 @@ This is only allowed if the image is not being executed. *Copyright (c) 2015-2019, Arm Limited and Contributors. All rights reserved.* -.. _Trusted Board Boot: ../design/trusted-board-boot.rst -.. _Porting Guide: ../getting_started/porting-guide.rst -.. _here: ../getting_started/image-terminology.rst -.. _Authentication Framework Design: ../design/auth-framework.rst .. _Universally Unique Identifier: https://tools.ietf.org/rfc/rfc4122.txt - .. |Flow Diagram| image:: ../resources/diagrams/fwu_flow.png .. |FWU state machine| image:: ../resources/diagrams/fwu_states.png |