On Tue, 18 Oct 2022 at 16:26, Ilias Apalodimas <ilias.apalodi...@linaro.org> wrote: > > On Tue, Oct 18, 2022 at 05:13:37PM +0530, Sughosh Ganu wrote: > > Add documentation for the FWU Multi Bank Update feature. The document > > describes the steps needed for setting up the platform for the > > feature, as well as steps for enabling the feature on the platform. > > > > Signed-off-by: Sughosh Ganu <sughosh.g...@linaro.org> > > --- > > Changes since V13: None > > > > doc/develop/uefi/fwu_updates.rst | 184 +++++++++++++++++++++++++++++++ > > doc/develop/uefi/index.rst | 1 + > > doc/develop/uefi/uefi.rst | 12 ++ > > 3 files changed, 197 insertions(+) > > create mode 100644 doc/develop/uefi/fwu_updates.rst > > > > diff --git a/doc/develop/uefi/fwu_updates.rst > > b/doc/develop/uefi/fwu_updates.rst > > new file mode 100644 > > index 0000000000..068616ce83 > > --- /dev/null > > +++ b/doc/develop/uefi/fwu_updates.rst > > @@ -0,0 +1,184 @@ > > +.. SPDX-License-Identifier: GPL-2.0+ > > +.. Copyright (c) 2022 Linaro Limited > > + > > +FWU Multi Bank Updates in U-Boot > > +================================ > > + > > +The FWU Multi Bank Update feature implements the firmware update > > +mechanism described in the PSA Firmware Update for A-profile Arm > > +Architecture specification [1]. Certain aspects of the Dependable > > +Boot specification [2] are also implemented. The feature provides a > > +mechanism to have multiple banks of updatable firmware images and for > > +updating the firmware images on the non-booted bank. On a successful > > +update, the platform boots from the updated bank on subsequent > > +boot. The UEFI capsule-on-disk update feature is used for performing > > +the actual updates of the updatable firmware images. > > + > > +The bookkeeping of the updatable images is done through a structure > > +called metadata. Currently, the FWU metadata supports identification > > +of images based on image GUIDs stored on a GPT partitioned storage > > +media. There are plans to extend the metadata structure for non GPT > > +partitioned devices as well. > > + > > +Accessing the FWU metadata is done through generic API's which are > > +defined in a driver which complies with the U-Boot's driver model. A > > +new uclass UCLASS_FWU_MDATA has been added for accessing the FWU > > +metadata. Individual drivers can be added based on the type of storage > > +media, and its partitioning method. Details of the storage device > > +containing the FWU metadata partitions are specified through a U-Boot > > +specific device tree property `fwu-mdata-store`. Please refer to > > +U-Boot `doc <doc/device-tree-bindings/firmware/fwu-mdata-gpt.yaml>`__ > > +for the device tree bindings. > > + > > +Enabling the FWU Multi Bank Update feature > > +------------------------------------------ > > + > > +The feature can be enabled by specifying the following configs:: > > + > > + CONFIG_EFI_CAPSULE_ON_DISK=y > > + CONFIG_EFI_CAPSULE_FIRMWARE_MANAGEMENT=y > > + CONFIG_EFI_CAPSULE_FIRMWARE_RAW=y > > + > > + CONFIG_FWU_MULTI_BANK_UPDATE=y > > + CONFIG_FWU_MDATA=y > > + CONFIG_FWU_MDATA_GPT_BLK=y > > + CONFIG_FWU_NUM_BANKS=<val> > > + CONFIG_FWU_NUM_IMAGES_PER_BANK=<val> > > + > > +in the .config file > > + > > +By enabling the CONFIG_CMD_FWU_METADATA config option, the > > +fwu_mdata_read command can be used to check the current state of the > > +FWU metadata structure. > > + > > +The first group of configuration settings enable the UEFI > > +capsule-on-disk update functionality. The second group of configs > > +enable the FWU Multi Bank Update functionality. Please refer to the > > +section :ref:`uefi_capsule_update_ref` for more details on generation > > +of the UEFI capsule. > > + > > +Setting up the device for GPT partitioned storage > > +------------------------------------------------- > > + > > +Before enabling the functionality in U-Boot, a GPT partitioned storage > > +device is required. Assuming a GPT partitioned storage device, the > > +storage media needs to be partitioned with the correct number of > > +partitions, given the number of banks and number of images per bank > > +that the platform is going to support. Each updatable firmware image > > +will be stored on a separate partition. In addition, the two copies > > +of the FWU metadata will be stored on two separate partitions. These > > +partitions need to be created at the time of the platform's > > +provisioning. > > + > > +As an example, a platform supporting two banks with each bank > > +containing three images would need to have 2 * 3 = 6 partitions plus > > +the two metadata partitions, or 8 partitions. In addition the storage > > +media can have additional partitions of non-updatable images, like the > > +EFI System Partition(ESP), a partition for the root file system > > +etc. An example list of images on the storage medium would be > > + > > +* FWU metadata 1 > > +* U-Boot 1 > > +* OP-TEE 1 > > +* FWU metadata 2 > > +* OP-TEE 2 > > +* U-Boot 2 > > +* ESP > > +* rootfs > > + > > +When generating the partitions, a few aspects need to be taken care > > +of. Each GPT partition entry in the GPT header has two GUIDs:: > > + > > +* PartitionTypeGUID > > +* UniquePartitionGUID > > + > > +The PartitionTypeGUID value should correspond to the > > +``image_type_uuid`` field of the FWU metadata. This field is used to > > +identify a given type of updatable firmware image, e.g. U-Boot, > > +OP-TEE, FIP etc. This GUID should also be used for specifying the > > +`--guid` parameter when generating the capsule. > > + > > +The UniquePartitionGUID value should correspond to the ``image_uuid`` > > +field in the FWU metadata. This GUID is used to identify images of a > > +given image type in different banks. > > + > > +The FWU specification defines the GUID value to be used for the > > +metadata partitions. This would be the PartitionTypeGUID for the > > +metadata partitions. Similarly, the UEFI specification defines the ESP > > +GUID to be be used. > > + > > +When generating the metadata, the ``image_type_uuid`` and the > > +``image_uuid`` values should match the *PartitionTypeGUID* and the > > +*UniquePartitionGUID* values respectively. > > + > > +Performing the Update > > +--------------------- > > + > > +Once the storage media has been partitioned and populated with the > > +metadata partitions, the UEFI capsule-on-disk update functionality can > > +be used for performing the update. Refer to the section > > +:ref:`uefi_capsule_update_ref` for details on how the update can be > > +invoked. > > + > > +On a successful update, the FWU metadata gets updated to reflect the > > +bank from which the platform would be booting on subsequent boot. > > + > > +Based on the value of bit15 of the Flags member of the capsule header, > > +the updated images would either be accepted by the U-Boot's UEFI > > +implementation, or by the Operating System. If the Operating System is > > +accepting the firmware images, it does so by generating an empty > > +*accept* capsule. The Operating System can also reject the updated > > +firmware by generating a *revert* capsule. The empty capsule can be > > +applied by using the exact same procedure used for performing the > > +capsule-on-disk update. > > + > > +The task of accepting the different firmware images, post an update > > +may be done by multiple, separate components in the Operating > > +System. To help identify the firmware image that is being accepted, > > +the accept capsule passes the image GUID of the firmware image being > > +accepted. The relevant code in U-Boot then sets the Accept bit of the > > +corresponding firmware image for which the accept capsule was > > +found. Only when all the firmware components in a bank have been > > +accepted does the platform transition from trial state to regular > > +state. > > + > > +The revert capsule on the other hand does not pass any image GUID, > > +since reverting any image of the bank has the same result of the > > +platform booting from the other bank on subsequent boot. > > + > > +In the scenario that bit15 of the Flags member of the capsule header > > +has not been set, the images being updated are accepted by the > > +U-Boot's UEFI firmware implementation by default, on successful > > +updation of the image.
s/updation/update/ For this fixed, Acked-by: Etienne Carriere <etienne.carri...@linaro.org> br, etienne > > + > > +Generating an empty capsule > > +--------------------------- > > + > > +The empty capsule can be generated using the mkeficapsule utility. To > > +build the tool, enable:: > > + > > + CONFIG_TOOLS_MKEFICAPSULE=y > > + > > +Run the following commands to generate the accept/revert capsules:: > > + > > +.. code-block:: bash > > + > > + $ ./tools/mkeficapsule \ > > + [--fw-accept --guid <image guid>] | \ > > + [--fw-revert] \ > > + <capsule_file_name> > > + > > +Some examples of using the mkeficapsule tool for generation of the > > +empty capsule would be:: > > + > > +.. code-block:: bash > > + > > + $ ./tools/mkeficapsule --fw-accept --guid <image guid> \ > > + <accept_capsule_name> > > + $ ./tools/mkeficapsule --fw-revert <revert_capsule_name> > > + > > +Links > > +----- > > + > > +* [1] https://developer.arm.com/documentation/den0118/a/ - FWU > > Specification > > +* [2] > > https://git.codelinaro.org/linaro/dependable-boot/mbfw/uploads/6f7ddfe3be24e18d4319e108a758d02e/mbfw.pdf > > - Dependable Boot Specification > > diff --git a/doc/develop/uefi/index.rst b/doc/develop/uefi/index.rst > > index 7e65dbc5d5..e26b1fbe05 100644 > > --- a/doc/develop/uefi/index.rst > > +++ b/doc/develop/uefi/index.rst > > @@ -13,3 +13,4 @@ can be run an UEFI payload. > > uefi.rst > > u-boot_on_efi.rst > > iscsi.rst > > + fwu_updates.rst > > diff --git a/doc/develop/uefi/uefi.rst b/doc/develop/uefi/uefi.rst > > index cd84706953..e0835beba4 100644 > > --- a/doc/develop/uefi/uefi.rst > > +++ b/doc/develop/uefi/uefi.rst > > @@ -277,6 +277,8 @@ Enable ``CONFIG_OPTEE``, ``CONFIG_CMD_OPTEE_RPMB`` and > > ``CONFIG_EFI_MM_COMM_TEE` > > > > [1] https://optee.readthedocs.io/en/latest/building/efi_vars/stmm.html > > > > +.. _uefi_capsule_update_ref: > > + > > Enabling UEFI Capsule Update feature > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > > > @@ -377,6 +379,16 @@ following command:: > > > > dfu list > > > > +When the FWU Multi Bank Update feature is enabled on the platform, the > > +image index is used only to identify the image index with the image > > +GUID. The image index would not correspond to the dfu alt number. This > > +is because the FWU feature supports multiple partitions(banks) of > > +updatable images, and the actual dfu alt number to which the image is > > +to be written to is determined at runtime, based on the value of the > > +update bank to which the image is to be written. For more information > > +on the FWU Multi Bank Update feature, please refer `doc > > +<doc/develop/uefi/fwu_updates.rst>`__. > > + > > When using the FMP for FIT images, the image index value needs to be > > set to 1. > > > > -- > > 2.34.1 > > > > Acked-by: Ilias Apalodimas <ilias.apalodi...@linaro.org>