[PATCH v10 15/15] FWU: doc: Add documentation for the FWU feature

[Jassi Brar]

On Thu, 15 Sept 2022 at 03:16, Sughosh Ganu <sughosh.ganu at linaro.org> wrote:

> diff --git a/doc/develop/uefi/fwu_updates.rst b/doc/develop/uefi/fwu_updates.rst
> new file mode 100644
> index 0000000000..fad3fbb3a8
> --- /dev/null
> +++ b/doc/develop/uefi/fwu_updates.rst
> @@ -0,0 +1,165 @@
> +.. 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 it's 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=y
> +    CONFIG_EFI_CAPSULE_FIRMWARE_RAW=y
> +
> +    CONFIG_FWU_MULTI_BANK_UPDATE=y
> +    CONFIG_CMD_FWU_METADATA=y
> +    CONFIG_DM_FWU_MDATA=y
>
s/CONFIG_DM_FWU_MDATA/CONFIG_FWU_MDATA