On Thu, 15 Sept 2022 at 03:16, Sughosh Ganu <sughosh.g...@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
