On 1/19/22 19:55, Sughosh Ganu wrote:
The patchset adds support for the FWU Multi Bank Update[1]
feature. Certain aspects of the Dependable Boot[2] specification have
also been implemented.

The document "Platform Security Firmware Update for the A-profile Arm
Architecture Beta" [1] that you relate to describes updating using FF-A
[5] as a communication protocol between a normal world client and an
update agent in the secure world. [1] further describes an API for this
communication. I cannot see that you are implementing this:

* U-Boot is living in the normal world, so it cannot be the update agent
of [1].
* Implementing the client of [1] in U-Boot would not require board
specific changes.

This patch set comes without any documentation update. We need a patch
which adds documents to U-Boot describing

* the design of the update mechanism
* the usage of the update mechanism

before we can start the review of the patches.

Best regards

Heinrich

[1] Platform Security Firmware Update for the A-profile Arm Architecture
Beta
https://developer.arm.com/documentation/den0118/a

[5] Arm Firmware Framework for Arm A-profile
https://developer.arm.com/documentation/den0077/latest


The FWU multi bank update feature is used for supporting multiple
sets(also called banks) of firmware image(s), allowing the platform to
boot from a different bank, in case it fails to boot from the active
bank. This functionality is supported by keeping the relevant
information in a structure called metadata, which provides information
on the images. Among other parameters, the metadata structure contains
information on the currect active bank that is being used to boot
image(s).

Functionality is being added to work with the UEFI capsule driver in
u-boot. The metadata is read to gather information on the update bank,
which is the bank to which the firmware images would be flashed to. On
a successful completion of the update of all components, the active
bank field in the metadata is updated, to reflect the bank from which
the platform will boot on the subsequent boots.

Currently, the feature is being enabled on the STM32MP157C-DK2
board which boots a FIP image from a uSD card partitioned with the GPT
partioning scheme. This also requires changes in the previous stage of
bootloader, which parses the metadata and selects the bank to boot the
image(s) from. Support is being added in tf-a(BL2 stage) for the
STM32MP157C-DK2 board to boot the active bank images. These changes
are under review currently[3].
 >
These patches are based on top of the series from Takahiro to add
Authentication support to mkeficapsule utility[4]

[1] - https://developer.arm.com/documentation/den0118/a
[2] - 
https://staging-git.codelinaro.org/linaro/firmware-dual-banked-updates/test
[3] - https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/12566
[4] - https://patchwork.ozlabs.org/project/uboot/list/?series=281549

Changes since V2:
* Use uint*_t types in fwu_mdata.h since the file is to be reused in
   other projects
* Keep only the FWU metadata structures in fwu_mdata.h
* Move all other function and macro declarations in fwu.h
* Keep common implementations of fwu_update_active_index and
   fwu_revert_boot_index in fwu_mdata.c
* Add a update_mdata function pointer in the fwu_mdata_ops structure
* Move the function definition of fwu_verify_mdata to fwu_mdata.c to
   facilitate reuse
* Remove the block device specific desc->devnum parameter for the
   fwu_plat_get_alt_num function call
* Change the implementation of fwu_plat_get_alt_num to get the devnum
   in the function before calling gpt_plat_get_alt_num
* Add logic to delete the TrialStateCtr variable if system is not in
   Trial State
* Add logic to check if bit 15(OS Acceptance) of the Flags member in
   the capsule header is set
* Add logic to set the accept bit of all images from a capsule if the
   OS Acceptance bit in the capsule header is not set
* Include the log.h and stdio.h header files

Sughosh Ganu (9):
   FWU: Add FWU metadata structure and functions for accessing metadata
   FWU: Add FWU metadata access functions for GPT partitioned block
     devices
   FWU: stm32mp1: Add helper functions for accessing FWU metadata
   FWU: STM32MP1: Add support to read boot index from backup register
   EFI: FMP: Add provision to update image's ImageTypeId in image
     descriptor
   FWU: Add boot time checks as highlighted by the FWU specification
   FWU: Add support for FWU Multi Bank Update feature
   FWU: cmd: Add a command to read FWU metadata
   mkeficapsule: Add support for generating empty capsules

  board/st/stm32mp1/stm32mp1.c        | 183 ++++++++++
  cmd/Kconfig                         |   7 +
  cmd/Makefile                        |   1 +
  cmd/fwu_mdata.c                     |  67 ++++
  common/board_r.c                    |   6 +
  include/fwu.h                       |  81 +++++
  include/fwu_mdata.h                 |  69 ++++
  lib/Kconfig                         |   6 +
  lib/Makefile                        |   1 +
  lib/efi_loader/efi_capsule.c        | 233 ++++++++++++-
  lib/efi_loader/efi_firmware.c       |  90 ++++-
  lib/efi_loader/efi_setup.c          |   3 +-
  lib/fwu_updates/Kconfig             |  31 ++
  lib/fwu_updates/Makefile            |  11 +
  lib/fwu_updates/fwu.c               | 198 +++++++++++
  lib/fwu_updates/fwu_mdata.c         | 358 +++++++++++++++++++
  lib/fwu_updates/fwu_mdata_gpt_blk.c | 521 ++++++++++++++++++++++++++++
  tools/eficapsule.h                  |   8 +
  tools/mkeficapsule.c                | 102 +++++-
  19 files changed, 1955 insertions(+), 21 deletions(-)
  create mode 100644 cmd/fwu_mdata.c
  create mode 100644 include/fwu.h
  create mode 100644 include/fwu_mdata.h
  create mode 100644 lib/fwu_updates/Kconfig
  create mode 100644 lib/fwu_updates/Makefile
  create mode 100644 lib/fwu_updates/fwu.c
  create mode 100644 lib/fwu_updates/fwu_mdata.c
  create mode 100644 lib/fwu_updates/fwu_mdata_gpt_blk.c


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