[v12,00/15] FWU: Add FWU Multi Bank Update feature support

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 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 and
Synquacer boards. The DK2 board boots a FIP image from a uSD card
partitioned with the GPT partioning scheme, while the Synquacer board
boots a FIP image from a MTD partitioned SPI NOR flash device.

This feature also requires changes in a previous stage of
bootloader, which parses the metadata and selects the bank to boot the
image(s) from. Support has being added in tf-a(BL2 stage) for the
STM32MP157C-DK2 board to boot the active bank images. These changes 
have been merged to the upstream tf-a repository.

The patch for adding a python test for the feature has been developed,
and was sent in the version 5 of the patches[3]. However, the test
script depends on adding support for the feature on MTD SPI NOR
devices, and that is being done as part of the Synquacer
patches. Hence these set of patches do not have the test script for
the feature. That will be added through the patches for adding support
for the feauture on Synquacer platform.

[1] - https://developer.arm.com/documentation/den0118/a
[2] - https://git.codelinaro.org/linaro/dependable-boot/mbfw/uploads/6f7ddfe3be24e18d4319e108a758d02e/mbfw.pdf
[3] - https://lists.denx.de/pipermail/u-boot/2022-June/485992.html

Changes since V11:
* Use an enum for IMAGE_ACCEPT_SET/IMAGE_ACCEPT_CLEAR
* Remove empty line under fwu_get_dev_mdata()
* Use uclass_first_device_err() in place of uclass_first_device()
* Couple of other nits from Etienne about using if (ret)
* Declare mdata_parts as an array in gpt_get_mdata_partitions()
* Put the assignment to the return value in gpt_check_mdata_validity()
  as suggested by Etienne
* Reword the commit subject line as suggested by Etienne
* Add a function fwu_alt_num_for_dfu_dev() to get the alt number based
  on the DFU backend device as suggested by Ilias
* Change the logic of fwu_gpt_get_alt_num() as suggested by Ilias
* Remove the superfluous braces in fwu_boottime_checks()
* Describe the config CONFIG_CMD_FWU_METADATA separately
* Remove some superfluous configs from the list of config symbols
  needed for building the feature

Sughosh Ganu (15):
  dt/bindings: Add bindings for GPT based FWU Metadata storage device
  FWU: Add FWU metadata structure and driver for accessing metadata
  FWU: Add FWU metadata access driver for GPT partitioned block devices
  stm32mp1: dk2: Add a node for the FWU metadata device
  stm32mp1: Add image information for capsule updates
  FWU: Add helper functions for accessing FWU metadata
  FWU: STM32MP1: Add support to read boot index from backup register
  event: Add an event for main_loop
  FWU: Add boot time checks as highlighted by the FWU specification
  FWU: Add support for the FWU Multi Bank Update feature
  FWU: cmd: Add a command to read FWU metadata
  test: dm: Add test cases for FWU Metadata uclass
  mkeficapsule: Add support for generating empty capsules
  mkeficapsule: Add support for setting OEM flags in capsule header
  FWU: doc: Add documentation for the FWU feature

 arch/arm/dts/stm32mp157c-dk2-u-boot.dtsi      |   7 +
 arch/arm/mach-stm32mp/include/mach/stm32.h    |   5 +
 arch/sandbox/Kconfig                          |   6 +
 arch/sandbox/dts/test.dts                     |   7 +-
 board/sandbox/sandbox.c                       |   8 +
 board/st/stm32mp1/stm32mp1.c                  |  39 ++
 cmd/Kconfig                                   |   6 +
 cmd/Makefile                                  |   1 +
 cmd/fwu_mdata.c                               |  79 +++
 common/board_r.c                              |   3 +
 common/event.c                                |   3 +
 configs/sandbox64_defconfig                   |   5 +-
 doc/develop/uefi/fwu_updates.rst              | 182 ++++++
 doc/develop/uefi/index.rst                    |   1 +
 doc/develop/uefi/uefi.rst                     |  10 +
 .../firmware/fwu-mdata-gpt.yaml               |  32 +
 doc/mkeficapsule.1                            |  33 +-
 doc/usage/cmd/fwu_mdata.rst                   |  43 ++
 doc/usage/index.rst                           |   1 +
 drivers/Kconfig                               |   2 +
 drivers/Makefile                              |   1 +
 drivers/fwu-mdata/Kconfig                     |  16 +
 drivers/fwu-mdata/Makefile                    |   8 +
 drivers/fwu-mdata/fwu-mdata-uclass.c          | 107 +++
 drivers/fwu-mdata/gpt_blk.c                   | 357 ++++++++++
 include/configs/stm32mp15_common.h            |   4 +
 include/dm/uclass-id.h                        |   1 +
 include/event.h                               |   3 +
 include/fwu.h                                 | 299 +++++++++
 include/fwu_mdata.h                           |  67 ++
 lib/Kconfig                                   |   6 +
 lib/Makefile                                  |   1 +
 lib/efi_loader/efi_capsule.c                  | 207 +++++-
 lib/efi_loader/efi_firmware.c                 |  14 +
 lib/fwu_updates/Kconfig                       |  33 +
 lib/fwu_updates/Makefile                      |   7 +
 lib/fwu_updates/fwu.c                         | 608 ++++++++++++++++++
 lib/fwu_updates/fwu_gpt.c                     | 119 ++++
 test/dm/Makefile                              |   1 +
 test/dm/fwu_mdata.c                           | 149 +++++
 test/dm/fwu_mdata_disk_image.h                | 112 ++++
 .../test_capsule_firmware_fit.py              |   1 -
 .../test_capsule_firmware_signed_fit.py       |   1 -
 tools/Makefile                                |   2 +-
 tools/eficapsule.h                            |   8 +
 tools/mkeficapsule.c                          | 109 +++-
 46 files changed, 2692 insertions(+), 22 deletions(-)
 create mode 100644 cmd/fwu_mdata.c
 create mode 100644 doc/develop/uefi/fwu_updates.rst
 create mode 100644 doc/device-tree-bindings/firmware/fwu-mdata-gpt.yaml
 create mode 100644 doc/usage/cmd/fwu_mdata.rst
 create mode 100644 drivers/fwu-mdata/Kconfig
 create mode 100644 drivers/fwu-mdata/Makefile
 create mode 100644 drivers/fwu-mdata/fwu-mdata-uclass.c
 create mode 100644 drivers/fwu-mdata/gpt_blk.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_gpt.c
 create mode 100644 test/dm/fwu_mdata.c
 create mode 100644 test/dm/fwu_mdata_disk_image.h