[U-Boot] [PATCH 0/7] android: Implement A/B boot process

[Alistair Strachan]

On Tue, Nov 27, 2018 at 11:57 AM Ruslan Trofymenko
<ruslan.trofymenko at linaro.org> wrote:
>
> This patch series adds support for Android A/B boot process [1].
> Main steps of A/B boot process are:
>   - A/B metadata integrity check
>   - looking for the current slot (where the system should be
>     booting from)
>   - getting the name of the current boot partition (boot_a or boot_b)
>     and loading the corresponding Android boot image
>   - getting the name of the current system partition (system_a or
>     system_b) and passing of its full name via kernel command line
>     (like 'root=/dev/mmcblk1p11')
>   - passing current slot via kernel command line (like
>     'androidboot.slot_suffix=_a') and via A/B metadata (e.g. via
>     misc partition)
>   - A/B metadata processing: setting the boot success flag for
>     current slot, handling the retry counter, etc
>
> A/B metadata is organized according to Android reference [2] and stored
> on 'misc' partition. On the first A/B boot process, when 'misc'
> partition doesn't contain required data, default A/B metadata will be
> created and stored in 'misc' partition. In the end of the Android boot,
> 'update_verifier' and 'update_engine' services are processing the
> A/B metadata through the Boot Control HAL. To confirm the boot was
> successful using current slot, "boot success" flag must be set on
> Android side.
>
> To enable Android A/B support in U-Boot:
>   1. Set the following config options:
>
>          CONFIG_ANDROID_AB=y
>          CONFIG_CMD_ANDROID_AB_SELECT=y
>
>   2. Change the disk layout so that it has sloted boot partitions.
>      E.g. instead of 'boot' and 'system' partitions there should be
>      'boot_a', 'boot_b', 'system_a' and 'system_b' partitions.
>
> To be able to actually test this patch series, the A/B features must
> be implemented and enabled in Android as well (see [1] for details).
>
> Documentation and corresponding test for A/B boot is present here. The
> last patch in this series integrates A/B boot support on AM57xx based
> boards (though it's not enabled by default). Future users of A/B boot
> feature can use it as a reference.
>
> This series is a part of previous submission [3] by Alex Deymo. It
> contains only A/B feature that was stripped out from there with some
> modifications for using with "bootm" command preferred in upstream.
>
> [1] https://source.android.com/devices/tech/ota/ab/ab_implement
> [2] bootable/recovery/bootloader_message/include/bootloader_message/bootloader_message.h
> [3] https://lists.denx.de/pipermail/u-boot/2017-April/285841.html
>
> Ruslan Trofymenko (7):
>   cmd: part: Add 'number' sub-command
>   disk: part: Extend API to get partition info
>   common: Implement A/B metadata
>   cmd: Add 'android_ab_select' command
>   test/py: Add base test case for A/B updates
>   doc: android: Add simple guide for A/B updates
>   env: am57xx: Implement A/B boot process
>
>  cmd/Kconfig                          |  11 ++
>  cmd/Makefile                         |   1 +
>  cmd/android_ab_select.c              |  53 +++++++
>  cmd/part.c                           |  16 +-
>  common/Kconfig                       |  10 ++
>  common/Makefile                      |   1 +
>  common/android_ab.c                  | 278 +++++++++++++++++++++++++++++++++++
>  configs/sandbox_defconfig            |   2 +
>  disk/part.c                          |  68 +++++++++
>  doc/README.android-ab                |  67 +++++++++
>  include/android_ab.h                 |  34 +++++
>  include/android_bootloader_message.h | 164 +++++++++++++++++++++
>  include/environment/ti/boot.h        |  44 +++++-
>  include/part.h                       |  21 +++
>  test/py/tests/test_ab.py             |  74 ++++++++++
>  15 files changed, 839 insertions(+), 5 deletions(-)
>  create mode 100644 cmd/android_ab_select.c
>  create mode 100644 common/android_ab.c
>  create mode 100644 doc/README.android-ab
>  create mode 100644 include/android_ab.h
>  create mode 100644 include/android_bootloader_message.h
>  create mode 100644 test/py/tests/test_ab.py

Looks good, thanks Ruslan!

Reviewed-by: Alistair Strachan <astrachan at google.com>

>
> --
> 2.7.4
>