[PATCH v3 0/8] qcom: implement capsule updates

[Caleb Connolly]

Hi Sumit,

On 05/06/2024 07:31, Sumit Garg wrote:
> Hi Caleb,
> 
> On Mon, 3 Jun 2024 at 18:19, Caleb Connolly <caleb.connolly at linaro.org> wrote:
>>
>> Hook up support for capsule updates loaded from disk on Qualcomm
>> platforms.
>>
>> Most Qualcomm devices have an A/B partition layout, with most partitions
>> duplicated. The metadata on which slot is active is stored in the GPT
>> headers in the vendor-specific attribute bits of each partition.
> 
> It's good to see capsule updates support coming up for Qualcomm
> platforms. AFAICS, with this series we only update U-Boot on the
> current active partition. IOW, real A/B support is still not
> supported. Do you think it is possible for U-Boot to update metadata
> in GPT headers and for proprietary bootloaders to pick up the U-Boot
> from the updated partition?

Yes this would be possible, I have some WIP patches to let us modify the 
slot attribute bits and write back the header.

The reason I haven't implement A/B is because we don't support it from 
the OS level on any of the boards I work on. We often patch ABL to 
disable or skip the slot logic and flash a partition table without 
slots. It also unlocks a bunch of additional complexity...

This isn't super high on my todo list but I'd be happy to help if 
someone wants to enable this functionality. We'd need:

1. Upstream support for modifying the GPT (see my PoC at [1] and [2]).
2. Logic to configure flashing the active or inactive slot

This logic would have to run after the capsule update, I don't know if 
there is currently a way to add a callback after the update.

If we enable updating other images (like XBL, hyp, tz, etc), we would 
need to either agree that a capsule update would have to update ALL 
partitions, or implement logic to copy over partitions that weren't 
flashed to the other slot.

[1]: 
https://git.codelinaro.org/linaro/qcomlt/u-boot/-/commit/34d3de6f79550527746303e0bf6337fa37e31fe5

[2]: 
https://git.codelinaro.org/linaro/qcomlt/u-boot/-/commit/656d9e816bef85e586460a999cc7874255be9f1d
> 
> -Sumit
> 
>>
>> Add support for reading this attributes via the disk_partition struct
>> and using them to determine which boot partition U-Boot is flashed to
>> and generate the appropriate DFU string.
>>
>> This logic is gated behind a check to ensure that U-Boot is actually
>> being chainloaded and not run via some other mechanism.
>>
>> SCSI support for most Qualcomm platforms is not yet enabled upstream,
>> but will follow in future patches.
>>
>> This series enables capsule updates on the RB2, however [1] is required
>> for it to work properly (as otherwise MMC won't be available).
>>
>> [1]: https://lore.kernel.org/u-boot/20240527-b4-clk-stub-v2-0-29013855e343@linaro.org/
>>
>> To: Tom Rini <trini at konsulko.com>
>> To: Simon Glass <sjg at chromium.org>
>> To: Lukasz Majewski <lukma at denx.de>
>> To: Mattijs Korpershoek <mkorpershoek at baylibre.com>
>> To: Caleb Connolly <caleb.connolly at linaro.org>
>> To: Neil Armstrong <neil.armstrong at linaro.org>
>> To: Sumit Garg <sumit.garg at linaro.org>
>> Cc: Ilias Apalodimas <ilias.apalodimas at linaro.org>
>> Cc: u-boot at lists.denx.de
>> Cc: u-boot-qcom at groups.io
>>
>> Changes in v3:
>> - Address comments in scsi dfu support
>> - enable CONFIG_DFU_SCSI for qcom
>> - Link to v2: https://lore.kernel.org/r/20240527-b4-qcom-capsule-updates-v2-0-47583d7ad428@linaro.org
>>
>> Changes in v2:
>> - Add qcom capsule update support patches
>> - Link to v1: https://lore.kernel.org/r/20240409-b4-dfu-scsi-v1-0-3e1441a60376@linaro.org
>>
>> ---
>> Caleb Connolly (8):
>>        dfu: add scsi backend
>>        disk: expose partition type flags
>>        mmc: msm_sdhci: work around a bug when writing
>>        mach-snapdragon: implement capsule update support
>>        qcom_defconfig: savedefconfig
>>        mach-snapdragon: use SYSRESET_PSCI
>>        mach-snapdragon: bump up heap size
>>        qcom_defconfig: enable capsule update support
>>
>>   arch/arm/Kconfig                          |   2 +
>>   arch/arm/mach-snapdragon/Kconfig          |   3 +
>>   arch/arm/mach-snapdragon/Makefile         |   1 +
>>   arch/arm/mach-snapdragon/board.c          |   8 +-
>>   arch/arm/mach-snapdragon/capsule_update.c | 147 ++++++++++
>>   arch/arm/mach-snapdragon/qcom-priv.h      |   6 +
>>   configs/qcom_defconfig                    |  19 +-
>>   disk/part_efi.c                           |   1 +
>>   doc/usage/dfu.rst                         |  32 +++
>>   drivers/dfu/Kconfig                       |   7 +
>>   drivers/dfu/Makefile                      |   1 +
>>   drivers/dfu/dfu.c                         |   5 +-
>>   drivers/dfu/dfu_scsi.c                    | 435 ++++++++++++++++++++++++++++++
>>   drivers/mmc/msm_sdhci.c                   |   7 +
>>   include/configs/qcom.h                    |   5 +
>>   include/dfu.h                             |  26 ++
>>   include/part.h                            |   1 +
>>   17 files changed, 695 insertions(+), 11 deletions(-)
>> ---
>> change-id: 20240523-b4-qcom-capsule-updates-ea2e4f8f0ff0
>> base-commit: 5d8881a0801241d68701e8644d495f1d535506f0
>>
>> // Caleb (they/them)
>>

-- 
// Caleb (they/them)