[RFC PATCH v2 3/8] FWU: stm32mp1: Add helper functions for accessing FWU metadata

[Masami Hiramatsu]

() should Hi Sughosh and Ilias,

I would like to confirm that what the plat_fill_gpt_partition_guids()
should return.

2021年12月19日(日) 16:07 Sughosh Ganu <sughosh.ganu at linaro.org>:

> +static int plat_fill_gpt_partition_guids(struct blk_desc *desc,
> +                                        efi_guid_t **part_guid_arr)
> +{
> +       int i, ret = 0;
> +       u32 part;
> +       struct dfu_entity *dfu;
> +       struct disk_partition info;
> +       efi_guid_t part_type_guid;
> +       int alt_num = dfu_get_alt_number();
> +
> +       dfu_init_env_entities(NULL, NULL);
> +
> +       for (i = 0, part = 1; i < alt_num; i++) {
> +               dfu = dfu_get_entity(i);
> +
> +               if (!dfu)
> +                       continue;
> +
> +               /*
> +                * Currently, Multi Bank update
> +                * feature is being supported
> +                * only on GPT partitioned
> +                * MMC/SD devices.
> +                */
> +               if (dfu->dev_type != DFU_DEV_MMC)
> +                       continue;
> +
> +               if (part_get_info(desc, part, &info)) {
> +                       part++;
> +                       continue;
> +               }
> +
> +               uuid_str_to_bin(info.type_guid, part_type_guid.b,
> +                               UUID_STR_FORMAT_GUID);
> +               guidcpy((*part_guid_arr + i), &part_type_guid);
> +               part++;
> +       }
> +
> +       dfu_free_entities();
> +
> +       return ret;
> +}

So on this platform which uses GPT partition for each bank, it stores
the GUID for each partition.
I think this information will be shown in the ESRT, but not used for
specifying capsule image_type_uuid.

This is strange.
Without this FWU multi-bank update, the array will only have the
image_type UUID.
Thus,  user can use ESRT to confirm what UUID should be specified for
the capsule file. (it has image-type UUID)
(of course that is fixed value on one platform anyway)

And when FWU multi-bank update is enabled, that changes to the
partition GUIDs. But those GUIDs are NOT used when making the capsule
file nor doing the update process, because we should not specify the
bank index directly, right?

We will set a unique image-type UUID on each image entry, and use it
for making a capsule file, but the capsule file itself doesn't specify
the banks. And acceptance/revert capsule file also doesn't specify it.
Acceptance file will also uses image_type UUID, but not the partition
UUID for the bank.

Maybe I'm wrong, but I'm confusing. And this is important for the
platform which doesn't use GPT.

Thank you,


-- 
Masami Hiramatsu