[PATCH v9 3/4] Boot var automatic management for removable medias

[Heinrich Schuchardt]

On 6/18/23 07:45, Heinrich Schuchardt wrote:
> On 6/7/23 17:05, Raymond Mao wrote:
>> Changes for complying to EFI spec §3.5.1.1
>> 'Removable Media Boot Behavior'.
>> Boot variables can be automatically generated during a removable
>> media is probed. At the same time, unused boot variables will be
>> detected and removed.
>>
>> Please note that currently the function 'efi_disk_remove' has no
>> ability to distinguish below two scenarios
>> a) Unplugging of a removable media under U-Boot
>> b) U-Boot existing and booting an OS
>
> %s/existing/exiting/
>
>> Thus currently the boot variables management is not added into
>> 'efi_disk_remove' to avoid boot options being added/erased
>> repeatedly under scenario b) during power cycles
>> See TODO comments under function 'efi_disk_remove' for more details
>>
>> Signed-off-by: Raymond Mao <raymond.mao at linaro.org>
>> Reviewed-by: Heinrich Schuchardt <xypron.glpk at gmx.de>
>> Reviewed-by: Ilias Apalodimas <ilias.apalodimas at linaro.org>
>> ---
>> Changes in v3
>> - Split the patch into moving and renaming functions and
>>    individual patches for each changed functionality
>> Changes in v5
>> - Move function call of efi_bootmgr_update_media_device_boot_option()
>>    from efi_init_variables() to efi_init_obj_list()
>> Changes in v6
>> - Revert unrelated changes
>> Changes in v7
>> - adapt the return code of function
>>    efi_bootmgr_update_media_device_boot_option()
>> Changes in v8
>> - add a note in the commit message for future reference
>> Changes in v9
>> - amend the note text in the commit message
>> - add a TODO comment in 'efi_disk_remove'
>>
>>   lib/efi_loader/efi_disk.c  | 18 ++++++++++++++++++
>>   lib/efi_loader/efi_setup.c |  5 +++++
>>   2 files changed, 23 insertions(+)
>>
>> diff --git a/lib/efi_loader/efi_disk.c b/lib/efi_loader/efi_disk.c
>> index d2256713a8..8ccf3dd158 100644
>> --- a/lib/efi_loader/efi_disk.c
>> +++ b/lib/efi_loader/efi_disk.c
>> @@ -687,6 +687,13 @@ int efi_disk_probe(void *ctx, struct event *event)
>>               return -1;
>>       }
>>
>> +    /* only do the boot option management when UEFI sub-system is
>> initialized */
>> +    if (efi_obj_list_initialized == EFI_SUCCESS) {
>> +        ret = efi_bootmgr_update_media_device_boot_option();
>> +        if (ret != EFI_SUCCESS)
>> +            return -1;

This will cause build failures if CONFIG_CMD_BOOTEFI_BOOTMGR=n.
Please check that the configuration is enabled.

>> +    }
>> +
>>       return 0;
>>   }
>>
>> @@ -773,6 +780,17 @@ int efi_disk_remove(void *ctx, struct event *event)
>>           return efi_disk_delete_part(dev);
>>       else
>>           return 0;
>> +
>> +    /*
>> +     * TODO A flag to distinguish below 2 different scenarios of this
>> +     * function call is needed:
>> +     * a) Unplugging of a removable media under U-Boot
>> +     * b) U-Boot existing and booting an OS
>
> I guess you meant exiting.
>
> b) ExitBootServices() invoked or booting an operating system
>
> I will fix this when merging.
>
> Best regards
>
> Heinrich
>
>> +     * In case of scenario a),
>> efi_bootmgr_update_media_device_boot_option()
>> +     * needs to be invoked here to update the boot options and remove
>> the
>> +     * unnecessary ones.
>> +     */
>> +
>>   }
>>
>>   /**
>> diff --git a/lib/efi_loader/efi_setup.c b/lib/efi_loader/efi_setup.c
>> index 58d4e13402..877f3878d6 100644
>> --- a/lib/efi_loader/efi_setup.c
>> +++ b/lib/efi_loader/efi_setup.c
>> @@ -245,6 +245,11 @@ efi_status_t efi_init_obj_list(void)
>>       if (ret != EFI_SUCCESS)
>>           goto out;
>>
>> +    /* update boot option after variable service initialized */
>> +    ret = efi_bootmgr_update_media_device_boot_option();
>> +    if (ret != EFI_SUCCESS)
>> +        goto out;

This will cause build failures if CONFIG_CMD_BOOTEFI_BOOTMGR=n.
Please check that the configuration is enabled.

Best regards

Heinrich

>> +
>>       /* Define supported languages */
>>       ret = efi_init_platform_lang();
>>       if (ret != EFI_SUCCESS)
>