Re: Persistent Variable Storage and PlatformBootTimeOut

[Ard Biesheuvel <ard.biesheuvel@linaro.org>]

On 6 September 2016 at 12:13, Bhupesh Sharma <bhupesh.sharma@nxp.com> wrote:
> Hi EDK2 experts,
>
> We have recently added the support for storing UEFI run-time variables on underlying NOR
> Flash slave on our ARMV8 NXP board.
>
> We are successfully able to change the values of variables like boot-order using the latest
> MdeModulePkg BDS:
>
>         MdeModulePkg/Universal/BdsDxe/BdsDxe.inf
>
> and retrieve them on next board boot.
>
> While this works almost on all the places, we see that the Auto Boot Time we have set using the
> following PCD:
>         gEfiMdePkgTokenSpaceGuid.PcdPlatformBootTimeOut|20
>
> Doesn't work when one enters the BIOS screen and enters the Boot Maintenance Manager to change this
> value from say 20 to 10.
>
> On the next board boot, the PlatformBootTimeOut value is still 20.
>
> The same issue is replicable on latest EDK2 (master branch) on qemu for aarch64.
>
> Is this a known issue or are we missing something here?
>

You should declare it as

[PcdsDynamicHii.common.DEFAULT]
  gEfiMdePkgTokenSpaceGuid.PcdPlatformBootTimeOut|L"Timeout"|gEfiGlobalVariableGuid|0x0|10
# Variable: L"Timeout"

to connect the dynamic PCD to the EFI variable.