Re: [PATCH 05/10] StandaloneMmPkg/StandaloneMmCoreEntryPoint: drop explicit SerialPortLib call

[Achin Gupta <Achin.Gupta@arm.com>]

Hi Ard,

On Tue, Mar 05, 2019 at 02:32:43PM +0100, Ard Biesheuvel wrote:
> Sending DEBUG output to the serial port should only be done via
> DebugLib calls, which is in charge of initializing the serial
> port when appropriate. So drop the explicit SerialPortInitialize ()
> invocation, and rely on normal constructor ordering to get the
> serial port into the appropriate state at the right time.
>
> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> ---
>  StandaloneMmPkg/Library/StandaloneMmCoreEntryPoint/AArch64/StandaloneMmCoreEntryPoint.c | 3 ---
>  1 file changed, 3 deletions(-)
>
> diff --git a/StandaloneMmPkg/Library/StandaloneMmCoreEntryPoint/AArch64/StandaloneMmCoreEntryPoint.c b/StandaloneMmPkg/Library/StandaloneMmCoreEntryPoint/AArch64/StandaloneMmCoreEntryPoint.c
> index 5cca532456fd..c8e11a253d24 100644
> --- a/StandaloneMmPkg/Library/StandaloneMmCoreEntryPoint/AArch64/StandaloneMmCoreEntryPoint.c
> +++ b/StandaloneMmPkg/Library/StandaloneMmCoreEntryPoint/AArch64/StandaloneMmCoreEntryPoint.c
> @@ -232,9 +232,6 @@ _ModuleEntryPoint (
>    VOID                                    *TeData;
>    UINTN                                   TeDataSize;
>
> -  Status = SerialPortInitialize ();
> -  ASSERT_EFI_ERROR (Status);

This is done in the first few instructions after EL3 ERETs into S-EL0 to
initialise the StMM partition. The constructors will be called a bit later. I
agree with the change but does EDK2 provide a mechanism for early prints to the
console in case we need this in future.

cheers,
Achin

> -
>    // Get Secure Partition Manager Version Information
>    Status = GetSpmVersion ();
>    if (EFI_ERROR (Status)) {
> --
> 2.20.1
>