Re: [PATCH 1/1] EmbeddedPkg: Only print LibGetTime message about compile time epoch once

["Ard Biesheuvel" <ardb@kernel.org>]

On Fri, 5 Mar 2021 at 17:11, Rebecca Cran <rebecca@nuviainc.com> wrote:
>
> The message "LibGetTime: RtcEpochSeconds non volatile variable was not
> found - Using compilation time epoch." can be printed a very large
> number of times, causing log files to become excessively large. This is
> because the RtcEpochSeconds variable only gets set if LibSetTime is
> called, for example by running 'time 12:00' in the UEFI Shell.
>
> Avoid this by setting RtcEpochSeconds to BUILD_EPOCH (EpochSeconds)
> after printing the message. It's set to a volatile variable so the
> message will be displayed on future boots and not hidden.
>
> Commit 44ae214591e58af468eacb7b873eaa0bc187c4fa reduced the verbosity of
> the message to DEBUG_VERBOSE. Revert it back to DEBUG_INFO so it's more
> prominent now that it doesn't get printed so frequently.
>
> Signed-off-by: Rebecca Cran <rebecca@nuviainc.com>

Acked-by: Ard Biesheuvel <ardb@kernel.org>

> ---
>  EmbeddedPkg/Library/VirtualRealTimeClockLib/VirtualRealTimeClockLib.c | 10 +++++++++-
>  1 file changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/EmbeddedPkg/Library/VirtualRealTimeClockLib/VirtualRealTimeClockLib.c b/EmbeddedPkg/Library/VirtualRealTimeClockLib/VirtualRealTimeClockLib.c
> index 4210708cff36..de6fbb40e61b 100644
> --- a/EmbeddedPkg/Library/VirtualRealTimeClockLib/VirtualRealTimeClockLib.c
> +++ b/EmbeddedPkg/Library/VirtualRealTimeClockLib/VirtualRealTimeClockLib.c
> @@ -88,10 +88,18 @@ LibGetTime (
>      //
>      EpochSeconds = BUILD_EPOCH;
>      DEBUG ((
> -      DEBUG_VERBOSE,
> +      DEBUG_INFO,
>        "LibGetTime: %s non volatile variable was not found - Using compilation time epoch.\n",
>        mEpochVariableName
>        ));
> +
> +    EfiSetVariable (
> +      (CHAR16 *)mEpochVariableName,
> +      &gEfiCallerIdGuid,
> +      EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS,
> +      sizeof (EpochSeconds),
> +      &EpochSeconds
> +      );
>    }
>    Counter = GetPerformanceCounter ();
>    EpochSeconds += DivU64x64Remainder (Counter, Freq, &Remainder);
> --
> 2.26.2
>