Re: [PATCH edk2-platforms v4 29/34] Silicon/SynQuacer: implement 'clear NVRAM' feature using a DIP switch

[Leif Lindholm <leif.lindholm@linaro.org>]

On Fri, Nov 10, 2017 at 02:21:22PM +0000, Ard Biesheuvel wrote:
> Ordinary computers typically have a physical switch or jumper on the
> board that allows non-volatile settings to be cleared. Let's implement
> the same using DIP switch #1 on block #3, and clear the EFI variable
> store if it is set to ON at boot time.
> 
> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> ---
>  Platform/Socionext/DeveloperBox/DeveloperBox.dsc                                        |  4 ++++
>  Platform/Socionext/SynQuacerEvalBoard/SynQuacerEvalBoard.dsc                            |  4 ++++
>  Platform/Socionext/SynQuacerEvalBoard/SynQuacerEvalBoard.fdf                            |  1 +
>  Silicon/Socionext/SynQuacer/Library/SynQuacerPlatformPeiLib/SynQuacerPlatformPeiLib.c   | 25 +++++++++++++++++++-
>  Silicon/Socionext/SynQuacer/Library/SynQuacerPlatformPeiLib/SynQuacerPlatformPeiLib.inf |  6 +++++
>  Silicon/Socionext/SynQuacer/SynQuacer.dec                                               |  2 ++
>  6 files changed, 41 insertions(+), 1 deletion(-)
> 
> diff --git a/Platform/Socionext/DeveloperBox/DeveloperBox.dsc b/Platform/Socionext/DeveloperBox/DeveloperBox.dsc
> index 10d070773cdc..af978db2c034 100644
> --- a/Platform/Socionext/DeveloperBox/DeveloperBox.dsc
> +++ b/Platform/Socionext/DeveloperBox/DeveloperBox.dsc
> @@ -381,6 +381,9 @@ [PcdsFixedAtBuild.common]
>    gEfiMdeModulePkgTokenSpaceGuid.PcdAcpiDefaultCreatorId|0x4f524e4c # LNRO
>    gEfiMdeModulePkgTokenSpaceGuid.PcdAcpiDefaultCreatorRevision|1
>  
> +  # set DIP switch DSW3-PIN1 to clear the varstore
> +  gSynQuacerTokenSpaceGuid.PcdClearSettingsGpioPin|0
> +

Right, so could you change this value to 1 ...

>  [PcdsPatchableInModule]
>    gEfiMdeModulePkgTokenSpaceGuid.PcdVideoHorizontalResolution|0
>    gEfiMdeModulePkgTokenSpaceGuid.PcdVideoVerticalResolution|0
> @@ -418,6 +421,7 @@ [Components.common]
>    MdeModulePkg/Universal/FaultTolerantWritePei/FaultTolerantWritePei.inf
>    MdeModulePkg/Universal/Variable/Pei/VariablePei.inf
>    MdeModulePkg/Universal/CapsulePei/CapsulePei.inf
> +  Silicon/Socionext/SynQuacer/Drivers/SynQuacerGpioPei/SynQuacerGpioPei.inf
>    MdeModulePkg/Core/DxeIplPeim/DxeIpl.inf {
>      <LibraryClasses>
>        NULL|MdeModulePkg/Library/LzmaCustomDecompressLib/LzmaCustomDecompressLib.inf
> diff --git a/Platform/Socionext/SynQuacerEvalBoard/SynQuacerEvalBoard.dsc b/Platform/Socionext/SynQuacerEvalBoard/SynQuacerEvalBoard.dsc
> index 4630d78bce93..4034bcfe82c5 100644
> --- a/Platform/Socionext/SynQuacerEvalBoard/SynQuacerEvalBoard.dsc
> +++ b/Platform/Socionext/SynQuacerEvalBoard/SynQuacerEvalBoard.dsc
> @@ -369,6 +369,9 @@ [PcdsFixedAtBuild.common]
>    gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageFtwSpareBase|0x08420000
>    gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageFtwSpareSize|0x00010000
>  
> +  # set DIP switch DSW3-PIN1 to clear the varstore
> +  gSynQuacerTokenSpaceGuid.PcdClearSettingsGpioPin|0
> +
>  [PcdsPatchableInModule]
>    gEfiMdeModulePkgTokenSpaceGuid.PcdVideoHorizontalResolution|0
>    gEfiMdeModulePkgTokenSpaceGuid.PcdVideoVerticalResolution|0
> @@ -406,6 +409,7 @@ [Components.common]
>    MdeModulePkg/Universal/FaultTolerantWritePei/FaultTolerantWritePei.inf
>    MdeModulePkg/Universal/Variable/Pei/VariablePei.inf
>    MdeModulePkg/Universal/CapsulePei/CapsulePei.inf
> +  Silicon/Socionext/SynQuacer/Drivers/SynQuacerGpioPei/SynQuacerGpioPei.inf
>    MdeModulePkg/Core/DxeIplPeim/DxeIpl.inf {
>      <LibraryClasses>
>        NULL|MdeModulePkg/Library/LzmaCustomDecompressLib/LzmaCustomDecompressLib.inf
> diff --git a/Platform/Socionext/SynQuacerEvalBoard/SynQuacerEvalBoard.fdf b/Platform/Socionext/SynQuacerEvalBoard/SynQuacerEvalBoard.fdf
> index 365085c8f243..4577bd316a1f 100644
> --- a/Platform/Socionext/SynQuacerEvalBoard/SynQuacerEvalBoard.fdf
> +++ b/Platform/Socionext/SynQuacerEvalBoard/SynQuacerEvalBoard.fdf
> @@ -248,6 +248,7 @@ [FV.FVMAIN_COMPACT]
>    INF MdeModulePkg/Universal/FaultTolerantWritePei/FaultTolerantWritePei.inf
>    INF MdeModulePkg/Universal/Variable/Pei/VariablePei.inf
>    INF MdeModulePkg/Universal/CapsulePei/CapsulePei.inf
> +  INF Silicon/Socionext/SynQuacer/Drivers/SynQuacerGpioPei/SynQuacerGpioPei.inf
>    INF RuleOverride = FMP_IMAGE_DESC Platform/Socionext/SynQuacerEvalBoard/SystemFirmwareDescriptor/SystemFirmwareDescriptor.inf
>    INF MdeModulePkg/Core/DxeIplPeim/DxeIpl.inf
>  
> diff --git a/Silicon/Socionext/SynQuacer/Library/SynQuacerPlatformPeiLib/SynQuacerPlatformPeiLib.c b/Silicon/Socionext/SynQuacer/Library/SynQuacerPlatformPeiLib/SynQuacerPlatformPeiLib.c
> index 358dd5a91f08..bd8ee7a368f5 100644
> --- a/Silicon/Socionext/SynQuacer/Library/SynQuacerPlatformPeiLib/SynQuacerPlatformPeiLib.c
> +++ b/Silicon/Socionext/SynQuacer/Library/SynQuacerPlatformPeiLib/SynQuacerPlatformPeiLib.c
> @@ -21,6 +21,7 @@
>  #include <Library/PeiServicesLib.h>
>  #include <Platform/DramInfo.h>
>  #include <Ppi/DramInfo.h>
> +#include <Ppi/EmbeddedGpio.h>
>  #include <Ppi/MemoryDiscovered.h>
>  
>  STATIC
> @@ -103,10 +104,32 @@ PlatformPeim (
>    VOID
>    )
>  {
> -  EFI_STATUS      Status;
> +  EMBEDDED_GPIO_PPI   *Gpio;
> +  EFI_STATUS          Status;
> +  UINTN               Value;

And use a local variable Pin, initialized to
FixedPcdGet32 (PcdClearSettingsGpioPin) - 1?
(You could then also have an assert verifying PcdClearSettingsGpioPin
!= 0, to make fallback to default value flash warnings.)

>  
>    ASSERT (mDramInfo->NumRegions > 0);
>  
> +  Status = PeiServicesLocatePpi (&gEdkiiEmbeddedGpioPpiGuid, 0, NULL,
> +             (VOID **)&Gpio);
> +  ASSERT_EFI_ERROR (Status);
> +
> +  Status = Gpio->Set (Gpio, FixedPcdGet32 (PcdClearSettingsGpioPin),
> +                   GPIO_MODE_INPUT);
> +  if (EFI_ERROR (Status)) {
> +    DEBUG ((DEBUG_WARN, "%a: failed to set GPIO as input - %r\n", __FUNCTION__,
> +      Status));
> +  } else {
> +    Status = Gpio->Get (Gpio, FixedPcdGet32 (PcdClearSettingsGpioPin), &Value);
> +    if (EFI_ERROR (Status)) {
> +      DEBUG ((DEBUG_WARN, "%a: failed to get GPIO state - %r\n", __FUNCTION__,
> +        Status));
> +    } else if (Value > 0) {
> +      DEBUG ((DEBUG_INFO, "%a: clearing NVRAM\n", __FUNCTION__));
> +      PeiServicesSetBootMode (BOOT_WITH_DEFAULT_SETTINGS);
> +    }
> +  }
> +
>    //
>    // Record the first region into PcdSystemMemoryBase and PcdSystemMemorySize.
>    // This is the region we will use for UEFI itself.
> diff --git a/Silicon/Socionext/SynQuacer/Library/SynQuacerPlatformPeiLib/SynQuacerPlatformPeiLib.inf b/Silicon/Socionext/SynQuacer/Library/SynQuacerPlatformPeiLib/SynQuacerPlatformPeiLib.inf
> index 70eb715d44e3..a6501fb205e1 100644
> --- a/Silicon/Socionext/SynQuacer/Library/SynQuacerPlatformPeiLib/SynQuacerPlatformPeiLib.inf
> +++ b/Silicon/Socionext/SynQuacer/Library/SynQuacerPlatformPeiLib/SynQuacerPlatformPeiLib.inf
> @@ -25,6 +25,7 @@ [Sources]
>  
>  [Packages]
>    ArmPkg/ArmPkg.dec
> +  EmbeddedPkg/EmbeddedPkg.dec
>    MdePkg/MdePkg.dec
>    MdeModulePkg/MdeModulePkg.dec
>    Silicon/Socionext/SynQuacer/SynQuacer.dec
> @@ -40,11 +41,16 @@ [LibraryClasses]
>  [FixedPcd]
>    gArmTokenSpaceGuid.PcdFvBaseAddress
>    gArmTokenSpaceGuid.PcdFvSize
> +  gSynQuacerTokenSpaceGuid.PcdClearSettingsGpioPin
>    gSynQuacerTokenSpaceGuid.PcdDramInfoBase
>  
>  [Ppis]
> +  gEdkiiEmbeddedGpioPpiGuid             ## CONSUMES
>    gSynQuacerDramInfoPpiGuid             ## PRODUCES
>  
>  [Pcd]
>    gArmTokenSpaceGuid.PcdSystemMemoryBase
>    gArmTokenSpaceGuid.PcdSystemMemorySize
> +
> +[Depex]
> +  gEdkiiEmbeddedGpioPpiGuid
> diff --git a/Silicon/Socionext/SynQuacer/SynQuacer.dec b/Silicon/Socionext/SynQuacer/SynQuacer.dec
> index 1a683b81521b..c11550469cd0 100644
> --- a/Silicon/Socionext/SynQuacer/SynQuacer.dec
> +++ b/Silicon/Socionext/SynQuacer/SynQuacer.dec
> @@ -30,3 +30,5 @@ [PcdsFixedAtBuild]
>  
>    gSynQuacerTokenSpaceGuid.PcdNetsecEepromBase|0|UINT32|0x00000002
>    gSynQuacerTokenSpaceGuid.PcdNetsecPhyAddress|0|UINT8|0x00000003
> +
> +  gSynQuacerTokenSpaceGuid.PcdClearSettingsGpioPin|0|UINT32|0x00000004

And add a small comment for this line that this refers to block 3 and
0 means "don't use"?

/
    Leif