Re: [edk2-devel] [PATCH v2 3/7] Platform/ARM/N1Sdp: Introduce platform DXE driver

["PierreGondois" <pierre.gondois@arm.com>]

Hi Khasim,

I have some remarks about the patch:

On 10/10/21 19:29, Khasim Mohammed via groups.io wrote:
> Add an initial platform DXE driver and support for ramdisk devices.
>
> Signed-off-by: Deepak Pandey <Deepak.Pandey@arm.com>
> Signed-off-by: Khasim Syed Mohammed <khasim.mohammed@arm.com>
> ---
>  .../N1Sdp/Drivers/PlatformDxe/PlatformDxe.c   | 51 +++++++++++++++++++
>  .../N1Sdp/Drivers/PlatformDxe/PlatformDxe.inf | 44 ++++++++++++++++
>  2 files changed, 95 insertions(+)
>  create mode 100644 Platform/ARM/N1Sdp/Drivers/PlatformDxe/PlatformDxe.c
>  create mode 100644 Platform/ARM/N1Sdp/Drivers/PlatformDxe/PlatformDxe.inf
>
> diff --git a/Platform/ARM/N1Sdp/Drivers/PlatformDxe/PlatformDxe.c b/Platform/ARM/N1Sdp/Drivers/PlatformDxe/PlatformDxe.c
> new file mode 100644
> index 0000000000..3abe2228ad
> --- /dev/null
> +++ b/Platform/ARM/N1Sdp/Drivers/PlatformDxe/PlatformDxe.c
> @@ -0,0 +1,51 @@
> +/** @file
> +
> +  Copyright (c) 2021, ARM Limited. All rights reserved.<BR>
> +
> +  SPDX-License-Identifier: BSD-2-Clause-Patent
> +
> +**/
> +
> +#include <Library/DebugLib.h>
> +#include <Library/UefiBootServicesTableLib.h>
> +#include <Protocol/RamDisk.h>
> +
> +/**
> +  Entrypoint of Platform Dxe Driver
> +
> +  @param  ImageHandle[in]       The firmware allocated handle for the EFI image.
> +  @param  SystemTable[in]       A pointer to the EFI System Table.
> +
> +  @retval EFI_SUCCESS           The entry point is executed successfully.
It seems the function can also return other error codes.
> +**/
> +EFI_STATUS
> +EFIAPI
> +ArmN1SdpEntryPoint (
> +  IN EFI_HANDLE         ImageHandle,
> +  IN EFI_SYSTEM_TABLE   *SystemTable
> +  )
> +{
> +  EFI_STATUS                 Status;
> +  EFI_RAM_DISK_PROTOCOL      *RamDisk;
> +  EFI_DEVICE_PATH_PROTOCOL   *DevicePath;
> +
> +  Status = EFI_UNSUPPORTED;
> +  if (FeaturePcdGet (PcdRamDiskSupported)) {
> +    Status = gBS->LocateProtocol (&gEfiRamDiskProtocolGuid, NULL, (VOID**) &RamDisk);
> +    if (EFI_ERROR (Status)) {
> +      DEBUG ((DEBUG_ERROR, "%a: Couldn't find the RAM Disk protocol - %r\n", __FUNCTION__, Status));

These 2 lines seem quite long, is it possible to split them on multiple
lines ?

(Same for the debug message below)

> +      return Status;
> +    }
> +
> +    Status = RamDisk->Register (
> +               (UINTN)PcdGet32 (PcdRamDiskBase),
> +               (UINTN)PcdGet32 (PcdRamDiskSize),
> +               &gEfiVirtualCdGuid,
> +               NULL,
> +               &DevicePath);

I think the gEfiVirtualCdGuid should be listed in a [Guid] section of
the .inf file with the following comment:

## SOMETIMES_CONSUMES   ## GUID

The same should be done for
Platform/ARM/Morello/Drivers/PlatformDxe/PlatformDxeFvp.c

NIT: is it possible to have the closing parenthesis on a new line as:

&DevicePath
);

> +    if (EFI_ERROR (Status)) {
> +      DEBUG ((DEBUG_ERROR, "%a: Failed to register RAM Disk - %r\n", __FUNCTION__, Status));
> +    }
> +  }
> +  return Status;
> +}
> diff --git a/Platform/ARM/N1Sdp/Drivers/PlatformDxe/PlatformDxe.inf b/Platform/ARM/N1Sdp/Drivers/PlatformDxe/PlatformDxe.inf
> new file mode 100644
> index 0000000000..925bde4063
> --- /dev/null
> +++ b/Platform/ARM/N1Sdp/Drivers/PlatformDxe/PlatformDxe.inf
> @@ -0,0 +1,44 @@
> +## @file
> +#  Platform DXE driver for N1Sdp
> +#
> +#  Copyright (c) 2021, ARM Limited. All rights reserved.<BR>
> +#
> +#  SPDX-License-Identifier: BSD-2-Clause-Patent
> +#
> +##
> +
> +[Defines]
> +  INF_VERSION                    = 0x0001001B
> +  BASE_NAME                      = PlatformDxe
> +  FILE_GUID                      = 11fc8b5a-377d-47a8-aee9-0093d3d3407f
> +  MODULE_TYPE                    = DXE_DRIVER
> +  VERSION_STRING                 = 1.0
> +  ENTRY_POINT                    = ArmN1SdpEntryPoint
> +
> +[Sources.common]
> +  PlatformDxe.c
> +
> +[Packages]
> +  ArmPkg/ArmPkg.dec
> +  ArmPlatformPkg/ArmPlatformPkg.dec
> +  EmbeddedPkg/EmbeddedPkg.dec
> +  MdeModulePkg/MdeModulePkg.dec
> +  MdePkg/MdePkg.dec
> +  Platform/ARM/N1Sdp/N1SdpPlatform.dec
> +
> +[LibraryClasses]
> +  HobLib
> +  UefiDriverEntryPoint
> +
> +[Protocols]
> +  gEfiRamDiskProtocolGuid
> +
> +[FeaturePcd]
> +  gArmN1SdpTokenSpaceGuid.PcdRamDiskSupported
> +
> +[FixedPcd]
> +  gArmN1SdpTokenSpaceGuid.PcdRamDiskBase
> +  gArmN1SdpTokenSpaceGuid.PcdRamDiskSize
> +
> +[Depex]
> +  gEfiRamDiskProtocolGuid