Re: [PATCH v3 20/21] SecurityPkg/RngDxe: Add Arm support of RngDxe

["Yao, Jiewen" <jiewen.yao@intel.com>]

> + #ifdef MDE_CPU_AARCH64
> +  // Check FEAT_RNG before advertising PcdCpuRngSupportedAlgorithm.
> +  if (ArmHasRngExt ()) {

Usually, we don't prefer use "#ifdef" in a common code.

Instead, the general pattern is to define Architecture specific directory, and move architecture specific doe there.

Thank you
Yao Jiewen


> -----Original Message-----
> From: Pierre.Gondois@arm.com <Pierre.Gondois@arm.com>
> Sent: Wednesday, June 29, 2022 11:03 PM
> To: devel@edk2.groups.io
> Cc: Sami Mujawar <sami.mujawar@arm.com>; Leif Lindholm
> <quic_llindhol@quicinc.com>; Ard Biesheuvel <ardb+tianocore@kernel.org>;
> Rebecca Cran <rebecca@bsdio.com>; Kinney, Michael D
> <michael.d.kinney@intel.com>; Gao, Liming <gaoliming@byosoft.com.cn>; Yao,
> Jiewen <jiewen.yao@intel.com>; Wang, Jian J <jian.j.wang@intel.com>
> Subject: [PATCH v3 20/21] SecurityPkg/RngDxe: Add Arm support of RngDxe
> 
> From: Pierre Gondois <pierre.gondois@arm.com>
> 
> Bugzilla: 3668 (https://bugzilla.tianocore.org/show_bug.cgi?id=3668)
> 
> Add RngDxe support for Arm. This implementation uses the TrngLib
> to support the RawAlgorithm and doens't support the RNDR instruction.
> 
> Signed-off-by: Pierre Gondois <Pierre.Gondois@arm.com>
> ---
>  SecurityPkg/RandomNumberGenerator/RngDxe/ArmRngDxe.c | 8 ++++++--
>  SecurityPkg/RandomNumberGenerator/RngDxe/RngDxe.inf  | 9 ++++++---
>  SecurityPkg/SecurityPkg.dsc                          | 2 +-
>  3 files changed, 13 insertions(+), 6 deletions(-)
> 
> diff --git a/SecurityPkg/RandomNumberGenerator/RngDxe/ArmRngDxe.c
> b/SecurityPkg/RandomNumberGenerator/RngDxe/ArmRngDxe.c
> index ffa32a29dc6a..4775252d30b6 100644
> --- a/SecurityPkg/RandomNumberGenerator/RngDxe/ArmRngDxe.c
> +++ b/SecurityPkg/RandomNumberGenerator/RngDxe/ArmRngDxe.c
> @@ -22,6 +22,7 @@
> 
>  **/
> 
> +#include <Library/ArmLib.h>
>  #include <Library/BaseLib.h>
>  #include <Library/BaseMemoryLib.h>
>  #include <Library/UefiBootServicesTableLib.h>
> @@ -55,8 +56,9 @@ RngInitAvailableAlgoArray (
>    UINT16  MajorRevision;
>    UINT16  MinorRevision;
> 
> -  // Check RngGetBytes() before advertising PcdCpuRngSupportedAlgorithm.
> -  if (!EFI_ERROR (RngGetBytes (sizeof (Rand), (UINT8 *)&Rand))) {
> + #ifdef MDE_CPU_AARCH64
> +  // Check FEAT_RNG before advertising PcdCpuRngSupportedAlgorithm.
> +  if (ArmHasRngExt ()) {
>      CopyMem (
>        &mAvailableAlgoArray[mAvailableAlgoArrayCount],
>        PcdGetPtr (PcdCpuRngSupportedAlgorithm),
> @@ -75,6 +77,8 @@ RngInitAvailableAlgoArray (
>      DEBUG_CODE_END ();
>    }
> 
> + #endif
> +
>    // Raw algorithm (Trng)
>    if (!EFI_ERROR (GetTrngVersion (&MajorRevision, &MinorRevision))) {
>      CopyMem (
> diff --git a/SecurityPkg/RandomNumberGenerator/RngDxe/RngDxe.inf
> b/SecurityPkg/RandomNumberGenerator/RngDxe/RngDxe.inf
> index d2d0ff9ebb98..599a3085102d 100644
> --- a/SecurityPkg/RandomNumberGenerator/RngDxe/RngDxe.inf
> +++ b/SecurityPkg/RandomNumberGenerator/RngDxe/RngDxe.inf
> @@ -27,7 +27,7 @@ [Defines]
>  #
>  # The following information is for reference only and not required by the build
> tools.
>  #
> -#  VALID_ARCHITECTURES           = IA32 X64 AARCH64
> +#  VALID_ARCHITECTURES           = IA32 X64 AARCH64 ARM
>  #
> 
>  [Sources.common]
> @@ -40,7 +40,7 @@ [Sources.IA32, Sources.X64]
>    Rand/AesCore.c
>    Rand/AesCore.h
> 
> -[Sources.AARCH64]
> +[Sources.AARCH64, Sources.ARM]
>    ArmRngDxe.c
>    ArmTrng.c
> 
> @@ -49,6 +49,9 @@ [Packages]
>    MdePkg/MdePkg.dec
>    SecurityPkg/SecurityPkg.dec
> 
> +[Packages.AARCH64, Packages.ARM]
> +  ArmPkg/ArmPkg.dec
> +
>  [LibraryClasses]
>    UefiLib
>    UefiBootServicesTableLib
> @@ -58,7 +61,7 @@ [LibraryClasses]
>    TimerLib
>    RngLib
> 
> -[LibraryClasses.AARCH64]
> +[LibraryClasses.AARCH64, LibraryClasses.ARM]
>    TrngLib
> 
>  [Guids]
> diff --git a/SecurityPkg/SecurityPkg.dsc b/SecurityPkg/SecurityPkg.dsc
> index 490076542a33..882d639489ea 100644
> --- a/SecurityPkg/SecurityPkg.dsc
> +++ b/SecurityPkg/SecurityPkg.dsc
> @@ -292,7 +292,7 @@ [Components.IA32, Components.X64,
> Components.ARM, Components.AARCH64]
>    SecurityPkg/EnrollFromDefaultKeysApp/EnrollFromDefaultKeysApp.inf
> 
> SecurityPkg/VariableAuthenticated/SecureBootDefaultKeysDxe/SecureBootDefa
> ultKeysDxe.inf
> 
> -[Components.IA32, Components.X64, Components.AARCH64]
> +[Components.IA32, Components.X64, Components.AARCH64,
> Components.ARM]
>    #
>    # Random Number Generator
>    #
> --
> 2.25.1