Re: [PATCH v5 4/4] MdePkg/BaseMemoryLibOptDxe ARM|AARCH64: disallow use in SEC & PEI phases

["Gao, Liming" <liming.gao@intel.com>]

I have no comment.
Reviewed-by: Liming Gao <liming.gao@intel.com>

From: Ard Biesheuvel [mailto:ard.biesheuvel@linaro.org]
Sent: Tuesday, September 13, 2016 10:50 PM
To: edk2-devel-01 <edk2-devel@lists.01.org>; Gao, Liming <liming.gao@intel.com>; Leif Lindholm <leif.lindholm@linaro.org>; Kinney, Michael D <michael.d.kinney@intel.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Subject: Re: [PATCH v5 4/4] MdePkg/BaseMemoryLibOptDxe ARM|AARCH64: disallow use in SEC & PEI phases

Liming: do you have any comments on this patch?


On 9 September 2016 at 15:00, Ard Biesheuvel wrote:
> The new accelerated ARM and AARCH64 implementations take advantage of
> features that are only available when the MMU and Dcache are on. So
> restrict the use of this library to the DXE phase or later.
>
> Contributed-under: TianoCore Contribution Agreement 1.0
> Signed-off-by: Ard Biesheuvel
> ---
> MdePkg/Library/BaseMemoryLibOptDxe/BaseMemoryLibOptDxe.inf | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
> diff --git a/MdePkg/Library/BaseMemoryLibOptDxe/BaseMemoryLibOptDxe.inf b/MdePkg/Library/BaseMemoryLibOptDxe/BaseMemoryLibOptDxe.inf
> index 64d11b09ef06..5ddc0cbc2d77 100644
> --- a/MdePkg/Library/BaseMemoryLibOptDxe/BaseMemoryLibOptDxe.inf
> +++ b/MdePkg/Library/BaseMemoryLibOptDxe/BaseMemoryLibOptDxe.inf
> @@ -116,6 +116,15 @@ [Sources.X64]
> X64/CopyMem.S
> X64/IsZeroBuffer.nasm
>
> +[Defines.ARM, Defines.AARCH64]
> + #
> + # The ARM implementations of this library may perform unaligned accesses, and
> + # may use DC ZVA instructions that are only allowed when the MMU and D-cache
> + # are on. Since SEC, PEI_CORE and PEIM modules may execute with the MMU off,
> + # omit them from the supported module types list for this library.
> + #
> + LIBRARY_CLASS = BaseMemoryLib|DXE_CORE DXE_DRIVER DXE_RUNTIME_DRIVER UEFI_DRIVER UEFI_APPLICATION
> +
> [Sources.ARM]
> Arm/ScanMem.S |GCC
> Arm/SetMem.S |GCC
> --
> 2.7.4
>