On 08/03/16 10:21, Ard Biesheuvel wrote:
> The clang developers have made a backward incompatible change to the
> command line arguments, and have replaced '-mllvm -arm-use-movt=0'
> with '-mno-movt'. This does not matter for most ARM platforms, and
> therefore it has been removed from the default CLANG35/ARM CC flags
> in patch 1c63516075b3 ("BaseTools CLANG35: drop problematic use-movt
> and save-temps options"), but as it turns out, the relocatable PrePi
> implementation used by ArmVirtQemuKernel and ArmVirtXen will fail to
> build if it contains MOVT/MOVW pairs, due to the fact that these are
> not runtime relocatable under ELF.
>
> Since they are runtime relocatable under PE/COFF, and GenFw does the
> right thing when encountering them, selectively controlling their
> use is more appropriate than disabling them altogether. Therefore,
> this patch adds the -mno-movt argument only for the platforms that
> use the relocatable PrePi, and only for the module types that may
> be pulled into its build.
>
> Contributed-under: TianoCore Contribution Agreement 1.0
> Signed-off-by: Ard Biesheuvel <ard.biesheu...@linaro.org>
> ---
> ArmVirtPkg/ArmVirtQemuKernel.dsc | 8 ++++++++
> ArmVirtPkg/ArmVirtXen.dsc | 9 +++++++++
> 2 files changed, 17 insertions(+)
>
> diff --git a/ArmVirtPkg/ArmVirtQemuKernel.dsc
> b/ArmVirtPkg/ArmVirtQemuKernel.dsc
> index 01a1d9b4613b..6c536d9bbd2d 100644
> --- a/ArmVirtPkg/ArmVirtQemuKernel.dsc
> +++ b/ArmVirtPkg/ArmVirtQemuKernel.dsc
> @@ -45,6 +45,9 @@ [LibraryClasses.ARM]
> ArmLib|ArmPkg/Library/ArmLib/ArmV7/ArmV7Lib.inf
> ArmCpuLib|ArmPkg/Drivers/ArmCpuLib/ArmCortexA15Lib/ArmCortexA15Lib.inf
>
> +[LibraryClasses.ARM.SEC]
> + ArmLib|ArmPkg/Library/ArmLib/ArmV7/ArmV7LibSec.inf
> +
How does this library resolution change relate to the stated purpose of
the patch?
Thanks
Laszlo
> [LibraryClasses.common]
> ArmMmuLib|ArmPkg/Library/ArmMmuLib/ArmMmuBaseLib.inf
>
> @@ -77,6 +80,11 @@ [BuildOptions]
> GCC:*_*_ARM_PLATFORM_FLAGS == -mcpu=cortex-a15
> -I$(WORKSPACE)/ArmVirtPkg/Include
> *_*_AARCH64_PLATFORM_FLAGS == -I$(WORKSPACE)/ArmVirtPkg/Include
>
> +[BuildOptions.ARM.EDKII.SEC, BuildOptions.ARM.EDKII.BASE]
> + # Avoid MOVT/MOVW instruction pairs in code that may end up in the PIE
> + # executable we build for the relocatable PrePi. They are not runtime
> + # relocatable in ELF.
> + *_CLANG35_*_CC_FLAGS = -mno-movt
>
>
> ################################################################################
> #
> diff --git a/ArmVirtPkg/ArmVirtXen.dsc b/ArmVirtPkg/ArmVirtXen.dsc
> index 5ad1bf630bda..4ebead5ba6e6 100644
> --- a/ArmVirtPkg/ArmVirtXen.dsc
> +++ b/ArmVirtPkg/ArmVirtXen.dsc
> @@ -44,6 +44,9 @@ [LibraryClasses.ARM]
> ArmLib|ArmPkg/Library/ArmLib/ArmV7/ArmV7Lib.inf
> ArmCpuLib|ArmPkg/Drivers/ArmCpuLib/ArmCortexA15Lib/ArmCortexA15Lib.inf
>
> +[LibraryClasses.ARM.SEC]
> + ArmLib|ArmPkg/Library/ArmLib/ArmV7/ArmV7LibSec.inf
> +
> [LibraryClasses.common]
> ArmMmuLib|ArmPkg/Library/ArmMmuLib/ArmMmuBaseLib.inf
>
> @@ -77,6 +80,12 @@ [BuildOptions]
> GCC:*_*_ARM_PLATFORM_FLAGS == -mcpu=cortex-a15
> -I$(WORKSPACE)/ArmVirtPkg/Include
> GCC:*_*_AARCH64_PLATFORM_FLAGS == -I$(WORKSPACE)/ArmVirtPkg/Include
>
> +[BuildOptions.ARM.EDKII.SEC, BuildOptions.ARM.EDKII.BASE]
> + # Avoid MOVT/MOVW instruction pairs in code that may end up in the PIE
> + # executable we build for the relocatable PrePi. They are not runtime
> + # relocatable in ELF.
> + *_CLANG35_*_CC_FLAGS = -mno-movt
> +
>
> ################################################################################
> #
> # Pcd Section - list of all EDK II PCD Entries defined by this Platform
>
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