[OE-core] [PATCH v3] binutils : enable x86_64-pep for producing EFI binaries on x86/x86-64

[Khem Raj]

LGTM
On Thu, Jul 26, 2018 at 4:51 PM Christopher Clark
<christopher.w.clark at gmail.com> wrote:
>
> On x86 and x86_64 architectures, add the x86_64-pep emulation support
> to the linker to enable production of Portable Executables for EFI
> binaries.
>
> Enables building the x86-64 EFI variant of the Xen hypervisor.
>
> Signed-off-by: Christopher Clark <christopher.clark6 at baesystems.com>
> ---
> Changes in v3:
>
> * Use overrides rather than a function to add the configure flags.
>
> I've used a construction that should allow other layers to override a
> single variable to provide different extra targets if needed.
>
> * Only make this change for x86 and x86-64.
>
> The linker flag for x86-64 EFI binaries is known: x86_64-pep.
> Make this available on both x86-64 and x86, so multiarch is covered.
>
> The linker flag for constructing 32-bit x86 EFI binaries is not known by me,
> and is not easily discoverable via inspecting the binutils source or
> queries of the internet. 32-bit x86 UEFI appears to be very uncommon.
>
> * No change for the ARM architectures in this patch.
>
> I have no data on what linker flags are required for EFI on ARM,
> and again I'm drawing a blank via source inspection and internet
> query. If additional lines for arm and aarch64 are added later,
> they will fit well with the structure added by this patch.
>
> The ARM64 build of the Xen hypervisor does not need additional toolchain
> support for construction an EFI image as its PE/COFF header is coded in
> assembly.
>
> * Using gmail 'From'/'Author' address as it is preferred for contact.
>   S-o-b address as provided is required for attribution. Unchanged from v2.
>
>  meta/recipes-devtools/binutils/binutils.inc | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/meta/recipes-devtools/binutils/binutils.inc b/meta/recipes-devtools/binutils/binutils.inc
> index 37813dd..9f06d94 100644
> --- a/meta/recipes-devtools/binutils/binutils.inc
> +++ b/meta/recipes-devtools/binutils/binutils.inc
> @@ -74,12 +74,17 @@ EXTRA_OECONF = "--program-prefix=${TARGET_PREFIX} \
>                  --enable-deterministic-archives \
>                  --enable-plugins \
>                  ${LDGOLD} \
> -                ${@bb.utils.contains('DISTRO_FEATURES', 'multiarch', '--enable-64-bit-bfd', '', d)}"
> +                ${@bb.utils.contains('DISTRO_FEATURES', 'multiarch', '--enable-64-bit-bfd', '', d)} \
> +                ${ENABLE_EXTRA_TARGETS}"
>
>  LDGOLD_class-native = ""
>  LDGOLD_class-crosssdk = ""
>  LDGOLD ?= "${@bb.utils.contains('DISTRO_FEATURES', 'ld-is-gold', '--enable-gold=default --enable-threads', '--enable-gold --enable-ld=default --enable-threads', d)}"
>
> +ARCH_EFI_EMULATION_x86-64 = "x86_64-pep"
> +ARCH_EFI_EMULATION_x86 = "x86_64-pep"
> +ENABLE_EXTRA_TARGETS ?= "--enable-targets=${ARCH_EFI_EMULATION}"
> +
>  # This is necessary due to a bug in the binutils Makefiles
>  # EXTRA_OEMAKE = "configure-build-libiberty all"
>
> --
> 2.7.4
>