From: Matt Fleming <matt.fleming@xxxxxxxxx> Building a 32-bit kernel with CONFIG_X86_USE_3DNOW and CONFIG_EFI_STUB leads to the following build error, drivers/firmware/efi/libstub/lib.a(efi-stub-helper.o): In function `efi_relocate_kernel': efi-stub-helper.c:(.text+0xda5): undefined reference to `_mmx_memcpy' This is due to the fact that the EFI boot stub pulls in the 3DNow optimized versions of the memcpy() prototype from arch/x86/include/asm/string_32.h, even though the _mmx_memcpy() implementation isn't available in the EFI stub. For now, predicate CONFIG_EFI on !CONFIG_X86_USE_3DNOW. This is most definitely a temporary fix. A complete solution will involve selectively including kernel headers/symbols into the early-boot execution environment of the EFI boot stub, i.e. something analogous to the way that the _SETUP symbol is used. Previous attempts have been made to fix this kind of problem, though none seem to have ever been merged, http://lkml.kernel.org/r/20120329104822.GA17233@xxxxxxxxxxxxxxx Clearly, this problem has been around for a long time. Reported-by: Ingo Molnar <mingo@xxxxxxxxxx> Cc: H. Peter Anvin <hpa@xxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Signed-off-by: Matt Fleming <matt.fleming@xxxxxxxxx> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 801ed36c2e49..fcad2e15e92a 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1520,7 +1520,7 @@ config X86_SMAP config EFI bool "EFI runtime service support" - depends on ACPI + depends on ACPI && !X86_USE_3DNOW select UCS2_STRING select EFI_RUNTIME_WRAPPERS ---help--- -- 1.9.0 -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
