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| author | Matt Fleming <matt.fleming@intel.com> | 2014-08-05 00:12:19 +0100 |
|---|---|---|
| committer | H. Peter Anvin <hpa@linux.intel.com> | 2014-08-04 16:26:46 -0700 |
| commit | b16d8c231e4d03fefc7de1b8b62bad5659ee8070 (patch) | |
| tree | 33bf510153d6fa8e20e12bc8d80ee2f04cb2c65d /arch/x86/Kconfig | |
| parent | 99a5603e2a1f146ac0c6414d8a3669aa749ccff8 (diff) | |
| download | lwn-b16d8c231e4d03fefc7de1b8b62bad5659ee8070.tar.gz lwn-b16d8c231e4d03fefc7de1b8b62bad5659ee8070.zip | |
x86/efi: Fix 3DNow optimization build failure in EFI stub
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_STUB 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@x1.osrc.amd.com
Clearly, this problem has been around for a long time.
Reported-by: Ingo Molnar <mingo@kernel.org>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Link: http://lkml.kernel.org/r/1407193939-27813-1-git-send-email-matt@console-pimps.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Diffstat (limited to 'arch/x86/Kconfig')
| -rw-r--r-- | arch/x86/Kconfig | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 801ed36c2e49..7ea8aaaab7fc 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1536,7 +1536,7 @@ config EFI config EFI_STUB bool "EFI stub support" - depends on EFI + depends on EFI && !X86_USE_3DNOW ---help--- This kernel feature allows a bzImage to be loaded directly by EFI firmware without the use of a bootloader. |