lkml.org 
[lkml]   [2014]   [Aug]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v2] x86/efi: Fix 3DNow optimization build failure in EFI stub
Date
From: Matt Fleming <matt.fleming@intel.com>

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: H. Peter Anvin <hpa@zytor.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

---

v2: Only disallow CONFIG_X86_USE_3DNOW for EFI_STUB, not for the EFI
runtime services.

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.
--
1.9.0


\
 
 \ /
  Last update: 2014-08-05 01:41    [W:0.030 / U:1.148 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site