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authorH. Peter Anvin <hpa@zytor.com>2009-12-25 15:40:38 -0800
committerH. Peter Anvin <hpa@zytor.com>2009-12-25 15:40:38 -0800
commit17a2a9b57a9a7d2fd8f97df951b5e63e0bd56ef5 (patch)
tree4835ed4adac9ab7a4ee6e550557f71fd823dc70c /arch/x86
parent8bee738bb1979c8bf7b42716b772522ab7d26b0c (diff)
x86, compress: Force i386 instructions for the decompressor
Recently, some distros have started shipping versions of gcc which default to -march=i686. This breaks building kernels for pre-i686 machines, even if they have been selected in Kconfig, due to the generation of CMOV instructions. There isn't enough benefit to try to preserve the generation of these instructions even when selected, so simply force -march=i386 for the decompressor when building a 32-bit kernel. Reported-and-tested-by: Chris Rankin <rankincj@yahoo.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com> LKML-Reference: <219280.97558.qm@web52907.mail.re2.yahoo.com>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/boot/compressed/Makefile1
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile
index f8ed0658404c..f25bbd37765a 100644
--- a/arch/x86/boot/compressed/Makefile
+++ b/arch/x86/boot/compressed/Makefile
@@ -9,6 +9,7 @@ targets := vmlinux.lds vmlinux vmlinux.bin vmlinux.bin.gz vmlinux.bin.bz2 vmlinu
KBUILD_CFLAGS := -m$(BITS) -D__KERNEL__ $(LINUX_INCLUDE) -O2
KBUILD_CFLAGS += -fno-strict-aliasing -fPIC
KBUILD_CFLAGS += -DDISABLE_BRANCH_PROFILING
+cflags-$(CONFIG_X86_32) := -march=i386
cflags-$(CONFIG_X86_64) := -mcmodel=small
KBUILD_CFLAGS += $(cflags-y)
KBUILD_CFLAGS += $(call cc-option,-ffreestanding)