From 17a2a9b57a9a7d2fd8f97df951b5e63e0bd56ef5 Mon Sep 17 00:00:00 2001 From: "H. Peter Anvin" Date: Fri, 25 Dec 2009 15:40:38 -0800 Subject: [PATCH] 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 Signed-off-by: H. Peter Anvin LKML-Reference: <219280.97558.qm@web52907.mail.re2.yahoo.com> --- arch/x86/boot/compressed/Makefile | 1 + 1 file changed, 1 insertion(+) 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)