Compiling the purgatory code with clang results in using of mmx registers. $ objdump -d arch/x86/purgatory/purgatory.ro | grep xmm 112: 0f 28 00 movaps (%rax),%xmm0 115: 0f 11 07 movups %xmm0,(%rdi) 122: 0f 28 00 movaps (%rax),%xmm0 125: 0f 11 47 10 movups %xmm0,0x10(%rdi) Add -mno-sse, -mno-mmx, -mno-sse2 to avoid generating SSE instructions. Signed-off-by: Vaibhav Rustagi <vaibhavrustagi@xxxxxxxxxx> --- arch/x86/purgatory/Makefile | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/x86/purgatory/Makefile b/arch/x86/purgatory/Makefile index 3cf302b26332..3589ec4a28c7 100644 --- a/arch/x86/purgatory/Makefile +++ b/arch/x86/purgatory/Makefile @@ -20,6 +20,7 @@ KCOV_INSTRUMENT := n # sure how to relocate those. Like kexec-tools, use custom flags. KBUILD_CFLAGS := -fno-strict-aliasing -Wall -Wstrict-prototypes -fno-zero-initialized-in-bss -fno-builtin -ffreestanding -c -Os -mcmodel=large +KBUILD_CFLAGS += -mno-mmx -mno-sse -mno-sse2 KBUILD_CFLAGS += -m$(BITS) KBUILD_CFLAGS += $(call cc-option,-fno-PIE) -- 2.22.0.510.g264f2c817a-goog