[PATCH 1/2] x86/purgatory: add -mno-sse, -mno-mmx, -mno-sse2 to Makefile

From: Vaibhav Rustagi
Date: Wed Jul 17 2019 - 20:02:46 EST


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