path: root/arch/um/Makefile-i386
diff options
authorPaolo 'Blaisorblade' Giarrusso <>2005-10-30 15:00:07 -0800
committerLinus Torvalds <>2005-10-30 17:37:16 -0800
commit96d55b882b85b26711a06d8fb2c901df9d52a48b (patch)
tree309b8993ad321c050411a8dd74729180488a5dcc /arch/um/Makefile-i386
parentf3ac9fbf7a0b9493377ee88d9b5b2933ff3f7ade (diff)
[PATCH] uml: reuse i386 cpu-specific tuning
Make UML share the underlying cpu-specific tuning done on i386. Actually, for now many config options aren't used a lot - but that can be done later. Also, UML relies on GCC optimization for things like memcpy and such more than i386, so specifying the correct -march and -mtune should be enough. Later, we may want to correct some other stuff. For instance, since FPU context switching, for us, is done (at least partially, i.e. between our kernelspace and userspace) by the host, we may allow usage of FPU operations by GCC. This doesn't hold for kernelspace vs. kernelspace, but we don't support preemption. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <> Signed-off-by: Andrew Morton <> Signed-off-by: Linus Torvalds <>
Diffstat (limited to 'arch/um/Makefile-i386')
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/um/Makefile-i386 b/arch/um/Makefile-i386
index 2ee8a2858117..4a0b375101eb 100644
--- a/arch/um/Makefile-i386
+++ b/arch/um/Makefile-i386
@@ -32,3 +32,13 @@ CFLAGS += -U__$(SUBARCH)__ -U$(SUBARCH)
ifneq ($(CONFIG_GPROF),y)
+# First of all, tune CFLAGS for the specific CPU. This actually sets cflags-y.
+include $(srctree)/arch/i386/Makefile.cpu
+# prevent gcc from keeping the stack 16 byte aligned. Taken from i386.
+cflags-y += $(call cc-option,-mpreferred-stack-boundary=2)
+CFLAGS += $(cflags-y)
+USER_CFLAGS += $(cflags-y)