From 96d55b882b85b26711a06d8fb2c901df9d52a48b Mon Sep 17 00:00:00 2001 From: Paolo 'Blaisorblade' Giarrusso Date: Sun, 30 Oct 2005 15:00:07 -0800 Subject: [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 --- arch/um/Kconfig | 6 ++++++ arch/um/Makefile-i386 | 10 ++++++++++ 2 files changed, 16 insertions(+) (limited to 'arch/um') diff --git a/arch/um/Kconfig b/arch/um/Kconfig index 684e1f8..ceaf6e4 100644 --- a/arch/um/Kconfig +++ b/arch/um/Kconfig @@ -40,6 +40,12 @@ config IRQ_RELEASE_METHOD bool default y +menu "Host processor type and features" + +source "arch/i386/Kconfig.cpu" + +endmenu + menu "UML-specific options" config MODE_TT diff --git a/arch/um/Makefile-i386 b/arch/um/Makefile-i386 index 2ee8a28..4a0b375 100644 --- a/arch/um/Makefile-i386 +++ b/arch/um/Makefile-i386 @@ -32,3 +32,13 @@ CFLAGS += -U__$(SUBARCH)__ -U$(SUBARCH) ifneq ($(CONFIG_GPROF),y) ARCH_CFLAGS += -DUM_FASTCALL endif + +# 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) + -- cgit v1.1