build: use -m16 where available instead of asm(".code16gcc")
GCC 4.9 and clang 3.5 support the -m16 option on the command line which
supersedes the hackish ".code16gcc" assembler directive. Use it where
possible.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
diff --git a/Makefile b/Makefile
index edc8d8d..d788ffe 100644
--- a/Makefile
+++ b/Makefile
@@ -61,13 +61,15 @@
COMMONCFLAGS += $(call cc-option,$(CC),-nopie,)
COMMONCFLAGS += $(call cc-option,$(CC),-fno-stack-protector,)
COMMONCFLAGS += $(call cc-option,$(CC),-fno-stack-protector-all,)
+COMMA := ,
CFLAGS32FLAT := $(COMMONCFLAGS) -DMODE16=0 -DMODESEGMENT=0 -fomit-frame-pointer
CFLAGSSEG := $(COMMONCFLAGS) -DMODESEGMENT=1 -fno-defer-pop \
$(call cc-option,$(CC),-fno-jump-tables,-DMANUAL_NO_JUMP_TABLE) \
$(call cc-option,$(CC),-fno-tree-switch-conversion,)
CFLAGS32SEG := $(CFLAGSSEG) -DMODE16=0 -fomit-frame-pointer
-CFLAGS16INC := $(CFLAGSSEG) -DMODE16=1 -Wa,src/code16gcc.s \
+CFLAGS16INC := $(CFLAGSSEG) -DMODE16=1 \
+ $(call cc-option,$(CC),-m16,-Wa$(COMMA)src/code16gcc.s) \
$(call cc-option,$(CC),--param large-stack-frame=4,-fno-inline)
CFLAGS16 := $(CFLAGS16INC) -fomit-frame-pointer