Patch set updated for coreboot: x86: don't create MAINBOARDDIR/romstage.inc for !ROMCC boards

[Aaron Durbin]

Aaron Durbin ([e-mail]) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/11503

-gerrit

commit 557de991414d1340fabbd4619ed3a2adaffb85ad
Author: Aaron Durbin 
Date:   Thu Sep 3 11:01:17 2015 -0500

x86: don't create MAINBOARDDIR/romstage.inc for !ROMCC boards

Previously, the x86 romstage build process was unconditionally
    creating a romstage.inc and adding it to crt0s. This step is
    inherently not necessary in the !ROMCC case becaue the romstage.inc
    was created by the compiler outputting assembler. That means
    MAINBOARDDIR/romstage.c is truly a C environment that requires
    some sort of assembler stub to call into (cache_as_ram.inc from
    the chipset dirs). Therefore, remove this processing. The result
    is that MAINBOARDDIR/romstage.c can use the normal build steps
    in creating an object and linking. The layout of romstage.elf
    will change but that's only from a symbol perspective.

BUG=chrome-os-partner:44827
    BRANCH=None
    TEST=Built multitude of boards. Compared readelf -e output.

Change-Id: I9b8079caaaa55e3ae20d3db4c9b8be04cdc41ab7
    Signed-off-by: Aaron Durbin 
---
 src/arch/x86/Makefile.inc | 24 ++++++++++--------------
 1 file changed, 10 insertions(+), 14 deletions(-)

diff --git a/src/arch/x86/Makefile.inc b/src/arch/x86/Makefile.inc
index f58c142..8f8e4bc 100644
--- a/src/arch/x86/Makefile.inc
+++ b/src/arch/x86/Makefile.inc
@@ -125,13 +125,19 @@ endif

crt0s += $(cpu_incs-y)

-crt0s += $(obj)/mainboard/$(MAINBOARDDIR)/romstage.inc
+ifneq ($(CONFIG_ROMCC),y)
+
+romstage-srcs += $(src)/mainboard/$(MAINBOARDDIR)/romstage.c

-ifeq ($(CONFIG_ROMCC),y)
+else # CONFIG_ROMCC == y
+
+# This order matters. The mainboards requiring ROMCC need their mainboard
+# code to follow the prior crt0s files for program flow control. The
+# romstage.inc from the MAINBOARDDIR is implicitly main() for romstage
+# because of the instruction sequen fall-through.
+crt0s += $(obj)/mainboard/$(MAINBOARDDIR)/romstage.inc
 crt0s += $(src)/arch/x86/crt0_romcc_epilogue.inc
-endif

-ifeq ($(CONFIG_ROMCC),y)
 ifeq ($(CONFIG_MMX),y)
    ifeq ($(CONFIG_SSE),y)
    	ROMCCFLAGS := -mcpu=p4 -O2 # MMX, SSE
@@ -156,17 +162,7 @@ $(objcbfs)/romstage%.elf: $(objcbfs)/romstage%.debug
 $(obj)/mainboard/$(MAINBOARDDIR)/romstage.inc: $(src)/mainboard/$(MAINBOARDDIR)/romstage.c $(objutil)/romcc/romcc $(OPTION_TABLE_H) $(obj)/build.h $(obj)/config.h
    printf "    ROMCC      romstage.inc\n"
    $(ROMCC) -c -S $(ROMCCFLAGS) -D__ROMSTAGE__ -D__PRE_RAM__ -I. $(CPPFLAGS_romstage) $< -o $@
-else

-$(obj)/mainboard/$(MAINBOARDDIR)/romstage.pre.inc: $(src)/mainboard/$(MAINBOARDDIR)/romstage.c $(OPTION_TABLE_H) $(obj)/build.h $(obj)/config.h
-	@printf "    CC         romstage.inc\n"
-	$(CC_romstage) $(CPPFLAGS_romstage) $(CFLAGS_romstage) -MMD -D__ROMSTAGE__ -D__PRE_RAM__ -I$(src) -I. -I$(obj) -c -S $< -o $@
-
-$(obj)/mainboard/$(MAINBOARDDIR)/romstage.inc: $(obj)/mainboard/$(MAINBOARDDIR)/romstage.pre.inc
-	@printf "    POST       romstage.inc\n"
-	sed -e 's/.rodata/.rom.data/g' -e 's/^.text/.section .rom.text/g' \
-		-e 's/^.section .text/.section .rom.text/g' $^ > $@.tmp
-	mv $@.tmp $@
 endif

romstage-srcs += $(objgenerated)/crt0.S