[LinuxBIOS] [PATCH] v3: duplicate less code

Carl-Daniel Hailfinger c-d.hailfinger.devel.2006 at gmx.net
Wed Dec 5 02:56:26 CET 2007

To reduce code duplication, make sure STAGE2_OBJ does not contain
any object already mentioned in STAGE0_OBJ.
This saves 386 bytes in qemu stage2 (~240 bytes after LZMA compression).

Build tested and runtime tested in Qemu.

Signed-off-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006 at gmx.net>

Index: LinuxBIOSv3-filteroutduplicatedshared/arch/x86/Makefile
--- LinuxBIOSv3-filteroutduplicatedshared/arch/x86/Makefile	(Revision 539)
+++ LinuxBIOSv3-filteroutduplicatedshared/arch/x86/Makefile	(Arbeitskopie)
@@ -198,11 +198,16 @@
 STAGE2_OBJ += $(obj)/util/x86emu/libx86emu.a $(LIBGCC_FILE_NAME)
-$(obj)/linuxbios.stage2 $(obj)/linuxbios.stage2.map: $(obj)/stage0.init $(STAGE2_OBJ)
+# To reduce code duplication, always make sure STAGE2_OBJ does not contain
+# any object from STAGE0_OBJ.
+STAGE2_OBJ_NEEDED = $(filter-out $(STAGE0_OBJ), $(STAGE2_OBJ))
+$(obj)/linuxbios.stage2 $(obj)/linuxbios.stage2.map: $(obj)/stage0.init $(STAGE2_OBJ_NEEDED)
 	$(Q)# leave a .o with full symbols in it for debugging.
 	$(Q)printf "  LD      $(subst $(shell pwd)/,,$(@))\n"
 	$(Q)$(LD) -R $(obj)/stage0.o -Ttext 0x1000 --entry=stage2 \
-		  -o $(obj)/linuxbios.stage2 $(STAGE2_OBJ)
+		  -o $(obj)/linuxbios.stage2 $(STAGE2_OBJ_NEEDED)
 	$(Q)$(NM) $(obj)/linuxbios.stage2 | sort -u > $(obj)/linuxbios.stage2.map

More information about the coreboot mailing list