[U-Boot] [PATCH] Strip dead code on omap3 devices

[Charles Manning]

Garbage collect code that isn't used.

Saves a good few kbytes.

Signed-off-by: Charles Manning <cdhmanning at gmail.com>
---
 Makefile                      |    2 +-
 arch/arm/config.mk            |    6 ++++++
 arch/arm/cpu/armv7/u-boot.lds |    6 +++---
 3 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/Makefile b/Makefile
index 713dba1..1ba3e3a 100644
--- a/Makefile
+++ b/Makefile
@@ -368,7 +368,7 @@ $(obj)u-boot.dis:	$(obj)u-boot
 GEN_UBOOT = \
 		UNDEF_SYM=`$(OBJDUMP) -x $(LIBBOARD) $(LIBS) | \
 		sed  -n -e 's/.*\($(SYM_PREFIX)__u_boot_cmd_.*\)/-u\1/p'|sort|uniq`;\
-		cd $(LNDIR) && $(LD) $(LDFLAGS) $(LDFLAGS_$(@F)) $$UNDEF_SYM $(__OBJS) \
+		cd $(LNDIR) && $(LD) $(LDFLAGS) $(LDFLAGSFINAL) $(LDFLAGS_$(@F)) 
$$UNDEF_SYM $(__OBJS) \
 			--start-group $(__LIBS) --end-group $(PLATFORM_LIBS) \
 			-Map u-boot.map -o u-boot
 $(obj)u-boot:	depend \
diff --git a/arch/arm/config.mk b/arch/arm/config.mk
index fcc26a2..02cc9b2 100644
--- a/arch/arm/config.mk
+++ b/arch/arm/config.mk
@@ -67,3 +67,9 @@ LDSCRIPT := $(SRCTREE)/$(CPUDIR)/u-boot.lds
 ifndef CONFIG_NAND_SPL
 LDFLAGS_u-boot += -pie
 endif
+
+# Dead code stripping
+CFLAGS += -ffunction-sections
+CFLAGS += -fdata-sections
+LDFLAGS += --cref
+LDFLAGSFINAL += --cref --gc-sections
diff --git a/arch/arm/cpu/armv7/u-boot.lds b/arch/arm/cpu/armv7/u-boot.lds
index dbae54d..f1267b5 100644
--- a/arch/arm/cpu/armv7/u-boot.lds
+++ b/arch/arm/cpu/armv7/u-boot.lds
@@ -34,8 +34,8 @@ SECTIONS
 	. = ALIGN(4);
 	.text	:
 	{
-		arch/arm/cpu/armv7/start.o	(.text)
-		*(.text)
+		KEEP(arch/arm/cpu/armv7/start.o	(.text*))
+		*(.text*)
 	}
 
 	. = ALIGN(4);
@@ -70,7 +70,7 @@ SECTIONS
 
 	.bss __rel_dyn_start (OVERLAY) : {
 		__bss_start = .;
-		*(.bss)
+		*(.bss*)
 		 . = ALIGN(4);
 		__bss_end__ = .;
 	}
-- 
1.7.1