Extend build-system for SPL framework

Signed-off-by: Aneesh V <aneesh@ti.com>
Signed-off-by: Daniel Schwierzeck <daniel.schwierzeck@googlemail.com>
diff --git a/Makefile b/Makefile
index 62c2078..9478059 100644
--- a/Makefile
+++ b/Makefile
@@ -104,10 +104,11 @@
 endif # ifneq ($(BUILD_DIR),)
 
 OBJTREE		:= $(if $(BUILD_DIR),$(BUILD_DIR),$(CURDIR))
+SPLTREE		:= $(OBJTREE)/spl
 SRCTREE		:= $(CURDIR)
 TOPDIR		:= $(SRCTREE)
 LNDIR		:= $(OBJTREE)
-export	TOPDIR SRCTREE OBJTREE
+export	TOPDIR SRCTREE OBJTREE SPLTREE
 
 MKCONFIG	:= $(SRCTREE)/mkconfig
 export MKCONFIG
diff --git a/config.mk b/config.mk
index 2eb7fa2..ed44d03 100644
--- a/config.mk
+++ b/config.mk
@@ -23,19 +23,31 @@
 
 #########################################################################
 
-ifneq ($(OBJTREE),$(SRCTREE))
 ifeq ($(CURDIR),$(SRCTREE))
 dir :=
 else
 dir := $(subst $(SRCTREE)/,,$(CURDIR))
 endif
 
+ifneq ($(OBJTREE),$(SRCTREE))
+# Create object files for SPL in a separate directory
+ifeq ($(CONFIG_SPL_BUILD),y)
+obj := $(if $(dir),$(SPLTREE)/$(dir)/,$(SPLTREE)/)
+else
 obj := $(if $(dir),$(OBJTREE)/$(dir)/,$(OBJTREE)/)
+endif
 src := $(if $(dir),$(SRCTREE)/$(dir)/,$(SRCTREE)/)
 
 $(shell mkdir -p $(obj))
 else
+# Create object files for SPL in a separate directory
+ifeq ($(CONFIG_SPL_BUILD),y)
+obj := $(if $(dir),$(SPLTREE)/$(dir)/,$(SPLTREE)/)
+
+$(shell mkdir -p $(obj))
+else
 obj :=
+endif
 src :=
 endif
 
@@ -160,10 +172,25 @@
 
 CPPFLAGS := $(DBGFLAGS) $(OPTFLAGS) $(RELFLAGS)		\
 	-D__KERNEL__
+
+# Enable garbage collection of un-used sections for SPL
+ifeq ($(CONFIG_SPL_BUILD),y)
+CPPFLAGS += -ffunction-sections -fdata-sections
+LDFLAGS_FINAL += --gc-sections
+endif
+
 ifneq ($(CONFIG_SYS_TEXT_BASE),)
 CPPFLAGS += -DCONFIG_SYS_TEXT_BASE=$(CONFIG_SYS_TEXT_BASE)
 endif
 
+ifneq ($(CONFIG_SPL_TEXT_BASE),)
+CPPFLAGS += -DCONFIG_SPL_TEXT_BASE=$(CONFIG_SPL_TEXT_BASE)
+endif
+
+ifeq ($(CONFIG_SPL_BUILD),y)
+CPPFLAGS += -DCONFIG_SPL_BUILD
+endif
+
 ifneq ($(RESET_VECTOR_ADDRESS),)
 CPPFLAGS += -DRESET_VECTOR_ADDRESS=$(RESET_VECTOR_ADDRESS)
 endif
@@ -206,6 +233,11 @@
 LDFLAGS_u-boot += -Ttext $(CONFIG_SYS_TEXT_BASE)
 endif
 
+LDFLAGS_u-boot-spl += -T $(obj)u-boot-spl.lds $(LDFLAGS_FINAL)
+ifneq ($(CONFIG_SPL_TEXT_BASE),)
+LDFLAGS_u-boot-spl += -Ttext $(CONFIG_SPL_TEXT_BASE)
+endif
+
 # Location of a usable BFD library, where we define "usable" as
 # "built for ${HOST}, supports ${TARGET}".  Sensible values are
 # - When cross-compiling: the root of the cross-environment