TPL : introduce the TPL based on the SPL

Due to the nand SPL on some board(e.g. P1022DS)has a size limit, it can
not be more than 4K. So, the SPL cannot initialize the DDR with the SPD
code. This patch introduces TPL to enable a loader stub that is loaded
by the code from the SPL. It initializes the DDR with the SPD or other
operations.

The TPL's size is sizeable, the maximum size is decided by the memory's
size that TPL runs. It initializes the DDR through SPD code, and copys
final uboot image to DDR. So there are three stage uboot images:
	* spl_boot, * tpl_boot, * final uboot image

Signed-off-by: Ying Zhang <b40530@freescale.com>
Acked-by: York Sun <yorksun@freescale.com>
diff --git a/Makefile b/Makefile
index 43b57da..8d7159d 100644
--- a/Makefile
+++ b/Makefile
@@ -102,10 +102,11 @@
 
 OBJTREE		:= $(if $(BUILD_DIR),$(BUILD_DIR),$(CURDIR))
 SPLTREE		:= $(OBJTREE)/spl
+TPLTREE		:= $(OBJTREE)/tpl
 SRCTREE		:= $(CURDIR)
 TOPDIR		:= $(SRCTREE)
 LNDIR		:= $(OBJTREE)
-export	TOPDIR SRCTREE OBJTREE SPLTREE
+export	TOPDIR SRCTREE OBJTREE SPLTREE TPLTREE
 
 MKCONFIG	:= $(SRCTREE)/mkconfig
 export MKCONFIG
@@ -397,6 +398,7 @@
 ALL-$(CONFIG_NAND_U_BOOT) += $(obj)u-boot-nand.bin
 ALL-$(CONFIG_ONENAND_U_BOOT) += $(obj)u-boot-onenand.bin
 ALL-$(CONFIG_SPL) += $(obj)spl/u-boot-spl.bin
+ALL-$(CONFIG_TPL) += $(obj)tpl/u-boot-tpl.bin
 ALL-$(CONFIG_OF_SEPARATE) += $(obj)u-boot.dtb $(obj)u-boot-dtb.bin
 ifneq ($(CONFIG_SPL_TARGET),)
 ALL-$(CONFIG_SPL) += $(obj)$(subst ",,$(CONFIG_SPL_TARGET))
@@ -475,13 +477,25 @@
 $(obj)u-boot.dis:	$(obj)u-boot
 		$(OBJDUMP) -d $< > $@
 
+# $@ is output, $(1) and $(2) are inputs, $(3) is padded intermediate,
+# $(4) is pad-to
+SPL_PAD_APPEND = \
+		$(OBJCOPY) ${OBJCFLAGS} --pad-to=$(4) -I binary -O binary \
+		$(1) $(obj)$(3); \
+		cat $(obj)$(3) $(obj)$(2) > $@; \
+		rm $(obj)$(3)
 
+ifdef CONFIG_TPL
+SPL_PAYLOAD := $(obj)tpl/u-boot-with-tpl.bin
+else
+SPL_PAYLOAD := $(obj)u-boot.bin
+endif
 
-$(obj)u-boot-with-spl.bin: $(obj)spl/u-boot-spl.bin $(obj)u-boot.bin
-		$(OBJCOPY) ${OBJCFLAGS} --pad-to=$(CONFIG_SPL_PAD_TO) \
-			-I binary -O binary $< $(obj)spl/u-boot-spl-pad.bin
-		cat $(obj)spl/u-boot-spl-pad.bin $(obj)u-boot.bin > $@
-		rm $(obj)spl/u-boot-spl-pad.bin
+$(obj)u-boot-with-spl.bin: $(obj)spl/u-boot-spl.bin $(SPL_PAYLOAD)
+		$(call SPL_PAD_APPEND,$<,$(SPL_PAYLOAD),spl/u-boot-spl-pad.bin,$(CONFIG_SPL_PAD_TO))
+
+$(obj)tpl/u-boot-with-tpl.bin: $(obj)tpl/u-boot-tpl.bin $(obj)u-boot.bin
+		$(call SPL_PAD_APPEND,$<,u-boot.bin,tpl/u-boot-tpl-pad.bin,$(CONFIG_TPL_PAD_TO))
 
 $(obj)u-boot-with-spl.imx: $(obj)spl/u-boot-spl.bin $(obj)u-boot.bin
 		$(MAKE) -C $(SRCTREE)/arch/arm/imx-common \
@@ -607,6 +621,9 @@
 $(obj)spl/u-boot-spl.bin:	$(SUBDIR_TOOLS) depend
 		$(MAKE) -C spl all
 
+$(obj)tpl/u-boot-tpl.bin:	$(SUBDIR_TOOLS) depend
+		$(MAKE) -C spl all CONFIG_TPL_BUILD=y
+
 updater:
 		$(MAKE) -C tools/updater all
 
@@ -614,6 +631,7 @@
 # parallel sub-makes creating .depend files simultaneously.
 depend dep:	$(TIMESTAMP_FILE) $(VERSION_FILE) \
 		$(obj)include/spl-autoconf.mk \
+		$(obj)include/tpl-autoconf.mk \
 		$(obj)include/autoconf.mk \
 		$(obj)include/generated/generic-asm-offsets.h \
 		$(obj)include/generated/asm-offsets.h
@@ -696,6 +714,15 @@
 	mv $@.tmp $@
 
 # Auto-generate the spl-autoconf.mk file (which is included by all makefiles for SPL)
+$(obj)include/tpl-autoconf.mk: $(obj)include/config.h
+	@$(XECHO) Generating $@ ; \
+	set -e ; \
+	: Extract the config macros ; \
+	$(CPP) $(CFLAGS) -DCONFIG_TPL_BUILD  -DCONFIG_SPL_BUILD\
+			-DDO_DEPS_ONLY -dM include/common.h | \
+	sed -n -f tools/scripts/define2mk.sed > $@.tmp && \
+	mv $@.tmp $@
+
 $(obj)include/spl-autoconf.mk: $(obj)include/config.h
 	@$(XECHO) Generating $@ ; \
 	set -e ; \
@@ -706,12 +733,14 @@
 
 $(obj)include/generated/generic-asm-offsets.h:	$(obj)include/autoconf.mk.dep \
 	$(obj)include/spl-autoconf.mk \
+	$(obj)include/tpl-autoconf.mk \
 	$(obj)lib/asm-offsets.s
 	@$(XECHO) Generating $@
 	tools/scripts/make-asm-offsets $(obj)lib/asm-offsets.s $@
 
 $(obj)lib/asm-offsets.s:	$(obj)include/autoconf.mk.dep \
 	$(obj)include/spl-autoconf.mk \
+	$(obj)include/tpl-autoconf.mk \
 	$(src)lib/asm-offsets.c
 	@mkdir -p $(obj)lib
 	$(CC) -DDO_DEPS_ONLY \
@@ -720,12 +749,14 @@
 
 $(obj)include/generated/asm-offsets.h:	$(obj)include/autoconf.mk.dep \
 	$(obj)include/spl-autoconf.mk \
+	$(obj)include/tpl-autoconf.mk \
 	$(obj)$(CPUDIR)/$(SOC)/asm-offsets.s
 	@$(XECHO) Generating $@
 	tools/scripts/make-asm-offsets $(obj)$(CPUDIR)/$(SOC)/asm-offsets.s $@
 
 $(obj)$(CPUDIR)/$(SOC)/asm-offsets.s:	$(obj)include/autoconf.mk.dep \
-	$(obj)include/spl-autoconf.mk
+	$(obj)include/spl-autoconf.mk \
+	$(obj)include/tpl-autoconf.mk
 	@mkdir -p $(obj)$(CPUDIR)/$(SOC)
 	if [ -f $(src)$(CPUDIR)/$(SOC)/asm-offsets.c ];then \
 		$(CC) -DDO_DEPS_ONLY \
@@ -798,7 +829,8 @@
 	@rm -f $(obj)include/config.h $(obj)include/config.mk \
 		$(obj)board/*/config.tmp $(obj)board/*/*/config.tmp \
 		$(obj)include/autoconf.mk $(obj)include/autoconf.mk.dep \
-		$(obj)include/spl-autoconf.mk
+		$(obj)include/spl-autoconf.mk \
+		$(obj)include/tpl-autoconf.mk
 
 %_config::	unconfig
 	@$(MKCONFIG) -A $(@:_config=)
@@ -884,6 +916,8 @@
 	@rm -f $(obj)nand_spl/{u-boot-nand_spl.lds,u-boot-spl,u-boot-spl.map}
 	@rm -f $(obj)spl/{u-boot-spl,u-boot-spl.bin,u-boot-spl.map}
 	@rm -f $(obj)spl/u-boot-spl.lds
+	@rm -f $(obj)tpl/{u-boot-tpl,u-boot-tpl.bin,u-boot-tpl.map}
+	@rm -f $(obj)tpl/u-boot-spl.lds
 	@rm -f $(obj)MLO MLO.byteswap
 	@rm -f $(obj)SPL
 	@rm -f $(obj)tools/xway-swap-bytes