imx: add rules for U-Boot DTB support

Signed-off-by: Stefano Babic <sbabic@denx.de>

Makefile

@@ -757,6 +757,9 @@ dtbs dts/dt.dtb: checkdtc u-boot
 u-boot-dtb.bin: u-boot.bin dts/dt.dtb FORCE
 	$(call if_changed,cat)
 
+%.imx: %.bin
+	$(Q)$(MAKE) $(build)=arch/arm/imx-common $@
+
 quiet_cmd_copy = COPY    $@
       cmd_copy = cp $< $@
 
@@ -810,9 +813,6 @@ MKIMAGEFLAGS_u-boot.pbl = -n $(CONFIG_SYS_FSL_PBL_RCW) \
 u-boot.img u-boot.kwb u-boot.pbl: u-boot.bin FORCE
 	$(call if_changed,mkimage)
 
-u-boot.imx: u-boot.bin
-	$(Q)$(MAKE) $(build)=arch/arm/imx-common $@
-
 u-boot.sha1:	u-boot.bin
 		tools/ubsha1 u-boot.bin
 

arch/arm/config.mk

@@ -119,6 +119,10 @@ ifndef CONFIG_SPL_BUILD
 ALL-y += SPL
 endif
 else
+ifeq ($(CONFIG_OF_SEPARATE),y)
+ALL-y += u-boot-dtb.imx
+else
 ALL-y += u-boot.imx
 endif
 endif
+endif

arch/arm/imx-common/Makefile

@@ -42,6 +42,14 @@ MKIMAGEFLAGS_u-boot.imx = -n $(filter-out $< $(PHONY),$^) -T imximage \
 u-boot.imx: u-boot.bin $(IMX_CONFIG) FORCE
 	$(call if_changed,mkimage)
 
+ifeq ($(CONFIG_OF_SEPARATE),y)
+MKIMAGEFLAGS_u-boot-dtb.imx = -n $(filter-out $< $(PHONY),$^) -T imximage \
+	-e $(CONFIG_SYS_TEXT_BASE)
+
+u-boot-dtb.imx: u-boot-dtb.bin $(IMX_CONFIG) FORCE
+	$(call if_changed,mkimage)
+endif
+
 MKIMAGEFLAGS_SPL = -n $(filter-out $< $(PHONY),$^) -T imximage \
 	-e $(CONFIG_SPL_TEXT_BASE)