[PATCH] arm: imx: add u-boot-nand.imx to boot from NAND without SPL

[Luca Ceresoli]

U-Boot can be booted from NAND without SPL by prepending the DCD header to
the actual U-Boot binary. However this requires prepending 1024 bytes to
u-boot.imx (DCD + u-boot.bin).

There is already a similar target to build spl/u-boot-nand-spl.imx, add the
same option for no-SPL boot.

Tested on i.MX6ULL.

The resulting layout of u-boot-nand.imx is:

 - Offset 0x0000 (0 KiB): padding
 - Offset 0x0400 (1 KiB): DCD header
 - Offset 0x1000 (4 KiB): u-boot.bin

Signed-off-by: Luca Ceresoli <luca.ceresoli at bootlin.com>
---
 Makefile                   | 3 +++
 arch/arm/mach-imx/Makefile | 6 ++++++
 2 files changed, 9 insertions(+)

diff --git a/Makefile b/Makefile
index e760bacf9451..db124476d6e6 100644
--- a/Makefile
+++ b/Makefile
@@ -1522,6 +1522,9 @@ endif
 u-boot.uim: u-boot.bin FORCE
 	$(Q)$(MAKE) $(build)=arch/arm/mach-imx $@
 
+u-boot-nand.imx: u-boot.imx FORCE
+	$(Q)$(MAKE) $(build)=arch/arm/mach-imx $@
+
 u-boot-with-spl.imx u-boot-with-nand-spl.imx: SPL $(if $(CONFIG_OF_SEPARATE),u-boot.img,u-boot.uim) FORCE
 	$(Q)$(MAKE) $(build)=arch/arm/mach-imx $@
 
diff --git a/arch/arm/mach-imx/Makefile b/arch/arm/mach-imx/Makefile
index 4dfc60eedc43..c386132dacd1 100644
--- a/arch/arm/mach-imx/Makefile
+++ b/arch/arm/mach-imx/Makefile
@@ -132,6 +132,12 @@ u-boot.imx: MKIMAGEOUTPUT = u-boot.imx.log
 u-boot.imx: u-boot.bin u-boot.cfgout $(PLUGIN).bin FORCE
 	$(call if_changed,mkimage)
 
+quiet_cmd_u-boot-nand_imx = GEN     $@
+cmd_u-boot-nand_imx = (dd bs=1024 count=1 if=/dev/zero 2>/dev/null) | cat - $< > $@
+
+u-boot-nand.imx: u-boot.imx FORCE
+	$(call if_changed,u-boot-nand_imx)
+
 ifeq ($(CONFIG_MULTI_DTB_FIT),y)
 MKIMAGEFLAGS_u-boot-dtb.imx = -n $(filter-out $(PLUGIN).bin $< $(PHONY),$^) \
 	-T $(IMAGE_TYPE) -e $(CONFIG_TEXT_BASE)
-- 
2.34.1