[PATCH v4 09/13] binman: Support packaging U-Boot for scenarios like OF_BOARD or OF_PRIOR_STAGE

[Bin Meng]

For scenarios like OF_BOARD or OF_PRIOR_STAGE, no device tree blob is
provided in the U-Boot build phase hence the binman node information
is not available. In order to support such use case, a new Kconfig
option BINMAN_STANDALONE_FDT is introduced, to tell the build system
that a device tree blob containing binman node is explicitly required
when using binman to package U-Boot.

Signed-off-by: Bin Meng <bmeng.cn at gmail.com>

---

Changes in v4:
- update the makefile dependency on u-boot.img instead of u-boot.bin

Changes in v3:
- rename the Kconfig option name to BINMAN_STANDALONE_FDT
- make BINMAN_STANDALONE_FDT default y for OF_BOARD as well
- reword the Kconfig option help message a little bit

Changes in v2:
- new patch: "binman: Support packaging U-Boot for scenarios like OF_PRIOR_STAGE"

 Makefile    |  3 ++-
 dts/Kconfig | 18 ++++++++++++++++++
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/Makefile b/Makefile
index 3d88559b67..1dbf0b0b8c 100644
--- a/Makefile
+++ b/Makefile
@@ -918,6 +918,7 @@ endif
 endif
 INPUTS-$(CONFIG_TPL) += tpl/u-boot-tpl.bin
 INPUTS-$(CONFIG_OF_SEPARATE) += u-boot.dtb
+INPUTS-$(CONFIG_BINMAN_STANDALONE_FDT) += u-boot.dtb
 ifeq ($(CONFIG_SPL_FRAMEWORK),y)
 INPUTS-$(CONFIG_OF_SEPARATE) += u-boot-dtb.img
 endif
@@ -1392,7 +1393,7 @@ u-boot-lzma.img: u-boot.bin.lzma FORCE
 
 u-boot-dtb.img u-boot.img u-boot.kwb u-boot.pbl u-boot-ivt.img: \
 		$(if $(CONFIG_SPL_LOAD_FIT),u-boot-nodtb.bin \
-			$(if $(CONFIG_OF_SEPARATE)$(CONFIG_OF_EMBED)$(CONFIG_OF_HOSTFILE),dts/dt.dtb) \
+			$(if $(CONFIG_OF_SEPARATE)$(CONFIG_OF_EMBED)$(CONFIG_OF_HOSTFILE)$(CONFIG_BINMAN_STANDALONE_FDT),dts/dt.dtb) \
 		,$(UBOOT_BIN)) FORCE
 	$(call if_changed,mkimage)
 	$(BOARD_SIZE_CHECK)
diff --git a/dts/Kconfig b/dts/Kconfig
index 99ce75e1a2..dabe0080c1 100644
--- a/dts/Kconfig
+++ b/dts/Kconfig
@@ -19,6 +19,24 @@ config BINMAN
 	bool
 	select DTOC
 
+config BINMAN_STANDALONE_FDT
+	bool
+	depends on BINMAN
+	default y if OF_BOARD || OF_PRIOR_STAGE
+	help
+	  This option tells U-Boot build system that a standalone device tree
+	  source is explicitly required when using binman to package U-Boot.
+
+	  This is not necessary in a common scenario where a device tree source
+	  that contains the binman node is provided in the arch/<arch>/dts
+	  directory for a specific board. Such device tree sources are built for
+	  OF_SEPARATE or OF_EMBED. However for a scenario like the board device
+	  tree blob is not provided in the U-Boot build tree, but fed to U-Boot
+	  in the runtime, e.g.: in the OF_PRIOR_STAGE case that it is passed by
+	  a prior stage bootloader. For such scenario, a standalone device tree
+	  blob containing binman node to describe how to package U-Boot should
+	  be provided explicitly.
+
 menu "Device Tree Control"
 	depends on SUPPORT_OF_CONTROL
 
-- 
2.25.1