fdt: Add DEV_TREE_BIN option to specify a device tree binary file

In some cases, an externally-built device tree binary is required to be
attached to U-Boot. An example is when using image signing, since in that
case the .dtb file must include the public keys.

Add a DEV_TREE_BIN option to the Makefile, and update the documentation.

Usage is something like:

	make DEV_TREE_BIN=boot/am335x-boneblack-pubkey.dtb

Signed-off-by: Simon Glass <sjg@chromium.org>

diff --git a/Makefile b/Makefile
index e77b639a049f547670aec113b4dcac81fa68273a..866a8c4f30511276685a8f73a4635166ab7ee9e1 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -832,7 +832,7 @@ MKIMAGEFLAGS_u-boot.kwb = -n $(srctree)/$(CONFIG_SYS_KWD_CONFIG:"%"=%) \
 MKIMAGEFLAGS_u-boot.pbl = -n $(srctree)/$(CONFIG_SYS_FSL_PBL_RCW:"%"=%) \
                -R $(srctree)/$(CONFIG_SYS_FSL_PBL_PBI:"%"=%) -T pblimage
 
 MKIMAGEFLAGS_u-boot.pbl = -n $(srctree)/$(CONFIG_SYS_FSL_PBL_RCW:"%"=%) \
                -R $(srctree)/$(CONFIG_SYS_FSL_PBL_PBI:"%"=%) -T pblimage
 

-u-boot.img u-boot.kwb u-boot.pbl: u-boot.bin FORCE
+u-boot.img u-boot.kwb u-boot.pbl: u-boot$(if $(CONFIG_OF_SEPARATE),-dtb,).bin FORCE

        $(call if_changed,mkimage)
 
 MKIMAGEFLAGS_u-boot-dtb.img = $(MKIMAGEFLAGS_u-boot.img)
        $(call if_changed,mkimage)
 
 MKIMAGEFLAGS_u-boot-dtb.img = $(MKIMAGEFLAGS_u-boot.img)

diff --git a/doc/README.fdt-control b/doc/README.fdt-control
index 0ceebe7aa6f959fb901a21a45931ee245836eac7..be92d7ae88384ac784a9c30ddd8c640277e01ee5 100644 (file)
--- a/doc/README.fdt-control
+++ b/doc/README.fdt-control
@@ -122,7 +122,8 @@ This should include your CPU or SOC's device tree file, placed in
 arch/<arch>/dts, and then make any adjustments required.
 
 If CONFIG_OF_EMBED is defined, then it will be picked up and built into
 arch/<arch>/dts, and then make any adjustments required.
 
 If CONFIG_OF_EMBED is defined, then it will be picked up and built into

-the U-Boot image (including u-boot.bin).
+the U-Boot image (including u-boot.bin). This is suitable for debugging
+and development only and is not recommended for production devices.

 
 If CONFIG_OF_SEPARATE is defined, then it will be built and placed in
 a u-boot.dtb file alongside u-boot.bin. A common approach is then to
 
 If CONFIG_OF_SEPARATE is defined, then it will be built and placed in
 a u-boot.dtb file alongside u-boot.bin. A common approach is then to


@@ -130,7 +131,10 @@ join the two:
 
        cat u-boot.bin u-boot.dtb >image.bin
 
 
        cat u-boot.bin u-boot.dtb >image.bin
 

-and then flash image.bin onto your board.
+and then flash image.bin onto your board. Note that U-Boot creates
+u-boot-dtb.bin which does the above step for you also. If you are using
+CONFIG_SPL_FRAMEWORK, then u-boot.img will be built to include the device
+tree binary.

 
 If CONFIG_OF_HOSTFILE is defined, then it will be read from a file on
 startup. This is only useful for sandbox. Use the -d flag to U-Boot to
 
 If CONFIG_OF_HOSTFILE is defined, then it will be read from a file on
 startup. This is only useful for sandbox. Use the -d flag to U-Boot to


@@ -138,6 +142,14 @@ specify the file to read.
 
 You cannot use more than one of these options at the same time.
 
 
 You cannot use more than one of these options at the same time.
 

+To use a device tree file that you have compiled yourself, pass
+DEV_TREE_BIN=<filename> to 'make', as in:
+
+       make DEV_TREE_BIN=boot/am335x-boneblack-pubkey.dtb
+
+Then U-Boot will copy that file to u-boot.dtb, put it in the .img file
+if used, and u-boot-dtb.bin.
+

 If you wish to put the fdt at a different address in memory, you can
 define the "fdtcontroladdr" environment variable. This is the hex
 address of the fdt binary blob, and will override either of the options.
 If you wish to put the fdt at a different address in memory, you can
 define the "fdtcontroladdr" environment variable. This is the hex
 address of the fdt binary blob, and will override either of the options.

diff --git a/dts/Makefile b/dts/Makefile
index 3fca5f5c2f5df968b9b924c97d873a478ca222a7..f344efe64b83f51eac4c312aa5d8d529147b20c5 100644 (file)
--- a/dts/Makefile
+++ b/dts/Makefile
@@ -12,7 +12,11 @@ ifeq ($(DEVICE_TREE),)
 DEVICE_TREE := unset
 endif
 
 DEVICE_TREE := unset
 endif
 

+ifneq ($(DEV_TREE_BIN),)
+DTB := $(DEV_TREE_BIN)
+else

 DTB := arch/$(ARCH)/dts/$(DEVICE_TREE).dtb
 DTB := arch/$(ARCH)/dts/$(DEVICE_TREE).dtb

+endif

 
 $(obj)/dt.dtb: $(DTB) FORCE
        $(call if_changed,shipped)
 
 $(obj)/dt.dtb: $(DTB) FORCE
        $(call if_changed,shipped)