Oleksij and Kevin's Useless Devices.
        O&KUD Max9331

 AR9331 400MHz MIPS
   64M DRAM
   16M SPI Flash
    4G USB Nand Flash
     3 User LEDs
     3 Ports(1Wan/2Lan)
     1 TTL Debug Uart

Signed-off-by: Du Huanpeng <u74147@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

The embedded DTBs are compiled by the chain of pattern rules as follows:

  %.dts -> %.dtb -> %.dtb.S -> %.dtb.o       for barebox proper
  %.dts -> %.dtb -> %.dtb.S -> %.dtb.pbl.o   for pbl

Barebox introduced {obj,pbl,lwl}-dtb-y syntax to put the intermediate
files into extra-y. The purposes of doing so were:

 [1] prevent GNU Make from deleting the intermediate files
 [2] include .*.cmd files

In contrast, Linux does not use a special syntax for embedding DTBs
into the kernel.

For example, as you see in arch/sh/boot/dts/Makefile of Linux 5.6,

   obj-y += <basename>.dtb.o

... just works.

This is because scripts/Kbuild.include specifies .SECONDARY to cater
to [1], and scripts/Makefile.build adds the intermediates to 'targets'
to deal with [2].

Barebox had already imported the same code from Linux, so you can use
obj-y instead of obj-dtb-y, like Linux.

pbl-dtb-y and lwl-dtb-y are barebox-specific cases, so I added the
%.dtb.pbl.o pattern to intermediate_targets.

Going forward, please use obj-y, pbl-y, or lwl-y.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Linux MIPS uses <soc-name>_<board-name>.dts board dts-file
naming scheme so use it in barebox too.

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

This commit is based on Sascha's ARM commits:

    commit a9e7e68
    Author: Sascha Hauer <s.hauer@pengutronix.de>
    Date:   Fri Dec 11 08:02:02 2015 +0100

        ARM: dts: Add *.dtb.lzo to clean files

    commit f5b552f
    Author: Sascha Hauer <s.hauer@pengutronix.de>
    Date:   Fri May 9 09:11:49 2014 +0200

        ARM: dts: Add generated files to clean rule

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

To build an object file from a device tree currently we currently
have to add them to the Makefile twice, once to dtb-y and once to
obj-y. This patch introduces obj-dtb-y and pbl-dtb-y to directly
compile a device tree object file for inclusion in the barebox binary
or the pbl respectively.
The now unneeded dtb-y targets are removed.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Add intermediate .S files to .SECONDARY. Otherwise make deletes them
and regenerates them each build.
Also remove KBUILD_DTBS since the make system descends in dts/ anyway.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Otherwise a rebuild of the dtb file is triggered each build.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>