Add '-ansi' to DTS_CPPFLAGS to avoid unwanted expansion of dts content
that matches some predefined macros.

Example: A number of PowerPC related *.dts files in the kernel define a
property named 'linux,network-index' which (w/o '-ansi') is expanded to
'1,network-index' by the preprocessor because of '#define linux 1.'

Signed-off-by: Horst Kronstorfer <hkronsto@frequentis.com>

Make sure that $(LDSCRIPT) is not empty before calling process_lds
with 'cat $(LDSCRIPT)' else cat will block waiting for input from
stdin.

Signed-off-by: Horst Kronstorfer <hkronsto@frequentis.com>

Some architectures, for example Microblaze, doesn't need a
splitted device tree because every Microblaze hw design is
different. The individuell Microblaze device tree will be
auto generated by FPGA design tools and could be used directly
with dtc.

The auto generated dts for Microblaze can not processed by CPP.
Unfortunately that is the default procedure in U-Boot to merge
a splitted device tree (substitution of ARCH_CPU_DTS).

Microblaze will never use the ARCH_CPU_DTS substitution and we
introduce the new board specific substitution variable BOARD_DTS
that points into vendor/board/dts subdir with the file name
of CONFIG_DEFAULT_DEVICE_TREE. The common dts file in vendor/dts
subdir (defined by CONFIG_DEFAULT_DEVICE_TREE) contain a single
include line that can processed by CPP:

    /include/ BOARD_DTS

Signed-off-by: Stephan Linz <linz@li-pro.net>
Tested-by: Michal Simek <monstr@monstr.eu>
Acked-by: Simon Glass <sjg@chromium.org>

Commit 896bbb53 "fdt: avoid bad MAKEALL status" added logic to capture
the result code from dtc by echoing $? to stdout and capturing it using
$(). However, dtc emits some diagnostics to stderr and some to stdout.
The diagnostics send to stdout ended up getting captured via $() rather
than being echo'd to the user. This caused those diagnostics to be passed
to the exit command, which would then fail with the following cryptic
error message:

    /bin/sh: line 1: exit: too many arguments

Solve this by redirecting all dtc output to stderr so that $() does not
capture it. This allows the user to see the actual error message from dtc.

Cc: Wolfgang Denk <wd@denx.de>
Cc: Simon Glass <sjg@chromium.org>
Cc: albert.u.boot@aribaud.net
Cc: Tom Warren <twarren@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Simon Glass <sjg@chromium.org>

Current versions of  dtc  always print a message like

	DTC: dts->dtb  on file "dt.dtb.tmp"

which cannot even be suppressed with "-qqq".  To avoid incorrect
MAKEALL status, we manually filter out this message.  This is a bit
complicated, as we have to make sure to set a correct return code.

Also, get rid of the temp file: dtc accepts "-" for stdin.

Signed-off-by: Wolfgang Denk <wd@denx.de>
Cc: Simon Glass <sjg@chromium.org>
Acked-by: Simon Glass <sjg@chromium.org>

Fix: FATAL ERROR: Couldn't open "../arch/arm/dts/tegra20.dtsi": No
such file or directory

Signed-off-by: Wolfgang Denk <wd@denx.de>
Cc: Simon Glass <sjg@chromium.org>
Acked-by: Simon Glass <sjg@chromium.org>

This new option allows U-Boot to embed a binary device tree into its image
to allow run-time control of peripherals. This device tree is for U-Boot's
own use and is not necessarily the same one as is passed to the kernel.

The device tree compiler output should be placed in the $(obj)
rooted tree. Since $(OBJCOPY) insists on adding the path to the
generated symbol names, to ensure consistency it should be
invoked from the directory where the .dtb file is located and
given the input file name without the path.

This commit contains my entry for the ugliest Makefile / shell interaction
competition.

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